Source import

.classpath

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.7"/>
+	<classpathentry combineaccessrules="false" kind="src" path="/MightyUtils"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

.gitignore

@@ -1,12 +1,6 @@
-*.class
-
-# Mobile Tools for Java (J2ME)
-.mtj.tmp/
-
-# Package Files #
-*.jar
-*.war
-*.ear
-
-# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
-hs_err_pid*
+/bin/
+/target/
+/~local/
+*.log
+.attach_pid*
+*~

.project

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>GameCore</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

.settings/org.eclipse.jdt.core.prefs

@@ -0,0 +1,11 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.7
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.7
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.7

README.md

@@ -2,3 +2,5 @@ gamecore
 ========
 
 Versatile Java game engine with pluggable backends
+
+TODO: better readme and tutorial games

src/junk/AppInitOptions.java

@@ -0,0 +1,133 @@
+package junk;
+
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.Level;
+
+import mightypork.gamecore.core.AppBackend;
+import mightypork.gamecore.resources.ResourceSetup;
+import mightypork.gamecore.resources.loading.AsyncResourceLoader;
+import mightypork.gamecore.resources.loading.ResourceLoader;
+
+
+/**
+ * Init options holder class
+ */
+public class AppInitOptions {
+	
+	String logDir = "log";
+	String logFilePrefix = "runtime";
+	
+	String screenshotDir = "screenshots";
+	
+	boolean busLogging = false;
+	
+	String configFile = "settings.cfg";
+	String configComment = "Main config file";
+	
+	final List<ResourceSetup> resourceLists = new ArrayList<>();
+	final List<KeySetup> keyLists = new ArrayList<>();
+	final List<ConfigSetup> configLists = new ArrayList<>();
+	
+	ResourceLoader resourceLoader = new AsyncResourceLoader();
+	Level logLevel = Level.ALL;
+	public boolean sigleInstance = true;
+	Level logSoutLevel = Level.ALL;
+	
+	
+	public void setConfigFile(String filename, String comment)
+	{
+		configFile = filename;
+		configComment = comment;
+	}
+	
+	
+	public void addConfig(ConfigSetup cfg)
+	{
+		configLists.add(cfg);
+	}
+	
+	
+	public void addKeys(KeySetup keys)
+	{
+		keyLists.add(keys);
+	}
+	
+	
+	public void addResources(ResourceSetup res)
+	{
+		resourceLists.add(res);
+	}
+	
+	
+	public void setBackend(AppBackend backend)
+	{
+		this.backend = backend;
+	}
+	
+	
+	/**
+	 * Set whether to run in single instance mode, or allow multiple instances.<br>
+	 * Multiple instances running can cause various collisions (eg. when writing
+	 * config file or logging).
+	 * 
+	 * @param sigleInstance true to allow only one instance
+	 */
+	public void setSigleInstance(boolean sigleInstance)
+	{
+		this.sigleInstance = sigleInstance;
+	}
+	
+	
+	/**
+	 * Set working directory path. If not exists, it will be created.
+	 * 
+	 * @param workdir work dir path
+	 */
+	public void setWorkdir(File workdir)
+	{
+		this.workdir = workdir;
+	}
+	
+	
+	public void setBusLogging(boolean yes)
+	{
+		busLogging = yes;
+	}
+	
+	
+	public void setLogOptions(String logDir, String filePrefix, int archivedCount, Level logLevel)
+	{
+		this.logDir = logDir;
+		this.logFilePrefix = filePrefix;
+		this.logArchiveCount = archivedCount;
+		this.logLevel = logLevel;
+	}
+	
+	
+	public void setResourceLoader(ResourceLoader resLoader)
+	{
+		resourceLoader = resLoader;
+	}
+	
+	
+	public void setScreenshotDir(String path)
+	{
+		this.screenshotDir = path;
+	}
+	
+	
+	public void setLockFile(String lockFile)
+	{
+		this.lockFile = lockFile;
+	}
+	
+	
+	public void setLogLevel(Level logLevel, Level soutLevel)
+	{
+		this.logLevel = logLevel;
+		this.logSoutLevel = soutLevel;
+	}
+}

src/junk/BaseApp.java

@@ -0,0 +1,184 @@
+package junk;
+
+
+import java.lang.Thread.UncaughtExceptionHandler;
+
+import mightypork.gamecore.backends.lwjgl.LwjglInputModule;
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.core.AppBackend;
+import mightypork.gamecore.core.MainLoop;
+import mightypork.gamecore.core.WorkDir;
+import mightypork.gamecore.core.config.Config;
+import mightypork.gamecore.gui.screens.ScreenRegistry;
+import mightypork.gamecore.gui.screens.impl.CrossfadeOverlay;
+import mightypork.gamecore.resources.Res;
+import mightypork.gamecore.resources.ResourceSetup;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Basic screen-based game with subsystems.<br>
+ * This class takes care of the initialization sequence.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class BaseApp extends App implements UncaughtExceptionHandler {
+	
+	// modules
+	private MainLoop gameLoop;
+	private ScreenRegistry screenRegistry;
+	
+	private boolean started = false;
+	private boolean lockObtained = false;
+	
+	// init opt holder
+	private final AppInitOptions opt = new AppInitOptions();
+	
+	
+	/**
+	 * Get init options
+	 * 
+	 * @return opt holder
+	 */
+	public AppInitOptions getInitOptions()
+	{
+		if (started) {
+			throw new IllegalStateException("Cannot alter init options after starting the App.");
+		}
+		
+		return opt;
+	}
+	
+	
+	public BaseApp(AppBackend backend) {
+		super(backend);
+	}
+	
+	
+	/**
+	 * Start the application
+	 */
+	@Override
+	public final void start()
+	{
+		initialize();
+		
+		Log.i("Starting main loop...");
+		
+		// open first screen	!!!
+		started = true;
+		gameLoop.start();
+	}
+	
+	
+	/**
+	 * Init the app
+	 */
+	protected void initialize()
+	{
+		WorkDir.init(opt.workdir);
+		
+		if (opt.sigleInstance) initLock();
+		lockObtained = true;
+		
+		for (final RouteSetup rs : opt.routeLists) {
+			WorkDir.registerRoutes(rs);
+		}
+		WorkDir.addPath("_screenshot_dir", opt.screenshotDir);
+		
+		// apply configurations
+		Config.init(WorkDir.getFile(opt.configFile), opt.configComment);
+		
+		// add keys to config
+		for (final KeySetup l : opt.keyLists) {
+			Config.registerKeys(l);
+		}
+		
+		// add options to config
+		for (final ConfigSetup c : opt.configLists) {
+			Config.registerOptions(c);
+		}
+		Config.load();
+		
+		/*
+		 * Display
+		 */
+		Log.f2("Initializing Display System...");
+		initDisplay(gfx());
+		
+		/*
+		 * Audio
+		 */
+		Log.f2("Initializing Sound System...");
+		soundSystem = new SoundSystem(this);
+		initSoundSystem(soundSystem);
+		
+		/*
+		 * Input
+		 */
+		Log.f2("Initializing Input System...");
+		inputSystem = new LwjglInputModule(this);
+		initInputSystem(inputSystem);
+		
+		/*
+		 * Prepare main loop
+		 */
+		Log.f1("Creating Screen Registry and Game Loop...");
+		screenRegistry = new ScreenRegistry(this);
+		gameLoop = createMainLoop();
+		gameLoop.setRootRenderable(screenRegistry);
+		
+		/*
+		 * Load resources
+		 * 
+		 * Resources should be registered to registries, and AsyncResourceLoader will load them.
+		 */
+		Log.f1("Loading resources...");
+		if (opt.resourceLoader != null) {
+			opt.resourceLoader.init(this);
+		}
+		
+		Res.init(this);
+		
+		for (final ResourceSetup rl : opt.resourceLists) {
+			Res.load(rl);
+		}
+		
+		/*
+		 * Screen registry
+		 * 
+		 * Must be after resources, because screens can request them during instantiation.
+		 */
+		Log.f2("Registering screens...");
+		initScreens(screenRegistry);
+	}
+	
+	
+	/**
+	 * Register game screens to the registry.
+	 * 
+	 * @param screens
+	 */
+	protected void initScreens(ScreenRegistry screens)
+	{
+		screens.addOverlay(new CrossfadeOverlay(this));
+	}
+	
+	
+	/**
+	 * Create game loop instance
+	 * 
+	 * @return the game loop.
+	 */
+	protected MainLoop createMainLoop()
+	{
+		return new MainLoop(this);
+	}
+	
+	
+	protected void beforeShutdown()
+	{
+		// ???
+		if (lockObtained) Config.save();
+	}
+}

src/junk/DisplaySystem.java

@@ -0,0 +1,299 @@
+//package junk;
+//
+//
+//import static org.lwjgl.opengl.GL11.*;
+//
+//import java.nio.ByteBuffer;
+//
+//import mightypork.gamecore.backend.lwjgl.AwtScreenshot;
+//import mightypork.gamecore.core.modules.AppAccess;
+//import mightypork.gamecore.core.modules.AppModule;
+//import mightypork.gamecore.render.events.DisplayReadyEvent;
+//import mightypork.gamecore.render.events.ViewportChangeEvent;
+//import mightypork.utils.logging.Log;
+//import mightypork.utils.math.constraints.rect.Rect;
+//import mightypork.utils.math.constraints.rect.RectBound;
+//import mightypork.utils.math.constraints.vect.Vect;
+//import mightypork.utils.math.timing.FpsMeter;
+//
+//import org.lwjgl.BufferUtils;
+//import org.lwjgl.LWJGLException;
+//import org.lwjgl.opengl.Display;
+//import org.lwjgl.opengl.DisplayMode;
+//
+//
+///**
+// * Display system
+// * 
+// * @author Ondřej Hruška (MightyPork)
+// */
+//@Deprecated
+//public class DisplaySystem extends AppModule implements RectBound {
+//	
+//	private DisplayMode windowDisplayMode;
+//	private int targetFps;
+//	private FpsMeter fpsMeter;
+//	private boolean fullscreenSwitchRequested;
+//	
+//	/** Current screen size */
+//	private static final Vect screenSize = new Vect() {
+//		
+//		@Override
+//		public double y()
+//		{
+//			return Display.getHeight();
+//		}
+//		
+//		
+//		@Override
+//		public double x()
+//		{
+//			return Display.getWidth();
+//		}
+//	};
+//	
+//	private static final Rect rect = Rect.make(screenSize);
+//	
+//	
+//	/**
+//	 * @param app app access
+//	 */
+//	public DisplaySystem(AppAccess app) {
+//		super(app);
+//	}
+//	
+//	
+//	@Override
+//	protected void deinit()
+//	{
+//		Display.destroy();
+//	}
+//	
+//	
+//	/**
+//	 * Set target fps (for syncing in endFrame() call).<br>
+//	 * With vsync enabled, the target fps may not be met.
+//	 * 
+//	 * @param fps requested fps
+//	 */
+//	public void setTargetFps(int fps)
+//	{
+//		this.targetFps = fps;
+//	}
+//	
+//	
+//	/**
+//	 * Create a main window
+//	 * 
+//	 * @param width requested width
+//	 * @param height requested height
+//	 * @param resizable is resizable by the user
+//	 * @param fullscreen is in fullscreen
+//	 * @param title window title
+//	 */
+//	public void createMainWindow(int width, int height, boolean resizable, boolean fullscreen, String title)
+//	{
+//		try {
+//			Display.setDisplayMode(windowDisplayMode = new DisplayMode(width, height));
+//			Display.setResizable(resizable);
+//			Display.setVSyncEnabled(true);
+//			Display.setTitle(title);
+//			Display.create();
+//			
+//			fpsMeter = new FpsMeter();
+//			
+//			if (fullscreen) {
+//				switchFullscreen();
+//				Display.update();
+//			}
+//			
+//			getEventBus().send(new DisplayReadyEvent());
+//			
+//		} catch (final LWJGLException e) {
+//			throw new RuntimeException("Could not initialize screen", e);
+//		}
+//	}
+//	
+//	
+//	/**
+//	 * Toggle FS if possible
+//	 */
+//	public void switchFullscreen()
+//	{
+//		fullscreenSwitchRequested = true;
+//	}
+//	
+//	
+//	private void doSwitchFullscreen()
+//	{
+//		try {
+//			
+//			if (!Display.isFullscreen()) {
+//				Log.f3("Entering fullscreen.");
+//				// save window resize
+//				windowDisplayMode = new DisplayMode(Display.getWidth(), Display.getHeight());
+//				
+//				Display.setDisplayMode(Display.getDesktopDisplayMode());
+//				Display.setFullscreen(true);
+//				Display.update();
+//			} else {
+//				Log.f3("Leaving fullscreen.");
+//				Display.setDisplayMode(windowDisplayMode);
+//				Display.update();
+//			}
+//			
+//			getEventBus().send(new ViewportChangeEvent(getSize()));
+//			
+//		} catch (final Throwable t) {
+//			Log.e("Failed to toggle fullscreen mode.", t);
+//			try {
+//				Display.setDisplayMode(windowDisplayMode);
+//				Display.update();
+//			} catch (final Throwable t1) {
+//				throw new RuntimeException("Failed to revert failed fullscreen toggle.", t1);
+//			}
+//		}
+//	}
+//	
+//	
+//	/**
+//	 * Take screenshot (expensive processing is done on-demand when screenshot
+//	 * is processed).
+//	 * 
+//	 * @return screenshot object
+//	 */
+//	public static AwtScreenshot prepareScreenshot()
+//	{
+//		glReadBuffer(GL_FRONT);
+//		final int width = Display.getWidth();
+//		final int height = Display.getHeight();
+//		final int bpp = 4;
+//		final ByteBuffer buffer = BufferUtils.createByteBuffer(width * height * bpp);
+//		glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
+//		
+//		final AwtScreenshot sc = new AwtScreenshot(width, height, bpp, buffer);
+//		
+//		return sc;
+//	}
+//	
+//	
+//	/**
+//	 * @return true if close was requested (i.e. click on cross)
+//	 */
+//	public static boolean isCloseRequested()
+//	{
+//		return Display.isCloseRequested();
+//	}
+//	
+//	
+//	/**
+//	 * Get fullscreen state
+//	 * 
+//	 * @return is fullscreen
+//	 */
+//	public static boolean isFullscreen()
+//	{
+//		return Display.isFullscreen();
+//	}
+//	
+//	
+//	/**
+//	 * Get screen size. This Vect is final and views at it can safely be made.
+//	 * 
+//	 * @return size
+//	 */
+//	public static Vect getSize()
+//	{
+//		return screenSize;
+//	}
+//	
+//	
+//	/**
+//	 * Get screen rect. Static version of getRect().
+//	 * 
+//	 * @return size
+//	 */
+//	public static Rect getBounds()
+//	{
+//		return rect;
+//	}
+//	
+//	
+//	/**
+//	 * @return screen width
+//	 */
+//	public static int getWidth()
+//	{
+//		return screenSize.xi();
+//	}
+//	
+//	
+//	/**
+//	 * @return screen height
+//	 */
+//	public static int getHeight()
+//	{
+//		return screenSize.yi();
+//	}
+//	
+//	
+//	/**
+//	 * Start a OpenGL frame
+//	 */
+//	public void beginFrame()
+//	{
+//		// handle resize
+//		if (Display.wasResized()) {
+//			getEventBus().send(new ViewportChangeEvent(getSize()));
+//		}
+//		
+//		if (fullscreenSwitchRequested) {
+//			fullscreenSwitchRequested = false;
+//			doSwitchFullscreen();
+//		}
+//		
+//		glLoadIdentity();
+//		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+//		fpsMeter.frame();
+//	}
+//	
+//	
+//	/**
+//	 * End an OpenGL frame, flip buffers, sync to fps.
+//	 */
+//	public void endFrame()
+//	{
+//		Display.update(false); // don't poll input devices
+//		Display.sync(targetFps);
+//	}
+//	
+//	
+//	/**
+//	 * Get screen rect. This Rect is final and views at it can safely be made.
+//	 */
+//	@Override
+//	public Rect getRect()
+//	{
+//		return getBounds();
+//	}
+//	
+//	
+//	/**
+//	 * @return current FPS
+//	 */
+//	public long getFps()
+//	{
+//		return fpsMeter.getFPS();
+//	}
+//	
+//	
+//	/**
+//	 * Get screen center. This vect is final and views at it can safely be made.
+//	 * 
+//	 * @return screen center.
+//	 */
+//	public static Vect getCenter()
+//	{
+//		return rect.center();
+//	}
+//}

src/junk/Render.java

@@ -0,0 +1,542 @@
+//package junk;
+//
+//
+//import static org.lwjgl.opengl.GL11.*;
+//
+//import java.io.IOException;
+//
+//import mightypork.gamecore.resources.textures.FilterMode;
+//import mightypork.gamecore.resources.textures.ITexture;
+//import mightypork.gamecore.resources.textures.TxQuad;
+//import mightypork.utils.files.FileUtils;
+//import mightypork.utils.logging.Log;
+//import mightypork.utils.math.color.Color;
+//import mightypork.utils.math.color.pal.RGB;
+//import mightypork.utils.math.constraints.rect.Rect;
+//import mightypork.utils.math.constraints.rect.caching.RectDigest;
+//import mightypork.utils.math.constraints.vect.Vect;
+//import mightypork.utils.math.constraints.vect.VectConst;
+//
+//import org.lwjgl.opengl.GL11;
+//import org.newdawn.slick.opengl.Texture;
+//import org.newdawn.slick.opengl.TextureLoader;
+//
+//
+///**
+// * Render utilities
+// * 
+// * @author Ondřej Hruška (MightyPork)
+// */
+//@Deprecated
+//public class Render {
+//	
+//	public static final VectConst AXIS_X = Vect.make(1, 0, 0);
+//	public static final VectConst AXIS_Y = Vect.make(0, 1, 0);
+//	public static final VectConst AXIS_Z = Vect.make(0, 0, 1);
+//	
+//	
+//	/**
+//	 * Bind GL color
+//	 * 
+//	 * @param color Color color
+//	 */
+//	public static void setColor(Color color)
+//	{
+//		if (color != null) glColor4d(color.r(), color.g(), color.b(), color.a());
+//	}
+//	
+//	
+//	/**
+//	 * Bind GL color
+//	 * 
+//	 * @param color Color color
+//	 * @param alpha alpha multiplier
+//	 */
+//	public static void setColor(Color color, double alpha)
+//	{
+//		if (color != null) glColor4d(color.r(), color.g(), color.b(), color.a() * alpha);
+//	}
+//	
+//	
+//	/**
+//	 * Translate
+//	 * 
+//	 * @param x
+//	 * @param y
+//	 */
+//	public static void translate(double x, double y)
+//	{
+//		glTranslated(x, y, 0);
+//	}
+//	
+//	
+//	/**
+//	 * Translate
+//	 * 
+//	 * @param x
+//	 * @param y
+//	 * @param z
+//	 */
+//	public static void translate(double x, double y, double z)
+//	{
+//		glTranslated(x, y, z);
+//	}
+//	
+//	
+//	/**
+//	 * Translate with coord
+//	 * 
+//	 * @param coord coord
+//	 */
+//	public static void translate(Vect coord)
+//	{
+//		glTranslated(coord.x(), coord.y(), coord.z());
+//	}
+//	
+//	
+//	/**
+//	 * Translate with coord, discard Z
+//	 * 
+//	 * @param coord coord
+//	 */
+//	public static void translateXY(Vect coord)
+//	{
+//		glTranslated(coord.x(), coord.y(), 0);
+//	}
+//	
+//	
+//	/**
+//	 * Scale
+//	 * 
+//	 * @param x
+//	 * @param y
+//	 */
+//	public static void scale(double x, double y)
+//	{
+//		glScaled(x, y, 0);
+//	}
+//	
+//	
+//	/**
+//	 * Scale
+//	 * 
+//	 * @param x
+//	 * @param y
+//	 * @param z
+//	 */
+//	public static void scale(double x, double y, double z)
+//	{
+//		glScaled(x, y, z);
+//	}
+//	
+//	
+//	/**
+//	 * Scale
+//	 * 
+//	 * @param factor vector of scaling factors
+//	 */
+//	public static void scale(Vect factor)
+//	{
+//		glScaled(factor.x(), factor.y(), factor.z());
+//	}
+//	
+//	
+//	/**
+//	 * Scale by X factor
+//	 * 
+//	 * @param factor scaling factor
+//	 */
+//	public static void scaleXY(double factor)
+//	{
+//		glScaled(factor, factor, 1);
+//	}
+//	
+//	
+//	/**
+//	 * Scale by X factor
+//	 * 
+//	 * @param factor scaling factor
+//	 */
+//	public static void scaleX(double factor)
+//	{
+//		glScaled(factor, 1, 1);
+//	}
+//	
+//	
+//	/**
+//	 * Scale by Y factor
+//	 * 
+//	 * @param factor scaling factor
+//	 */
+//	public static void scaleY(double factor)
+//	{
+//		glScaled(1, factor, 1);
+//	}
+//	
+//	
+//	/**
+//	 * Scale by Z factor
+//	 * 
+//	 * @param factor scaling factor
+//	 */
+//	public static void scaleZ(double factor)
+//	{
+//		glScaled(1, 1, factor);
+//	}
+//	
+//	
+//	/**
+//	 * Rotate around X axis
+//	 * 
+//	 * @param angle deg
+//	 */
+//	public static void rotateX(double angle)
+//	{
+//		rotate(angle, AXIS_X);
+//	}
+//	
+//	
+//	/**
+//	 * Rotate around Y axis
+//	 * 
+//	 * @param angle deg
+//	 */
+//	public static void rotateY(double angle)
+//	{
+//		rotate(angle, AXIS_Y);
+//	}
+//	
+//	
+//	/**
+//	 * Rotate around Z axis
+//	 * 
+//	 * @param angle deg
+//	 */
+//	public static void rotateZ(double angle)
+//	{
+//		rotate(angle, AXIS_Z);
+//	}
+//	
+//	
+//	/**
+//	 * Rotate
+//	 * 
+//	 * @param angle rotate angle
+//	 * @param axis rotation axis
+//	 */
+//	public static void rotate(double angle, Vect axis)
+//	{
+//		final Vect vec = axis.norm(1);
+//		glRotated(angle, vec.x(), vec.y(), vec.z());
+//	}
+//	
+//	private static int pushed = 0;
+//	/** Can be used to avoid texture binding and glBegin/glEnd in textured quads */
+//	public static boolean batchTexturedQuadMode;
+//	
+//	
+//	/**
+//	 * Store GL state
+//	 */
+//	public static void pushState()
+//	{
+//		pushed++;
+//		
+//		if (pushed >= 100) {
+//			Log.w("Suspicious number of state pushes: " + pushed);
+//		}
+//		
+//		GL11.glPushAttrib(GL11.GL_ALL_ATTRIB_BITS);
+//		GL11.glPushClientAttrib(GL11.GL_ALL_CLIENT_ATTRIB_BITS);
+//		GL11.glMatrixMode(GL11.GL_MODELVIEW);
+//		GL11.glPushMatrix();
+//		GL11.glMatrixMode(GL11.GL_PROJECTION);
+//		GL11.glPushMatrix();
+//		GL11.glMatrixMode(GL11.GL_MODELVIEW);
+//	}
+//	
+//	
+//	/**
+//	 * Restore Gl state
+//	 */
+//	public static void popState()
+//	{
+//		if (pushed == 0) {
+//			Log.w("Pop without push.");
+//		}
+//		
+//		pushed--;
+//		
+//		GL11.glMatrixMode(GL11.GL_PROJECTION);
+//		GL11.glPopMatrix();
+//		GL11.glMatrixMode(GL11.GL_MODELVIEW);
+//		GL11.glPopMatrix();
+//		GL11.glPopClientAttrib();
+//		GL11.glPopAttrib();
+//	}
+//	
+//	
+//	/**
+//	 * Store matrix
+//	 */
+//	public static void pushMatrix()
+//	{
+//		GL11.glPushMatrix();
+//	}
+//	
+//	
+//	/**
+//	 * Restore Gl state
+//	 */
+//	public static void popMatrix()
+//	{
+//		GL11.glPopMatrix();
+//	}
+//	
+//	
+//	/**
+//	 * Load texture
+//	 * 
+//	 * @param resourcePath
+//	 * @param filtering filtering mode to use while loading.
+//	 * @return the loaded texture
+//	 */
+//	public synchronized static Texture loadSlickTexture(String resourcePath, FilterMode filtering)
+//	{
+//		
+//		try {
+//			
+//			final String ext = FileUtils.getExtension(resourcePath).toUpperCase();
+//			
+//			final Texture texture = TextureLoader.getTexture(ext, FileUtils.getResource(resourcePath), false, filtering.num);
+//			
+//			if (texture == null) {
+//				Log.w("Texture " + resourcePath + " could not be loaded.");
+//			}
+//			
+//			return texture;
+//			
+//		} catch (final IOException e) {
+//			Log.e("Loading of texture " + resourcePath + " failed.", e);
+//			throw new RuntimeException("Could not load texture " + resourcePath + ".", e);
+//		}
+//		
+//	}
+//	
+//	
+//	/**
+//	 * Render quad 2D
+//	 * 
+//	 * @param rect rectangle
+//	 * @param color draw color
+//	 */
+//	public static void quad(Rect rect, Color color)
+//	{
+//		setColor(color);
+//		quad(rect);
+//	}
+//	
+//	
+//	/**
+//	 * Render quad
+//	 * 
+//	 * @param quad the quad to draw (px)
+//	 */
+//	public static void quad(Rect quad)
+//	{
+//		final RectDigest q = quad.digest();
+//		
+//		// draw with color
+//		
+//		glDisable(GL_TEXTURE_2D);
+//		
+//		// quad
+//		glBegin(GL_QUADS);
+//		glVertex2d(q.left, q.bottom);
+//		glVertex2d(q.right, q.bottom);
+//		glVertex2d(q.right, q.top);
+//		glVertex2d(q.left, q.top);
+//		glEnd();
+//	}
+//	
+//	
+//	/**
+//	 * Draw quad with horizontal gradient
+//	 * 
+//	 * @param quad drawn quad bounds
+//	 * @param color1 left color
+//	 * @param color2 right color
+//	 */
+//	public static void quadGradH(Rect quad, Color color1, Color color2)
+//	{
+//		quadColor(quad, color1, color2, color2, color1);
+//	}
+//	
+//	
+//	public static void quadColor(Rect quad, Color color)
+//	{
+//		quadColor(quad, color, color, color, color);
+//	}
+//	
+//	
+//	/**
+//	 * Draw quad with coloured vertices.
+//	 * 
+//	 * @param quad drawn quad bounds
+//	 * @param colorHMinVMin
+//	 * @param colorHMaxVMin
+//	 * @param colorHMaxVMax
+//	 * @param colorHMinVMax
+//	 */
+//	public static void quadColor(Rect quad, Color colorHMinVMin, Color colorHMaxVMin, Color colorHMaxVMax, Color colorHMinVMax)
+//	{
+//		final RectDigest r = quad.digest();
+//		
+//		// draw with color
+//		
+//		glDisable(GL_TEXTURE_2D);
+//		
+//		glBegin(GL_QUADS);
+//		setColor(colorHMinVMax);
+//		glVertex2d(r.left, r.bottom);
+//		
+//		setColor(colorHMaxVMax);
+//		glVertex2d(r.right, r.bottom);
+//		
+//		setColor(colorHMaxVMin);
+//		glVertex2d(r.right, r.top);
+//		
+//		setColor(colorHMinVMin);
+//		glVertex2d(r.left, r.top);
+//		glEnd();
+//	}
+//	
+//	
+//	/**
+//	 * Draw quad with vertical gradient
+//	 * 
+//	 * @param quad drawn quad bounds
+//	 * @param color1 top color
+//	 * @param color2 bottom color
+//	 */
+//	public static void quadGradV(Rect quad, Color color1, Color color2)
+//	{
+//		quadColor(quad, color1, color1, color2, color2);
+//	}
+//	
+//	
+//	/**
+//	 * Render textured rect
+//	 * 
+//	 * @param quad rectangle (px)
+//	 * @param txquad texture quad
+//	 */
+//	public static void quadTextured(Rect quad, TxQuad txquad)
+//	{
+//		quadTextured(quad, txquad, RGB.WHITE);
+//	}
+//	
+//	
+//	/**
+//	 * Render textured rect
+//	 * 
+//	 * @param quad rectangle (px)
+//	 * @param txquad texture instance
+//	 * @param tint color tint
+//	 */
+//	public static void quadTextured(Rect quad, TxQuad txquad, Color tint)
+//	{
+//		if (!batchTexturedQuadMode) {
+//			glEnable(GL_TEXTURE_2D);
+//			txquad.tx.bind();
+//			glBegin(GL_QUADS);
+//			setColor(tint);
+//		}
+//		
+//		final RectDigest q = quad.digest();
+//		final RectDigest u = txquad.uvs.digest();
+//		
+//		final double offs = 0.0001;// hack to avoid white stitching
+//		
+//		double tL = u.left + offs, tR = u.right - offs, tT = u.top + offs, tB = u.bottom - offs;
+//		
+//		// handle flip
+//		if (txquad.isFlippedY()) {
+//			final double swap = tT;
+//			tT = tB;
+//			tB = swap;
+//		}
+//		
+//		if (txquad.isFlippedX()) {
+//			final double swap = tL;
+//			tL = tR;
+//			tR = swap;
+//		}
+//		
+//		final double w = txquad.tx.getWidth01();
+//		final double h = txquad.tx.getHeight01();
+//		
+//		// quad with texture
+//		glTexCoord2d(tL * w, tB * h);
+//		glVertex2d(q.left, q.bottom);
+//		
+//		glTexCoord2d(tR * w, tB * h);
+//		glVertex2d(q.right, q.bottom);
+//		
+//		glTexCoord2d(tR * w, tT * h);
+//		glVertex2d(q.right, q.top);
+//		
+//		glTexCoord2d(tL * w, tT * h);
+//		glVertex2d(q.left, q.top);
+//		
+//		if (!batchTexturedQuadMode) glEnd();
+//	}
+//	
+//	
+//	/**
+//	 * Setup Ortho projection for 2D graphics
+//	 * 
+//	 * @param size viewport size (screen size)
+//	 */
+//	public static void setupOrtho(Vect size)
+//	{
+//		// fix projection for changed size
+//		glMatrixMode(GL_PROJECTION);
+//		glLoadIdentity();
+//		glViewport(0, 0, size.xi(), size.yi());
+//		glOrtho(0, size.xi(), size.yi(), 0, -1000, 1000);
+//		
+//		// back to modelview
+//		glMatrixMode(GL_MODELVIEW);
+//		
+//		glLoadIdentity();
+//		
+//		glDisable(GL_LIGHTING);
+//		
+//		glClearDepth(1f);
+//		glEnable(GL_DEPTH_TEST);
+//		glDepthFunc(GL_LEQUAL);
+//		
+//		glEnable(GL_NORMALIZE);
+//		
+//		glShadeModel(GL_SMOOTH);
+//		
+//		glEnable(GL_BLEND);
+//		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+//	}
+//	
+//	
+//	public static void enterBatchTexturedQuadMode(ITexture texture)
+//	{
+//		texture.bind();
+//		glBegin(GL11.GL_QUADS);
+//		batchTexturedQuadMode = true;
+//	}
+//	
+//	
+//	public static void leaveBatchTexturedQuadMode()
+//	{
+//		glEnd();
+//		batchTexturedQuadMode = false;
+//	}
+//}

src/junk/SoundSystem.java

@@ -0,0 +1,261 @@
+package junk;
+
+
+//package mightypork.gamecore.resources.audio;
+//
+//
+//import java.nio.FloatBuffer;
+//import java.util.ArrayList;
+//import java.util.List;
+//
+//import mightypork.gamecore.backend.lwjgl.SlickAudio;
+//import mightypork.gamecore.core.modules.App;
+//import mightypork.gamecore.resources.ResourceLoadRequest;
+//import mightypork.gamecore.resources.audio.players.EffectPlayer;
+//import mightypork.gamecore.resources.audio.players.LoopPlayer;
+//import mightypork.gamecore.util.BufferHelper;
+//import mightypork.utils.eventbus.clients.BusNode;
+//import mightypork.utils.interfaces.Destroyable;
+//import mightypork.utils.interfaces.Updateable;
+//import mightypork.utils.logging.Log;
+//import mightypork.utils.math.constraints.vect.Vect;
+//import mightypork.utils.math.constraints.vect.var.VectVar;
+//
+//import org.lwjgl.openal.AL;
+//import org.lwjgl.openal.AL10;
+//import org.newdawn.slick.openal.SoundStore;
+//
+//
+///**
+// * Sound system class (only one instance should be made per application)
+// * 
+// * @author Ondřej Hruška (MightyPork)
+// */
+//@Deprecated
+//public class SoundSystem extends BusNode implements Updateable, Destroyable {
+//	
+//	private static final Vect INITIAL_LISTENER_POS = Vect.ZERO;
+//	private static final int MAX_SOURCES = 256;
+//	
+//	private static VectVar listener = Vect.makeVar();
+//	private static boolean soundSystemInited = false;
+//	
+//	
+//	/**
+//	 * Set listener pos
+//	 * 
+//	 * @param pos
+//	 */
+//	public static void setListener(Vect pos)
+//	{
+//		listener.setTo(pos);
+//		final FloatBuffer buf3 = BufferHelper.alloc(3);
+//		final FloatBuffer buf6 = BufferHelper.alloc(6);
+//		buf3.clear();
+//		BufferHelper.fill(buf3, (float) pos.x(), (float) pos.y(), (float) pos.z());
+//		AL10.alListener(AL10.AL_POSITION, buf3);
+//		buf3.clear();
+//		BufferHelper.fill(buf3, 0, 0, 0);
+//		AL10.alListener(AL10.AL_VELOCITY, buf3);
+//		buf6.clear();
+//		BufferHelper.fill(buf6, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f);
+//		AL10.alListener(AL10.AL_ORIENTATION, buf6);
+//	}
+//	
+//	
+//	/**
+//	 * @return listener coordinate
+//	 */
+//	public static Vect getListener()
+//	{
+//		return listener;
+//	}
+//	
+//	// -- instance --
+//	
+//	private final Volume masterVolume = new Volume(1D);
+//	private final Volume effectsVolume = new JointVolume(masterVolume);
+//	private final Volume loopsVolume = new JointVolume(masterVolume);
+//	
+//	private final List<LoopPlayer> loopPlayers = new ArrayList<>();
+//	private final List<DeferredAudio> resources = new ArrayList<>();
+//	
+//	
+//	/**
+//	 * @param busAccess app access
+//	 */
+//	public SoundSystem() {
+//		
+//		if (!soundSystemInited) {
+//			soundSystemInited = true;
+//			
+//			try {
+//				SoundStore.get().setMaxSources(MAX_SOURCES);
+//				SoundStore.get().init();
+//				setListener(INITIAL_LISTENER_POS);
+//				
+//				App.bus().send(new AudioReadyEvent());
+//			} catch (final Throwable t) {
+//				Log.e("Error initializing sound system.", t);
+//			}
+//		}
+//	}
+//	
+//	
+//	@Override
+//	public void destroy()
+//	{
+//		for (final DeferredAudio r : resources) {
+//			r.destroy();
+//		}
+//		
+//		SoundStore.get().clear();
+//		AL.destroy();
+//	}
+//	
+//	
+//	@Override
+//	public void update(double delta)
+//	{
+//		for (final Updateable lp : loopPlayers) {
+//			lp.update(delta);
+//		}
+//	}
+//	
+//	
+//	/**
+//	 * Create effect resource
+//	 * 
+//	 * @param resource resource path
+//	 * @param pitch default pitch (1 = unchanged)
+//	 * @param gain default gain (0-1)
+//	 * @return player
+//	 */
+//	public EffectPlayer createEffect(String resource, double pitch, double gain)
+//	{
+//		return new EffectPlayer(createResource(resource), pitch, gain, effectsVolume);
+//	}
+//	
+//	
+//	/**
+//	 * Register loop resource (music / effect loop)
+//	 * 
+//	 * @param resource resource path
+//	 * @param pitch default pitch (1 = unchanged)
+//	 * @param gain default gain (0-1)
+//	 * @param fadeIn default time for fadeIn
+//	 * @param fadeOut default time for fadeOut
+//	 * @return player
+//	 */
+//	public LoopPlayer createLoop(String resource, double pitch, double gain, double fadeIn, double fadeOut)
+//	{
+//		final LoopPlayer p = new LoopPlayer(createResource(resource), pitch, gain, loopsVolume);
+//		p.setFadeTimes(fadeIn, fadeOut);
+//		loopPlayers.add(p);
+//		return p;
+//	}
+//	
+//	
+//	/**
+//	 * Create {@link DeferredAudio} for a resource
+//	 * 
+//	 * @param res a resource name
+//	 * @return the resource
+//	 * @throws IllegalArgumentException if resource is already registered
+//	 */
+//	private DeferredAudio createResource(String res)
+//	{
+//		final DeferredAudio a = new SlickAudio(res);
+//		App.bus().send(new ResourceLoadRequest(a));
+//		resources.add(a);
+//		return a;
+//	}
+//	
+//	
+//	/**
+//	 * Fade out all loops (ie. for screen transitions)
+//	 */
+//	public void fadeOutAllLoops()
+//	{
+//		for (final LoopPlayer p : loopPlayers) {
+//			p.fadeOut();
+//		}
+//	}
+//	
+//	
+//	/**
+//	 * Pause all loops (leave volume unchanged)
+//	 */
+//	public void pauseAllLoops()
+//	{
+//		for (final LoopPlayer p : loopPlayers) {
+//			p.pause();
+//		}
+//	}
+//	
+//	
+//	/**
+//	 * Set level of master volume
+//	 * 
+//	 * @param d level
+//	 */
+//	public void setMasterVolume(double d)
+//	{
+//		masterVolume.set(d);
+//	}
+//	
+//	
+//	/**
+//	 * Set level of effects volume
+//	 * 
+//	 * @param d level
+//	 */
+//	public void setEffectsVolume(double d)
+//	{
+//		effectsVolume.set(d);
+//	}
+//	
+//	
+//	/**
+//	 * Set level of music volume
+//	 * 
+//	 * @param d level
+//	 */
+//	public void setMusicVolume(double d)
+//	{
+//		loopsVolume.set(d);
+//	}
+//	
+//	
+//	/**
+//	 * Get level of master volume
+//	 * 
+//	 * @return level
+//	 */
+//	public double getMasterVolume()
+//	{
+//		return masterVolume.get();
+//	}
+//	
+//	
+//	/**
+//	 * Get level of effects volume
+//	 * 
+//	 * @return level
+//	 */
+//	public double getEffectsVolume()
+//	{
+//		return effectsVolume.get();
+//	}
+//	
+//	
+//	/**
+//	 * Get level of music volume
+//	 * 
+//	 * @return level
+//	 */
+//	public double getMusicVolume()
+//	{
+//		return loopsVolume.get();
+//	}
+//}

src/mightypork/gamecore/audio/AudioModule.java

@@ -0,0 +1,220 @@
+package mightypork.gamecore.audio;
+
+
+import java.util.ArrayList;
+import java.util.List;
+
+import mightypork.gamecore.audio.players.EffectPlayer;
+import mightypork.gamecore.audio.players.LoopPlayer;
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.core.BackendModule;
+import mightypork.gamecore.resources.loading.ResourceLoadRequest;
+import mightypork.utils.interfaces.Updateable;
+import mightypork.utils.math.constraints.vect.Vect;
+
+
+/**
+ * Abstract audio module.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class AudioModule extends BackendModule implements Updateable {
+	
+	/**
+	 * Set listener position
+	 * 
+	 * @param pos listener position
+	 */
+	public abstract void setListenerPos(Vect pos);
+	
+	
+	/**
+	 * Get current listener position
+	 * 
+	 * @return listener position
+	 */
+	public abstract Vect getListenerPos();
+	
+	// -- instance --
+	
+	private final Volume masterVolume = new Volume(1D);
+	private final Volume effectsVolume = new JointVolume(masterVolume);
+	private final Volume loopsVolume = new JointVolume(masterVolume);
+	
+	private final List<LoopPlayer> loopPlayers = new ArrayList<>();
+	private final List<DeferredAudio> resources = new ArrayList<>();
+	
+	
+	@Override
+	public void destroy()
+	{
+		for (final DeferredAudio r : resources) {
+			r.destroy();
+		}
+		
+		deinitSoundSystem();
+	}
+	
+	
+	/**
+	 * Deinitialize the soud system, release resources etc.<br>
+	 * Audio resources are already destroyed.
+	 */
+	protected abstract void deinitSoundSystem();
+	
+	
+	@Override
+	public void update(double delta)
+	{
+		for (final Updateable lp : loopPlayers) {
+			lp.update(delta);
+		}
+	}
+	
+	
+	/**
+	 * Create effect resource
+	 * 
+	 * @param resource resource path
+	 * @param pitch default pitch (1 = unchanged)
+	 * @param gain default gain (0-1)
+	 * @return player
+	 */
+	public EffectPlayer createEffect(String resource, double pitch, double gain)
+	{
+		return new EffectPlayer(createResource(resource), pitch, gain, effectsVolume);
+	}
+	
+	
+	/**
+	 * Register loop resource (music / effect loop)
+	 * 
+	 * @param resource resource path
+	 * @param pitch default pitch (1 = unchanged)
+	 * @param gain default gain (0-1)
+	 * @param fadeIn default time for fadeIn
+	 * @param fadeOut default time for fadeOut
+	 * @return player
+	 */
+	public LoopPlayer createLoop(String resource, double pitch, double gain, double fadeIn, double fadeOut)
+	{
+		final LoopPlayer p = new LoopPlayer(createResource(resource), pitch, gain, loopsVolume);
+		p.setFadeTimes(fadeIn, fadeOut);
+		loopPlayers.add(p);
+		return p;
+	}
+	
+	
+	/**
+	 * Create {@link DeferredAudio} for a resource, request deferred load and
+	 * add to the resources list.
+	 * 
+	 * @param res a resource name
+	 * @return the resource
+	 * @throws IllegalArgumentException if resource is already registered
+	 */
+	protected DeferredAudio createResource(String res)
+	{
+		final DeferredAudio a = doCreateResource(res);
+		App.bus().send(new ResourceLoadRequest(a));
+		resources.add(a);
+		return a;
+	}
+	
+	
+	/**
+	 * Create a backend-specific deferred audio resource
+	 * 
+	 * @param res resource path
+	 * @return Deferred Audio
+	 */
+	protected abstract DeferredAudio doCreateResource(String res);
+	
+	
+	/**
+	 * Fade out all loops (= fade out the currently playing loops)
+	 */
+	public void fadeOutAllLoops()
+	{
+		for (final LoopPlayer p : loopPlayers) {
+			p.fadeOut();
+		}
+	}
+	
+	
+	/**
+	 * Pause all loops (leave volume unchanged)
+	 */
+	public void pauseAllLoops()
+	{
+		for (final LoopPlayer p : loopPlayers) {
+			p.pause();
+		}
+	}
+	
+	
+	/**
+	 * Set level of master volume (volume multiplier)
+	 * 
+	 * @param volume level (0..1)
+	 */
+	public void setMasterVolume(double volume)
+	{
+		masterVolume.set(volume);
+	}
+	
+	
+	/**
+	 * Set level of effects volume (volume multiplier)
+	 * 
+	 * @param volume level (0..1)
+	 */
+	public void setEffectsVolume(double volume)
+	{
+		effectsVolume.set(volume);
+	}
+	
+	
+	/**
+	 * Set level of loops volume (volume multiplier)
+	 * 
+	 * @param volume level (0..1)
+	 */
+	public void setLoopsVolume(double volume)
+	{
+		loopsVolume.set(volume);
+	}
+	
+	
+	/**
+	 * Get level of master volume (volume multiplier)
+	 * 
+	 * @return level (0..1)
+	 */
+	public double getMasterVolume()
+	{
+		return masterVolume.get();
+	}
+	
+	
+	/**
+	 * Get level of effects volume (volume multiplier)
+	 * 
+	 * @return level (0..1)
+	 */
+	public double getEffectsVolume()
+	{
+		return effectsVolume.get();
+	}
+	
+	
+	/**
+	 * Get level of loops volume (volume multiplier)
+	 * 
+	 * @return level (0..1)
+	 */
+	public double getLoopsVolume()
+	{
+		return loopsVolume.get();
+	}
+}

src/mightypork/gamecore/audio/DeferredAudio.java

@@ -0,0 +1,47 @@
+package mightypork.gamecore.audio;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.resources.BaseDeferredResource;
+import mightypork.utils.annotations.Alias;
+import mightypork.utils.math.constraints.vect.Vect;
+
+
+/**
+ * Abstract deferred audio, to be extended in backend.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@Alias(name = "Audio")
+public abstract class DeferredAudio extends BaseDeferredResource implements IAudio {
+	
+	/**
+	 * Create audio
+	 * 
+	 * @param resourceName resource to load (when needed)
+	 */
+	public DeferredAudio(String resourceName) {
+		super(resourceName);
+	}
+	
+	
+	@Override
+	public void play(double pitch, double gain, boolean loop)
+	{
+		play(pitch, gain, loop, App.audio().getListenerPos());
+	}
+	
+	
+	@Override
+	public void play(double pitch, double gain, boolean loop, double x, double y)
+	{
+		play(pitch, gain, loop, x, y, App.audio().getListenerPos().z());
+	}
+	
+	
+	@Override
+	public void play(double pitch, double gain, boolean loop, Vect pos)
+	{
+		play(pitch, gain, loop, pos.x(), pos.y(), pos.z());
+	}
+}

src/mightypork/gamecore/audio/IAudio.java

@@ -0,0 +1,99 @@
+package mightypork.gamecore.audio;
+
+
+import mightypork.utils.interfaces.Destroyable;
+import mightypork.utils.math.constraints.vect.Vect;
+
+
+/**
+ * Audio resource interface (backend independent)
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface IAudio extends Destroyable {
+	
+	/**
+	 * Pause loop (remember position and stop playing) - if was looping
+	 */
+	void pauseLoop();
+	
+	
+	/**
+	 * Resume loop (if was paused)
+	 */
+	void resumeLoop();
+	
+	
+	/**
+	 * Adjust gain for the currently playing effect (can be used for fading
+	 * music)
+	 * 
+	 * @param gain gain to set 0..1
+	 */
+	void adjustGain(double gain);
+	
+	
+	/**
+	 * Stop audio playback
+	 */
+	void stop();
+	
+	
+	/**
+	 * @return true if the audio is playing
+	 */
+	boolean isPlaying();
+	
+	
+	/**
+	 * @return trie if the audio is paused
+	 */
+	boolean isPaused();
+	
+	
+	/**
+	 * Play as sound effect at listener position
+	 * 
+	 * @param pitch pitch (1 = default)
+	 * @param gain gain (0-1)
+	 * @param loop looping
+	 */
+	void play(double pitch, double gain, boolean loop);
+	
+	
+	/**
+	 * Play as sound effect at given X-Y position
+	 * 
+	 * @param pitch pitch (1 = default)
+	 * @param gain gain (0-1)
+	 * @param loop looping
+	 * @param x
+	 * @param y
+	 */
+	void play(double pitch, double gain, boolean loop, double x, double y);
+	
+	
+	/**
+	 * Play as sound effect at given position
+	 * 
+	 * @param pitch pitch (1 = default)
+	 * @param gain gain (0-1)
+	 * @param loop looping
+	 * @param x
+	 * @param y
+	 * @param z
+	 */
+	void play(double pitch, double gain, boolean loop, double x, double y, double z);
+	
+	
+	/**
+	 * Play as sound effect at given position
+	 * 
+	 * @param pitch pitch (1 = default)
+	 * @param gain gain (0-1)
+	 * @param loop looping
+	 * @param pos coord
+	 */
+	void play(double pitch, double gain, boolean loop, Vect pos);
+	
+}

src/mightypork/gamecore/audio/JointVolume.java

@@ -0,0 +1,51 @@
+package mightypork.gamecore.audio;
+
+
+import mightypork.utils.math.Calc;
+
+
+/**
+ * Volume combined of multiple volumes, combining them (multiplication).
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class JointVolume extends Volume {
+	
+	private final Volume[] volumes;
+	
+	
+	/**
+	 * Create joint volume with master gain of 1
+	 * 
+	 * @param volumes individual volumes to join
+	 */
+	@SafeVarargs
+	public JointVolume(Volume... volumes) {
+		super(1D);
+		this.volumes = volumes;
+	}
+	
+	
+	/**
+	 * Get combined gain (multiplied)
+	 */
+	@Override
+	public Double get()
+	{
+		double d = super.get();
+		for (final Volume v : volumes)
+			d *= v.get();
+		
+		return Calc.clamp(d, 0, 1);
+	}
+	
+	
+	/**
+	 * Set master gain
+	 */
+	@Override
+	public void set(Double o)
+	{
+		super.set(o);
+	}
+}

src/mightypork/gamecore/audio/SoundRegistry.java

@@ -0,0 +1,83 @@
+package mightypork.gamecore.audio;
+
+
+import java.util.HashMap;
+import java.util.Map;
+
+import mightypork.gamecore.audio.players.EffectPlayer;
+import mightypork.gamecore.audio.players.LoopPlayer;
+import mightypork.gamecore.core.App;
+
+
+/**
+ * Audio resource storage
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class SoundRegistry {
+	
+	private final Map<String, EffectPlayer> effects = new HashMap<>();
+	private final Map<String, LoopPlayer> loops = new HashMap<>();
+	
+	
+	/**
+	 * Register effect resource
+	 * 
+	 * @param key sound key
+	 * @param resource resource path
+	 * @param pitch default pitch (1 = unchanged)
+	 * @param gain default gain (0-1)
+	 */
+	public void addEffect(String key, String resource, double pitch, double gain)
+	{
+		effects.put(key, App.audio().createEffect(resource, pitch, gain));
+	}
+	
+	
+	/**
+	 * Register loop resource (music / effect loop)
+	 * 
+	 * @param key sound key
+	 * @param resource resource path
+	 * @param pitch default pitch (1 = unchanged)
+	 * @param gain default gain (0-1)
+	 * @param fadeIn default time for fadeIn
+	 * @param fadeOut default time for fadeOut
+	 */
+	public void addLoop(String key, String resource, double pitch, double gain, double fadeIn, double fadeOut)
+	{
+		loops.put(key, App.audio().createLoop(resource, pitch, gain, fadeIn, fadeOut));
+	}
+	
+	
+	/**
+	 * Get a loop player for key
+	 * 
+	 * @param key sound key
+	 * @return loop player
+	 */
+	public LoopPlayer getLoop(String key)
+	{
+		final LoopPlayer p = loops.get(key);
+		if (p == null) {
+			throw new RuntimeException("Unknown sound loop \"" + key + "\".");
+		}
+		return p;
+	}
+	
+	
+	/**
+	 * Get a effect player for key
+	 * 
+	 * @param key sound key
+	 * @return effect player
+	 */
+	public EffectPlayer getEffect(String key)
+	{
+		final EffectPlayer p = effects.get(key);
+		if (p == null) {
+			throw new RuntimeException("Unknown sound effect \"" + key + "\".");
+		}
+		return p;
+	}
+}

src/mightypork/gamecore/audio/Volume.java

@@ -0,0 +1,29 @@
+package mightypork.gamecore.audio;
+
+
+import mightypork.utils.math.Calc;
+import mightypork.utils.struct.Mutable;
+
+
+/**
+ * Mutable volume 0-1
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class Volume extends Mutable<Double> {
+	
+	/**
+	 * @param d initial value
+	 */
+	public Volume(Double d) {
+		super(d);
+	}
+	
+	
+	@Override
+	public void set(Double d)
+	{
+		super.set(Calc.clamp(d, 0, 1));
+	}
+	
+}

src/mightypork/gamecore/audio/players/BaseAudioPlayer.java

@@ -0,0 +1,105 @@
+package mightypork.gamecore.audio.players;
+
+
+import mightypork.gamecore.audio.DeferredAudio;
+import mightypork.gamecore.audio.Volume;
+import mightypork.utils.interfaces.Destroyable;
+
+
+/**
+ * Basic abstract player
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class BaseAudioPlayer implements Destroyable {
+	
+	/** the track */
+	private final DeferredAudio audio;
+	
+	/** base gain for sfx */
+	private final double baseGain;
+	
+	/** base pitch for sfx */
+	private final double basePitch;
+	
+	/** dedicated volume control */
+	private final Volume gainMultiplier;
+	
+	
+	/**
+	 * @param track audio resource
+	 * @param basePitch base pitch (pitch multiplier)
+	 * @param baseGain base gain (volume multiplier)
+	 * @param volume colume control
+	 */
+	public BaseAudioPlayer(DeferredAudio track, double basePitch, double baseGain, Volume volume) {
+		this.audio = track;
+		
+		this.baseGain = baseGain;
+		this.basePitch = basePitch;
+		
+		if (volume == null) volume = new Volume(1D);
+		
+		this.gainMultiplier = volume;
+	}
+	
+	
+	@Override
+	public void destroy()
+	{
+		audio.destroy();
+	}
+	
+	
+	/**
+	 * @return audio resource
+	 */
+	protected DeferredAudio getAudio()
+	{
+		return audio;
+	}
+	
+	
+	/**
+	 * Get play gain, computed based on volume and given multiplier
+	 * 
+	 * @param multiplier extra volume adjustment
+	 * @return computed gain
+	 */
+	protected double computeGain(double multiplier)
+	{
+		return baseGain * gainMultiplier.get() * multiplier;
+	}
+	
+	
+	/**
+	 * Get pitch
+	 * 
+	 * @param multiplier pitch adjustment
+	 * @return computed pitch
+	 */
+	protected double computePitch(double multiplier)
+	{
+		return basePitch * multiplier;
+	}
+	
+	
+	/**
+	 * Get if audio is valid
+	 * 
+	 * @return is valid
+	 */
+	protected boolean hasAudio()
+	{
+		return (audio != null);
+	}
+	
+	
+	/**
+	 * force load the resource
+	 */
+	public void load()
+	{
+		if (hasAudio()) audio.load();
+	}
+}

src/mightypork/gamecore/audio/players/EffectPlayer.java

@@ -0,0 +1,66 @@
+package mightypork.gamecore.audio.players;
+
+
+import mightypork.gamecore.audio.DeferredAudio;
+import mightypork.gamecore.audio.Volume;
+import mightypork.utils.math.constraints.vect.Vect;
+
+
+/**
+ * Player for one-off effects
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class EffectPlayer extends BaseAudioPlayer {
+	
+	/**
+	 * @param track audio resource
+	 * @param basePitch base pitch (pitch multiplier)
+	 * @param baseGain base gain (volume multiplier)
+	 * @param volume volume control
+	 */
+	public EffectPlayer(DeferredAudio track, double basePitch, double baseGain, Volume volume) {
+		super(track, (float) basePitch, (float) baseGain, volume);
+	}
+	
+	
+	/**
+	 * Play at listener
+	 * 
+	 * @param pitch play pitch
+	 * @param gain play gain
+	 */
+	public void play(double pitch, double gain)
+	{
+		if (!hasAudio()) return;
+		
+		getAudio().play(computePitch(pitch), computeGain(gain), false);
+	}
+	
+	
+	/**
+	 * Play at listener
+	 * 
+	 * @param gain play gain
+	 */
+	public void play(double gain)
+	{
+		play(1, gain);
+	}
+	
+	
+	/**
+	 * Play at given position
+	 * 
+	 * @param pitch play pitch
+	 * @param gain play gain
+	 * @param pos play position
+	 */
+	public void play(double pitch, double gain, Vect pos)
+	{
+		if (!hasAudio()) return;
+		
+		getAudio().play(computePitch(pitch), computeGain(gain), false, pos);
+	}
+	
+}

src/mightypork/gamecore/audio/players/LoopPlayer.java

@@ -0,0 +1,166 @@
+package mightypork.gamecore.audio.players;
+
+
+import mightypork.gamecore.audio.DeferredAudio;
+import mightypork.gamecore.audio.Volume;
+import mightypork.utils.interfaces.Pauseable;
+import mightypork.utils.interfaces.Updateable;
+import mightypork.utils.math.animation.NumAnimated;
+
+
+/**
+ * Audio loop player (with fading, good for music)
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class LoopPlayer extends BaseAudioPlayer implements Updateable, Pauseable {
+	
+	private int sourceID = -1;
+	
+	/** animator for fade in and fade out */
+	private final NumAnimated fadeAnim = new NumAnimated(0);
+	
+	private double lastUpdateGain = 0;
+	
+	/** flag that track is paused */
+	private boolean paused = true;
+	
+	/** Default fadeIn time */
+	private double inTime = 1;
+	
+	/** Default fadeOut time */
+	private double outTime = 1;
+	
+	
+	/**
+	 * @param track audio resource
+	 * @param basePitch base pitch (pitch multiplier)
+	 * @param baseGain base gain (volume multiplier)
+	 * @param volume volume control
+	 */
+	public LoopPlayer(DeferredAudio track, double basePitch, double baseGain, Volume volume) {
+		super(track, (float) basePitch, (float) baseGain, volume);
+		
+		paused = true;
+	}
+	
+	
+	/**
+	 * Set fading duration (seconds)
+	 * 
+	 * @param in duration of fade-in
+	 * @param out duration of fade-out
+	 */
+	public void setFadeTimes(double in, double out)
+	{
+		inTime = in;
+		outTime = out;
+	}
+	
+	
+	private void initLoop()
+	{
+		if (hasAudio() && sourceID == -1) {
+			getAudio().play(computePitch(1), computeGain(1), true);
+			getAudio().pauseLoop();
+		}
+	}
+	
+	
+	@Override
+	public void pause()
+	{
+		if (!hasAudio() || paused) return;
+		
+		initLoop();
+		
+		getAudio().pauseLoop();
+		paused = true;
+	}
+	
+	
+	@Override
+	public boolean isPaused()
+	{
+		return paused;
+	}
+	
+	
+	@Override
+	public void resume()
+	{
+		if (!hasAudio() || !paused) return;
+		
+		initLoop();
+		
+		paused = false;
+		
+		getAudio().adjustGain(computeGain(fadeAnim.value()));
+	}
+	
+	
+	@Override
+	public void update(double delta)
+	{
+		if (!hasAudio() || paused) return;
+		
+		initLoop();
+		
+		fadeAnim.update(delta);
+		
+		final double gain = computeGain(fadeAnim.value());
+		if (!paused && gain != lastUpdateGain) {
+			getAudio().adjustGain(gain);
+			lastUpdateGain = gain;
+		}
+		
+		if (gain == 0 && !paused) pause(); // pause on zero volume
+	}
+	
+	
+	/**
+	 * Resume if paused, and fade in (pick up from current volume).
+	 * 
+	 * @param secs
+	 */
+	public void fadeIn(double secs)
+	{
+		if (!hasAudio()) return;
+		
+		if (isPaused()) fadeAnim.setTo(0);
+		resume();
+		fadeAnim.fadeIn(secs);
+	}
+	
+	
+	/**
+	 * Fade out and pause when reached zero volume
+	 * 
+	 * @param secs fade duration
+	 */
+	public void fadeOut(double secs)
+	{
+		if (!hasAudio()) return;
+		if (isPaused()) return;
+		fadeAnim.fadeOut(secs);
+	}
+	
+	
+	/**
+	 * Fade in with default duration
+	 */
+	public void fadeIn()
+	{
+		fadeIn(inTime);
+	}
+	
+	
+	/**
+	 * Fade out with default duration
+	 */
+	public void fadeOut()
+	{
+		fadeOut(outTime);
+	}
+	
+}

src/mightypork/gamecore/core/App.java

@@ -0,0 +1,277 @@
+package mightypork.gamecore.core;
+
+
+import java.util.ArrayList;
+import java.util.List;
+
+import mightypork.gamecore.audio.AudioModule;
+import mightypork.gamecore.core.config.Config;
+import mightypork.gamecore.core.events.ShutdownEvent;
+import mightypork.gamecore.graphics.GraphicsModule;
+import mightypork.gamecore.input.InputModule;
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.eventbus.EventBus;
+import mightypork.utils.eventbus.clients.BusNode;
+import mightypork.utils.eventbus.clients.DelegatingList;
+import mightypork.utils.eventbus.events.DestroyEvent;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Game base class & static subsystem access
+ * 
+ * @author MightyPork
+ */
+public class App extends BusNode {
+	
+	private static App instance;
+	
+	private final AppBackend backend;
+	private final EventBus eventBus = new EventBus();
+	private boolean started = false;
+	
+	protected final DelegatingList plugins = new DelegatingList();
+	protected final List<InitTask> initializers = new ArrayList<>();
+	
+	
+	/**
+	 * Create an app with given backend.
+	 * 
+	 * @param backend
+	 */
+	public App(AppBackend backend) {
+		if (App.instance != null) {
+			throw new IllegalStateException("App already initialized");
+		}
+		
+		// store current instance in static field
+		App.instance = this;
+		
+		// join the bus
+		this.eventBus.subscribe(this);
+		
+		// create plugin registry attached to bus
+		this.eventBus.subscribe(this.plugins);
+		
+		// initialize and use backend
+		this.backend = backend;
+		this.eventBus.subscribe(backend);
+		this.backend.bind(this);
+		this.backend.initialize();
+	}
+	
+	
+	/**
+	 * Add a plugin to the app. Plugins can eg. listen to bus events and react
+	 * to them.
+	 * 
+	 * @param plugin the added plugin.
+	 */
+	public void addPlugin(AppPlugin plugin)
+	{
+		if (started) {
+			throw new IllegalStateException("App already started, cannot add plugins.");
+		}
+		
+		// attach to event bus
+		plugins.add(plugin);
+		plugin.bind(this);
+		plugin.initialize();
+	}
+	
+	
+	/**
+	 * Add an initializer to the app.
+	 * 
+	 * @param initializer
+	 */
+	public void addInitTask(InitTask initializer)
+	{
+		if (started) {
+			throw new IllegalStateException("App already started, cannot add initializers.");
+		}
+		
+		initializers.add(initializer);
+	}
+	
+	
+	/**
+	 * Get current backend
+	 * 
+	 * @return the backend
+	 */
+	public AppBackend getBackend()
+	{
+		return backend;
+	}
+	
+	
+	/**
+	 * Initialize the App and start operating.<br>
+	 * This method should be called after adding all required initializers and
+	 * plugins.
+	 */
+	public final void start()
+	{
+		if (started) {
+			throw new IllegalStateException("Already started.");
+		}
+		started = true;
+		
+		// pre-init hook, just in case anyone wanted to have one.
+		Log.f2("Calling pre-init hook...");
+		preInit();
+		
+		Log.i("=== Starting initialization sequence ===");
+		
+		// sort initializers by order.
+		List<InitTask> orderedInitializers = InitTask.inOrder(initializers);
+		
+		for (InitTask initializer : orderedInitializers) {
+			Log.f1("Running init task \"" + initializer.getName() + "\"...");
+			initializer.bind(this);
+			initializer.init();
+			initializer.run();
+		}
+		
+		Log.i("=== Initialization sequence completed ===");
+		
+		// user can now start the main loop etc.
+		Log.f2("Calling post-init hook...");
+		postInit();
+	}
+	
+	
+	/**
+	 * Hook called before the initialization sequence starts.
+	 */
+	@Stub
+	protected void preInit()
+	{
+	}
+	
+	
+	/**
+	 * Hook called after the initialization sequence is finished.
+	 */
+	@Stub
+	protected void postInit()
+	{
+	}
+	
+	
+	/**
+	 * Shut down the running instance.<br>
+	 * Deinitialize backend modules and terminate the JVM.
+	 */
+	public static void shutdown()
+	{
+		if (instance != null) {
+			Log.i("Dispatching Shutdown event...");
+			
+			bus().send(new ShutdownEvent(new Runnable() {
+				
+				@Override
+				public void run()
+				{
+					try {
+						final EventBus bus = bus();
+						if (bus != null) {
+							bus.send(new DestroyEvent());
+							bus.destroy();
+						}
+					} catch (final Throwable e) {
+						Log.e(e);
+					}
+					
+					Log.i("Shutdown completed.");
+					System.exit(0);
+				}
+			}));
+			
+		} else {
+			Log.w("App is not running.");
+			System.exit(0);
+		}
+	}
+	
+	
+	/**
+	 * Get the currently running App instance.
+	 * 
+	 * @return app instance
+	 */
+	public static App instance()
+	{
+		return instance;
+	}
+	
+	
+	/**
+	 * Get graphics module from the running app's backend
+	 * 
+	 * @return graphics module
+	 */
+	public static GraphicsModule gfx()
+	{
+		return instance.backend.getGraphics();
+	}
+	
+	
+	/**
+	 * Get audio module from the running app's backend
+	 * 
+	 * @return audio module
+	 */
+	public static AudioModule audio()
+	{
+		return instance.backend.getAudio();
+	}
+	
+	
+	/**
+	 * Get input module from the running app's backend
+	 * 
+	 * @return input module
+	 */
+	public static InputModule input()
+	{
+		return instance.backend.getInput();
+	}
+	
+	
+	/**
+	 * Get event bus instance.
+	 * 
+	 * @return event bus
+	 */
+	public static EventBus bus()
+	{
+		return instance.eventBus;
+	}
+	
+	
+	/**
+	 * Get the main config, if initialized.
+	 * 
+	 * @return main config
+	 * @throws IllegalArgumentException if there is no such config.
+	 */
+	public static Config cfg()
+	{
+		return cfg("main");
+	}
+	
+	
+	/**
+	 * Get a config by alias.
+	 * 
+	 * @param alias config alias
+	 * @return the config
+	 * @throws IllegalArgumentException if there is no such config.
+	 */
+	public static Config cfg(String alias)
+	{
+		return Config.forAlias(alias);
+	}
+}

src/mightypork/gamecore/core/AppBackend.java

@@ -0,0 +1,65 @@
+package mightypork.gamecore.core;
+
+
+import mightypork.gamecore.audio.AudioModule;
+import mightypork.gamecore.graphics.GraphicsModule;
+import mightypork.gamecore.input.InputModule;
+import mightypork.utils.eventbus.clients.BusNode;
+
+
+/**
+ * Application backend interface (set of core modules).<br>
+ * The goal of this abstraction is to allow easy migration to different
+ * environment with different libraries etc. It should be as simple as using
+ * different backend.
+ * 
+ * @author MightyPork
+ */
+public abstract class AppBackend extends BusNode {
+	
+	protected App app;
+	
+	
+	/**
+	 * Assign an app instance.
+	 * 
+	 * @param app app
+	 */
+	public void bind(App app)
+	{
+		if (this.app != null) {
+			throw new IllegalStateException("App already set.");
+		}
+		this.app = app;
+	}
+	
+	
+	/**
+	 * Initialize backend modules, add them to event bus.
+	 */
+	public abstract void initialize();
+	
+	
+	/**
+	 * Get graphics module (screen manager, texture and font loader, renderer)
+	 * 
+	 * @return graphics module
+	 */
+	public abstract GraphicsModule getGraphics();
+	
+	
+	/**
+	 * Get audio module (
+	 * 
+	 * @return audio module
+	 */
+	public abstract AudioModule getAudio();
+	
+	
+	/**
+	 * Get input module
+	 * 
+	 * @return input module
+	 */
+	public abstract InputModule getInput();
+}

src/mightypork/gamecore/core/AppPlugin.java

@@ -0,0 +1,34 @@
+package mightypork.gamecore.core;
+
+
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.eventbus.clients.BusNode;
+
+
+/**
+ * App plugin. Plugins are an easy way to extend app functionality.<br>
+ * Typically, a plugin waits for trigger event(s) and performs some action upon
+ * receiving them.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class AppPlugin extends BusNode {
+	
+	protected App app;
+	
+	
+	void bind(App app)
+	{
+		this.app = app;
+	}
+	
+	
+	/**
+	 * Initialize the plugin for the given App.<br>
+	 * The plugin is already attached to the event bus.
+	 */
+	@Stub
+	public void initialize()
+	{
+	}
+}

src/mightypork/gamecore/core/BackendModule.java

@@ -0,0 +1,24 @@
+package mightypork.gamecore.core;
+
+
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.eventbus.clients.BusNode;
+import mightypork.utils.interfaces.Destroyable;
+
+
+/**
+ * Abstract application backend module.
+ * 
+ * @author MightyPork
+ */
+public abstract class BackendModule extends BusNode implements Destroyable {
+	
+	public abstract void init();
+	
+	
+	@Override
+	@Stub
+	public void destroy()
+	{
+	}
+}

src/mightypork/gamecore/core/InitTask.java

@@ -0,0 +1,150 @@
+package mightypork.gamecore.core;
+
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+
+import mightypork.utils.Reflect;
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * App initializer. A sequence of initializers is executed once the start()
+ * method on App is called. Adding initializers is one way to customize the App
+ * behavior and features.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class InitTask {
+	
+	protected App app;
+	
+	
+	/**
+	 * Assign the initialized app instance to a protected "app" field.
+	 * 
+	 * @param app app
+	 */
+	void bind(App app)
+	{
+		this.app = app;
+	}
+	
+	
+	/**
+	 * An intialization method that is called before the run() method.<br>
+	 * This method should be left unimplemented in the task, and can be used to
+	 * configure the init task when using it as anonymous inner type.
+	 */
+	@Stub
+	public void init()
+	{
+	}
+	
+	
+	/**
+	 * Run the initalizer on app.
+	 */
+	public abstract void run();
+	
+	
+	/**
+	 * Get name of this initializer (for dependency resolver).<br>
+	 * The name should be short, snake_case and precise.
+	 * 
+	 * @return name
+	 */
+	public abstract String getName();
+	
+	
+	/**
+	 * Get what other initializers must be already loaded before this can load.<br>
+	 * Depending on itself or creating a circular dependency will cause error.<br>
+	 * If the dependencies cannot be satisfied, the initialization sequence will
+	 * be aborted.
+	 * 
+	 * @return array of names of required initializers.
+	 */
+	@Stub
+	public String[] getDependencies()
+	{
+		return new String[] {};
+	}
+	
+	
+	/**
+	 * Order init tasks so that all dependencies are loaded before thye are
+	 * needed by the tasks.
+	 * 
+	 * @param tasks task list
+	 * @return task list ordered
+	 */
+	public static List<InitTask> inOrder(List<InitTask> tasks)
+	{
+		List<InitTask> remaining = new ArrayList<>(tasks);
+		
+		List<InitTask> ordered = new ArrayList<>();
+		Set<String> loaded = new HashSet<>();
+		
+		// resolve task order
+		int addedThisIteration = 0;
+		do {
+			for (Iterator<InitTask> i = remaining.iterator(); i.hasNext();) {
+				InitTask task = i.next();
+				
+				String[] deps = task.getDependencies();
+				if (deps == null) deps = new String[] {};
+				
+				int unmetDepsCount = deps.length;
+				
+				for (String d : deps) {
+					if (loaded.contains(d)) unmetDepsCount--;
+				}
+				
+				if (unmetDepsCount == 0) {
+					ordered.add(task);
+					loaded.add(task.getName());
+					i.remove();
+					addedThisIteration++;
+				}
+			}
+		} while (addedThisIteration > 0);
+		
+		// check if any tasks are left out
+		if (remaining.size() > 0) {
+			
+			// build error message for each bad task
+			int badInitializers = 0;
+			for (InitTask task : remaining) {
+				if (Reflect.hasAnnotation(task.getClass(), OptionalInitTask.class)) {
+					continue;
+				}
+				
+				badInitializers++;
+				
+				String notSatisfied = "";
+				
+				for (String d : task.getDependencies()) {
+					if (!loaded.contains(d)) {
+						
+						if (!notSatisfied.isEmpty()) {
+							notSatisfied += ", ";
+						}
+						
+						notSatisfied += d;
+					}
+				}
+				
+				Log.w("InitTask \"" + task.getName() + "\" - missing dependencies: " + notSatisfied);
+			}
+			
+			if (badInitializers > 0) throw new RuntimeException("Some InitTask dependencies could not be satisfied.");
+		}
+		
+		return ordered;
+	}
+}

src/mightypork/gamecore/core/MainLoop.java

@@ -0,0 +1,130 @@
+package mightypork.gamecore.core;
+
+
+import java.util.Deque;
+import java.util.concurrent.ConcurrentLinkedDeque;
+
+import mightypork.gamecore.graphics.Renderable;
+import mightypork.gamecore.gui.screens.ScreenRegistry;
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.eventbus.clients.BusNode;
+import mightypork.utils.eventbus.events.UpdateEvent;
+import mightypork.utils.interfaces.Destroyable;
+import mightypork.utils.logging.Log;
+import mightypork.utils.math.timing.Profiler;
+import mightypork.utils.math.timing.TimerDelta;
+
+
+/**
+ * Delta-timed game loop with task queue etc.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class MainLoop extends BusNode implements Destroyable {
+	
+	private static final double MAX_TIME_TASKS = 1 / 30D; // (avoid queue from hogging timing)
+	private static final double MAX_DELTA = 1 / 20D; // (skip huge gaps caused by loading resources etc)
+	
+	private final Deque<Runnable> tasks = new ConcurrentLinkedDeque<>();
+	private TimerDelta timer;
+	private Renderable rootRenderable;
+	private volatile boolean running = true;
+	
+	
+	/**
+	 * Set primary renderable
+	 * 
+	 * @param rootRenderable main {@link Renderable}, typically a
+	 *            {@link ScreenRegistry}
+	 */
+	public void setRootRenderable(Renderable rootRenderable)
+	{
+		this.rootRenderable = rootRenderable;
+	}
+	
+	
+	/**
+	 * Start the loop
+	 */
+	public void start()
+	{
+		timer = new TimerDelta();
+		
+		while (running) {
+			App.gfx().beginFrame();
+			
+			double delta = timer.getDelta();
+			if (delta > MAX_DELTA) {
+				Log.f3("(timing) Cropping delta: was " + delta + " , limit " + MAX_DELTA);
+				delta = MAX_DELTA;
+			}
+			
+			App.bus().sendDirect(new UpdateEvent(delta));
+			
+			Runnable r;
+			final long t = Profiler.begin();
+			while ((r = tasks.poll()) != null) {
+				Log.f3(" * Main loop task.");
+				r.run();
+				if (Profiler.end(t) > MAX_TIME_TASKS) {
+					Log.f3("! Postponing main loop tasks to next cycle.");
+					break;
+				}
+			}
+			
+			beforeRender();
+			
+			if (rootRenderable != null) {
+				rootRenderable.render();
+			}
+			
+			afterRender();
+			
+			App.gfx().endFrame();
+		}
+	}
+	
+	
+	/**
+	 * Called before render
+	 */
+	@Stub
+	protected void beforeRender()
+	{
+		//
+	}
+	
+	
+	/**
+	 * Called after render
+	 */
+	@Stub
+	protected void afterRender()
+	{
+		//
+	}
+	
+	
+	@Override
+	public void destroy()
+	{
+		running = false;
+	}
+	
+	
+	/**
+	 * Add a task to queue to be executed in the main loop (OpenGL thread)
+	 * 
+	 * @param request task
+	 * @param priority if true, skip other tasks
+	 */
+	public synchronized void queueTask(Runnable request, boolean priority)
+	{
+		if (priority) {
+			tasks.addFirst(request);
+		} else {
+			tasks.addLast(request);
+		}
+	}
+	
+}

src/mightypork/gamecore/core/OptionalInitTask.java

@@ -0,0 +1,19 @@
+package mightypork.gamecore.core;
+
+
+import java.lang.annotation.*;
+
+
+/**
+ * Indicates that an {@link InitTask} can safely be ignored if it's dependencies
+ * are not satisfied.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+@Documented
+@Inherited
+public @interface OptionalInitTask {
+	
+}

src/mightypork/gamecore/core/WorkDir.java

@@ -0,0 +1,91 @@
+package mightypork.gamecore.core;
+
+
+import java.io.File;
+import java.util.HashMap;
+import java.util.Map;
+
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Static application workdir accessor.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class WorkDir {
+	
+	private static File workdir;
+	private static Map<String, String> namedPaths = new HashMap<>();
+	
+	
+	public static void init(File workdir)
+	{
+		WorkDir.workdir = workdir;
+	}
+	
+	
+	/**
+	 * Add a path alias (dir or file), relative to the workdir.
+	 * 
+	 * @param alias path alias
+	 * @param path path relative to workdir
+	 */
+	public static void addPath(String alias, String path)
+	{
+		namedPaths.put(alias, path);
+	}
+	
+	
+	/**
+	 * Get workdir folder, create if not exists.
+	 * 
+	 * @param path dir path relative to workdir
+	 * @return dir file
+	 */
+	public static File getDir(String path)
+	{
+		if (namedPaths.containsKey(path)) path = namedPaths.get(path);
+		
+		final File f = new File(workdir, path);
+		if (!f.exists()) {
+			if (!f.mkdirs()) {
+				Log.w("Could not create a directory: " + f + " (path: " + path + ")");
+			}
+		}
+		
+		return f;
+	}
+	
+	
+	/**
+	 * Get workdir file, create parent if not exists.
+	 * 
+	 * @param path dir path relative to workdir
+	 * @return dir file
+	 */
+	public static File getFile(String path)
+	{
+		if (namedPaths.containsKey(path)) path = namedPaths.get(path);
+		
+		final File f = new File(workdir, path);
+		
+		// create the parent dir
+		if (!f.getParent().equals(workdir)) {
+			f.getParentFile().mkdirs();
+		}
+		
+		return f;
+		
+	}
+	
+	
+	/**
+	 * @return the workdir File
+	 */
+	public static File getWorkDir()
+	{
+		return workdir;
+	}
+	
+}

src/mightypork/gamecore/core/config/Config.java

@@ -0,0 +1,269 @@
+package mightypork.gamecore.core.config;
+
+
+import java.util.HashMap;
+import java.util.Map;
+
+import mightypork.gamecore.core.WorkDir;
+import mightypork.gamecore.input.Key;
+import mightypork.gamecore.input.KeyStroke;
+import mightypork.utils.config.propmgr.Property;
+import mightypork.utils.config.propmgr.PropertyManager;
+import mightypork.utils.config.propmgr.PropertyStore;
+import mightypork.utils.config.propmgr.store.PropertyFile;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Settings repository.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class Config {
+	
+	protected static Map<String, Config> configs = new HashMap<>();
+	
+	private Map<String, KeyStrokeProperty> strokes = new HashMap<>();
+	
+	private PropertyManager propertyManager;
+	
+	
+	/**
+	 * Get a config from the static map, by given alias
+	 * 
+	 * @param alias alias
+	 * @return the config
+	 */
+	public static Config forAlias(String alias)
+	{
+		Config c = configs.get(alias);
+		
+		if (c == null) {
+			throw new IllegalArgumentException("There is no config with alias \"" + alias + "\"");
+		}
+		
+		return c;
+	}
+	
+	
+	/**
+	 * Register a config by alias.
+	 * 
+	 * @param alias config alias
+	 * @param config the config
+	 */
+	public static void register(String alias, Config config)
+	{
+		if (configs.get(alias) != null) {
+			throw new IllegalArgumentException("The alias \"" + alias + "\" is already used.");
+		}
+		
+		configs.put(alias, config);
+	}
+	
+	
+	/**
+	 * Initialize property manager for a file
+	 * 
+	 * @param file config file, relative to workdir
+	 * @param headComment file comment
+	 */
+	public Config(String file, String headComment) {
+		this(new PropertyFile(WorkDir.getFile(file), headComment));
+	}
+	
+	
+	/**
+	 * Initialize property manager for a given store
+	 * 
+	 * @param store property store backing the property manager
+	 */
+	public Config(PropertyStore store) {
+		if (propertyManager != null) {
+			throw new IllegalStateException("Config already initialized.");
+		}
+		
+		propertyManager = new PropertyManager(store);
+	}
+	
+	
+	/**
+	 * Add a keystroke property
+	 * 
+	 * @param key key in config file
+	 * @param defval default value (keystroke datastring)
+	 * @param comment optional comment, can be null
+	 */
+	public void addKeyStroke(String key, String defval, String comment)
+	{
+		final KeyStrokeProperty kprop = new KeyStrokeProperty(prefixKeyStroke(key), KeyStroke.createFromString(defval), comment);
+		strokes.put(prefixKeyStroke(key), kprop);
+		propertyManager.addProperty(kprop);
+	}
+	
+	
+	/**
+	 * Add a boolean property (flag)
+	 * 
+	 * @param key key in config file
+	 * @param defval default value
+	 * @param comment optional comment, can be null
+	 */
+	public void addBoolean(String key, boolean defval, String comment)
+	{
+		propertyManager.addBoolean(key, defval, comment);
+	}
+	
+	
+	/**
+	 * Add an integer property
+	 * 
+	 * @param key key in config file
+	 * @param defval default value
+	 * @param comment optional comment, can be null
+	 */
+	public void addInteger(String key, int defval, String comment)
+	{
+		propertyManager.addInteger(key, defval, comment);
+	}
+	
+	
+	/**
+	 * Add a double property
+	 * 
+	 * @param key key in config file
+	 * @param defval default value
+	 * @param comment optional comment, can be null
+	 */
+	public void addDouble(String key, double defval, String comment)
+	{
+		propertyManager.addDouble(key, defval, comment);
+	}
+	
+	
+	/**
+	 * Add a string property
+	 * 
+	 * @param key key in config file
+	 * @param defval default value
+	 * @param comment optional comment, can be null
+	 */
+	public void addString(String key, String defval, String comment)
+	{
+		propertyManager.addString(key, defval, comment);
+	}
+	
+	
+	/**
+	 * Add an arbitrary property (can be custom type)
+	 * 
+	 * @param prop the property to add
+	 */
+	public <T> void addProperty(Property<T> prop)
+	{
+		propertyManager.addProperty(prop);
+	}
+	
+	
+	/**
+	 * Load config from file
+	 */
+	public void load()
+	{
+		propertyManager.load();
+	}
+	
+	
+	/**
+	 * Save config to file
+	 */
+	public void save()
+	{
+		Log.f3("Saving config.");
+		propertyManager.save();
+	}
+	
+	
+	/**
+	 * Get an option for key
+	 * 
+	 * @param key
+	 * @return option value
+	 */
+	public <T> T getValue(String key)
+	{
+		try {
+			if (propertyManager.getProperty(key) == null) {
+				throw new IllegalArgumentException("No such property: " + key);
+			}
+			
+			return propertyManager.getValue(key);
+		} catch (final ClassCastException cce) {
+			throw new RuntimeException("Property of incompatible type: " + key);
+		}
+	}
+	
+	
+	/**
+	 * Set option to a value. Call the save() method to make the change
+	 * permanent.
+	 * 
+	 * @param key option key
+	 * @param value value to set
+	 */
+	public <T> void setValue(String key, T value)
+	{
+		if (propertyManager.getProperty(key) == null) {
+			throw new IllegalArgumentException("No such property: " + key);
+		}
+		
+		propertyManager.setValue(key, value);
+	}
+	
+	
+	/**
+	 * Add "key." before the given config file key
+	 * 
+	 * @param cfgKey config key
+	 * @return key. + cfgKey
+	 */
+	private String prefixKeyStroke(String cfgKey)
+	{
+		return "key." + cfgKey;
+	}
+	
+	
+	/**
+	 * Get keystroke for name
+	 * 
+	 * @param cfgKey stroke identifier in config file
+	 * @return the stroke
+	 */
+	public KeyStroke getKeyStroke(String cfgKey)
+	{
+		final KeyStrokeProperty kp = strokes.get(prefixKeyStroke(cfgKey));
+		if (kp == null) {
+			throw new IllegalArgumentException("No such stroke: " + cfgKey);
+		}
+		
+		return kp.getValue();
+	}
+	
+	
+	/**
+	 * Set a keystroke for name
+	 * 
+	 * @param cfgKey stroke identifier in config file
+	 * @param key stroke key
+	 * @param mod stroke modifiers
+	 */
+	public void setKeyStroke(String cfgKey, Key key, int mod)
+	{
+		final KeyStrokeProperty kp = strokes.get(prefixKeyStroke(cfgKey));
+		if (kp == null) {
+			throw new IllegalArgumentException("No such stroke: " + cfgKey);
+		}
+		
+		kp.getValue().setTo(key, mod);
+	}
+}

src/mightypork/gamecore/core/config/InitTaskConfig.java

@@ -0,0 +1,75 @@
+package mightypork.gamecore.core.config;
+
+
+import mightypork.gamecore.core.InitTask;
+import mightypork.utils.annotations.Stub;
+
+
+/**
+ * Initialize config. To apply this initializer, you must extend it. That
+ * ensures that the workdir initializer has already finished when the code is
+ * executed (such as resolving a file path for the config file).
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class InitTaskConfig extends InitTask {
+	
+	/**
+	 * Add a config with given alias
+	 * 
+	 * @param alias config alias
+	 * @param config config to add
+	 */
+	protected void addConfig(String alias, Config config)
+	{
+		Config.register(alias, config);
+	}
+	
+	
+	/**
+	 * Initialize the main config.
+	 * 
+	 * @return the main config.
+	 */
+	protected abstract Config buildConfig();
+	
+	
+	/**
+	 * Initialize extra configs.<br>
+	 * the addConfig() method can be used to register configs.
+	 */
+	@Stub
+	protected void buildExtraConfigs()
+	{
+	}
+	
+	
+	// locked to encourage the use of the build* methods.
+	@Override
+	public final void init()
+	{
+	}
+	
+	
+	@Override
+	public final void run()
+	{
+		addConfig("main", buildConfig());
+		buildExtraConfigs();
+	}
+	
+	
+	@Override
+	public String getName()
+	{
+		return "config";
+	}
+	
+	
+	@Override
+	public String[] getDependencies()
+	{
+		return new String[] { "workdir" };
+	}
+	
+}

src/mightypork/gamecore/core/config/KeyStrokeProperty.java

@@ -0,0 +1,55 @@
+package mightypork.gamecore.core.config;
+
+
+import mightypork.gamecore.input.Key;
+import mightypork.gamecore.input.KeyStroke;
+import mightypork.gamecore.input.Keys;
+import mightypork.utils.config.propmgr.Property;
+
+
+/**
+ * Key property.<br>
+ * The stored value must stay the same instance ({@link KeyStroke} is mutable).<br>
+ * That ensures that bindings based on this keystroke are automatically updated
+ * when the settings change.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class KeyStrokeProperty extends Property<KeyStroke> {
+	
+	public KeyStrokeProperty(String key, KeyStroke defaultValue, String comment) {
+		super(key, defaultValue, comment);
+	}
+	
+	
+	@Override
+	public void fromString(String string)
+	{
+		if (string != null) {
+			// keep the same instance
+			
+			final Key backup_key = value.getKey();
+			final int backup_mod = value.getMod();
+			
+			value.loadFromString(string);
+			if (value.getKey() == Keys.NONE) {
+				value.setTo(backup_key, backup_mod);
+			}
+		}
+	}
+	
+	
+	@Override
+	public String toString()
+	{
+		return value.saveToString();
+	}
+	
+	
+	@Override
+	public void setValue(Object value)
+	{
+		// keep the same instance
+		this.value.setTo(((KeyStroke) value).getKey(), ((KeyStroke) value).getMod());
+	}
+}

src/mightypork/gamecore/core/events/MainLoopRequest.java

@@ -0,0 +1,44 @@
+package mightypork.gamecore.core.events;
+
+
+import mightypork.gamecore.core.MainLoop;
+import mightypork.utils.eventbus.BusEvent;
+import mightypork.utils.eventbus.events.flags.SingleReceiverEvent;
+
+
+/**
+ * Request to execute given {@link Runnable} in main loop.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@SingleReceiverEvent
+public class MainLoopRequest extends BusEvent<MainLoop> {
+	
+	private final Runnable task;
+	private final boolean priority;
+	
+	
+	/**
+	 * @param task task to run on main thread in rendering context
+	 */
+	public MainLoopRequest(Runnable task) {
+		this(task, false);
+	}
+	
+	
+	/**
+	 * @param task task to run on main thread in rendering context
+	 * @param priority if true, skip other tasks in queue
+	 */
+	public MainLoopRequest(Runnable task, boolean priority) {
+		this.task = task;
+		this.priority = priority;
+	}
+	
+	
+	@Override
+	public void handleBy(MainLoop handler)
+	{
+		handler.queueTask(task, priority);
+	}
+}

src/mightypork/gamecore/core/events/ShutdownEvent.java

@@ -0,0 +1,47 @@
+package mightypork.gamecore.core.events;
+
+
+import mightypork.utils.eventbus.BusEvent;
+import mightypork.utils.eventbus.EventBus;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Shutdown event.<br>
+ * This event is dispatched when the <code>App.shutdown()</code> method is
+ * called. If no client consumes it, the shutdown will immediately follow.<br>
+ * This is a way to allow clients to abort the shutdown (ie. ask user to save
+ * game). After the game is saved, the <code>App.shutdown()</code> method can be
+ * called again.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class ShutdownEvent extends BusEvent<ShutdownListener> {
+	
+	private Runnable shutdownTask;
+	
+	
+	public ShutdownEvent(Runnable doShutdown) {
+		this.shutdownTask = doShutdown;
+	}
+	
+	
+	@Override
+	protected void handleBy(ShutdownListener handler)
+	{
+		handler.onShutdown(this);
+	}
+	
+	
+	@Override
+	public void onDispatchComplete(EventBus bus)
+	{
+		if (!isConsumed()) {
+			Log.i("Shutting down...");
+			shutdownTask.run();
+		} else {
+			Log.i("Shutdown aborted.");
+		}
+	}
+	
+}

src/mightypork/gamecore/core/events/ShutdownListener.java

@@ -0,0 +1,18 @@
+package mightypork.gamecore.core.events;
+
+
+/**
+ * Quit request listener; implementing client can abort shutdown.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface ShutdownListener {
+	
+	/**
+	 * Intercept quit request.<br>
+	 * Consume the event to abort shutdown (ie. ask user to save)
+	 * 
+	 * @param event quit request event.
+	 */
+	void onShutdown(ShutdownEvent event);
+}

src/mightypork/gamecore/core/init/InitTaskCrashHandler.java

@@ -0,0 +1,42 @@
+package mightypork.gamecore.core.init;
+
+
+import java.lang.Thread.UncaughtExceptionHandler;
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.core.InitTask;
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Add a crash handler to the app.<br>
+ * For customized crash message / crash dialog etc, override the
+ * uncaughtException() method.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class InitTaskCrashHandler extends InitTask implements UncaughtExceptionHandler {
+	
+	@Override
+	public void run()
+	{
+		Thread.setDefaultUncaughtExceptionHandler(this);
+	}
+	
+	
+	@Override
+	@Stub
+	public void uncaughtException(Thread thread, Throwable throwable)
+	{
+		Log.e("The game has crashed.", throwable);
+		App.shutdown();
+	}
+	
+	
+	@Override
+	public String getName()
+	{
+		return "crash_handler";
+	}
+}

src/mightypork/gamecore/core/init/InitTaskDisplay.java

@@ -0,0 +1,97 @@
+package mightypork.gamecore.core.init;
+
+
+import mightypork.gamecore.core.InitTask;
+import mightypork.gamecore.graphics.GraphicsModule;
+
+
+/**
+ * Setup main window.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class InitTaskDisplay extends InitTask {
+	
+	private int width = 800, height = 600, fps = 60;
+	private boolean resizable, fullscreen;
+	private String title = "Game";
+	
+	
+	/**
+	 * Set initial window size
+	 * 
+	 * @param width width (px)
+	 * @param height height (px)
+	 */
+	public void setSize(int width, int height)
+	{
+		this.width = width;
+		this.height = height;
+	}
+	
+	
+	/**
+	 * Set whether the window should be resizable
+	 * 
+	 * @param resizable true for resizable
+	 */
+	public void setResizable(boolean resizable)
+	{
+		this.resizable = resizable;
+	}
+	
+	
+	/**
+	 * Set window title
+	 * 
+	 * @param title title text
+	 */
+	public void setTitle(String title)
+	{
+		this.title = title;
+	}
+	
+	
+	/**
+	 * Set desired framerate.
+	 * 
+	 * @param fps FPS
+	 */
+	public void setTargetFps(int fps)
+	{
+		this.fps = fps;
+	}
+	
+	
+	/**
+	 * Set whether the window should start in fullscreen
+	 * 
+	 * @param fullscreen true for fullscreen
+	 */
+	public void setFullscreen(boolean fullscreen)
+	{
+		this.fullscreen = fullscreen;
+	}
+	
+	
+	@Override
+	public void run()
+	{
+		GraphicsModule gfx = app.getBackend().getGraphics();
+		
+		gfx.setSize(width, height);
+		gfx.setResizable(resizable);
+		gfx.setTitle(title);
+		gfx.setTargetFps(fps);
+		
+		if (fullscreen) gfx.setFullscreen(true);
+	}
+	
+	
+	@Override
+	public String getName()
+	{
+		return "display";
+	}
+	
+}

src/mightypork/gamecore/core/init/InitTaskIonizables.java

@@ -0,0 +1,74 @@
+package mightypork.gamecore.core.init;
+
+
+import java.io.IOException;
+
+import mightypork.gamecore.core.InitTask;
+import mightypork.utils.ion.Ion;
+import mightypork.utils.ion.IonInput;
+import mightypork.utils.ion.IonOutput;
+import mightypork.utils.ion.IonizerBinary;
+import mightypork.utils.math.algo.Coord;
+import mightypork.utils.math.algo.Move;
+
+
+/**
+ * Register extra ionizables added by the game library (non-native ION types).<br>
+ * This initializer can be called anywhere in the initialization sequence.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class InitTaskIonizables extends InitTask {
+	
+	@Override
+	public void run()
+	{
+		Ion.registerIndirect(255, new IonizerBinary<Coord>() {
+			
+			@Override
+			public void save(Coord object, IonOutput out) throws IOException
+			{
+				out.writeInt(object.x);
+				out.writeInt(object.y);
+			}
+			
+			
+			@Override
+			public Coord load(IonInput in) throws IOException
+			{
+				final int x = in.readInt();
+				final int y = in.readInt();
+				return new Coord(x, y);
+			}
+			
+		});
+		
+		Ion.registerIndirect(254, new IonizerBinary<Move>() {
+			
+			@Override
+			public void save(Move object, IonOutput out) throws IOException
+			{
+				out.writeInt(object.x());
+				out.writeInt(object.y());
+			}
+			
+			
+			@Override
+			public Move load(IonInput in) throws IOException
+			{
+				final int x = in.readInt();
+				final int y = in.readInt();
+				return new Move(x, y);
+			}
+			
+		});
+	}
+	
+	
+	@Override
+	public String getName()
+	{
+		return "ion";
+	}
+	
+}

src/mightypork/gamecore/core/init/InitTaskLog.java

@@ -0,0 +1,108 @@
+package mightypork.gamecore.core.init;
+
+
+import java.io.File;
+import java.util.logging.Level;
+
+import mightypork.gamecore.core.InitTask;
+import mightypork.gamecore.core.WorkDir;
+import mightypork.utils.logging.Log;
+import mightypork.utils.logging.writers.LogWriter;
+import mightypork.utils.string.StringUtil;
+
+
+/**
+ * Init main logger and console log printing.<br>
+ * Must be called after workdir is initialized.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class InitTaskLog extends InitTask {
+	
+	private String logDir = "log";
+	private String logName = "runtime";
+	private int archiveCount = 5;
+	
+	private Level levelWrite = Level.ALL;
+	private Level levelPrint = Level.ALL;
+	
+	
+	/**
+	 * Set log directory (relative to workdir).<br>
+	 * Defaults to "log".
+	 * 
+	 * @param logDir log directory.
+	 */
+	public void setLogDir(String logDir)
+	{
+		this.logDir = logDir;
+	}
+	
+	
+	/**
+	 * Set log name. This name is used as a prefix for archived log files.<br>
+	 * Should contain only valid filename characters.<br>
+	 * Defaults to "runtime".
+	 * 
+	 * @param logName log name
+	 */
+	public void setLogName(String logName)
+	{
+		if (!StringUtil.isValidFilenameString(logName)) {
+			throw new IllegalArgumentException("Invalid log name.");
+		}
+		
+		this.logName = logName;
+	}
+	
+	
+	/**
+	 * Set number of logs to keep in the logs directory.<br>
+	 * Set to 0 to keep just the last log, -1 to keep unlimited number of logs.<br>
+	 * Defaults to 5.
+	 * 
+	 * @param archiveCount logs to keep
+	 */
+	public void setArchiveCount(int archiveCount)
+	{
+		this.archiveCount = archiveCount;
+	}
+	
+	
+	/**
+	 * Set logging levels (minimal level of message to be accepted)<br>
+	 * Defaults to ALL, ALL.
+	 * 
+	 * @param levelWrite level for writing to file
+	 * @param levelPrint level for writing to stdout / stderr
+	 */
+	public void setLevels(Level levelWrite, Level levelPrint)
+	{
+		this.levelWrite = levelWrite;
+		this.levelPrint = levelPrint;
+	}
+	
+	
+	@Override
+	public void run()
+	{
+		final LogWriter log = Log.create(logName, new File(WorkDir.getDir(logDir), logName + ".log"), archiveCount);
+		Log.setMainLogger(log);
+		Log.setLevel(levelWrite);
+		Log.setSysoutLevel(levelPrint);
+	}
+	
+	
+	@Override
+	public String getName()
+	{
+		return "log";
+	}
+	
+	
+	@Override
+	public String[] getDependencies()
+	{
+		return new String[] { "workdir" };
+	}
+}

src/mightypork/gamecore/core/init/InitTaskLogHeader.java

@@ -0,0 +1,54 @@
+package mightypork.gamecore.core.init;
+
+
+import java.io.IOException;
+
+import mightypork.gamecore.core.InitTask;
+import mightypork.gamecore.core.OptionalInitTask;
+import mightypork.gamecore.core.WorkDir;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * initializer task that writes a system info header to the log file.<br>
+ * Must be called after log is initialized.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@OptionalInitTask
+public class InitTaskLogHeader extends InitTask {
+	
+	@Override
+	public void run()
+	{
+		String txt = "";
+		
+		txt += "\n### SYSTEM INFO ###\n\n";
+		txt += " Platform ...... " + System.getProperty("os.name") + "\n";
+		txt += " Runtime ....... " + System.getProperty("java.runtime.name") + "\n";
+		txt += " Java .......... " + System.getProperty("java.version") + "\n";
+		txt += " Launch path ... " + System.getProperty("user.dir") + "\n";
+		
+		try {
+			txt += " Workdir ....... " + WorkDir.getWorkDir().getCanonicalPath() + "\n";
+		} catch (final IOException e) {
+			Log.e(e);
+		}
+		
+		Log.i(txt);
+	}
+	
+	
+	@Override
+	public String getName()
+	{
+		return "log_header";
+	}
+	
+	
+	@Override
+	public String[] getDependencies()
+	{
+		return new String[] { "log", "workdir" };
+	}
+}

src/mightypork/gamecore/core/init/InitTaskWorkdir.java

@@ -0,0 +1,136 @@
+package mightypork.gamecore.core.init;
+
+
+import java.io.File;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import javax.swing.JOptionPane;
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.core.InitTask;
+import mightypork.gamecore.core.WorkDir;
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.files.InstanceLock;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Initializer that takes care of setting up the proper workdir.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class InitTaskWorkdir extends InitTask {
+	
+	private File workdirPath;
+	private boolean doLock;
+	private String lockFile = ".lock";
+	private Map<String, String> namedPaths = new HashMap<>();
+	
+	
+	/**
+	 * @param workdir path to the working directory
+	 * @param lock whether to lock the directory (single instance mode)
+	 */
+	public InitTaskWorkdir(File workdir, boolean lock) {
+		this.workdirPath = workdir;
+		this.doLock = lock;
+	}
+	
+	
+	/**
+	 * Set workdir root path
+	 * 
+	 * @param path workdir path
+	 */
+	public void setWorkdirPath(File path)
+	{
+		this.workdirPath = path;
+	}
+	
+	
+	/**
+	 * Set whether the workdir should be locked when the app is running, to
+	 * prevent other instances from running simultaneously.
+	 * 
+	 * @param lock
+	 */
+	public void setInstanceLock(boolean lock)
+	{
+		this.doLock = lock;
+	}
+	
+	
+	/**
+	 * Set name of the lock file.
+	 * 
+	 * @param lockFile
+	 */
+	public void setLockFileName(String lockFile)
+	{
+		this.lockFile = lockFile;
+	}
+	
+	
+	/**
+	 * Add a named path
+	 * 
+	 * @param alias path alias (snake_case)
+	 * @param path path (relative to the workdir)
+	 */
+	public void addPath(String alias, String path)
+	{
+		namedPaths.put(alias, path);
+	}
+	
+	
+	@Override
+	public void run()
+	{
+		WorkDir.init(workdirPath);
+		
+		// lock working directory
+		if (doLock) {
+			final File lock = WorkDir.getFile(lockFile);
+			if (!InstanceLock.onFile(lock)) {
+				onLockError();
+				return;
+			}
+		}
+		
+		for (Entry<String, String> e : namedPaths.entrySet()) {
+			WorkDir.addPath(e.getKey(), e.getValue());
+		}
+	}
+	
+	
+	/**
+	 * Called when the lock file could not be obtained (cannot write or already
+	 * exists).<br>
+	 * Feel free to override this method to define custom behavior.
+	 */
+	@Stub
+	protected void onLockError()
+	{
+		Log.e("Could not obtain lock file.\nOnly one instance can run at a time.");
+		
+		//@formatter:off
+		JOptionPane.showMessageDialog(
+				null,
+				"Another instance is already running.\n(Delete the "+lockFile +" file in the working directory to override)",
+				"Lock Error",
+				JOptionPane.ERROR_MESSAGE
+		);
+		//@formatter:on
+		
+		App.shutdown();
+	}
+	
+	
+	@Override
+	public String getName()
+	{
+		return "workdir";
+	}
+}

src/mightypork/gamecore/core/plugins/screenshot/InitTaskPluginScreenshot.java

@@ -0,0 +1,68 @@
+package mightypork.gamecore.core.plugins.screenshot;
+
+
+import mightypork.gamecore.core.InitTask;
+import mightypork.gamecore.core.WorkDir;
+
+
+/**
+ * Register screenshot plugin to the App.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class InitTaskPluginScreenshot extends InitTask {
+	
+	private String screenshotDir;
+	
+	
+	/**
+	 * Initialize to use the "screenshots" directory
+	 */
+	public InitTaskPluginScreenshot() {
+		this("screenshots");
+	}
+	
+	
+	/**
+	 * Initialize to use the given directory for saving.
+	 * 
+	 * @param dir screenshot dir (relative to workdir)
+	 */
+	public InitTaskPluginScreenshot(String dir) {
+		this.screenshotDir = dir;
+	}
+	
+	
+	/**
+	 * Set screenshot directory
+	 * 
+	 * @param dir screenshot dir (relative to workdir)
+	 */
+	public void setScreenshotDir(String dir)
+	{
+		this.screenshotDir = dir;
+	}
+	
+	
+	@Override
+	public void run()
+	{
+		WorkDir.addPath("_screenshot_dir", screenshotDir);
+		app.addPlugin(new ScreenshotPlugin());
+	}
+	
+	
+	@Override
+	public String getName()
+	{
+		return "plugin_screenshot";
+	}
+	
+	
+	@Override
+	public String[] getDependencies()
+	{
+		return new String[] { "workdir" };
+	}
+	
+}

src/mightypork/gamecore/core/plugins/screenshot/ScreenshotPlugin.java

@@ -0,0 +1,34 @@
+package mightypork.gamecore.core.plugins.screenshot;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.core.AppPlugin;
+import mightypork.gamecore.core.events.MainLoopRequest;
+import mightypork.utils.Support;
+
+
+/**
+ * This plugin waits for a {@link ScreenshotRequest} event.<br>
+ * Upon receiving it, a screenshot is captured and written to file
+ * asynchronously.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class ScreenshotPlugin extends AppPlugin {
+	
+	/**
+	 * Take screenshot. Called by the trigger event.
+	 */
+	void takeScreenshot()
+	{
+		App.bus().send(new MainLoopRequest(new Runnable() {
+			
+			@Override
+			public void run()
+			{
+				Runnable tts = new TaskTakeScreenshot();
+				Support.runAsThread(tts);
+			}
+		}));
+	}
+}

src/mightypork/gamecore/core/plugins/screenshot/ScreenshotRequest.java

@@ -0,0 +1,22 @@
+package mightypork.gamecore.core.plugins.screenshot;
+
+
+import mightypork.utils.eventbus.BusEvent;
+import mightypork.utils.eventbus.events.flags.SingleReceiverEvent;
+
+
+/**
+ * Event used to request screenshot capture.
+ * 
+ * @author MightyPork
+ */
+@SingleReceiverEvent
+public class ScreenshotRequest extends BusEvent<ScreenshotPlugin> {
+	
+	@Override
+	protected void handleBy(ScreenshotPlugin handler)
+	{
+		handler.takeScreenshot();
+	}
+	
+}

src/mightypork/gamecore/core/plugins/screenshot/TaskTakeScreenshot.java

@@ -0,0 +1,100 @@
+package mightypork.gamecore.core.plugins.screenshot;
+
+
+import java.io.File;
+import java.io.IOException;
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.core.WorkDir;
+import mightypork.gamecore.graphics.Screenshot;
+import mightypork.utils.Support;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Task that takes screenshot and asynchronously saves it to a file.<br>
+ * Can be run in a separate thread, but must be instantiated in the render
+ * thread.
+ * 
+ * @author MightyPork
+ */
+public class TaskTakeScreenshot implements Runnable {
+	
+	private final Screenshot scr;
+	
+	
+	/**
+	 * Take screenshot. Must be called in render thread.
+	 */
+	public TaskTakeScreenshot() {
+		scr = App.gfx().takeScreenshot();
+	}
+	
+	
+	@Override
+	public void run()
+	{
+		// generate unique filename
+		final File file = getScreenshotFile();
+		
+		Log.f3("Saving screenshot to file: " + file);
+		
+		// save to disk
+		try {
+			scr.save(file);
+		} catch (final IOException e) {
+			Log.e("Failed to save screenshot.", e);
+		}
+	}
+	
+	
+	/**
+	 * @return File to save the screenshot to.
+	 */
+	protected File getScreenshotFile()
+	{
+		final String fname = getBaseFilename();
+		return findFreeFile(fname);
+	}
+	
+	
+	/**
+	 * @return directory for screenshots
+	 */
+	protected File getScreenshotDirectory()
+	{
+		return WorkDir.getDir("_screenshot_dir");
+	}
+	
+	
+	/**
+	 * Get base filename for the screenshot, without extension.
+	 * 
+	 * @return filename
+	 */
+	protected String getBaseFilename()
+	{
+		return Support.getTime("yyyy-MM-dd_HH-mm-ss");
+	}
+	
+	
+	/**
+	 * Find first free filename for the screenshot, by adding -NUMBER after the
+	 * base filename and before extension.
+	 * 
+	 * @param base_name base filename
+	 * @return full path to screenshot file
+	 */
+	protected File findFreeFile(String base_name)
+	{
+		File file;
+		int index = 0;
+		while (true) {
+			file = new File(getScreenshotDirectory(), base_name + (index > 0 ? "-" + index : "") + ".png");
+			if (!file.exists()) break;
+			index++;
+		}
+		return file;
+	}
+	
+}

src/mightypork/gamecore/graphics/FullscreenToggleRequest.java

@@ -0,0 +1,16 @@
+package mightypork.gamecore.graphics;
+
+
+import mightypork.utils.eventbus.BusEvent;
+import mightypork.utils.eventbus.events.flags.SingleReceiverEvent;
+
+
+@SingleReceiverEvent
+public class FullscreenToggleRequest extends BusEvent<GraphicsModule> {
+	
+	@Override
+	protected void handleBy(GraphicsModule handler)
+	{
+		handler.switchFullscreen();
+	}
+}

src/mightypork/gamecore/graphics/GraphicsModule.java

@@ -0,0 +1,406 @@
+package mightypork.gamecore.graphics;
+
+
+import mightypork.gamecore.core.BackendModule;
+import mightypork.gamecore.graphics.textures.DeferredTexture;
+import mightypork.gamecore.graphics.textures.TxQuad;
+import mightypork.gamecore.gui.events.ViewportChangeEvent;
+import mightypork.utils.math.color.Color;
+import mightypork.utils.math.color.Grad;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.vect.Vect;
+import mightypork.utils.math.constraints.vect.VectConst;
+import mightypork.utils.math.timing.FpsMeter;
+
+
+/**
+ * Render and display backend module.<br>
+ * This module takes care of setting and getting screen size and parameters,
+ * drawing on screen and timing render frames.
+ * 
+ * @author MightyPork
+ */
+public abstract class GraphicsModule extends BackendModule {
+	
+	protected static final VectConst AXIS_X = Vect.make(1, 0, 0);
+	protected static final VectConst AXIS_Y = Vect.make(0, 1, 0);
+	protected static final VectConst AXIS_Z = Vect.make(0, 0, 1);
+	
+	
+	/**
+	 * Set drawing color
+	 * 
+	 * @param color color
+	 */
+	public abstract void setColor(Color color);
+	
+	
+	/**
+	 * Set drawing color, adjust alpha
+	 * 
+	 * @param color color
+	 * @param alpha alpha multiplier
+	 */
+	public abstract void setColor(Color color, double alpha);
+	
+	
+	/**
+	 * Translate by x, y
+	 * 
+	 * @param x x offset
+	 * @param y y offset
+	 */
+	public abstract void translate(double x, double y);
+	
+	
+	/**
+	 * Translate by x, y, z
+	 * 
+	 * @param x x offset
+	 * @param y y offset
+	 * @param z z offset
+	 */
+	public abstract void translate(double x, double y, double z);
+	
+	
+	/**
+	 * Translate by offset vector
+	 * 
+	 * @param offset offset coordinate
+	 */
+	public abstract void translate(Vect offset);
+	
+	
+	/**
+	 * Translate by offset vector, ignore Z
+	 * 
+	 * @param offset offset coordinate
+	 */
+	public abstract void translateXY(Vect offset);
+	
+	
+	/**
+	 * Set scale for translations and coordinates
+	 * 
+	 * @param x x scale
+	 * @param y y scale
+	 */
+	public abstract void scale(double x, double y);
+	
+	
+	/**
+	 * Set scale for translations and coordinates
+	 * 
+	 * @param x x scale
+	 * @param y y scale
+	 * @param z z scale
+	 */
+	public abstract void scale(double x, double y, double z);
+	
+	
+	/**
+	 * Set scale for translations and coordinates
+	 * 
+	 * @param scale vector
+	 */
+	public abstract void scale(Vect scale);
+	
+	
+	/**
+	 * Set scale for translations and coordinates (same value for X and Y scale)
+	 * 
+	 * @param scale scaling factor
+	 */
+	public abstract void scaleXY(double scale);
+	
+	
+	/**
+	 * Set X scale for translations and coordinates
+	 * 
+	 * @param scale scaling factor
+	 */
+	public abstract void scaleX(double scale);
+	
+	
+	/**
+	 * Set Y scale for translations and coordinates
+	 * 
+	 * @param scale scaling factor
+	 */
+	public abstract void scaleY(double scale);
+	
+	
+	/**
+	 * Set Z scale for translations and coordinates
+	 * 
+	 * @param scale scaling factor
+	 */
+	public abstract void scaleZ(double scale);
+	
+	
+	/**
+	 * Rotate coordinate system around X axis
+	 * 
+	 * @param angle rotation (in degrees)
+	 */
+	public abstract void rotateX(double angle);
+	
+	
+	/**
+	 * Rotate coordinate system around Y axis
+	 * 
+	 * @param angle rotation (in degrees)
+	 */
+	public abstract void rotateY(double angle);
+	
+	
+	/**
+	 * Rotate coordinate system around Z axis
+	 * 
+	 * @param angle rotation (in degrees)
+	 */
+	public abstract void rotateZ(double angle);
+	
+	
+	/**
+	 * Rotate coordinate system around given axis
+	 * 
+	 * @param angle rotation angle
+	 * @param axis rotation axis (unit vector)
+	 */
+	public abstract void rotate(double angle, Vect axis);
+	
+	
+	/**
+	 * Store render state on stack<br>
+	 * This includes pushGeometry and pushColor.
+	 */
+	public abstract void pushState();
+	
+	
+	/**
+	 * Restore state from stack (must be pushed first)<br>
+	 * This includes popColor and popGeometry.
+	 */
+	public abstract void popState();
+	
+	
+	/**
+	 * Store current rotation and translation on stack
+	 */
+	public abstract void pushGeometry();
+	
+	
+	/**
+	 * Restore rotation and translation from stack
+	 */
+	public abstract void popGeometry();
+	
+	
+	/**
+	 * Store color on stack (so it can later be restored)
+	 */
+	public abstract void pushColor();
+	
+	
+	/**
+	 * Restore color from stack (must be pushed first)
+	 */
+	public abstract void popColor();
+	
+	
+	/**
+	 * Render 2D quad with currently set color
+	 * 
+	 * @param rect drawn rect
+	 */
+	public abstract void quad(Rect rect);
+	
+	
+	/**
+	 * Render 2D quad with given color.<br>
+	 * This may change current drawing color.
+	 * 
+	 * @param rect rectangle
+	 * @param color draw color
+	 */
+	public abstract void quad(Rect rect, Color color);
+	
+	
+	/**
+	 * Render 2D quad with gradient.<br>
+	 * This may change current drawing color.
+	 * 
+	 * @param rect rectangle
+	 * @param grad gradient
+	 */
+	public abstract void quad(Rect rect, Grad grad);
+	
+	
+	/**
+	 * Render textured quad with current color
+	 * 
+	 * @param rect rectangle to draw
+	 * @param txquad texture quad
+	 */
+	public abstract void quad(Rect rect, TxQuad txquad);
+	
+	
+	/**
+	 * Render textured quad with given color
+	 * 
+	 * @param rect rectangle to draw
+	 * @param txquad texture instance
+	 * @param color color tint
+	 */
+	public abstract void quad(Rect rect, TxQuad txquad, Color color);
+	
+	
+	/**
+	 * Setup projection for 2D graphics, using current scren size
+	 */
+	public abstract void setupProjection();
+	
+	
+	/**
+	 * Get backend-flavoured lazy texture
+	 * 
+	 * @param path path to texture
+	 * @return the lazy texture
+	 */
+	public abstract DeferredTexture getLazyTexture(String path);
+	
+	
+	/**
+	 * Set target fps (for syncing in endFrame() call).<br>
+	 * With vsync enabled, the target fps may not be met.
+	 * 
+	 * @param fps requested fps
+	 */
+	public abstract void setTargetFps(int fps);
+	
+	
+	/**
+	 * Set fullscreen. The fullscreen state will be changed when possible (eg.
+	 * at the end of the current frame) and a {@link ViewportChangeEvent} will
+	 * be fired.
+	 * 
+	 * @param fs true for fullscreen
+	 */
+	public abstract void setFullscreen(boolean fs);
+	
+	
+	/**
+	 * Request fullscreen toggle. See setFullscreen() for more info)
+	 */
+	public abstract void switchFullscreen();
+	
+	
+	/**
+	 * Get fullscreen state (note that methods changing fullscreen may not have
+	 * immediate effect, so this method may report the old state if the
+	 * fullscreen state has not yet been changed).
+	 * 
+	 * @return is fullscreen
+	 */
+	public abstract boolean isFullscreen();
+	
+	
+	/**
+	 * Take screenshot (expensive processing should be done in separate thread
+	 * when screenshot is saved).<br>
+	 * This method is utilized by the Screenshot plugin.
+	 * 
+	 * @return screenshot object
+	 */
+	public abstract Screenshot takeScreenshot();
+	
+	
+	/**
+	 * Start a render frame - clear buffers, prepare rendering context etc.
+	 */
+	public abstract void beginFrame();
+	
+	
+	/**
+	 * End a render frame: flip buffers, sync to fps...
+	 */
+	public abstract void endFrame();
+	
+	
+	/**
+	 * Set display dimensions
+	 * 
+	 * @param width display width (pixels)
+	 * @param height display height (pixels)
+	 */
+	public abstract void setSize(int width, int height);
+	
+	
+	/**
+	 * Set window titlebar text
+	 * 
+	 * @param title titlebar text
+	 */
+	public abstract void setTitle(String title);
+	
+	
+	/**
+	 * Enable or disable VSync
+	 * 
+	 * @param vsync true for vsync enabled
+	 */
+	public abstract void setVSync(boolean vsync);
+	
+	
+	/**
+	 * Set window resizable / fixed
+	 * 
+	 * @param resizable true for resizable
+	 */
+	public abstract void setResizable(boolean resizable);
+	
+	
+	/**
+	 * Get screen rect. Should always return the same Rect instance.
+	 * 
+	 * @return the rect
+	 */
+	public abstract Rect getRect();
+	
+	
+	/**
+	 * Get current FPS (eg. measured by a {@link FpsMeter})
+	 * 
+	 * @return current FPS
+	 */
+	public abstract long getFps();
+	
+	
+	/**
+	 * Get screen center. Should always return the same Vect instance.
+	 * 
+	 * @return screen center.
+	 */
+	public abstract Vect getCenter();
+	
+	
+	/**
+	 * Get screen size. Should always return the same Vect instance.
+	 * 
+	 * @return size
+	 */
+	public abstract Vect getSize();
+	
+	
+	/**
+	 * @return screen width
+	 */
+	public abstract int getWidth();
+	
+	
+	/**
+	 * @return screen height
+	 */
+	public abstract int getHeight();
+}

src/mightypork/gamecore/graphics/Renderable.java

@@ -0,0 +1,16 @@
+package mightypork.gamecore.graphics;
+
+
+/**
+ * Can be rendered
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface Renderable {
+	
+	/**
+	 * Render on screen.
+	 */
+	void render();
+	
+}

src/mightypork/gamecore/graphics/Screenshot.java

@@ -0,0 +1,34 @@
+package mightypork.gamecore.graphics;
+
+
+import java.io.File;
+import java.io.IOException;
+
+
+/**
+ * <p>
+ * Screenshot object used to save screenshot to a file. The Screenshot object is
+ * created by the Graphics module.
+ * </p>
+ * <p>
+ * Screenshot typically takes a byte buffer and converts it to image before
+ * saving to file. This image can be cached to speed up repeated saving.
+ * </p>
+ * <p>
+ * Once created (passing byte buffer in constructor), the Screenshot should be
+ * safe to process (call the save() method) in separate thread.
+ * </p>
+ * 
+ * @author MightyPork
+ */
+public interface Screenshot {
+	
+	/**
+	 * Process byte buffer and write image to a file.<br>
+	 * Image can be cached for future save.
+	 * 
+	 * @param file target file
+	 * @throws IOException on error writing to file
+	 */
+	void save(File file) throws IOException;
+}

src/mightypork/gamecore/graphics/fonts/DeferredFont.java

@@ -0,0 +1,98 @@
+package mightypork.gamecore.graphics.fonts;
+
+
+import mightypork.gamecore.graphics.textures.FilterMode;
+import mightypork.gamecore.resources.BaseDeferredResource;
+
+
+/**
+ * Abstract deferred font stub.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class DeferredFont extends BaseDeferredResource implements IFont {
+	
+	public static enum FontStyle
+	{
+		PLAIN(0), BOLD(1), ITALIC(2), BOLD_ITALIC(3);
+		
+		public int numval;
+		
+		
+		/**
+		 * Font style
+		 * 
+		 * @param style style index as in awt Font. Not using constants to be
+		 *            independent on awt.
+		 */
+		private FontStyle(int style) {
+			this.numval = style;
+		}
+	}
+	
+	protected double size = 12;
+	protected FontStyle style = FontStyle.PLAIN;
+	protected String chars = Glyphs.basic;
+	protected FilterMode filter = FilterMode.NEAREST;
+	protected boolean antialias = false;
+	protected double discardTop = 0;
+	protected double discardBottom = 0;
+	
+	
+	public DeferredFont(String resource) {
+		super(resource);
+	}
+	
+	
+	public void setSize(double size)
+	{
+		this.size = size;
+	}
+	
+	
+	public void setStyle(FontStyle style)
+	{
+		this.style = style;
+	}
+	
+	
+	public void setChars(String chars)
+	{
+		this.chars = chars;
+	}
+	
+	
+	public void setFilter(FilterMode filter)
+	{
+		this.filter = filter;
+	}
+	
+	
+	public void setAntialias(boolean antialias)
+	{
+		this.antialias = antialias;
+	}
+	
+	
+	@Override
+	public void setDiscardRatio(double top, double bottom)
+	{
+		discardTop = top;
+		discardBottom = bottom;
+	}
+	
+	
+	@Override
+	public double getTopDiscardRatio()
+	{
+		return discardTop;
+	}
+	
+	
+	@Override
+	public double getBottomDiscardRatio()
+	{
+		return discardBottom;
+	}
+	
+}

src/mightypork/gamecore/graphics/fonts/FontRegistry.java

@@ -0,0 +1,79 @@
+package mightypork.gamecore.graphics.fonts;
+
+
+import java.util.HashMap;
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.resources.loading.ResourceLoadRequest;
+import mightypork.utils.eventbus.clients.BusNode;
+
+
+/**
+ * Font loader and registry
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class FontRegistry extends BusNode {
+	
+	private final HashMap<String, IFont> fonts = new HashMap<>();
+	private final HashMap<String, String> aliases = new HashMap<>();
+	
+	
+	/**
+	 * Load a {@link DeferredLwjglFont}
+	 * 
+	 * @param key font key
+	 * @param font font instance
+	 */
+	public void addFont(String key, DeferredFont font)
+	{
+		App.bus().send(new ResourceLoadRequest(font));
+		
+		fonts.put(key, font);
+	}
+	
+	
+	/**
+	 * Add a {@link IFont} to the bank.
+	 * 
+	 * @param key font key
+	 * @param font font instance
+	 */
+	public void addFont(String key, IFont font)
+	{
+		fonts.put(key, font);
+	}
+	
+	
+	/**
+	 * Add a font alias.
+	 * 
+	 * @param alias_key alias key
+	 * @param font_key font key
+	 */
+	public void addAlias(String alias_key, String font_key)
+	{
+		aliases.put(alias_key, font_key);
+	}
+	
+	
+	/**
+	 * Get a loaded {@link Texture}
+	 * 
+	 * @param key texture key
+	 * @return the texture
+	 */
+	public IFont getFont(String key)
+	{
+		IFont f = fonts.get(key);
+		
+		if (f == null) f = fonts.get(aliases.get(key));
+		
+		if (f == null) {
+			throw new RuntimeException("There's no font called " + key + "!");
+		}
+		
+		return f;
+	}
+	
+}

src/mightypork/gamecore/graphics/fonts/FontRenderer.java

@@ -0,0 +1,213 @@
+package mightypork.gamecore.graphics.fonts;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.utils.math.AlignX;
+import mightypork.utils.math.color.Color;
+import mightypork.utils.math.color.pal.RGB;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.vect.Vect;
+
+
+/**
+ * Font renderer
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class FontRenderer {
+	
+	private IFont font;
+	
+	private Color color;
+	
+	
+	/**
+	 * @param font used font
+	 */
+	public FontRenderer(IFont font) {
+		this(font, RGB.WHITE);
+	}
+	
+	
+	/**
+	 * @param font used font
+	 * @param color drawing color
+	 */
+	public FontRenderer(IFont font, Color color) {
+		this.font = font;
+		this.color = color;
+	}
+	
+	
+	/**
+	 * Get region needed to draw text at size
+	 * 
+	 * @param text text to draw
+	 * @param height drawing height
+	 * @return taken space (width, height)
+	 */
+	public Vect getNeededSpace(String text, double height)
+	{
+		return font.getNeededSpace(text).mul(getScale(height));
+	}
+	
+	
+	/**
+	 * Get width needed to draw text at size
+	 * 
+	 * @param text text to draw
+	 * @param height drawing height
+	 * @return needed width
+	 */
+	public double getWidth(String text, double height)
+	{
+		return getNeededSpace(text, height).x();
+	}
+	
+	
+	private double getScale(double height)
+	{
+		return height / font.getLineHeight();
+	}
+	
+	
+	/**
+	 * Change drawing font
+	 * 
+	 * @param font font to use for drawing
+	 */
+	public void setFont(IFont font)
+	{
+		this.font = font;
+	}
+	
+	
+	/**
+	 * Set drawing color
+	 * 
+	 * @param color color
+	 */
+	public void setColor(Color color)
+	{
+		this.color = color;
+	}
+	
+	
+	/**
+	 * Draw on screen
+	 * 
+	 * @param text text to draw
+	 * @param pos origin (min coord)
+	 * @param height drawing height
+	 * @param color drawing color
+	 */
+	public void draw(String text, Vect pos, double height, Color color)
+	{
+		App.gfx().pushGeometry();
+		
+		final double sc = getScale(height);
+		
+		App.gfx().translate(pos.x(), pos.y());
+		App.gfx().scaleXY(sc);
+		
+		font.draw(text, color);
+		
+		App.gfx().popGeometry();
+	}
+	
+	
+	/**
+	 * Draw on screen
+	 * 
+	 * @param text text to draw
+	 * @param bounds drawing bounds (height for font height, horizontal bounds
+	 *            for align)
+	 * @param align horizontal alignment (with respect to bounds)
+	 */
+	public void draw(String text, Rect bounds, AlignX align)
+	{
+		this.draw(text, bounds, align, this.color);
+	}
+	
+	
+	/**
+	 * Draw on screen
+	 * 
+	 * @param text text to draw
+	 * @param bounds drawing bounds (height for font height, horizontal bounds
+	 *            for align)
+	 * @param align horizontal alignment (with respect to bounds)
+	 * @param color drawing color
+	 */
+	public void draw(String text, Rect bounds, AlignX align, Color color)
+	{
+		Vect start;
+		
+		switch (align) {
+			case LEFT:
+				start = bounds.topLeft();
+				break;
+			
+			case CENTER:
+				start = bounds.topCenter();
+				break;
+			
+			case RIGHT:
+			default:
+				start = bounds.topRight();
+				break;
+		}
+		
+		draw(text, start, bounds.height().value(), align, color);
+	}
+	
+	
+	/**
+	 * Draw on screen
+	 * 
+	 * @param text text to draw
+	 * @param pos origin (min coord)
+	 * @param height drawing height
+	 * @param align horizontal alignment
+	 */
+	public void draw(String text, Vect pos, double height, AlignX align)
+	{
+		draw(text, pos, height, align, this.color);
+	}
+	
+	
+	/**
+	 * Draw on screen
+	 * 
+	 * @param text text to draw
+	 * @param pos origin (min coord)
+	 * @param height drawing height
+	 * @param align horizontal alignment
+	 * @param color drawing color
+	 */
+	public void draw(String text, Vect pos, double height, AlignX align, Color color)
+	{
+		
+		final double w = getWidth(text, height);
+		
+		Vect start;
+		
+		switch (align) {
+			case LEFT:
+				start = pos;
+				break;
+			
+			case CENTER:
+				start = pos.sub(w / 2D, 0);
+				break;
+			
+			case RIGHT:
+			default:
+				start = pos.sub(w, 0);
+				break;
+		}
+		
+		draw(text, start, height, color);
+	}
+	
+}

src/mightypork/gamecore/graphics/fonts/Glyphs.java

@@ -0,0 +1,23 @@
+package mightypork.gamecore.graphics.fonts;
+
+
+/**
+ * Glyph tables, can be used for font loading.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class Glyphs {
+	
+	public static final String latin = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+	public static final String latin_extra = "ŒÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜŸÝßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿĚŠČŘŽŤŇĎŮěščřžťňďůŁłđ";
+	public static final String numbers = "0123456789";
+	public static final String punctuation = ".-,.?!:;\"'";
+	public static final String punctuation_extra = "()¿¡»«›‹“”‘’„…";
+	public static final String symbols = "[]{}#$%&§*+/<=>@\\^_|~°";
+	public static final String symbols_extra = "¥€£¢`ƒ†‡ˆ‰•¤¦¨ªº¹²³¬­¯±´µ¶·¸¼½¾×÷™©­®→↓←↑";
+	
+	public static final String basic = latin + numbers + punctuation + symbols;
+	public static final String extra = latin_extra + punctuation_extra + symbols_extra;
+	public static final String all = basic + extra;
+	
+}

src/mightypork/gamecore/graphics/fonts/IFont.java

@@ -0,0 +1,76 @@
+package mightypork.gamecore.graphics.fonts;
+
+
+import mightypork.utils.math.color.Color;
+import mightypork.utils.math.constraints.vect.Vect;
+
+
+/**
+ * Interface bor drawable font.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface IFont {
+	
+	/**
+	 * Draw without scaling at (0, 0) in given color.
+	 * 
+	 * @param text text to draw
+	 * @param color draw color
+	 */
+	void draw(String text, Color color);
+	
+	
+	/**
+	 * Get suize needed to render give string
+	 * 
+	 * @param text string to check
+	 * @return coord (width, height)
+	 */
+	Vect getNeededSpace(String text);
+	
+	
+	/**
+	 * @return font height
+	 */
+	int getLineHeight();
+	
+	
+	/**
+	 * @param text texted text
+	 * @return space needed
+	 */
+	int getWidth(String text);
+	
+	
+	/**
+	 * @return specified font size
+	 */
+	int getFontSize();
+	
+	
+	/**
+	 * Set what vertical ratio of the font size is blank and should be cut off
+	 * when rendering
+	 * 
+	 * @param top top ratio (0-1)
+	 * @param bottom bottom ratio (0-1)
+	 */
+	void setDiscardRatio(double top, double bottom);
+	
+	
+	/**
+	 * Get top discard ratio (blank unused space)
+	 * 
+	 * @return ratio
+	 */
+	double getTopDiscardRatio();
+	
+	
+	/**
+	 * Get bottom discard ratio (blank unused space)
+	 * 
+	 * @return ratio
+	 */
+	double getBottomDiscardRatio();
+}

src/mightypork/gamecore/graphics/textures/DeferredTexture.java

@@ -0,0 +1,57 @@
+package mightypork.gamecore.graphics.textures;
+
+
+import mightypork.gamecore.resources.BaseDeferredResource;
+import mightypork.gamecore.resources.loading.MustLoadInRenderingContext;
+import mightypork.utils.annotations.Alias;
+import mightypork.utils.math.constraints.rect.Rect;
+
+
+/**
+ * Deferred texture (to be extended by backend texture)
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@Alias(name = "Texture")
+@MustLoadInRenderingContext
+public abstract class DeferredTexture extends BaseDeferredResource implements ITexture {
+	
+	protected FilterMode filter = FilterMode.NEAREST;
+	protected WrapMode wrap = WrapMode.CLAMP;
+	
+	
+	/**
+	 * @param resourcePath resource path
+	 */
+	public DeferredTexture(String resourcePath) {
+		super(resourcePath);
+	}
+	
+	
+	@Override
+	public TxQuad makeQuad(Rect uvs)
+	{
+		return new TxQuad(this, uvs);
+	}
+	
+	
+	@Override
+	public void setFilter(FilterMode filterMin)
+	{
+		this.filter = filterMin;
+	}
+	
+	
+	@Override
+	public void setWrap(WrapMode wrapping)
+	{
+		this.wrap = wrapping;
+	}
+	
+	
+	@Override
+	public QuadGrid grid(int x, int y)
+	{
+		return new QuadGrid(this, x, y);
+	}
+}

src/mightypork/gamecore/graphics/textures/FilterMode.java

@@ -0,0 +1,12 @@
+package mightypork.gamecore.graphics.textures;
+
+
+/**
+ * Texture filtering mode
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public enum FilterMode
+{
+	LINEAR, NEAREST;
+}

src/mightypork/gamecore/graphics/textures/ITexture.java

@@ -0,0 +1,64 @@
+package mightypork.gamecore.graphics.textures;
+
+
+import mightypork.utils.interfaces.Destroyable;
+import mightypork.utils.math.constraints.rect.Rect;
+
+
+/**
+ * Texture interface, backend independent
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface ITexture extends Destroyable {
+	
+	/**
+	 * Set filter for scaling
+	 * 
+	 * @param filter filter
+	 */
+	void setFilter(FilterMode filter);
+	
+	
+	/**
+	 * @param wrapping wrap mode
+	 */
+	void setWrap(WrapMode wrapping);
+	
+	
+	/**
+	 * Get a quad from this texture of given position/size
+	 * 
+	 * @param uvs quad rect
+	 * @return the quad
+	 */
+	TxQuad makeQuad(Rect uvs);
+	
+	
+	/**
+	 * Get a grid for given number of tiles
+	 * 
+	 * @param x horizontal tile count
+	 * @param y vertical tile count
+	 * @return grid
+	 */
+	QuadGrid grid(int x, int y);
+	
+	
+	/**
+	 * @return source image width (corresponding to width01)
+	 */
+	int getImageWidth();
+	
+	
+	/**
+	 * @return source image height (corresponding to height01)
+	 */
+	int getImageHeight();
+	
+	
+	/**
+	 * @return true if the image is RGBA
+	 */
+	boolean hasAlpha();
+}

src/mightypork/gamecore/graphics/textures/QuadGrid.java

@@ -0,0 +1,92 @@
+package mightypork.gamecore.graphics.textures;
+
+
+import mightypork.utils.math.constraints.rect.Rect;
+
+
+/**
+ * {@link TxQuad} and {@link TxSheet} building utility
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class QuadGrid {
+	
+	private final ITexture tx;
+	private final int txHeight;
+	private final int txWidth;
+	private final double tileW;
+	private final double tileH;
+	
+	
+	public QuadGrid(ITexture tx, int tilesX, int tilesY) {
+		this.tx = tx;
+		this.txWidth = tilesX;
+		this.txHeight = tilesY;
+		this.tileW = 1D / tilesX;
+		this.tileH = 1D / tilesY;
+	}
+	
+	
+	/**
+	 * Make square quad at given coords (one grid cell)
+	 * 
+	 * @param x x coordinate (cells)
+	 * @param y y coordinate (cells)
+	 * @return the quad
+	 */
+	public TxQuad makeQuad(double x, double y)
+	{
+		if (x < 0 || x >= txWidth || y < 0 || y >= txHeight) {
+			throw new IndexOutOfBoundsException("Requested invalid txquad coordinates.");
+		}
+		
+		return makeQuad(x, y, 1, 1);
+	}
+	
+	
+	/**
+	 * Make square quad at given coords, with arbitrary size. Coordinates are
+	 * multiples of cell size.
+	 * 
+	 * @param x x coordinate (cells)
+	 * @param y y coordinate (cells)
+	 * @param width width (cells)
+	 * @param height height (cells)
+	 * @return the quad
+	 */
+	public TxQuad makeQuad(double x, double y, double width, double height)
+	{
+		if (x < 0 || x >= txWidth || y < 0 || y >= txHeight) {
+			throw new IndexOutOfBoundsException("Requested invalid txquad coordinates.");
+		}
+		
+		if (x + width > txWidth || y + height > txHeight) {
+			throw new IndexOutOfBoundsException("Requested invalid txquad size (would go beyond texture size).");
+		}
+		
+		return tx.makeQuad(Rect.make(tileW * x, tileH * y, tileW * width, tileH * height));
+	}
+	
+	
+	/**
+	 * Make a sheet.
+	 * 
+	 * @param x x origin coordinate (cells)
+	 * @param y y origin coordinate (cells)
+	 * @param width width (cells)
+	 * @param height height (cells)
+	 * @return the sheet
+	 */
+	public TxSheet makeSheet(double x, double y, double width, double height)
+	{
+		if (x < 0 || x >= txWidth || y < 0 || y >= txHeight) {
+			throw new IndexOutOfBoundsException("Requested invalid txquad coordinates.");
+		}
+		
+		if (x + width > txWidth || y + height > txHeight) {
+			throw new IndexOutOfBoundsException("Requested invalid txsheet size (would go beyond texture size).");
+		}
+		
+		return makeQuad(x, y).makeSheet(width, height);
+	}
+}

src/mightypork/gamecore/graphics/textures/TextureRegistry.java

@@ -0,0 +1,143 @@
+package mightypork.gamecore.graphics.textures;
+
+
+import java.util.HashMap;
+import java.util.Map;
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.resources.loading.ResourceLoadRequest;
+import mightypork.utils.exceptions.KeyAlreadyExistsException;
+import mightypork.utils.math.constraints.rect.Rect;
+
+
+/**
+ * Texture storage and quad/sheet registry. Quads and Sheets are interchangeable
+ * once registered.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class TextureRegistry {
+	
+	private final Map<String, ITexture> textures = new HashMap<>();
+	private final Map<String, TxSheet> sheets = new HashMap<>();
+	
+	
+	/**
+	 * Load a texture from resource, without a key. This texture will not be
+	 * added to the bank.
+	 * 
+	 * @param resourcePath resource path of the texture
+	 * @param filter
+	 * @param wrap
+	 * @return texture reference
+	 */
+	public ITexture addTexture(String resourcePath, FilterMode filter, WrapMode wrap)
+	{
+		return addTexture(resourcePath, resourcePath, filter, wrap);
+	}
+	
+	
+	/**
+	 * Load a texture from resource; if key is not null, the texture will be
+	 * added to the bank.
+	 * 
+	 * @param key texture key, can be null.
+	 * @param resourcePath resource path of the texture
+	 * @param filter
+	 * @param wrap
+	 * @return texture reference
+	 */
+	public ITexture addTexture(String key, String resourcePath, FilterMode filter, WrapMode wrap)
+	{
+		if (key != null) if (textures.containsKey(key)) throw new KeyAlreadyExistsException();
+		
+		final DeferredTexture texture = App.gfx().getLazyTexture(resourcePath);
+		texture.setFilter(filter);
+		texture.setWrap(wrap);
+		
+		App.bus().send(new ResourceLoadRequest(texture));
+		
+		if (key != null) {
+			textures.put(key, texture);
+			add(key, texture.makeQuad(Rect.ONE));
+		}
+		
+		return texture;
+	}
+	
+	
+	/**
+	 * Add already created quad to the quad registry
+	 * 
+	 * @param quadKey key
+	 * @param quad quad to add
+	 */
+	public void add(String quadKey, TxQuad quad)
+	{
+		if (sheets.containsKey(quadKey)) throw new KeyAlreadyExistsException();
+		
+		sheets.put(quadKey, quad.makeSheet(1, 1));
+	}
+	
+	
+	/**
+	 * Add an already created sheet
+	 * 
+	 * @param sheetKey key
+	 * @param sheet sheet to add
+	 */
+	public void add(String sheetKey, TxSheet sheet)
+	{
+		if (sheets.containsKey(sheetKey)) throw new KeyAlreadyExistsException();
+		
+		sheets.put(sheetKey, sheet);
+	}
+	
+	
+	/**
+	 * Get a {@link TxQuad} for key; if it was added as sheet, the first quad
+	 * ofthe sheet is returned.
+	 * 
+	 * @param key quad key
+	 * @return the quad
+	 */
+	public TxQuad getQuad(String key)
+	{
+		return getSheet(key).getQuad(0); // get the first
+	}
+	
+	
+	/**
+	 * Get a loaded {@link ITexture}
+	 * 
+	 * @param key texture key
+	 * @return the texture
+	 */
+	public ITexture getTexture(String key)
+	{
+		final ITexture tx = textures.get(key);
+		
+		if (tx == null) throw new RuntimeException("There's no texture called \"" + key + "\"!");
+		
+		return tx;
+	}
+	
+	
+	/**
+	 * Get a {@link TxSheet} for key
+	 * 
+	 * @param key sheet key
+	 * @return the sheet
+	 */
+	public TxSheet getSheet(String key)
+	{
+		final TxSheet sh = sheets.get(key);
+		
+		if (sh == null) {
+			throw new RuntimeException("There's no sheet called  \"" + key + "\"!");
+		}
+		
+		return sh;
+	}
+	
+}

src/mightypork/gamecore/graphics/textures/TxQuad.java

@@ -0,0 +1,164 @@
+package mightypork.gamecore.graphics.textures;
+
+
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.rect.RectConst;
+
+
+/**
+ * Texture Quad (describing a part of a texture)
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class TxQuad {
+	
+	/** The texture */
+	public final ITexture tx;
+	/** Coords in texture (0-1) */
+	public final RectConst uvs;
+	
+	private boolean flipX;
+	private boolean flipY;
+	
+	
+	/**
+	 * TxQuad from origin and size in pixels
+	 * 
+	 * @param tx texture
+	 * @param xPx left top X (0-1)
+	 * @param yPx left top Y (0-1)
+	 * @param widthPx area width (0-1)
+	 * @param heightPx area height (0-1)
+	 * @return new TxQuad
+	 */
+	public static TxQuad fromSizePx(ITexture tx, double xPx, double yPx, double widthPx, double heightPx)
+	{
+		final double w = tx.getImageWidth();
+		final double h = tx.getImageHeight();
+		
+		return fromSize(tx, xPx / w, yPx / h, widthPx / w, heightPx / h);
+	}
+	
+	
+	/**
+	 * TxQuad from origin and size 0-1
+	 * 
+	 * @param tx texture
+	 * @param x1 left top X (0-1)
+	 * @param y1 left top Y (0-1)
+	 * @param width area width (0-1)
+	 * @param height area height (0-1)
+	 * @return new TxQuad
+	 */
+	public static TxQuad fromSize(ITexture tx, double x1, double y1, double width, double height)
+	{
+		return new TxQuad(tx, x1, y1, x1 + width, y1 + height);
+	}
+	
+	
+	/**
+	 * Make of coords
+	 * 
+	 * @param tx texture
+	 * @param x1 left top X (0-1)
+	 * @param y1 left top Y (0-1)
+	 * @param x2 right bottom X (0-1)
+	 * @param y2 right bottom Y (0-1)
+	 */
+	public TxQuad(ITexture tx, double x1, double y1, double x2, double y2) {
+		this(tx, Rect.make(x1, y1, x2, y2));
+	}
+	
+	
+	/**
+	 * @param tx Texture
+	 * @param uvs Rect of texture UVs (0-1); will be frozen.
+	 */
+	public TxQuad(ITexture tx, Rect uvs) {
+		this.tx = tx;
+		this.uvs = uvs.freeze();
+	}
+	
+	
+	/**
+	 * Clone another
+	 * 
+	 * @param txQuad a copied quad
+	 */
+	public TxQuad(TxQuad txQuad) {
+		this.tx = txQuad.tx;
+		this.uvs = txQuad.uvs;
+		this.flipX = txQuad.flipX;
+		this.flipY = txQuad.flipY;
+	}
+	
+	
+	/**
+	 * Get copy
+	 * 
+	 * @return copy of this
+	 */
+	public TxQuad copy()
+	{
+		return new TxQuad(this);
+	}
+	
+	
+	/**
+	 * Make a sheet starting with this quad, spannign to right and down.
+	 * 
+	 * @param width sheet width
+	 * @param height sheet height
+	 * @return sheet
+	 */
+	public TxSheet makeSheet(double width, double height)
+	{
+		return new TxSheet(this, (int) Math.round(width), (int) Math.round(height));
+	}
+	
+	
+	/**
+	 * @return copy flipped X
+	 */
+	public TxQuad flipX()
+	{
+		final TxQuad copy = new TxQuad(this);
+		copy.flipX ^= true;
+		return copy;
+	}
+	
+	
+	/**
+	 * @return copy flipped Y
+	 */
+	public TxQuad flipY()
+	{
+		final TxQuad copy = new TxQuad(this);
+		copy.flipY ^= true;
+		return copy;
+	}
+	
+	
+	public boolean isFlippedY()
+	{
+		return flipY;
+	}
+	
+	
+	public boolean isFlippedX()
+	{
+		return flipX;
+	}
+	
+	
+	/**
+	 * Use the same flit/other attributes as the original txQuad
+	 * 
+	 * @param original
+	 */
+	public void dupeAttrs(TxQuad original)
+	{
+		this.flipX = original.flipX;
+		this.flipY = original.flipY;
+	}
+}

src/mightypork/gamecore/graphics/textures/TxSheet.java

@@ -0,0 +1,121 @@
+package mightypork.gamecore.graphics.textures;
+
+
+import java.util.Random;
+
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Basic sprite sheet
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class TxSheet {
+	
+	private final TxQuad original;
+	private final TxQuad[] sprites;
+	private final int width;
+	
+	private final Random rand = new Random();
+	private final Random randForSeed = new Random();
+	private final int count;
+	
+	
+	public TxSheet(TxQuad tx, int width, int height) {
+		this.original = tx;
+		this.width = width;
+		this.count = width * height;
+		
+		this.sprites = new TxQuad[count];
+	}
+	
+	
+	/**
+	 * @return number of quads
+	 */
+	public int getQuadCount()
+	{
+		return count;
+	}
+	
+	
+	/**
+	 * Get a quad based on ratio 0-1 (0: first, 1: last)
+	 * 
+	 * @param ratio ratio
+	 * @return quad
+	 */
+	public TxQuad getQuad(double ratio)
+	{
+		return getQuad((int) Math.round((count - 1) * ratio));
+	}
+	
+	
+	/**
+	 * Get quad of index
+	 * 
+	 * @param index index
+	 * @return the quad
+	 */
+	public TxQuad getQuad(int index)
+	{
+		if (index < 0 || index >= count) {
+			Log.w("Index out of bounds: " + index + ", allowed: 0.." + count);
+			index = index % count;
+		}
+		
+		// lazy - init only when needed
+		if (sprites[index] == null) {
+			final int x = index % width;
+			final int y = index / width;
+			
+			final double origW = original.uvs.width().value();
+			final double origH = original.uvs.height().value();
+			
+			final TxQuad txq = new TxQuad(original.tx, original.uvs.move(x * origW, y * origH));
+			txq.dupeAttrs(original);
+			
+			sprites[index] = txq;
+		}
+		
+		return sprites[index];
+	}
+	
+	
+	/**
+	 * Get entirely random TxQuad from this sheet
+	 * 
+	 * @return the picked quad
+	 */
+	public TxQuad getRandomQuad()
+	{
+		return getQuad(rand.nextInt(count));
+	}
+	
+	
+	/**
+	 * Get random TxQuad from this sheet
+	 * 
+	 * @param seed random number generator seed
+	 * @return the picked quad
+	 */
+	public TxQuad getRandomQuad(long seed)
+	{
+		randForSeed.setSeed(seed);
+		return getQuad(randForSeed.nextInt(count));
+	}
+	
+	
+	/**
+	 * Get random TxQuad from this sheet
+	 * 
+	 * @param seed random number generator seed (double will be converted to
+	 *            long)
+	 * @return the picked quad
+	 */
+	public TxQuad getRandomQuad(double seed)
+	{
+		return getRandomQuad(Double.doubleToLongBits(seed));
+	}
+}

src/mightypork/gamecore/graphics/textures/WrapMode.java

@@ -0,0 +1,12 @@
+package mightypork.gamecore.graphics.textures;
+
+
+/**
+ * Texture wrap mode
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public enum WrapMode
+{
+	CLAMP, REPEAT;
+}

src/mightypork/gamecore/gui/Action.java

@@ -0,0 +1,54 @@
+package mightypork.gamecore.gui;
+
+
+import mightypork.utils.interfaces.Enableable;
+
+
+/**
+ * Triggered action
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class Action implements Runnable, Enableable {
+	
+	private boolean enabled = true;
+	
+	
+	/**
+	 * Enable the action
+	 * 
+	 * @param enable true to enable
+	 */
+	@Override
+	public final void setEnabled(boolean enable)
+	{
+		this.enabled = enable;
+	}
+	
+	
+	/**
+	 * @return true if this action is enabled.
+	 */
+	@Override
+	public final boolean isEnabled()
+	{
+		return enabled;
+	}
+	
+	
+	/**
+	 * Run the action, if it's enabled.
+	 */
+	@Override
+	public final void run()
+	{
+		if (enabled) execute();
+	}
+	
+	
+	/**
+	 * Do the work.
+	 */
+	protected abstract void execute();
+	
+}

src/mightypork/gamecore/gui/ActionGroup.java

@@ -0,0 +1,38 @@
+package mightypork.gamecore.gui;
+
+
+import java.util.HashSet;
+import java.util.Set;
+
+import mightypork.utils.interfaces.Enableable;
+
+
+public class ActionGroup implements Enableable {
+	
+	private boolean enabled = true;
+	
+	private final Set<Enableable> groupMembers = new HashSet<>();
+	
+	
+	@Override
+	public void setEnabled(boolean yes)
+	{
+		enabled = yes;
+		for (final Enableable e : groupMembers)
+			e.setEnabled(yes);
+	}
+	
+	
+	@Override
+	public boolean isEnabled()
+	{
+		return enabled;
+	}
+	
+	
+	public void add(Enableable action)
+	{
+		groupMembers.add(action);
+	}
+	
+}

src/mightypork/gamecore/gui/ActionTrigger.java

@@ -0,0 +1,17 @@
+package mightypork.gamecore.gui;
+
+
+/**
+ * Element that can be assigned an action (ie. button);
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface ActionTrigger {
+	
+	/**
+	 * Assign an action
+	 * 
+	 * @param action action
+	 */
+	void setAction(Action action);
+}

src/mightypork/gamecore/gui/components/BaseComponent.java

@@ -0,0 +1,169 @@
+package mightypork.gamecore.gui.components;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.graphics.Renderable;
+import mightypork.gamecore.gui.events.LayoutChangeEvent;
+import mightypork.gamecore.gui.events.LayoutChangeListener;
+import mightypork.utils.Support;
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.interfaces.Enableable;
+import mightypork.utils.logging.Log;
+import mightypork.utils.math.color.Color;
+import mightypork.utils.math.constraints.num.Num;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.rect.RectBound;
+import mightypork.utils.math.constraints.rect.caching.AbstractRectCache;
+import mightypork.utils.math.constraints.rect.proxy.RectProxy;
+
+
+/**
+ * {@link Renderable} with pluggable context. When caching is enabled, the
+ * layout update can be triggered by firing the {@link LayoutChangeEvent}.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class BaseComponent extends AbstractRectCache implements Component, LayoutChangeListener, Enableable {
+	
+	private Rect source;
+	private boolean visible = true;
+	private boolean enabled = true;
+	private int indirectDisableLevel = 0;
+	
+	private Num alphaMul = Num.ONE;
+	
+	
+	public BaseComponent() {
+		enableCaching(false);
+	}
+	
+	
+	@Override
+	public void setRect(RectBound rect)
+	{
+		this.source = new RectProxy(rect);
+	}
+	
+	
+	@Override
+	public final boolean isVisible()
+	{
+		return visible;
+	}
+	
+	
+	@Override
+	public final void setVisible(boolean visible)
+	{
+		this.visible = visible;
+	}
+	
+	
+	@Override
+	public final Rect getCacheSource()
+	{
+		return source.round(); // round to avoid visual artifacts in fonts and such
+	}
+	
+	
+	@Override
+	public final void render()
+	{
+		if (!isVisible()) return;
+		
+		Color.pushAlpha(alphaMul);
+		renderComponent();
+		Color.popAlpha();
+	}
+	
+	
+	@Override
+	public final void onLayoutChanged()
+	{
+		try {
+			poll();
+		} catch (final NullPointerException e) {
+			Log.e("Component is missing a bounding rect, at: " + Support.str(getClass()));
+		}
+	}
+	
+	
+	@Override
+	public final void onConstraintChanged()
+	{
+		updateLayout();
+	}
+	
+	
+	@Override
+	public final boolean isMouseOver()
+	{
+		return App.input().getMousePos().isInside(this);
+	}
+	
+	
+	/**
+	 * Draw the component (it's visible)
+	 */
+	protected abstract void renderComponent();
+	
+	
+	@Override
+	@Stub
+	public void updateLayout()
+	{
+	}
+	
+	
+	@Override
+	public void setEnabled(boolean yes)
+	{
+		enabled = yes;
+	}
+	
+	
+	@Override
+	public boolean isEnabled()
+	{
+		return enabled && isIndirectlyEnabled();
+	}
+	
+	
+	@Override
+	public final void setAlpha(Num alpha)
+	{
+		this.alphaMul = alpha;
+	}
+	
+	
+	@Override
+	public final void setAlpha(double alpha)
+	{
+		this.alphaMul = Num.make(alpha);
+	}
+	
+	
+	@Override
+	public void setIndirectlyEnabled(boolean yes)
+	{
+		if (!yes) {
+			indirectDisableLevel++;
+		} else {
+			if (indirectDisableLevel > 0) indirectDisableLevel--;
+		}
+	}
+	
+	
+	@Override
+	public boolean isIndirectlyEnabled()
+	{
+		return indirectDisableLevel == 0;
+	}
+	
+	
+	@Override
+	public boolean isDirectlyEnabled()
+	{
+		return enabled;
+	}
+}

src/mightypork/gamecore/gui/components/Component.java

@@ -0,0 +1,95 @@
+package mightypork.gamecore.gui.components;
+
+
+import mightypork.utils.interfaces.Enableable;
+import mightypork.utils.interfaces.Hideable;
+import mightypork.utils.math.constraints.num.Num;
+
+
+/**
+ * Basic UI component interface
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface Component extends Enableable, Hideable, PluggableRenderable {
+	
+	/**
+	 * Render the component, if it is visible.
+	 */
+	@Override
+	void render();
+	
+	
+	/**
+	 * The bounding rect was changed. The component should now update any cached
+	 * constraints derived from it.
+	 */
+	void updateLayout();
+	
+	
+	/**
+	 * @return true if mouse is currently over the component
+	 */
+	boolean isMouseOver();
+	
+	
+	/**
+	 * Set alpha multiplier for this and nested components
+	 * 
+	 * @param alpha alpha multiplier (dynamic value)
+	 */
+	void setAlpha(Num alpha);
+	
+	
+	/**
+	 * Set alpha multiplier for this and nested components
+	 * 
+	 * @param alpha alpha multiplier (constant value)
+	 */
+	void setAlpha(double alpha);
+	
+	
+	/**
+	 * Indirectly enable / disable, used for nested hierarchies.<br>
+	 * When component is twice indirectly disabled, it needs to be twice
+	 * indirectly enabled to be enabled again.
+	 * 
+	 * @param yes
+	 */
+	void setIndirectlyEnabled(boolean yes);
+	
+	
+	/**
+	 * Check if the compionent is not indirectly disabled. May still be directly
+	 * disabled.
+	 * 
+	 * @return indirectly enabled
+	 */
+	boolean isIndirectlyEnabled();
+	
+	
+	/**
+	 * Check if the component is directly enabled (set by setEnabled()). May
+	 * still be indirectly disabled.
+	 * 
+	 * @return directly enabled
+	 */
+	boolean isDirectlyEnabled();
+	
+	
+	/**
+	 * Set directly enabled (must be both directly and indirectly enabled to be
+	 * enabled completely)
+	 */
+	@Override
+	public void setEnabled(boolean yes);
+	
+	
+	/**
+	 * Check if the component is both directly and indirectly enabled
+	 * 
+	 * @return enabled
+	 */
+	@Override
+	public boolean isEnabled();
+}

src/mightypork/gamecore/gui/components/DynamicWidthComponent.java

@@ -0,0 +1,7 @@
+package mightypork.gamecore.gui.components;
+
+
+public interface DynamicWidthComponent extends Component {
+	
+	double computeWidth(double height);
+}

src/mightypork/gamecore/gui/components/InputComponent.java

@@ -0,0 +1,15 @@
+package mightypork.gamecore.gui.components;
+
+
+import mightypork.utils.eventbus.clients.ToggleableClient;
+import mightypork.utils.interfaces.Enableable;
+
+
+public abstract class InputComponent extends BaseComponent implements Enableable, ToggleableClient {
+	
+	@Override
+	public boolean isListening()
+	{
+		return isEnabled();
+	}
+}

src/mightypork/gamecore/gui/components/LayoutComponent.java

@@ -0,0 +1,122 @@
+package mightypork.gamecore.gui.components;
+
+
+import java.util.Collection;
+import java.util.LinkedList;
+
+import mightypork.utils.eventbus.clients.ClientHub;
+import mightypork.utils.eventbus.clients.DelegatingList;
+import mightypork.utils.math.constraints.rect.RectBound;
+
+
+public abstract class LayoutComponent extends BaseComponent implements ClientHub {
+	
+	private final DelegatingList clientList;
+	final LinkedList<Component> components = new LinkedList<>();
+	
+	
+	public LayoutComponent(RectBound context) {
+		this.clientList = new DelegatingList();
+		setRect(context);
+		enableCaching(true); // layout is typically updated only when screen resizes.
+	}
+	
+	
+	public LayoutComponent() {
+		this(null);
+	}
+	
+	
+	@Override
+	public Collection<Object> getChildClients()
+	{
+		return clientList;
+	}
+	
+	
+	@Override
+	public boolean doesDelegate()
+	{
+		return clientList.doesDelegate();
+	}
+	
+	
+	@Override
+	public boolean isListening()
+	{
+		return clientList.isListening();
+	}
+	
+	
+	@Override
+	public void addChildClient(Object client)
+	{
+		clientList.add(client);
+	}
+	
+	
+	@Override
+	public void removeChildClient(Object client)
+	{
+		clientList.remove(client);
+	}
+	
+	
+	@Override
+	public void setEnabled(boolean yes)
+	{
+		if (isDirectlyEnabled() != yes) {
+			super.setEnabled(yes);
+			
+			for (final Component c : components) {
+				c.setIndirectlyEnabled(yes);
+			}
+		}
+	}
+	
+	
+	/**
+	 * Connect to bus and add to element list
+	 * 
+	 * @param component added component, whose context has already been set.
+	 */
+	protected final void attach(Component component)
+	{
+		if (component == null) return;
+		if (component == this) {
+			throw new IllegalArgumentException("Uruboros. (infinite recursion evaded)");
+		}
+		
+		components.add(component);
+		addChildClient(component);
+	}
+	
+	
+	@Override
+	public void renderComponent()
+	{
+		for (final Component cmp : components) {
+			cmp.render();
+		}
+	}
+	
+	
+	@Override
+	public void updateLayout()
+	{
+		for (final Component cmp : components) {
+			cmp.updateLayout();
+		}
+	}
+	
+	
+	@Override
+	public void setIndirectlyEnabled(boolean yes)
+	{
+		super.setIndirectlyEnabled(yes);
+		
+		for (final Component cmp : components) {
+			cmp.setIndirectlyEnabled(yes);
+		}
+	}
+}

src/mightypork/gamecore/gui/components/LinearComponent.java

@@ -0,0 +1,77 @@
+package mightypork.gamecore.gui.components;
+
+
+import mightypork.utils.math.constraints.num.Num;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.rect.RectBound;
+import mightypork.utils.math.constraints.vect.Vect;
+import mightypork.utils.math.constraints.vect.proxy.VectAdapter;
+
+
+public abstract class LinearComponent extends BaseComponent implements DynamicWidthComponent {
+	
+	private final Rect rect = new Rect() {
+		
+		@Override
+		public Vect size()
+		{
+			return new Vect() {
+				
+				@Override
+				public double x()
+				{
+					return computeWidth(y());
+				}
+				
+				
+				@Override
+				public double y()
+				{
+					return height.value();
+				}
+				
+			};
+		}
+		
+		
+		@Override
+		public Vect origin()
+		{
+			return new VectAdapter() {
+				
+				@Override
+				protected Vect getSource()
+				{
+					return origin;
+				}
+			};
+		}
+	};
+	
+	private Vect origin;
+	private Num height;
+	
+	
+	public LinearComponent() {
+		super.setRect(rect);
+	}
+	
+	
+	@Override
+	public void setRect(RectBound rect)
+	{
+		throw new RuntimeException("Cannot assign a rect to a linear component. Set origin and height instead.");
+	}
+	
+	
+	public void setHeight(Num height)
+	{
+		this.height = height;
+	}
+	
+	
+	public void setOrigin(Vect origin)
+	{
+		this.origin = origin;
+	}
+}

src/mightypork/gamecore/gui/components/PluggableRenderable.java

@@ -0,0 +1,28 @@
+package mightypork.gamecore.gui.components;
+
+
+import mightypork.gamecore.graphics.Renderable;
+import mightypork.utils.math.constraints.rect.PluggableRectBound;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.rect.RectBound;
+
+
+/**
+ * Renderable that can be assigned different context
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface PluggableRenderable extends Renderable, PluggableRectBound {
+	
+	@Override
+	void render();
+	
+	
+	@Override
+	Rect getRect();
+	
+	
+	@Override
+	void setRect(RectBound rect);
+	
+}

src/mightypork/gamecore/gui/components/input/ClickableComponent.java

@@ -0,0 +1,49 @@
+package mightypork.gamecore.gui.components.input;
+
+
+import mightypork.gamecore.gui.Action;
+import mightypork.gamecore.gui.ActionTrigger;
+import mightypork.gamecore.gui.components.InputComponent;
+import mightypork.gamecore.input.events.MouseButtonEvent;
+import mightypork.gamecore.input.events.MouseButtonHandler;
+
+
+public abstract class ClickableComponent extends InputComponent implements ActionTrigger, MouseButtonHandler {
+	
+	protected boolean btnDownOver;
+	private Action action;
+	
+	
+	@Override
+	public void setAction(Action action)
+	{
+		this.action = action;
+	}
+	
+	
+	protected void triggerAction()
+	{
+		if (action != null && isEnabled()) action.run();
+	}
+	
+	
+	@Override
+	public void receive(MouseButtonEvent event)
+	{
+		if (!event.isButtonEvent()) return;
+		
+		if (event.isDown()) {
+			btnDownOver = event.isOver(this);
+		}
+		
+		if (event.isUp()) {
+			
+			if (btnDownOver && event.isOver(this)) {
+				triggerAction();
+				event.consume();
+			}
+			
+			btnDownOver = false;
+		}
+	}
+}

src/mightypork/gamecore/gui/components/input/ClickableWrapper.java

@@ -0,0 +1,63 @@
+package mightypork.gamecore.gui.components.input;
+
+
+import java.util.Collection;
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.utils.eventbus.clients.ClientList;
+import mightypork.utils.eventbus.clients.DelegatingClient;
+
+
+public class ClickableWrapper extends ClickableComponent implements DelegatingClient {
+	
+	private final Component wrapped;
+	private final ClientList list;
+	
+	
+	public ClickableWrapper(Component wrapped) {
+		this.wrapped = wrapped;
+		wrapped.setRect(this);
+		
+		list = new ClientList(wrapped);
+	}
+	
+	
+	@Override
+	public Collection<?> getChildClients()
+	{
+		return list;
+	}
+	
+	
+	@Override
+	public boolean doesDelegate()
+	{
+		return true;
+	}
+	
+	
+	@Override
+	protected void renderComponent()
+	{
+		wrapped.render();
+	}
+	
+	
+	@Override
+	public void setEnabled(boolean yes)
+	{
+		if (yes != super.isDirectlyEnabled()) {
+			super.setEnabled(yes);
+			wrapped.setIndirectlyEnabled(yes);
+		}
+	}
+	
+	
+	@Override
+	public void setIndirectlyEnabled(boolean yes)
+	{
+		super.setIndirectlyEnabled(yes);
+		wrapped.setIndirectlyEnabled(yes);
+	}
+	
+}

src/mightypork/gamecore/gui/components/input/TextButton.java

@@ -0,0 +1,77 @@
+package mightypork.gamecore.gui.components.input;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.graphics.fonts.IFont;
+import mightypork.gamecore.gui.components.DynamicWidthComponent;
+import mightypork.gamecore.gui.components.painters.TextPainter;
+import mightypork.utils.math.AlignX;
+import mightypork.utils.math.color.Color;
+import mightypork.utils.math.color.pal.RGB;
+import mightypork.utils.math.constraints.vect.Vect;
+import mightypork.utils.math.constraints.vect.var.VectVar;
+
+
+/**
+ * Menu-like button with shadow and push state
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class TextButton extends ClickableComponent implements DynamicWidthComponent {
+	
+	public final TextPainter textPainter;
+	
+	private final VectVar offset = Vect.makeVar();
+	
+	public Vect offsetPassive = height().div(16).toVectXY();
+	public Vect offsetOver = height().div(20).toVectXY();
+	public Vect offsetUnder = height().div(32).toVectXY();
+	
+	private final Color color;
+	
+	private boolean hoverMove = true;
+	
+	
+	public TextButton(IFont font, String text, Color color) {
+		this.color = color;
+		
+		this.textPainter = new TextPainter(font, AlignX.CENTER, this.color, text);
+		this.textPainter.setRect(this);
+		this.textPainter.setShadow(RGB.BLACK_30, offset);
+		textPainter.setVPaddingPercent(5);
+	}
+	
+	
+	@Override
+	protected void renderComponent()
+	{
+		if (isMouseOver()) {
+			if (App.input().isMouseButtonDown(0)) {
+				offset.setTo(offsetUnder);
+			} else {
+				offset.setTo(hoverMove ? offsetOver : offsetPassive);
+			}
+		} else {
+			offset.setTo(offsetPassive);
+		}
+		
+		textPainter.render();
+	}
+	
+	
+	/**
+	 * Disable offset change on hover
+	 */
+	public void disableHoverEffect()
+	{
+		hoverMove = false;
+	}
+	
+	
+	@Override
+	public double computeWidth(double height)
+	{
+		return textPainter.computeWidth(height);
+	}
+	
+}

src/mightypork/gamecore/gui/components/layout/ColumnLayout.java

@@ -0,0 +1,42 @@
+package mightypork.gamecore.gui.components.layout;
+
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.utils.math.constraints.rect.RectBound;
+
+
+public class ColumnLayout extends GridLayout {
+	
+	private int col = 0;
+	
+	
+	public ColumnLayout(int rows) {
+		this(null, rows);
+	}
+	
+	
+	public ColumnLayout(RectBound context, int cols) {
+		super(context, 1, cols);
+	}
+	
+	
+	public void add(final Component elem)
+	{
+		add(elem, 1);
+	}
+	
+	
+	public void add(final Component elem, int colSpan)
+	{
+		if (elem == null) return;
+		
+		put(elem, 0, col, 1, colSpan);
+		col += colSpan;
+	}
+	
+	
+	public void skip(int cols)
+	{
+		col += cols;
+	}
+}

src/mightypork/gamecore/gui/components/layout/ConstraintLayout.java

@@ -0,0 +1,36 @@
+package mightypork.gamecore.gui.components.layout;
+
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.gamecore.gui.components.LayoutComponent;
+import mightypork.utils.math.constraints.rect.RectBound;
+
+
+/**
+ * Layout for components with arbitrary constraints.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class ConstraintLayout extends LayoutComponent {
+	
+	public ConstraintLayout() {
+	}
+	
+	
+	public ConstraintLayout(RectBound context) {
+		super(context);
+	}
+	
+	
+	/**
+	 * Add a component to the layout.<br>
+	 * The component's rect must be set up manually.
+	 * 
+	 * @param component
+	 */
+	public void add(Component component)
+	{
+		attach(component);
+	}
+	
+}

src/mightypork/gamecore/gui/components/layout/FlowColumnLayout.java

@@ -0,0 +1,85 @@
+package mightypork.gamecore.gui.components.layout;
+
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.gamecore.gui.components.LayoutComponent;
+import mightypork.utils.math.AlignX;
+import mightypork.utils.math.constraints.num.Num;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.rect.RectBound;
+
+
+/**
+ * Holder with same-sized columns, aligned to left or right
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class FlowColumnLayout extends LayoutComponent {
+	
+	private int col = 0;
+	private Num elementWidth;
+	private final AlignX align;
+	
+	
+	/**
+	 * @param context context
+	 * @param elementWidth width of all elements
+	 * @param align component align. Legal values are LEFT and RIGHT.
+	 */
+	public FlowColumnLayout(RectBound context, Num elementWidth, AlignX align) {
+		super(context);
+		this.elementWidth = elementWidth;
+		this.align = align;
+		
+		if (align != AlignX.LEFT && align != AlignX.RIGHT) {
+			throw new IllegalArgumentException("Can align only left or right.");
+		}
+	}
+	
+	
+	/**
+	 * make a new holder.<br>
+	 * Context must be assigned before rendering.
+	 * 
+	 * @param elementWidth width of all elements
+	 * @param align component align. Legal values are LEFT and RIGHT.
+	 */
+	public FlowColumnLayout(Num elementWidth, AlignX align) {
+		this(null, elementWidth, align);
+	}
+	
+	
+	/**
+	 * Add an item
+	 * 
+	 * @param elem
+	 */
+	public void add(final Component elem)
+	{
+		if (elem == null) return;
+		
+		final Rect r;
+		
+		switch (align) {
+			case LEFT:
+				r = leftEdge().growRight(elementWidth).moveX(elementWidth.mul(col++));
+				break;
+			case RIGHT:
+				r = rightEdge().growLeft(elementWidth).moveX(elementWidth.mul(-(col++)));
+				break;
+			default:
+				throw new IllegalArgumentException("Bad align.");
+		}
+		
+		elem.setRect(r);
+		
+		attach(elem);
+	}
+	
+	
+	public void setElementWidth(Num elementWidth)
+	{
+		this.elementWidth = elementWidth;
+	}
+	
+}

src/mightypork/gamecore/gui/components/layout/FlowRowLayout.java

@@ -0,0 +1,84 @@
+package mightypork.gamecore.gui.components.layout;
+
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.gamecore.gui.components.LayoutComponent;
+import mightypork.utils.math.AlignY;
+import mightypork.utils.math.constraints.num.Num;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.rect.RectBound;
+
+
+/**
+ * Holder with same-sized rows, aligned to top or bottom
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class FlowRowLayout extends LayoutComponent {
+	
+	private int row = 0;
+	private Num elementHeight;
+	private final AlignY align;
+	
+	
+	/**
+	 * @param context context
+	 * @param elementHeight height of all elements
+	 * @param align component align. Legal values are TOP and BOTTOM.
+	 */
+	public FlowRowLayout(RectBound context, Num elementHeight, AlignY align) {
+		super(context);
+		this.elementHeight = elementHeight;
+		this.align = align;
+		
+		if (align != AlignY.TOP && align != AlignY.BOTTOM) {
+			throw new IllegalArgumentException("Can align only to top or bottom.");
+		}
+	}
+	
+	
+	/**
+	 * make a new holder.<br>
+	 * Context must be assigned before rendering.
+	 * 
+	 * @param elementHeight height of all elements
+	 * @param align component align. Legal values are TOP and BOTTOM.
+	 */
+	public FlowRowLayout(Num elementHeight, AlignY align) {
+		this(null, elementHeight, align);
+	}
+	
+	
+	/**
+	 * Add an item
+	 * 
+	 * @param elem
+	 */
+	public void add(final Component elem)
+	{
+		if (elem == null) return;
+		
+		final Rect r;
+		
+		switch (align) {
+			case TOP:
+				r = topEdge().growDown(elementHeight).moveY(elementHeight.mul(row++));
+				break;
+			case BOTTOM:
+				r = bottomEdge().growUp(elementHeight).moveY(elementHeight.mul(-(row++)));
+				break;
+			default:
+				throw new IllegalArgumentException("Bad align.");
+		}
+		
+		elem.setRect(r);
+		
+		attach(elem);
+	}
+	
+	
+	public void setElementHeight(Num elementHeight)
+	{
+		this.elementHeight = elementHeight;
+	}
+}

src/mightypork/gamecore/gui/components/layout/GridLayout.java

@@ -0,0 +1,78 @@
+package mightypork.gamecore.gui.components.layout;
+
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.gamecore.gui.components.LayoutComponent;
+import mightypork.utils.math.constraints.rect.RectBound;
+import mightypork.utils.math.constraints.rect.builders.TiledRect;
+
+
+/**
+ * Holder with table cells
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class GridLayout extends LayoutComponent {
+	
+	private final TiledRect tiler;
+	
+	
+	/**
+	 * @param context context
+	 * @param rows number of rows
+	 * @param cols number of columns
+	 */
+	public GridLayout(RectBound context, int rows, int cols) {
+		super(context);
+		this.tiler = tiles(cols, rows);
+	}
+	
+	
+	/**
+	 * make a new holder.<br>
+	 * Context must be assigned before rendering.
+	 * 
+	 * @param rows number of rows
+	 * @param cols number of columns
+	 */
+	public GridLayout(int rows, int cols) {
+		this(null, rows, cols);
+	}
+	
+	
+	/**
+	 * Add a row to the holder.
+	 * 
+	 * @param row row (one-based)
+	 * @param column column (one-based)
+	 * @param elem added component
+	 */
+	public void put(Component elem, int row, int column)
+	{
+		if (elem == null) return;
+		
+		elem.setRect(tiler.tile(column, row));
+		
+		attach(elem);
+	}
+	
+	
+	/**
+	 * Put with span
+	 * 
+	 * @param elem
+	 * @param row
+	 * @param column
+	 * @param rowspan
+	 * @param colspan
+	 */
+	public void put(Component elem, int row, int column, int rowspan, int colspan)
+	{
+		if (elem == null) return;
+		
+		elem.setRect(tiler.span(column, row, colspan, rowspan));
+		
+		attach(elem);
+	}
+	
+}

src/mightypork/gamecore/gui/components/layout/NullComponent.java

@@ -0,0 +1,18 @@
+package mightypork.gamecore.gui.components.layout;
+
+
+import mightypork.gamecore.gui.components.BaseComponent;
+
+
+/**
+ * Invisible component that does nothing at all; Null object pattern
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class NullComponent extends BaseComponent {
+	
+	@Override
+	protected void renderComponent()
+	{
+	}
+}

src/mightypork/gamecore/gui/components/layout/RowLayout.java

@@ -0,0 +1,42 @@
+package mightypork.gamecore.gui.components.layout;
+
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.utils.math.constraints.rect.RectBound;
+
+
+public class RowLayout extends GridLayout {
+	
+	private int row = 0;
+	
+	
+	public RowLayout(int rows) {
+		this(null, rows);
+	}
+	
+	
+	public RowLayout(RectBound context, int rows) {
+		super(context, rows, 1);
+	}
+	
+	
+	public void add(final Component elem)
+	{
+		add(elem, 1);
+	}
+	
+	
+	public void add(final Component elem, int rowSpan)
+	{
+		if (elem == null) return;
+		
+		put(elem, row, 0, rowSpan, 1);
+		row += rowSpan;
+	}
+	
+	
+	public void skip(int rows)
+	{
+		row += rows;
+	}
+}

src/mightypork/gamecore/gui/components/layout/linear/AbstractLinearWrapper.java

@@ -0,0 +1,78 @@
+package mightypork.gamecore.gui.components.layout.linear;
+
+
+import java.util.Collection;
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.gamecore.gui.components.LinearComponent;
+import mightypork.utils.eventbus.clients.ClientList;
+import mightypork.utils.eventbus.clients.DelegatingClient;
+
+
+/**
+ * Converts a component into a linear component
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class AbstractLinearWrapper extends LinearComponent implements DelegatingClient {
+	
+	protected final Component wrapped;
+	private final ClientList list;
+	
+	
+	/**
+	 * @param wrapped wrapped component. Can be null.
+	 */
+	public AbstractLinearWrapper(Component wrapped) {
+		this.wrapped = wrapped;
+		if (wrapped != null) {
+			if (wrapped instanceof LinearComponent) {
+				((LinearComponent) wrapped).setHeight(height());
+				((LinearComponent) wrapped).setOrigin(origin());
+			} else {
+				wrapped.setRect(this);
+			}
+		}
+		
+		list = new ClientList(wrapped);
+	}
+	
+	
+	@Override
+	protected void renderComponent()
+	{
+		if (wrapped != null) wrapped.render();
+	}
+	
+	
+	@Override
+	public Collection<?> getChildClients()
+	{
+		return list;
+	}
+	
+	
+	@Override
+	public boolean doesDelegate()
+	{
+		return true;
+	}
+	
+	
+	@Override
+	public void setEnabled(boolean yes)
+	{
+		if (yes != super.isDirectlyEnabled()) {
+			super.setEnabled(yes);
+			wrapped.setIndirectlyEnabled(yes);
+		}
+	}
+	
+	
+	@Override
+	public void setIndirectlyEnabled(boolean yes)
+	{
+		super.setIndirectlyEnabled(yes);
+		wrapped.setIndirectlyEnabled(yes);
+	}
+}

src/mightypork/gamecore/gui/components/layout/linear/LinearGap.java

@@ -0,0 +1,24 @@
+package mightypork.gamecore.gui.components.layout.linear;
+
+
+import mightypork.gamecore.gui.components.layout.NullComponent;
+import mightypork.utils.math.constraints.num.Num;
+
+
+/**
+ * Gap in linear layout
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class LinearGap extends LinearRectangle {
+	
+	public LinearGap(Num width) {
+		super(new NullComponent(), width);
+	}
+	
+	
+	public LinearGap(double heightPercent) {
+		this(Num.ZERO);
+		setWidth(height().perc(heightPercent));
+	}
+}

src/mightypork/gamecore/gui/components/layout/linear/LinearLayout.java

@@ -0,0 +1,93 @@
+package mightypork.gamecore.gui.components.layout.linear;
+
+
+import mightypork.gamecore.gui.components.DynamicWidthComponent;
+import mightypork.gamecore.gui.components.LayoutComponent;
+import mightypork.gamecore.gui.components.LinearComponent;
+import mightypork.utils.math.AlignX;
+import mightypork.utils.math.constraints.num.Num;
+import mightypork.utils.math.constraints.num.batch.NumSum;
+import mightypork.utils.math.constraints.rect.RectBound;
+import mightypork.utils.math.constraints.vect.Vect;
+import mightypork.utils.math.constraints.vect.proxy.VectAdapter;
+
+
+/**
+ * Layout that aligns elements while taking into account their actual
+ * dimensions.<br>
+ * Useful eg. for buttons that stretch based on text length.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class LinearLayout extends LayoutComponent {
+	
+	public LinearLayout(AlignX align) {
+		this.align = align;
+	}
+	
+	
+	public LinearLayout(RectBound context, AlignX align) {
+		super(context);
+		this.align = align;
+	}
+	
+	private final NumSum totalWidth = new NumSum();
+	
+	private final Vect leftAlignOrigin = LinearLayout.this.origin();
+	private final Vect centerAlignOrigin = LinearLayout.this.topCenter().sub(totalWidth.half(), Num.ZERO);
+	private final Vect rightAlignOrigin = LinearLayout.this.topRight().sub(totalWidth, Num.ZERO);
+	
+	private final Vect leftMostOrigin = new VectAdapter() {
+		
+		@Override
+		protected Vect getSource()
+		{
+			switch (align) {
+				default:
+				case LEFT:
+					return leftAlignOrigin;
+				case CENTER:
+					return centerAlignOrigin;
+				case RIGHT:
+					return rightAlignOrigin;
+			}
+		}
+	};
+	
+	private Vect nextOrigin = leftMostOrigin;
+	
+	private AlignX align = AlignX.LEFT;
+	
+	
+	public void add(DynamicWidthComponent dwcomp)
+	{
+		add(new LinearWrapper(dwcomp));
+	}
+	
+	
+	public void add(LinearComponent lincomp)
+	{
+		lincomp.setHeight(height());
+		lincomp.setOrigin(nextOrigin);
+		nextOrigin = nextOrigin.add(lincomp.width(), Num.ZERO);
+		totalWidth.addSummand(lincomp.width());
+		attach(lincomp);
+	}
+	
+	
+	public void setAlign(AlignX align)
+	{
+		this.align = align;
+	}
+	
+	
+	/**
+	 * Add a gap.
+	 * 
+	 * @param heightPercent percent of height for gap width
+	 */
+	public void gap(double heightPercent)
+	{
+		add(new LinearGap(heightPercent));
+	}
+}

src/mightypork/gamecore/gui/components/layout/linear/LinearRectangle.java

@@ -0,0 +1,31 @@
+package mightypork.gamecore.gui.components.layout.linear;
+
+
+import mightypork.gamecore.gui.components.Component;
+import mightypork.utils.math.constraints.num.Num;
+
+
+public class LinearRectangle extends AbstractLinearWrapper {
+	
+	private Num width;
+	
+	
+	public LinearRectangle(Component wrapped, Num width) {
+		super(wrapped);
+		this.width = width;
+	}
+	
+	
+	public void setWidth(Num width)
+	{
+		this.width = width;
+	}
+	
+	
+	@Override
+	public double computeWidth(double height)
+	{
+		return this.width.value();
+	}
+	
+}

src/mightypork/gamecore/gui/components/layout/linear/LinearSquare.java

@@ -0,0 +1,20 @@
+package mightypork.gamecore.gui.components.layout.linear;
+
+
+import mightypork.gamecore.gui.components.Component;
+
+
+public class LinearSquare extends AbstractLinearWrapper {
+	
+	public LinearSquare(Component wrapped) {
+		super(wrapped);
+	}
+	
+	
+	@Override
+	public double computeWidth(double height)
+	{
+		return height;
+	}
+	
+}

src/mightypork/gamecore/gui/components/layout/linear/LinearWrapper.java

@@ -0,0 +1,20 @@
+package mightypork.gamecore.gui.components.layout.linear;
+
+
+import mightypork.gamecore.gui.components.DynamicWidthComponent;
+
+
+public class LinearWrapper extends AbstractLinearWrapper {
+	
+	public LinearWrapper(DynamicWidthComponent wrapped) {
+		super(wrapped);
+	}
+	
+	
+	@Override
+	public double computeWidth(double height)
+	{
+		return ((DynamicWidthComponent) wrapped).computeWidth(height);
+	}
+	
+}

src/mightypork/gamecore/gui/components/painters/ImagePainter.java

@@ -0,0 +1,46 @@
+package mightypork.gamecore.gui.components.painters;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.graphics.textures.TxQuad;
+import mightypork.gamecore.gui.components.BaseComponent;
+import mightypork.gamecore.gui.components.DynamicWidthComponent;
+
+
+/**
+ * Draws image in given rect
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class ImagePainter extends BaseComponent implements DynamicWidthComponent {
+	
+	private TxQuad txQuad;
+	
+	
+	/**
+	 * @param txQuad drawn image
+	 */
+	public ImagePainter(TxQuad txQuad) {
+		this.txQuad = txQuad;
+	}
+	
+	
+	@Override
+	public void renderComponent()
+	{
+		App.gfx().quad(this, txQuad);
+	}
+	
+	
+	@Override
+	public double computeWidth(double height)
+	{
+		return (height / txQuad.uvs.height().value()) * txQuad.uvs.width().value();
+	}
+	
+	
+	public void setTxQuad(TxQuad txQuad)
+	{
+		this.txQuad = txQuad;
+	}
+}

src/mightypork/gamecore/gui/components/painters/QuadPainter.java

@@ -0,0 +1,62 @@
+package mightypork.gamecore.gui.components.painters;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.gui.components.BaseComponent;
+import mightypork.utils.annotations.FactoryMethod;
+import mightypork.utils.math.color.Color;
+import mightypork.utils.math.color.Grad;
+
+
+/**
+ * Draws image in given rect
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class QuadPainter extends BaseComponent {
+	
+	@FactoryMethod
+	public static QuadPainter gradH(Color colorLeft, Color colorRight)
+	{
+		return new QuadPainter(colorLeft, colorRight, colorRight, colorLeft);
+	}
+	
+	
+	@FactoryMethod
+	public static QuadPainter gradV(Color colorTop, Color colorBottom)
+	{
+		return new QuadPainter(colorTop, colorTop, colorBottom, colorBottom);
+	}
+	
+	private final Grad grad;
+	
+	
+	/**
+	 * Painter with solid color
+	 * 
+	 * @param color
+	 */
+	public QuadPainter(Color color) {
+		this.grad = new Grad(color, color, color, color);
+	}
+	
+	
+	/**
+	 * Painter with coloured vertices.
+	 * 
+	 * @param leftTop
+	 * @param rightTop
+	 * @param leftBottom
+	 * @param rightBottom
+	 */
+	public QuadPainter(Color leftTop, Color rightTop, Color leftBottom, Color rightBottom) {
+		this.grad = new Grad(leftTop, rightTop, rightBottom, leftBottom);
+	}
+	
+	
+	@Override
+	public void renderComponent()
+	{
+		App.gfx().quad(getRect(), grad);
+	}
+}

src/mightypork/gamecore/gui/components/painters/TextPainter.java

@@ -0,0 +1,163 @@
+package mightypork.gamecore.gui.components.painters;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.graphics.fonts.FontRenderer;
+import mightypork.gamecore.graphics.fonts.IFont;
+import mightypork.gamecore.gui.components.BaseComponent;
+import mightypork.gamecore.gui.components.DynamicWidthComponent;
+import mightypork.utils.math.AlignX;
+import mightypork.utils.math.color.Color;
+import mightypork.utils.math.color.pal.RGB;
+import mightypork.utils.math.constraints.num.Num;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.vect.Vect;
+import mightypork.utils.string.StringProvider;
+import mightypork.utils.string.StringWrapper;
+
+
+/**
+ * Text painting component.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class TextPainter extends BaseComponent implements DynamicWidthComponent {
+	
+	private static final boolean DEBUG_FONT_RENDER = false;
+	private final FontRenderer font;
+	private Color color;
+	private AlignX align;
+	private StringProvider text;
+	private boolean shadow;
+	
+	private double yPaddingPerc = 0;
+	
+	private Color shadowColor = RGB.BLACK;
+	private Vect shadowOffset = Vect.make(2, 2);
+	
+	
+	/**
+	 * @param font font to use
+	 */
+	public TextPainter(IFont font) {
+		this(font, AlignX.LEFT, RGB.WHITE);
+	}
+	
+	
+	public TextPainter(IFont font, Color color, String text) {
+		this(font, AlignX.LEFT, color, new StringWrapper(text));
+	}
+	
+	
+	public TextPainter(IFont font, Color color, StringProvider text) {
+		this(font, AlignX.LEFT, color, text);
+	}
+	
+	
+	public TextPainter(IFont font, Color color) {
+		this(font, AlignX.LEFT, color, (StringProvider) null);
+	}
+	
+	
+	public TextPainter(IFont font, AlignX align, Color color, String text) {
+		this(font, align, color, new StringWrapper(text));
+	}
+	
+	
+	public TextPainter(IFont font, AlignX align, Color color, StringProvider text) {
+		this.font = new FontRenderer(font);
+		this.color = color;
+		this.align = align;
+		this.text = text;
+	}
+	
+	
+	public TextPainter(IFont font, AlignX align, Color color) {
+		this(font, align, color, (StringProvider) null);
+	}
+	
+	
+	@Override
+	public void renderComponent()
+	{
+		if (text == null) return;
+		
+		final String str = text.getString();
+		
+		final Num shrY = height().perc(yPaddingPerc);
+		
+		final Rect rect = getRect().shrink(Num.ZERO, shrY);
+		
+		if (shadow) {
+			font.draw(str, rect.round(), align, shadowColor);
+		}
+		
+		final Rect r = (shadow ? rect.move(shadowOffset.neg()) : rect).round();
+		font.draw(str, r, align, color);
+		
+		if (DEBUG_FONT_RENDER) App.gfx().quad(r, RGB.PINK.withAlpha(0.4));
+	}
+	
+	
+	public void setShadow(Color color, Vect offset)
+	{
+		setShadow(true);
+		setShadowColor(color);
+		setShadowOffset(offset);
+	}
+	
+	
+	public void setShadow(boolean shadow)
+	{
+		this.shadow = shadow;
+	}
+	
+	
+	public void setShadowColor(Color shadowColor)
+	{
+		this.shadowColor = shadowColor;
+	}
+	
+	
+	public void setShadowOffset(Vect shadowOffset)
+	{
+		this.shadowOffset = shadowOffset;
+	}
+	
+	
+	public void setColor(Color color)
+	{
+		this.color = color;
+	}
+	
+	
+	public void setAlign(AlignX align)
+	{
+		this.align = align;
+	}
+	
+	
+	public void setText(String text)
+	{
+		this.text = new StringWrapper(text);
+	}
+	
+	
+	public void setText(StringProvider text)
+	{
+		this.text = text;
+	}
+	
+	
+	public void setVPaddingPercent(double percY)
+	{
+		yPaddingPerc = percY;
+	}
+	
+	
+	@Override
+	public double computeWidth(double height)
+	{
+		return font.getWidth(this.text.getString(), height * ((100 - yPaddingPerc * 2) / 100D));
+	}
+}

src/mightypork/gamecore/gui/events/LayoutChangeEvent.java

@@ -0,0 +1,30 @@
+package mightypork.gamecore.gui.events;
+
+
+import mightypork.utils.eventbus.BusEvent;
+import mightypork.utils.eventbus.events.flags.DirectEvent;
+import mightypork.utils.eventbus.events.flags.NonConsumableEvent;
+import mightypork.utils.eventbus.events.flags.NonRejectableEvent;
+
+
+/**
+ * Intended use is to notify UI component sub-clients that they should poll
+ * their cached constraints.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@DirectEvent
+@NonConsumableEvent
+@NonRejectableEvent
+public class LayoutChangeEvent extends BusEvent<LayoutChangeListener> {
+	
+	public LayoutChangeEvent() {
+	}
+	
+	
+	@Override
+	public void handleBy(LayoutChangeListener handler)
+	{
+		handler.onLayoutChanged();
+	}
+}

src/mightypork/gamecore/gui/events/LayoutChangeListener.java

@@ -0,0 +1,7 @@
+package mightypork.gamecore.gui.events;
+
+
+public interface LayoutChangeListener {
+	
+	public void onLayoutChanged();
+}

src/mightypork/gamecore/gui/events/ScreenRequest.java

@@ -0,0 +1,33 @@
+package mightypork.gamecore.gui.events;
+
+
+import mightypork.utils.eventbus.BusEvent;
+import mightypork.utils.eventbus.events.flags.SingleReceiverEvent;
+
+
+/**
+ * Request to change screen
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@SingleReceiverEvent
+public class ScreenRequest extends BusEvent<ScreenRequestListener> {
+	
+	private final String scrName;
+	
+	
+	/**
+	 * @param screenKey screen name
+	 */
+	public ScreenRequest(String screenKey) {
+		scrName = screenKey;
+	}
+	
+	
+	@Override
+	public void handleBy(ScreenRequestListener handler)
+	{
+		handler.showScreen(scrName);
+	}
+	
+}

src/mightypork/gamecore/gui/events/ScreenRequestListener.java

@@ -0,0 +1,15 @@
+package mightypork.gamecore.gui.events;
+
+
+/**
+ * {@link ScreenRequest} listener
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface ScreenRequestListener {
+	
+	/**
+	 * @param key screen to show
+	 */
+	void showScreen(String key);
+}

src/mightypork/gamecore/gui/events/ViewportChangeEvent.java

@@ -0,0 +1,44 @@
+package mightypork.gamecore.gui.events;
+
+
+import mightypork.utils.eventbus.BusEvent;
+import mightypork.utils.eventbus.events.flags.NonConsumableEvent;
+import mightypork.utils.eventbus.events.flags.NotLoggedEvent;
+import mightypork.utils.math.constraints.vect.Vect;
+
+
+/**
+ * Screen resolution or mode was changed
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@NonConsumableEvent
+@NotLoggedEvent
+public class ViewportChangeEvent extends BusEvent<ViewportChangeListener> {
+	
+	private final Vect screenSize;
+	
+	
+	/**
+	 * @param size new screen size
+	 */
+	public ViewportChangeEvent(Vect size) {
+		this.screenSize = size;
+	}
+	
+	
+	/**
+	 * @return new screen size
+	 */
+	public Vect getScreenSize()
+	{
+		return screenSize;
+	}
+	
+	
+	@Override
+	public void handleBy(ViewportChangeListener handler)
+	{
+		handler.onViewportChanged(this);
+	}
+}

src/mightypork/gamecore/gui/events/ViewportChangeListener.java

@@ -0,0 +1,17 @@
+package mightypork.gamecore.gui.events;
+
+
+/**
+ * {@link ViewportChangeEvent} listener
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public interface ViewportChangeListener {
+	
+	/**
+	 * Handle event
+	 * 
+	 * @param event
+	 */
+	void onViewportChanged(ViewportChangeEvent event);
+}

src/mightypork/gamecore/gui/screens/LayeredScreen.java

@@ -0,0 +1,112 @@
+package mightypork.gamecore.gui.screens;
+
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+import mightypork.utils.eventbus.clients.DelegatingClient;
+
+
+/**
+ * Screen with multiple instances of {@link ScreenLayer}
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class LayeredScreen extends Screen {
+	
+	/**
+	 * Wrapper for delegating client, to use custom client ordering.
+	 * 
+	 * @author Ondřej Hruška (MightyPork)
+	 */
+	private class LayersClient implements DelegatingClient {
+		
+		@SuppressWarnings({ "unchecked", "rawtypes" })
+		@Override
+		public Collection getChildClients()
+		{
+			return layersByEventPriority;
+		}
+		
+		
+		@Override
+		public boolean doesDelegate()
+		{
+			return true;
+		}
+		
+	}
+	
+	private final List<ScreenLayer> layersByZIndex = new ArrayList<>();
+	private final List<ScreenLayer> layersByEventPriority = new ArrayList<>();
+	
+	private final LayersClient layersClient = new LayersClient();
+	
+	
+	public LayeredScreen() {
+		addChildClient(layersClient);
+	}
+	
+	
+	@Override
+	protected void renderScreen()
+	{
+		for (final ScreenLayer layer : layersByZIndex) {
+			if (layer.isVisible()) layer.render();
+		}
+	}
+	
+	
+	/**
+	 * Add a layer to the screen.
+	 * 
+	 * @param layer
+	 */
+	protected void addLayer(ScreenLayer layer)
+	{
+		this.layersByZIndex.add(layer);
+		this.layersByEventPriority.add(layer);
+		
+		Collections.sort(layersByEventPriority, new Comparator<Overlay>() {
+			
+			@Override
+			public int compare(Overlay o1, Overlay o2)
+			{
+				return o2.getEventPriority() - o1.getEventPriority();
+			}
+			
+		});
+		
+		Collections.sort(layersByZIndex, new Comparator<Overlay>() {
+			
+			@Override
+			public int compare(Overlay o1, Overlay o2)
+			{
+				return o1.getZIndex() - o2.getZIndex();
+			}
+			
+		});
+	}
+	
+	
+	@Override
+	protected void onScreenEnter()
+	{
+		for (final ScreenLayer layer : layersByEventPriority) {
+			layer.onScreenEnter();
+		}
+	}
+	
+	
+	@Override
+	protected void onScreenLeave()
+	{
+		for (final ScreenLayer layer : layersByEventPriority) {
+			layer.onScreenLeave();
+		}
+	}
+	
+}

src/mightypork/gamecore/gui/screens/Overlay.java

@@ -0,0 +1,222 @@
+package mightypork.gamecore.gui.screens;
+
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.graphics.Renderable;
+import mightypork.gamecore.gui.components.layout.ConstraintLayout;
+import mightypork.gamecore.gui.events.LayoutChangeListener;
+import mightypork.gamecore.input.KeyBinder;
+import mightypork.gamecore.input.KeyBindingPool;
+import mightypork.gamecore.input.KeyStroke;
+import mightypork.gamecore.input.Trigger;
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.eventbus.clients.BusNode;
+import mightypork.utils.interfaces.Enableable;
+import mightypork.utils.interfaces.Hideable;
+import mightypork.utils.interfaces.Updateable;
+import mightypork.utils.math.color.Color;
+import mightypork.utils.math.constraints.num.Num;
+import mightypork.utils.math.constraints.vect.Vect;
+
+
+/**
+ * Abstract overlay.<br>
+ * Overlay is connected to event bus and is renderable.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class Overlay extends BusNode implements Comparable<Overlay>, Updateable, Renderable, KeyBinder, Hideable, Enableable, LayoutChangeListener {
+	
+	private boolean visible = true;
+	private boolean enabled = true;
+	
+	private final KeyBindingPool keybindings = new KeyBindingPool();
+	
+	/** Root layout, rendered and attached to the event bus. */
+	protected final ConstraintLayout root;
+	
+	/** Constraint: Mouse position. */
+	protected final Vect mouse;
+	
+	/** Extra rendered items (outside root) */
+	protected final Collection<Renderable> rendered = new ArrayList<>();
+	
+	/** Extra updated items (outside root - those can just implement Updateable) */
+	protected final Collection<Updateable> updated = new ArrayList<>();
+	private Num alphaMul = Num.ONE;
+	
+	
+	public Overlay() {
+		
+		this.mouse = App.input().getMousePos();
+		
+		this.root = new ConstraintLayout(App.gfx().getRect());
+		addChildClient(root);
+		addChildClient(keybindings);
+		
+		rendered.add(root);
+	}
+	
+	
+	@Override
+	public final void bindKey(KeyStroke stroke, Trigger edge, Runnable task)
+	{
+		keybindings.bindKey(stroke, edge, task);
+	}
+	
+	
+	@Override
+	public final void unbindKey(KeyStroke stroke)
+	{
+		keybindings.unbindKey(stroke);
+	}
+	
+	
+	@Override
+	public final boolean isVisible()
+	{
+		return visible;
+	}
+	
+	
+	@Override
+	public void setVisible(boolean visible)
+	{
+		if (visible != this.visible) {
+			this.visible = visible;
+			root.setVisible(visible);
+		}
+	}
+	
+	
+	@Override
+	public void setEnabled(boolean yes)
+	{
+		if (enabled != yes) {
+			this.enabled = yes;
+			root.setEnabled(yes);
+		}
+	}
+	
+	
+	@Override
+	public boolean isEnabled()
+	{
+		return enabled;
+	}
+	
+	
+	/**
+	 * Get rendering layer
+	 * 
+	 * @return higher = on top.
+	 */
+	@Stub
+	public abstract int getZIndex();
+	
+	
+	/**
+	 * Get event bus listening priority - useful to block incoming events.
+	 * 
+	 * @return higher = first.
+	 */
+	public int getEventPriority()
+	{
+		return getZIndex();
+	}
+	
+	
+	/**
+	 * Render the overlay. The caller MUST check for visibility himself.
+	 */
+	@Override
+	public void render()
+	{
+		if (!isVisible()) return;
+		
+		Color.pushAlpha(alphaMul);
+		for (final Renderable r : rendered) {
+			r.render();
+		}
+		
+		Color.popAlpha();
+	}
+	
+	
+	@Override
+	public void update(double delta)
+	{
+		if (!isEnabled()) return;
+		
+		for (final Updateable u : updated) {
+			u.update(delta);
+		}
+	}
+	
+	
+	@Override
+	public int compareTo(Overlay o)
+	{
+		return o.getEventPriority() - getEventPriority();
+	}
+	
+	
+	/**
+	 * <p>
+	 * Screen size changed.
+	 * </p>
+	 * <p>
+	 * Layouts / components should listen for this event and update their cached
+	 * constraints; components added to root or directly to this overlay as
+	 * child clients will receive the event.
+	 * </p>
+	 */
+	@Override
+	@Stub
+	public void onLayoutChanged()
+	{
+	}
+	
+	
+	public void setAlpha(Num alpha)
+	{
+		this.alphaMul = alpha;
+	}
+	
+	
+	public void setAlpha(double alpha)
+	{
+		this.alphaMul = Num.make(alpha);
+	}
+	
+	
+	public void show()
+	{
+		setVisible(true);
+		setEnabled(true);
+	}
+	
+	
+	public void hide()
+	{
+		setVisible(false);
+		setEnabled(false);
+	}
+	
+	
+	@Override
+	public boolean isListening()
+	{
+		return (isVisible() || isEnabled());
+	}
+	
+	
+	@Override
+	public boolean doesDelegate()
+	{
+		return isListening();
+	}
+}

src/mightypork/gamecore/gui/screens/Screen.java

@@ -0,0 +1,153 @@
+package mightypork.gamecore.gui.screens;
+
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.graphics.Renderable;
+import mightypork.gamecore.gui.events.LayoutChangeEvent;
+import mightypork.gamecore.gui.events.LayoutChangeListener;
+import mightypork.gamecore.input.KeyBinder;
+import mightypork.gamecore.input.KeyBindingPool;
+import mightypork.gamecore.input.KeyStroke;
+import mightypork.gamecore.input.Trigger;
+import mightypork.utils.annotations.Stub;
+import mightypork.utils.eventbus.clients.BusNode;
+import mightypork.utils.math.constraints.rect.Rect;
+import mightypork.utils.math.constraints.rect.RectBound;
+
+
+/**
+ * Screen class.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class Screen extends BusNode implements Renderable, RectBound, KeyBinder, LayoutChangeListener {
+	
+	private final KeyBindingPool keybindings = new KeyBindingPool();
+	
+	private volatile boolean active;
+	private volatile boolean needSetupViewport = false;
+	
+	
+	public Screen() {
+		
+		// disable events initially
+		setListening(false);
+		
+		addChildClient(keybindings);
+	}
+	
+	
+	private void fireLayoutChangeEvent()
+	{
+		App.bus().sendDirectToChildren(this, new LayoutChangeEvent());
+	}
+	
+	
+	@Override
+	public final void bindKey(KeyStroke stroke, Trigger edge, Runnable task)
+	{
+		keybindings.bindKey(stroke, edge, task);
+	}
+	
+	
+	@Override
+	public final void unbindKey(KeyStroke stroke)
+	{
+		keybindings.unbindKey(stroke);
+	}
+	
+	
+	/**
+	 * Prepare for being shown
+	 * 
+	 * @param shown true to show, false to hide
+	 */
+	public final void setActive(boolean shown)
+	{
+		if (shown) {
+			active = true;
+			needSetupViewport = true;
+			
+			fireLayoutChangeEvent();
+			onScreenEnter();
+			
+			// enable events
+			setListening(true);
+			
+		} else {
+			onScreenLeave();
+			
+			active = false;
+			
+			// disable events
+			setListening(false);
+		}
+	}
+	
+	
+	/**
+	 * @return true if screen is the current screen
+	 */
+	public final boolean isActive()
+	{
+		return active;
+	}
+	
+	
+	@Override
+	public void onLayoutChanged()
+	{
+		if (!isActive()) return;
+		
+		needSetupViewport = true;
+	}
+	
+	
+	@Override
+	public final Rect getRect()
+	{
+		return App.gfx().getRect();
+	}
+	
+	
+	@Override
+	public void render()
+	{
+		if (!isActive()) return;
+		
+		if (needSetupViewport) {
+			App.gfx().setupProjection();
+		}
+		
+		App.gfx().pushState();
+		
+		renderScreen();
+		
+		App.gfx().popState();
+	}
+	
+	
+	/**
+	 * Called when the screen becomes active
+	 */
+	@Stub
+	protected void onScreenEnter()
+	{
+	}
+	
+	
+	/**
+	 * Called when the screen is no longer active
+	 */
+	@Stub
+	protected void onScreenLeave()
+	{
+	}
+	
+	
+	/**
+	 * Render screen contents (context is ready for 2D rendering)
+	 */
+	protected abstract void renderScreen();
+	
+}

src/mightypork/gamecore/gui/screens/ScreenLayer.java

@@ -0,0 +1,50 @@
+package mightypork.gamecore.gui.screens;
+
+
+import mightypork.utils.annotations.Stub;
+
+
+/**
+ * Screen display layer
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public abstract class ScreenLayer extends Overlay {
+	
+	private final Screen screen;
+	
+	
+	/**
+	 * @param screen parent screen
+	 */
+	public ScreenLayer(Screen screen) {
+		this.screen = screen;
+	}
+	
+	
+	/**
+	 * @return parent screen instance
+	 */
+	protected final Screen getScreen()
+	{
+		return screen;
+	}
+	
+	
+	/**
+	 * Called when the screen becomes active
+	 */
+	@Stub
+	protected void onScreenEnter()
+	{
+	}
+	
+	
+	/**
+	 * Called when the screen is no longer active
+	 */
+	@Stub
+	protected void onScreenLeave()
+	{
+	}
+}

src/mightypork/gamecore/gui/screens/ScreenRegistry.java

@@ -0,0 +1,106 @@
+package mightypork.gamecore.gui.screens;
+
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.TreeSet;
+
+import mightypork.gamecore.core.App;
+import mightypork.gamecore.graphics.Renderable;
+import mightypork.gamecore.gui.events.LayoutChangeEvent;
+import mightypork.gamecore.gui.events.ScreenRequestListener;
+import mightypork.gamecore.gui.events.ViewportChangeEvent;
+import mightypork.gamecore.gui.events.ViewportChangeListener;
+import mightypork.utils.eventbus.clients.BusNode;
+import mightypork.utils.logging.Log;
+
+
+/**
+ * Game screens holder; Takes care of rendering and screen requests.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class ScreenRegistry extends BusNode implements ScreenRequestListener, ViewportChangeListener, Renderable {
+	
+	private final Map<String, Screen> screens = new HashMap<>();
+	private final Collection<Overlay> overlays = new TreeSet<>();
+	private volatile Screen active = null;
+	
+	
+	/**
+	 * Add a screen
+	 * 
+	 * @param name screen key for calling
+	 * @param screen added screen
+	 */
+	public void addScreen(String name, Screen screen)
+	{
+		screens.put(name, screen);
+		addChildClient(screen);
+	}
+	
+	
+	/**
+	 * Add an overlay
+	 * 
+	 * @param overlay added overlay
+	 */
+	public void addOverlay(Overlay overlay)
+	{
+		overlays.add(overlay);
+		addChildClient(overlay);
+	}
+	
+	
+	@Override
+	public void showScreen(String key)
+	{
+		Log.f3("Request to show screen \"" + key + "\"");
+		
+		// find screen to show
+		final Screen toShow = screens.get(key);
+		if (toShow == null) {
+			throw new RuntimeException("Screen " + key + " not defined.");
+		}
+		
+		// deactivate last screen
+		if (active != null) {
+			active.setActive(false);
+		}
+		
+		// activate new screen
+		toShow.setActive(true);
+		
+		active = toShow;
+		
+		fireLayoutUpdateEvent();
+	}
+	
+	
+	@Override
+	public void render()
+	{
+		if (active != null) {
+			active.render();
+			
+			for (final Overlay overlay : overlays) {
+				if (overlay.isVisible()) overlay.render();
+			}
+		}
+	}
+	
+	
+	@Override
+	public void onViewportChanged(ViewportChangeEvent event)
+	{
+		if (active != null) fireLayoutUpdateEvent();
+	}
+	
+	
+	private void fireLayoutUpdateEvent()
+	{
+		App.bus().sendDirectToChildren(this, new LayoutChangeEvent());
+	}
+	
+}