More refactoring towards backend system

src/mightypork/gamecore/backend/Backend.java

@@ -0,0 +1,34 @@
+package mightypork.gamecore.backend;
+
+
+import mightypork.gamecore.render.RenderModule;
+import mightypork.utils.eventbus.BusAccess;
+import mightypork.utils.eventbus.clients.RootBusNode;
+
+
+/**
+ * Application backend interface (set of core modules)
+ * 
+ * @author MightyPork
+ */
+public abstract class Backend extends RootBusNode {
+	
+	public Backend(BusAccess busAccess) {
+		super(busAccess);
+	}
+	
+	
+	/**
+	 * Initialize backend modules, add them to event bus.<br>
+	 * Event bus must already be available in the BusAccess.
+	 */
+	public abstract void initialize();
+	
+	
+	/**
+	 * Get graphics module (renderer)
+	 * 
+	 * @return graphics module
+	 */
+	public abstract RenderModule getRenderer();
+}

src/mightypork/gamecore/backend/BackendModule.java

@@ -0,0 +1,32 @@
+package mightypork.gamecore.backend;
+
+
+import mightypork.utils.annotations.DefaultImpl;
+import mightypork.utils.eventbus.BusAccess;
+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 {
+	
+	/**
+	 * Create a module with bus access
+	 * 
+	 * @param busAccess
+	 */
+	public BackendModule(BusAccess busAccess) {
+		super(busAccess);
+	}
+	
+	@Override
+	@DefaultImpl
+	public void destroy()
+	{	
+	}
+	
+}

src/mightypork/gamecore/backend/lwjgl/AwtScreenshot.java

@@ -0,0 +1,85 @@
+package mightypork.gamecore.backend.lwjgl;
+
+
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import javax.imageio.ImageIO;
+
+import mightypork.gamecore.render.Screenshot;
+
+
+/**
+ * Screenshot object, can be used to extract image or write to file.<br>
+ * Screenshot, once taken, can be safely processed in separate thread.<br>
+ * Based on {@link BufferedImage} and {@link ImageIO}.
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+public class AwtScreenshot implements Screenshot {
+	
+	private final int width;
+	private final int height;
+	private final int bpp;
+	private final ByteBuffer bytes;
+	private BufferedImage image;
+	
+	
+	/**
+	 * @param width image width
+	 * @param height image height
+	 * @param bpp bits per pixel (typically 4)
+	 * @param buffer
+	 */
+	public AwtScreenshot(int width, int height, int bpp, ByteBuffer buffer)
+	{
+		this.width = width;
+		this.height = height;
+		this.bpp = bpp;
+		this.bytes = buffer;
+	}
+	
+	
+	/**
+	 * Extract to an image.<br>
+	 * Subsequent calls will use a cached value.
+	 * 
+	 * @return image
+	 */
+	public BufferedImage getImage()
+	{
+		if (image != null) return image;
+		
+		image = new BufferedImage(this.width, this.height, BufferedImage.TYPE_INT_RGB);
+		
+		// convert to a buffered image
+		for (int x = 0; x < this.width; x++) {
+			for (int y = 0; y < this.height; y++) {
+				final int i = (x + (this.width * y)) * this.bpp;
+				final int r = this.bytes.get(i) & 0xFF;
+				final int g = this.bytes.get(i + 1) & 0xFF;
+				final int b = this.bytes.get(i + 2) & 0xFF;
+				image.setRGB(x, this.height - (y + 1), (0xFF << 24) | (r << 16) | (g << 8) | b);
+			}
+		}
+		
+		return image;
+	}
+	
+	
+	/**
+	 * Save to a file.<br>
+	 * Cached value is used if any.
+	 * 
+	 * @param file target file
+	 * @throws IOException on error writing to file
+	 */
+	@Override
+	public void save(File file) throws IOException
+	{
+		file.getParentFile().mkdirs();
+		ImageIO.write(getImage(), "PNG", file);
+	}
+}

src/mightypork/gamecore/backend/lwjgl/LwjglBackend.java

@@ -0,0 +1,37 @@
+package mightypork.gamecore.backend.lwjgl;
+
+
+import mightypork.gamecore.backend.Backend;
+import mightypork.gamecore.render.RenderModule;
+import mightypork.utils.eventbus.BusAccess;
+
+
+/**
+ * Game backend using LWJGL
+ * 
+ * @author MightyPork
+ */
+public class LwjglBackend extends Backend {
+	
+	public LwjglBackend(BusAccess busAccess) {
+		super(busAccess);
+	}
+
+
+	private LwjglRenderModule renderer;
+	
+	
+	@Override
+	public void initialize()
+	{
+		addChildClient(renderer = new LwjglRenderModule(this));
+	}
+	
+	
+	@Override
+	public RenderModule getRenderer()
+	{
+		return renderer;
+	}
+	
+}

src/mightypork/gamecore/backend/lwjgl/LwjglRenderModule.java

@@ -0,0 +1,641 @@
+package mightypork.gamecore.backend.lwjgl;
+
+
+import static org.lwjgl.opengl.GL11.*;
+
+import java.nio.ByteBuffer;
+import java.util.Stack;
+
+import org.lwjgl.BufferUtils;
+import org.lwjgl.LWJGLException;
+import org.lwjgl.opengl.Display;
+import org.lwjgl.opengl.DisplayMode;
+import org.lwjgl.opengl.GL11;
+
+import mightypork.gamecore.render.Grad;
+import mightypork.gamecore.render.RenderModule;
+import mightypork.gamecore.render.Screenshot;
+import mightypork.gamecore.render.events.DisplayReadyEvent;
+import mightypork.gamecore.render.events.ViewportChangeEvent;
+import mightypork.gamecore.resources.textures.ITexture;
+import mightypork.gamecore.resources.textures.LazyTexture;
+import mightypork.gamecore.resources.textures.TxQuad;
+import mightypork.utils.eventbus.BusAccess;
+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.timing.FpsMeter;
+
+
+/**
+ * LWJGL rendering module
+ * 
+ * @author MightyPork
+ */
+public class LwjglRenderModule extends RenderModule {
+	
+	public LwjglRenderModule(BusAccess busAccess) {
+		super(busAccess);
+	}
+	
+	/** Currently binded color */
+	private Color activeColor = null;
+	/** Currently binded color's alpha multiplier */
+	private double activeColorAlpha = 1;
+	/** Stack of pushed colors */
+	private Stack<Color> colorPushStack = new Stack<>();
+	/** Currently binded texture */
+	private ITexture activeTexture;
+	
+	/** Display mode used currently for the window */
+	private DisplayMode windowDisplayMode;
+	/** FPS the user wants */
+	private int targetFps;
+	/** FPS meter used for measuring actual FPS */
+	private FpsMeter fpsMeter;
+	
+	/** Flag that at the end of frame, fullscreen should be toggled. */
+	private boolean fullscreenToggleRequested;
+	/** Flag that at the end of frame, fullscreen should be set. */
+	private boolean fullscreenSetRequested;
+	/** State to which fullscreen should be set. */
+	private boolean fullscreenSetState;
+	
+	/** Current screen size */
+	private static final Vect screenSize = new Vect() {
+		
+		@Override
+		public double y()
+		{
+			return Display.getHeight();
+		}
+		
+		
+		@Override
+		public double x()
+		{
+			return Display.getWidth();
+		}
+	};
+	
+	/** Current screen rectangle */
+	private static final Rect rect = Rect.make(screenSize);
+	
+	
+	@Override
+	public void setColor(Color color)
+	{
+		setColor(color, 1);
+	}
+	
+	
+	@Override
+	public void setColor(Color color, double alpha)
+	{
+		if (color == null) color = RGB.WHITE;
+		
+		// color components can change over time - must use equals()
+		if (activeColorAlpha == alpha && color.equals(activeColor)) return;
+		
+		activeColor = color;
+		activeColorAlpha = alpha;
+		GL11.glColor4d(color.r(), color.g(), color.b(), alpha * color.a());
+	}
+	
+	
+	@Override
+	public void translate(double x, double y)
+	{
+		glTranslated(x, y, 0);
+	}
+	
+	
+	@Override
+	public void translate(double x, double y, double z)
+	{
+		glTranslated(x, y, z);
+	}
+	
+	
+	@Override
+	public void translate(Vect offset)
+	{
+		glTranslated(offset.x(), offset.y(), offset.z());
+	}
+	
+	
+	@Override
+	public void translateXY(Vect offset)
+	{
+		glTranslated(offset.x(), offset.y(), 0);
+	}
+	
+	
+	@Override
+	public void scale(double x, double y)
+	{
+		glScaled(x, y, 0);
+	}
+	
+	
+	@Override
+	public void scale(double x, double y, double z)
+	{
+		glScaled(x, y, z);
+	}
+	
+	
+	@Override
+	public void scale(Vect scale)
+	{
+		glScaled(scale.x(), scale.y(), scale.z());
+	}
+	
+	
+	@Override
+	public void scaleXY(double scale)
+	{
+		glScaled(scale, scale, 1);
+	}
+	
+	
+	@Override
+	public void scaleX(double scale)
+	{
+		glScaled(scale, 1, 1);
+	}
+	
+	
+	@Override
+	public void scaleY(double scale)
+	{
+		glScaled(1, scale, 1);
+	}
+	
+	
+	@Override
+	public void scaleZ(double scale)
+	{
+		glScaled(1, 1, scale);
+	}
+	
+	
+	@Override
+	public void rotateX(double angle)
+	{
+		rotate(angle, AXIS_X);
+	}
+	
+	
+	@Override
+	public void rotateY(double angle)
+	{
+		rotate(angle, AXIS_Y);
+	}
+	
+	
+	@Override
+	public void rotateZ(double angle)
+	{
+		rotate(angle, AXIS_Z);
+	}
+	
+	
+	@Override
+	public void rotate(double angle, Vect axis)
+	{
+		final Vect vec = axis.norm(1);
+		glRotated(angle, vec.x(), vec.y(), vec.z());
+	}
+	
+	
+	@Override
+	public void pushState()
+	{
+		GL11.glPushAttrib(GL11.GL_ALL_ATTRIB_BITS);
+		GL11.glPushClientAttrib(GL11.GL_ALL_CLIENT_ATTRIB_BITS);
+		GL11.glPushMatrix();
+	}
+	
+	
+	@Override
+	public void popState()
+	{
+		GL11.glPopMatrix();
+		GL11.glPopClientAttrib();
+		GL11.glPopAttrib();
+	}
+	
+	
+	@Override
+	public void pushGeometry()
+	{
+		GL11.glPushMatrix();
+	}
+	
+	
+	@Override
+	public void popGeometry()
+	{
+		GL11.glPopMatrix();
+	}
+	
+	
+	@Override
+	public void pushColor()
+	{
+		colorPushStack.push(activeColor);
+	}
+	
+	
+	@Override
+	public void popColor()
+	{
+		setColor(colorPushStack.pop());
+	}
+	
+	
+	@Override
+	public void quad(Rect rect)
+	{
+		final RectDigest q = rect.digest();
+		
+		// disable texture
+		if (activeTexture != null) {
+			activeTexture = null;
+			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();
+	}
+	
+	
+	@Override
+	public void quad(Rect rect, Color color)
+	{
+		setColor(color);
+		quad(rect);
+	}
+	
+	
+	@Override
+	public void quad(Rect rect, Grad grad)
+	{
+		final RectDigest r = rect.digest();
+		
+		// disable texture
+		if (activeTexture != null) {
+			activeTexture = null;
+			glDisable(GL_TEXTURE_2D);
+		}
+		
+		// quad
+		glBegin(GL_QUADS);
+		setColor(grad.leftBottom);
+		glVertex2d(r.left, r.bottom);
+		
+		setColor(grad.rightBottom);
+		glVertex2d(r.right, r.bottom);
+		
+		setColor(grad.rightTop);
+		glVertex2d(r.right, r.top);
+		
+		setColor(grad.leftTop);
+		glVertex2d(r.left, r.top);
+		glEnd();
+	}
+	
+	
+	@Override
+	public void quad(Rect rect, TxQuad txquad)
+	{
+		quad(rect, txquad, RGB.WHITE);
+	}
+	
+	
+	@Override
+	public void quad(Rect rect, TxQuad txquad, Color color)
+	{
+		// texture is loaded uniquely -> can compare with ==
+		if (activeTexture != txquad.tx) {
+			glEnable(GL_TEXTURE_2D);
+			activeTexture = txquad.tx;
+			activeTexture.bind();
+		}
+		
+		glBegin(GL_QUADS);
+		setColor(color);
+		
+		final RectDigest q = rect.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);
+		
+		glEnd();
+	}
+	
+	
+	@Override
+	public void setupProjection(Vect screenSize)
+	{
+		// fix projection for changed size
+		glMatrixMode(GL_PROJECTION);
+		glLoadIdentity();
+		glViewport(0, 0, screenSize.xi(), screenSize.yi());
+		glOrtho(0, screenSize.xi(), screenSize.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);
+	}
+	
+	
+	@Override
+	public LazyTexture getLazyTexture(String path)
+	{
+		return new SlickLazyTexture(path);
+	}
+	
+	
+	@Override
+	public void destroy()
+	{
+		Display.destroy();
+	}
+	
+	
+	@Override
+	public void setTargetFps(int fps)
+	{
+		this.targetFps = fps;
+	}
+	
+	
+	@Override
+	public void createDisplay()
+	{
+		if (Display.isCreated()) throw new IllegalStateException("Display already created.");
+		try {
+			Display.create();
+			
+			fpsMeter = new FpsMeter();
+			
+			if (fullscreenSetRequested && fullscreenSetState) {
+				doToggleFullscreen();
+				Display.update();
+				fullscreenSetRequested = false;
+			}
+			
+			getEventBus().send(new DisplayReadyEvent());
+			
+		} catch (final Exception e) {
+			throw new RuntimeException("Could not initialize display.", e);
+		}
+	}
+	
+	
+	@Override
+	public void setFullscreen(boolean fs)
+	{
+		fullscreenSetRequested = true;
+		fullscreenSetState = fs;
+	}
+	
+	
+	@Override
+	public void switchFullscreen()
+	{
+		fullscreenToggleRequested = true;
+	}
+	
+	
+	@Override
+	public boolean isFullscreen()
+	{
+		return Display.isFullscreen();
+	}
+	
+	
+	private void doToggleFullscreen()
+	{
+		doSetFullscreen(!Display.isFullscreen());
+	}
+	
+	
+	private void doSetFullscreen(boolean fs)
+	{
+		try {
+			
+			if (Display.isFullscreen() == fs) return; // no work
+				
+			if (fs) {
+				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 change fullscreen mode.", t);
+			try {
+				Display.setDisplayMode(windowDisplayMode);
+				Display.update();
+			} catch (final Throwable t1) {
+				throw new RuntimeException("Failed to revert failed fullscreen toggle.", t1);
+			}
+		}
+	}
+	
+	
+	@Override
+	public Screenshot takeScreenshot()
+	{
+		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;
+	}
+	
+	
+	@Override
+	public boolean isCloseRequested()
+	{
+		return Display.isCloseRequested();
+	}
+	
+	
+	@Override
+	public void beginFrame()
+	{
+		// handle resize
+		if (Display.wasResized()) {
+			getEventBus().send(new ViewportChangeEvent(getSize()));
+		}
+		
+		if (fullscreenToggleRequested) {
+			fullscreenToggleRequested = false;
+			doToggleFullscreen();
+		}
+		
+		if (fullscreenSetRequested) {
+			fullscreenSetRequested = false;
+			doSetFullscreen(fullscreenSetState);
+		}
+		
+		glLoadIdentity();
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		fpsMeter.frame();
+	}
+	
+	
+	@Override
+	public void endFrame()
+	{
+		Display.update(false); // don't poll input devices
+		Display.sync(targetFps);
+	}
+	
+	
+	@Override
+	public void setSize(int width, int height)
+	{
+		try {
+			Display.setDisplayMode(windowDisplayMode = new DisplayMode(width, height));
+		} catch (LWJGLException e) {
+			throw new RuntimeException(e);
+		}
+	}
+	
+	
+	@Override
+	public void setTitle(String title)
+	{
+		Display.setTitle(title);
+	}
+	
+	
+	@Override
+	public void setVSync(boolean vsync)
+	{
+		Display.setVSyncEnabled(vsync);
+	}
+	
+	
+	@Override
+	public void setResizable(boolean resizable)
+	{
+		Display.setResizable(resizable);
+	}
+	
+	
+	@Override
+	public Rect getRect()
+	{
+		return rect;
+	}
+	
+	
+	@Override
+	public long getFps()
+	{
+		return fpsMeter.getFPS();
+	}
+	
+	
+	@Override
+	public Vect getCenter()
+	{
+		return rect.center();
+	}
+	
+	
+	@Override
+	public int getWidth()
+	{
+		return Display.getWidth();
+	}
+	
+	
+	@Override
+	public int getHeight()
+	{
+		return Display.getHeight();
+	}
+	
+	
+	@Override
+	public Vect getSize()
+	{
+		return screenSize;
+	}
+	
+}

src/mightypork/gamecore/backend/lwjgl/SlickLazyTexture.java

@@ -0,0 +1,142 @@
+package mightypork.gamecore.backend.lwjgl;
+
+
+import java.io.IOException;
+
+import mightypork.gamecore.resources.TextureBasedResource;
+import mightypork.gamecore.resources.textures.*;
+import mightypork.utils.annotations.Alias;
+import mightypork.utils.files.FileUtils;
+import mightypork.utils.logging.Log;
+import org.lwjgl.opengl.GL11;
+import org.newdawn.slick.opengl.Texture;
+import org.newdawn.slick.opengl.TextureLoader;
+
+
+/**
+ * Deferred texture
+ * 
+ * @author Ondřej Hruška (MightyPork)
+ */
+@Alias(name = "Texture")
+@TextureBasedResource
+public class SlickLazyTexture extends LazyTexture {
+	
+	private org.newdawn.slick.opengl.Texture backingTexture;
+	private boolean alpha;
+	private boolean alphal;
+	
+	/**
+	 * @param resourcePath resource path
+	 */
+	public SlickLazyTexture(String resourcePath) {
+		super(resourcePath);
+	}
+	
+	@Override
+	protected synchronized void loadResource(String path)
+	{
+		try {
+			final String ext = FileUtils.getExtension(path).toUpperCase();
+			
+			final Texture texture = TextureLoader.getTexture(ext, FileUtils.getResource(path), false, filter.num);
+			
+			if (texture == null) {
+				Log.w("Texture " + path + " could not be loaded.");
+			}
+			
+			backingTexture = texture;
+			
+		} catch (final IOException e) {
+			Log.e("Loading of texture " + path + " failed.", e);
+			throw new RuntimeException("Could not load texture " + path + ".", e);
+		}
+	}
+	
+	
+	@Override
+	public boolean hasAlpha()
+	{
+		if (!ensureLoaded()) return false;
+		
+		if (!alphal) {
+			alphal = true;
+			alpha = backingTexture.hasAlpha();
+		}
+		
+		return alpha;
+	}
+	
+	
+	@Override
+	public void bind()
+	{
+		if (!ensureLoaded()) return;
+		
+		//GL11.glEnable(GL11.GL_TEXTURE_2D);
+		
+		GL11.glBindTexture(GL11.GL_TEXTURE_2D, getTextureID());
+		
+		GL11.glTexEnvf(GL11.GL_TEXTURE_ENV, GL11.GL_TEXTURE_ENV_MODE, GL11.GL_MODULATE);
+		
+		GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, wrap.num);
+		GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, wrap.num);
+		
+		GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, filter.num);
+		GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, filter.num);
+	}
+	
+	
+	@Override
+	public int getImageHeight()
+	{
+		if (!ensureLoaded()) return 0;
+		
+		return backingTexture.getImageHeight();
+	}
+	
+	
+	@Override
+	public int getImageWidth()
+	{
+		if (!ensureLoaded()) return 0;
+		
+		return backingTexture.getImageWidth();
+	}
+	
+	
+	@Override
+	public float getHeight01()
+	{
+		if (!ensureLoaded()) return 0;
+		
+		return backingTexture.getHeight();
+	}
+	
+	
+	@Override
+	public float getWidth01()
+	{
+		if (!ensureLoaded()) return 0;
+		
+		return backingTexture.getWidth();
+	}
+	
+	
+	@Override
+	public void destroy()
+	{
+		if (!isLoaded()) return;
+		
+		backingTexture.release();
+	}
+	
+	
+	@Override
+	public int getTextureID()
+	{
+		if (!ensureLoaded()) return -1;
+		
+		return backingTexture.getTextureID();
+	}
+}

src/mightypork/gamecore/core/modules/App.java

@@ -0,0 +1,85 @@
+package mightypork.gamecore.core.modules;
+
+
+import mightypork.gamecore.backend.Backend;
+import mightypork.gamecore.render.RenderModule;
+
+
+/**
+ * Game base class & static subsystem access
+ * 
+ * @author MightyPork
+ */
+public class App {
+	
+	private static App runningInstance;
+	private static Backend backend;
+	
+	
+	public App() {
+		if (App.isInitialized()) throw new IllegalStateException("App already initialized");
+		
+		// store current instance in static field
+		App.runningInstance = this;
+	}
+	
+	
+	/**
+	 * Create app with given backend.
+	 * 
+	 * @param backend backend to use
+	 */
+	public void setBackend(Backend backend)
+	{
+		// store used backend in static field
+		App.backend = backend;
+		
+		// initialize the backend
+		App.backend.initialize();
+	}
+	
+	
+	/**
+	 * Throw error if app is not initialized
+	 */
+	protected static void assertInitialized()
+	{
+		if (!App.isInitialized()) throw new IllegalStateException("App is not initialized.");
+		if (backend == null) throw new IllegalStateException("No backend set!");
+	}
+	
+	
+	/**
+	 * Check whether the app is initialized (backend assigned).
+	 * 
+	 * @return is initialized
+	 */
+	public static boolean isInitialized()
+	{
+		return runningInstance != null;
+	}
+	
+	
+	/**
+	 * Get current backend
+	 * 
+	 * @return the backend
+	 */
+	public static Backend getBackend()
+	{
+		assertInitialized();
+		return backend;
+	}
+	
+	
+	/**
+	 * Get renderer instance from the backend
+	 * 
+	 * @return backend
+	 */
+	public static RenderModule gfx()
+	{
+		assertInitialized();
+		return backend.getRenderer();
+	}
+}

src/mightypork/gamecore/core/modules/BaseApp.java

@@ -10,6 +10,7 @@ import java.util.logging.Level;
 
 import javax.swing.JOptionPane;
 
+import mightypork.gamecore.backend.Backend;
 import mightypork.gamecore.core.WorkDir;
 import mightypork.gamecore.core.WorkDir.RouteSetup;
 import mightypork.gamecore.core.config.Config;
@@ -45,7 +46,7 @@ import mightypork.utils.math.algo.Move;
  * 
  * @author Ondřej Hruška (MightyPork)
  */
-public abstract class BaseApp implements AppAccess, UncaughtExceptionHandler {
+public abstract class BaseApp extends App implements AppAccess, UncaughtExceptionHandler {
 	
 	/**
 	 * Init options holder class
@@ -176,8 +177,8 @@ public abstract class BaseApp implements AppAccess, UncaughtExceptionHandler {
 	}
 	
 	
-	public BaseApp(File workdir, boolean singleInstance)
-	{
+	public BaseApp(File workdir, boolean singleInstance) {
+		
 		WorkDir.init(workdir);
 		
 		opt.sigleInstance = singleInstance;
@@ -240,7 +241,6 @@ public abstract class BaseApp implements AppAccess, UncaughtExceptionHandler {
 		org.newdawn.slick.util.Log.setLogSystem(new SlickLogRedirector(log));
 		writeLogHeader();
 		
-		
 		Log.i("=== Starting initialization sequence ===");
 		
 		// pre-init hook
@@ -367,7 +367,6 @@ public abstract class BaseApp implements AppAccess, UncaughtExceptionHandler {
 			
 		});
 		
-		
 		Ion.registerIndirect(254, new IonizerBinary<Move>() {
 			
 			@Override
@@ -478,7 +477,6 @@ public abstract class BaseApp implements AppAccess, UncaughtExceptionHandler {
 	 * Triggered when lock cannot be obtained.<br>
 	 * App should terminate gracefully.
 	 */
-	
 	protected void onLockError()
 	{
 		Log.e("Could not obtain lock file.\nOnly one instance can run at a time.");

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

@@ -1,9 +1,9 @@
 package mightypork.gamecore.gui.components.painters;
 
 
+import mightypork.gamecore.core.modules.App;
 import mightypork.gamecore.gui.components.BaseComponent;
 import mightypork.gamecore.gui.components.DynamicWidthComponent;
-import mightypork.gamecore.render.Render;
 import mightypork.gamecore.resources.textures.TxQuad;
 
 
@@ -29,7 +29,7 @@ public class ImagePainter extends BaseComponent implements DynamicWidthComponent
 	@Override
 	public void renderComponent()
 	{
-		Render.quadTextured(this, txQuad);
+		App.gfx().quad(this, txQuad);
 	}
 	
 	

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

@@ -1,8 +1,9 @@
 package mightypork.gamecore.gui.components.painters;
 
 
+import mightypork.gamecore.core.modules.App;
 import mightypork.gamecore.gui.components.BaseComponent;
-import mightypork.gamecore.render.Render;
+import mightypork.gamecore.render.Grad;
 import mightypork.utils.annotations.FactoryMethod;
 import mightypork.utils.math.color.Color;
 
@@ -27,10 +28,7 @@ public class QuadPainter extends BaseComponent {
 		return new QuadPainter(colorTop, colorTop, colorBottom, colorBottom);
 	}
 	
-	private final Color colorHMinVMin;
-	private final Color colorHMaxVMin;
-	private final Color colorHMaxVMax;
-	private final Color colorHMinVMax;
+	private final Grad grad;
 	
 	
 	/**
@@ -38,35 +36,27 @@ public class QuadPainter extends BaseComponent {
 	 * 
 	 * @param color
 	 */
-	public QuadPainter(Color color)
-	{
-		this.colorHMinVMin = color;
-		this.colorHMaxVMin = color;
-		this.colorHMaxVMax = color;
-		this.colorHMinVMax = color;
+	public QuadPainter(Color color) {
+		this.grad = new Grad(color, color, color, color);
 	}
 	
 	
 	/**
 	 * Painter with coloured vertices.
 	 * 
-	 * @param colorHMinVMin
-	 * @param colorHMaxVMin
-	 * @param colorHMaxVMax
-	 * @param colorHMinVMax
+	 * @param leftTop
+	 * @param rightTop
+	 * @param leftBottom
+	 * @param rightBottom
 	 */
-	public QuadPainter(Color colorHMinVMin, Color colorHMaxVMin, Color colorHMaxVMax, Color colorHMinVMax)
-	{
-		this.colorHMinVMin = colorHMinVMin;
-		this.colorHMaxVMin = colorHMaxVMin;
-		this.colorHMaxVMax = colorHMaxVMax;
-		this.colorHMinVMax = colorHMinVMax;
+	public QuadPainter(Color leftTop, Color rightTop, Color leftBottom, Color rightBottom) {
+		this.grad = new Grad(leftTop, rightTop, rightBottom, leftBottom);
 	}
 	
 	
 	@Override
 	public void renderComponent()
 	{
-		Render.quadColor(getRect(), colorHMinVMin, colorHMaxVMin, colorHMaxVMax, colorHMinVMax);
+		App.gfx().quad(getRect(), grad);
 	}
 }

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

@@ -1,10 +1,10 @@
 package mightypork.gamecore.gui.components.painters;
 
 
+import mightypork.gamecore.core.modules.App;
 import mightypork.gamecore.gui.AlignX;
 import mightypork.gamecore.gui.components.BaseComponent;
 import mightypork.gamecore.gui.components.DynamicWidthComponent;
-import mightypork.gamecore.render.Render;
 import mightypork.gamecore.resources.fonts.FontRenderer;
 import mightypork.gamecore.resources.fonts.GLFont;
 import mightypork.utils.math.color.Color;
@@ -39,38 +39,32 @@ public class TextPainter extends BaseComponent implements DynamicWidthComponent
 	/**
 	 * @param font font to use
 	 */
-	public TextPainter(GLFont font)
-	{
+	public TextPainter(GLFont font) {
 		this(font, AlignX.LEFT, RGB.WHITE);
 	}
 	
 	
-	public TextPainter(GLFont font, Color color, String text)
-	{
+	public TextPainter(GLFont font, Color color, String text) {
 		this(font, AlignX.LEFT, color, new StringWrapper(text));
 	}
 	
 	
-	public TextPainter(GLFont font, Color color, StringProvider text)
-	{
+	public TextPainter(GLFont font, Color color, StringProvider text) {
 		this(font, AlignX.LEFT, color, text);
 	}
 	
 	
-	public TextPainter(GLFont font, Color color)
-	{
+	public TextPainter(GLFont font, Color color) {
 		this(font, AlignX.LEFT, color, (StringProvider) null);
 	}
 	
 	
-	public TextPainter(GLFont font, AlignX align, Color color, String text)
-	{
+	public TextPainter(GLFont font, AlignX align, Color color, String text) {
 		this(font, align, color, new StringWrapper(text));
 	}
 	
 	
-	public TextPainter(GLFont font, AlignX align, Color color, StringProvider text)
-	{
+	public TextPainter(GLFont font, AlignX align, Color color, StringProvider text) {
 		this.font = new FontRenderer(font);
 		this.color = color;
 		this.align = align;
@@ -78,8 +72,7 @@ public class TextPainter extends BaseComponent implements DynamicWidthComponent
 	}
 	
 	
-	public TextPainter(GLFont font, AlignX align, Color color)
-	{
+	public TextPainter(GLFont font, AlignX align, Color color) {
 		this(font, align, color, (StringProvider) null);
 	}
 	
@@ -102,7 +95,7 @@ public class TextPainter extends BaseComponent implements DynamicWidthComponent
 		final Rect r = (shadow ? rect.move(shadowOffset.neg()) : rect).round();
 		font.draw(str, r, align, color);
 		
-		if (DEBUG_FONT_RENDER) Render.quadColor(r, RGB.PINK.withAlpha(0.4));
+		if (DEBUG_FONT_RENDER) App.gfx().quad(r, RGB.PINK.withAlpha(0.4));
 	}
 	
 	

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

@@ -1,6 +1,7 @@
 package mightypork.gamecore.gui.screens;
 
 
+import mightypork.gamecore.core.modules.App;
 import mightypork.gamecore.core.modules.AppAccess;
 import mightypork.gamecore.core.modules.AppSubModule;
 import mightypork.gamecore.gui.events.LayoutChangeEvent;
@@ -10,7 +11,6 @@ import mightypork.gamecore.input.KeyBindingPool;
 import mightypork.gamecore.input.KeyStroke;
 import mightypork.gamecore.input.KeyStroke.Edge;
 import mightypork.gamecore.render.DisplaySystem;
-import mightypork.gamecore.render.Render;
 import mightypork.gamecore.render.Renderable;
 import mightypork.utils.annotations.DefaultImpl;
 import mightypork.utils.math.constraints.rect.Rect;
@@ -33,8 +33,7 @@ public abstract class Screen extends AppSubModule implements Renderable, RectBou
 	/**
 	 * @param app app access
 	 */
-	public Screen(AppAccess app)
-	{
+	public Screen(AppAccess app) {
 		super(app);
 		
 		// disable events initially
@@ -123,14 +122,14 @@ public abstract class Screen extends AppSubModule implements Renderable, RectBou
 		if (!isActive()) return;
 		
 		if (needSetupViewport) {
-			Render.setupOrtho(DisplaySystem.getSize());
+			App.gfx().setupProjection(DisplaySystem.getSize());
 		}
 		
-		Render.pushState();
+		App.gfx().pushState();
 		
 		renderScreen();
 		
-		Render.popState();
+		App.gfx().popState();
 	}
 	
 	

src/mightypork/gamecore/render/DisplaySystem.java

@@ -5,6 +5,7 @@ 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;
@@ -26,6 +27,7 @@ import org.lwjgl.opengl.DisplayMode;
  * 
  * @author Ondřej Hruška (MightyPork)
  */
+@Deprecated
 public class DisplaySystem extends AppModule implements RectBound {
 	
 	private DisplayMode windowDisplayMode;
@@ -161,7 +163,7 @@ public class DisplaySystem extends AppModule implements RectBound {
 	 * 
 	 * @return screenshot object
 	 */
-	public static Screenshot prepareScreenshot()
+	public static AwtScreenshot prepareScreenshot()
 	{
 		glReadBuffer(GL_FRONT);
 		final int width = Display.getWidth();
@@ -170,7 +172,7 @@ public class DisplaySystem extends AppModule implements RectBound {
 		final ByteBuffer buffer = BufferUtils.createByteBuffer(width * height * bpp);
 		glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
 		
-		final Screenshot sc = new Screenshot(width, height, bpp, buffer);
+		final AwtScreenshot sc = new AwtScreenshot(width, height, bpp, buffer);
 		
 		return sc;
 	}

src/mightypork/gamecore/render/Grad.java

@@ -0,0 +1,31 @@
+package mightypork.gamecore.render;
+
+
+import mightypork.utils.math.color.Color;
+
+
+/**
+ * Linear gradient (each vertex can have different color)
+ * 
+ * @author MightyPork
+ */
+public class Grad {
+	
+	public final Color leftTop, rightTop, rightBottom, leftBottom;
+	
+	
+	/**
+	 * Create a gradient
+	 * 
+	 * @param leftTop left top color
+	 * @param rightTop right top color
+	 * @param rightBottom right bottom color
+	 * @param leftBottom left bottom color
+	 */
+	public Grad(Color leftTop, Color rightTop, Color rightBottom, Color leftBottom) {
+		this.leftTop = leftTop;
+		this.rightTop = rightTop;
+		this.rightBottom = rightBottom;
+		this.leftBottom = leftBottom;
+	}
+}

src/mightypork/gamecore/render/GradH.java

@@ -0,0 +1,17 @@
+package mightypork.gamecore.render;
+
+
+import mightypork.utils.math.color.Color;
+
+
+/**
+ * Linear horizontal gradient
+ * 
+ * @author MightyPork
+ */
+public class GradH extends Grad {
+	
+	public GradH(Color left, Color right) {
+		super(left, right, right, left);
+	}
+}

src/mightypork/gamecore/render/GradV.java

@@ -0,0 +1,17 @@
+package mightypork.gamecore.render;
+
+
+import mightypork.utils.math.color.Color;
+
+
+/**
+ * Linear vertical gradient
+ * 
+ * @author MightyPork
+ */
+public class GradV extends Grad {
+	
+	public GradV(Color top, Color bottom) {
+		super(top, top, bottom, bottom);
+	}
+}

src/mightypork/gamecore/render/Render.java

@@ -6,7 +6,7 @@ import static org.lwjgl.opengl.GL11.*;
 import java.io.IOException;
 
 import mightypork.gamecore.resources.textures.FilterMode;
-import mightypork.gamecore.resources.textures.GLTexture;
+import mightypork.gamecore.resources.textures.ITexture;
 import mightypork.gamecore.resources.textures.TxQuad;
 import mightypork.utils.files.FileUtils;
 import mightypork.utils.logging.Log;
@@ -27,6 +27,7 @@ import org.newdawn.slick.opengl.TextureLoader;
  * 
  * @author Ondřej Hruška (MightyPork)
  */
+@Deprecated
 public class Render {
 	
 	public static final VectConst AXIS_X = Vect.make(1, 0, 0);
@@ -525,7 +526,7 @@ public class Render {
 	}
 	
 	
-	public static void enterBatchTexturedQuadMode(GLTexture texture)
+	public static void enterBatchTexturedQuadMode(ITexture texture)
 	{
 		texture.bind();
 		glBegin(GL11.GL_QUADS);

src/mightypork/gamecore/render/RenderModule.java

@@ -0,0 +1,420 @@
+package mightypork.gamecore.render;
+
+
+import mightypork.gamecore.backend.BackendModule;
+import mightypork.gamecore.resources.textures.LazyTexture;
+import mightypork.gamecore.resources.textures.TxQuad;
+import mightypork.utils.eventbus.BusAccess;
+import mightypork.utils.math.color.Color;
+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 RenderModule extends BackendModule {
+	
+	public RenderModule(BusAccess busAccess) {
+		super(busAccess);
+	}
+	
+	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
+	 * 
+	 * @param screenSize current viewport size
+	 */
+	public abstract void setupProjection(Vect screenSize);
+	
+	
+	/**
+	 * Get backend-flavoured lazy texture
+	 * 
+	 * @param path path to texture
+	 * @return the lazy texture
+	 */
+	public abstract LazyTexture 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);
+	
+	
+	/**
+	 * Create a main window
+	 */
+	public abstract void createDisplay();
+	
+	
+	/**
+	 * Set fullscreen
+	 * 
+	 * @param fs true for fullscreen
+	 */
+	public abstract void setFullscreen(boolean fs);
+	
+	
+	/**
+	 * Request fullscreen toggle (eg. at the end of render frame)
+	 */
+	public abstract void switchFullscreen();
+	
+	
+	/**
+	 * Get fullscreen state
+	 * 
+	 * @return is fullscreen
+	 */
+	public abstract boolean isFullscreen();
+	
+	
+	/**
+	 * Take screenshot (expensive processing should be done in separate thread
+	 * when screenshot is saved).
+	 * 
+	 * @return screenshot object
+	 */
+	public abstract Screenshot takeScreenshot();
+	
+	
+	/**
+	 * FIXME This should be moved to inout module
+	 * 
+	 * @return true if close was requested recently (i.e. click on cross)
+	 */
+	public abstract boolean isCloseRequested();
+	
+	
+	/**
+	 * 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 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 Vect 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();
+	
+	
+	/**
+	 * @return screen width
+	 */
+	public abstract int getWidth();
+	
+	
+	/**
+	 * @return screen height
+	 */
+	public abstract int getHeight();
+	
+	
+	/**
+	 * Get screen size. Should always return the same Vect instance.
+	 * 
+	 * @return size
+	 */
+	public abstract Vect getSize();
+}

src/mightypork/gamecore/render/Screenshot.java

@@ -1,81 +1,33 @@
 package mightypork.gamecore.render;
 
 
-import java.awt.image.BufferedImage;
 import java.io.File;
 import java.io.IOException;
-import java.nio.ByteBuffer;
-
-import javax.imageio.ImageIO;
 
 
 /**
- * Screenshot object, can be used to extract image or write to file.<br>
- * Screenshot, once taken, can be safely processed in separate thread.
+ * <p>
+ * Screenshot object, can be used to save image to file.
+ * </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 Ondřej Hruška (MightyPork)
+ * @author MightyPork
  */
-public class Screenshot {
-	
-	private final int width;
-	private final int height;
-	private final int bpp;
-	private final ByteBuffer bytes;
-	private BufferedImage image;
-	
+public interface Screenshot {
 	
 	/**
-	 * @param width image width
-	 * @param height image height
-	 * @param bpp bits per pixel (typically 4)
-	 * @param buffer
-	 */
-	public Screenshot(int width, int height, int bpp, ByteBuffer buffer)
-	{
-		this.width = width;
-		this.height = height;
-		this.bpp = bpp;
-		this.bytes = buffer;
-	}
-	
-	
-	/**
-	 * Extract to an image.<br>
-	 * Subsequent calls will use a cached value.
-	 * 
-	 * @return image
-	 */
-	public BufferedImage getImage()
-	{
-		if (image != null) return image;
-		
-		image = new BufferedImage(this.width, this.height, BufferedImage.TYPE_INT_RGB);
-		
-		// convert to a buffered image
-		for (int x = 0; x < this.width; x++) {
-			for (int y = 0; y < this.height; y++) {
-				final int i = (x + (this.width * y)) * this.bpp;
-				final int r = this.bytes.get(i) & 0xFF;
-				final int g = this.bytes.get(i + 1) & 0xFF;
-				final int b = this.bytes.get(i + 2) & 0xFF;
-				image.setRGB(x, this.height - (y + 1), (0xFF << 24) | (r << 16) | (g << 8) | b);
-			}
-		}
-		
-		return image;
-	}
-	
-	
-	/**
-	 * Save to a file.<br>
-	 * Cached value is used if any.
+	 * 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
 	 */
-	public void save(File file) throws IOException
-	{
-		file.getParentFile().mkdirs();
-		ImageIO.write(getImage(), "PNG", file);
-	}
+	void save(File file) throws IOException;
 }

src/mightypork/gamecore/render/TaskTakeScreenshot.java

@@ -4,22 +4,30 @@ package mightypork.gamecore.render;
 import java.io.File;
 import java.io.IOException;
 
+import mightypork.gamecore.backend.lwjgl.AwtScreenshot;
 import mightypork.gamecore.core.WorkDir;
+import mightypork.gamecore.core.modules.App;
 import mightypork.utils.Support;
 import mightypork.utils.logging.Log;
 
 import org.newdawn.slick.opengl.GLUtils;
 
 
+/**
+ * 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;
 	
 	
-	public TaskTakeScreenshot()
-	{
+	public TaskTakeScreenshot() {
 		GLUtils.checkGLContext();
-		scr = DisplaySystem.prepareScreenshot();
+		scr = App.gfx().takeScreenshot();
 	}
 	
 	

src/mightypork/gamecore/resources/Res.java

@@ -7,7 +7,7 @@ import mightypork.gamecore.resources.audio.players.EffectPlayer;
 import mightypork.gamecore.resources.audio.players.LoopPlayer;
 import mightypork.gamecore.resources.fonts.FontRegistry;
 import mightypork.gamecore.resources.fonts.GLFont;
-import mightypork.gamecore.resources.textures.GLTexture;
+import mightypork.gamecore.resources.textures.ITexture;
 import mightypork.gamecore.resources.textures.TextureRegistry;
 import mightypork.gamecore.resources.textures.TxQuad;
 import mightypork.gamecore.resources.textures.TxSheet;
@@ -43,7 +43,7 @@ public final class Res {
 	}
 	
 	
-	public static GLTexture getTexture(String key)
+	public static ITexture getTexture(String key)
 	{
 		return textures.getTexture(key);
 	}

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

@@ -1,8 +1,8 @@
 package mightypork.gamecore.resources.fonts;
 
 
+import mightypork.gamecore.core.modules.App;
 import mightypork.gamecore.gui.AlignX;
-import mightypork.gamecore.render.Render;
 import mightypork.utils.math.color.Color;
 import mightypork.utils.math.color.pal.RGB;
 import mightypork.utils.math.constraints.rect.Rect;
@@ -105,16 +105,16 @@ public class FontRenderer {
 	 */
 	public void draw(String text, Vect pos, double height, Color color)
 	{
-		Render.pushMatrix();
+		App.gfx().pushGeometry();
 		
 		final double sc = getScale(height);
 		
-		Render.translate(pos.x(), pos.y());
-		Render.scaleXY(sc);
+		App.gfx().translate(pos.x(), pos.y());
+		App.gfx().scaleXY(sc);
 		
 		font.draw(text, color);
 		
-		Render.popMatrix();
+		App.gfx().popGeometry();
 	}
 	
 	

src/mightypork/gamecore/resources/fonts/impl/TextureBackedFont.java

@@ -379,8 +379,6 @@ public class TextureBackedFont implements GLFont {
 	{
 		GLUtils.checkGLContext();
 		
-		LazyTexture.lastBind = null; // needs rebind.
-		
 		// PUSH
 		glPushAttrib(GL_ENABLE_BIT);
 		

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

@@ -10,7 +10,7 @@ import mightypork.utils.math.constraints.rect.Rect;
  * 
  * @author Ondřej Hruška (MightyPork)
  */
-public interface GLTexture extends Destroyable {
+public interface ITexture extends Destroyable {
 	
 	/**
 	 * Set filter for scaling

src/mightypork/gamecore/resources/textures/LazyTexture.java

@@ -1,38 +1,29 @@
 package mightypork.gamecore.resources.textures;
 
 
-import mightypork.gamecore.render.Render;
 import mightypork.gamecore.resources.BaseLazyResource;
 import mightypork.gamecore.resources.TextureBasedResource;
 import mightypork.utils.annotations.Alias;
 import mightypork.utils.math.constraints.rect.Rect;
 
-import org.lwjgl.opengl.GL11;
-
 
 /**
- * Deferred texture
+ * Deferred texture (to be extended by backend texture)
  * 
  * @author Ondřej Hruška (MightyPork)
  */
 @Alias(name = "Texture")
 @TextureBasedResource
-public class LazyTexture extends BaseLazyResource implements GLTexture {
+public abstract class LazyTexture extends BaseLazyResource implements ITexture {
 	
-	public static LazyTexture lastBind = null;
-	
-	private org.newdawn.slick.opengl.Texture backingTexture;
-	private FilterMode filter = FilterMode.NEAREST;
-	private WrapMode wrap = WrapMode.CLAMP;
-	private boolean alpha;
-	private boolean alphal;
+	protected FilterMode filter = FilterMode.NEAREST;
+	protected WrapMode wrap = WrapMode.CLAMP;
 	
 	
 	/**
 	 * @param resourcePath resource path
 	 */
-	public LazyTexture(String resourcePath)
-	{
+	public LazyTexture(String resourcePath) {
 		super(resourcePath);
 	}
 	
@@ -44,105 +35,6 @@ public class LazyTexture extends BaseLazyResource implements GLTexture {
 	}
 	
 	
-	@Override
-	protected synchronized void loadResource(String path)
-	{
-		backingTexture = Render.loadSlickTexture(path, filter);
-	}
-	
-	
-	@Override
-	public boolean hasAlpha()
-	{
-		if (!ensureLoaded()) return false;
-		
-		if (!alphal) {
-			alphal = true;
-			alpha = backingTexture.hasAlpha();
-		}
-		
-		return alpha;
-	}
-	
-	
-	@Override
-	public void bind()
-	{
-		if (!ensureLoaded()) return;
-		
-		GL11.glEnable(GL11.GL_TEXTURE_2D);
-		
-		if (lastBind != this) {
-			lastBind = this;
-			
-			GL11.glBindTexture(GL11.GL_TEXTURE_2D, getTextureID());
-			
-			GL11.glTexEnvf(GL11.GL_TEXTURE_ENV, GL11.GL_TEXTURE_ENV_MODE, GL11.GL_MODULATE);
-			
-			GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, wrap.num);
-			GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, wrap.num);
-			
-			GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, filter.num);
-			GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, filter.num);
-			
-		}
-	}
-	
-	
-	@Override
-	public int getImageHeight()
-	{
-		if (!ensureLoaded()) return 0;
-		
-		return backingTexture.getImageHeight();
-	}
-	
-	
-	@Override
-	public int getImageWidth()
-	{
-		if (!ensureLoaded()) return 0;
-		
-		return backingTexture.getImageWidth();
-	}
-	
-	
-	@Override
-	public float getHeight01()
-	{
-		if (!ensureLoaded()) return 0;
-		
-		return backingTexture.getHeight();
-	}
-	
-	
-	@Override
-	public float getWidth01()
-	{
-		if (!ensureLoaded()) return 0;
-		
-		return backingTexture.getWidth();
-	}
-	
-	
-	@Override
-	public void destroy()
-	{
-		if (!isLoaded()) return;
-		
-		backingTexture.release();
-	}
-	
-	
-	@Override
-	public int getTextureID()
-	{
-		if (!ensureLoaded()) return -1;
-		
-		return backingTexture.getTextureID();
-	}
-	
-	
 	@Override
 	public void setFilter(FilterMode filterMin)
 	{

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

@@ -11,14 +11,14 @@ import mightypork.utils.math.constraints.rect.Rect;
  */
 public class QuadGrid {
 	
-	private final GLTexture tx;
+	private final ITexture tx;
 	private final int txHeight;
 	private final int txWidth;
 	private final double tileW;
 	private final double tileH;
 	
 	
-	public QuadGrid(GLTexture tx, int tilesX, int tilesY)
+	public QuadGrid(ITexture tx, int tilesX, int tilesY)
 	{
 		this.tx = tx;
 		this.txWidth = tilesX;

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

@@ -4,6 +4,7 @@ package mightypork.gamecore.resources.textures;
 import java.util.HashMap;
 import java.util.Map;
 
+import mightypork.gamecore.core.modules.App;
 import mightypork.gamecore.core.modules.AppAccess;
 import mightypork.gamecore.core.modules.AppAccessAdapter;
 import mightypork.gamecore.resources.ResourceLoadRequest;
@@ -19,7 +20,7 @@ import mightypork.utils.math.constraints.rect.Rect;
  */
 public class TextureRegistry extends AppAccessAdapter {
 	
-	private final Map<String, GLTexture> textures = new HashMap<>();
+	private final Map<String, ITexture> textures = new HashMap<>();
 	private final Map<String, TxSheet> sheets = new HashMap<>();
 	
 	
@@ -41,7 +42,7 @@ public class TextureRegistry extends AppAccessAdapter {
 	 * @param wrap
 	 * @return texture reference
 	 */
-	public GLTexture addTexture(String resourcePath, FilterMode filter, WrapMode wrap)
+	public ITexture addTexture(String resourcePath, FilterMode filter, WrapMode wrap)
 	{
 		return addTexture(resourcePath, resourcePath, filter, wrap);
 	}
@@ -57,11 +58,11 @@ public class TextureRegistry extends AppAccessAdapter {
 	 * @param wrap
 	 * @return texture reference
 	 */
-	public GLTexture addTexture(String key, String resourcePath, FilterMode filter, WrapMode wrap)
+	public ITexture addTexture(String key, String resourcePath, FilterMode filter, WrapMode wrap)
 	{
 		if (key != null) if (textures.containsKey(key)) throw new KeyAlreadyExistsException();
 		
-		final LazyTexture texture = new LazyTexture(resourcePath);
+		final LazyTexture texture = App.gfx().getLazyTexture(resourcePath);
 		texture.setFilter(filter);
 		texture.setWrap(wrap);
 		
@@ -118,14 +119,14 @@ public class TextureRegistry extends AppAccessAdapter {
 	
 	
 	/**
-	 * Get a loaded {@link GLTexture}
+	 * Get a loaded {@link ITexture}
 	 * 
 	 * @param key texture key
 	 * @return the texture
 	 */
-	public GLTexture getTexture(String key)
+	public ITexture getTexture(String key)
 	{
-		final GLTexture tx = textures.get(key);
+		final ITexture tx = textures.get(key);
 		
 		if (tx == null) throw new RuntimeException("There's no texture called \"" + key + "\"!");
 		

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

@@ -13,7 +13,7 @@ import mightypork.utils.math.constraints.rect.RectConst;
 public class TxQuad {
 	
 	/** The texture */
-	public final GLTexture tx;
+	public final ITexture tx;
 	/** Coords in texture (0-1) */
 	public final RectConst uvs;
 	
@@ -31,7 +31,7 @@ public class TxQuad {
 	 * @param heightPx area height (0-1)
 	 * @return new TxQuad
 	 */
-	public static TxQuad fromSizePx(GLTexture tx, double xPx, double yPx, double widthPx, double heightPx)
+	public static TxQuad fromSizePx(ITexture tx, double xPx, double yPx, double widthPx, double heightPx)
 	{
 		final double w = tx.getImageWidth();
 		final double h = tx.getImageHeight();
@@ -50,7 +50,7 @@ public class TxQuad {
 	 * @param height area height (0-1)
 	 * @return new TxQuad
 	 */
-	public static TxQuad fromSize(GLTexture tx, double x1, double y1, double width, double height)
+	public static TxQuad fromSize(ITexture tx, double x1, double y1, double width, double height)
 	{
 		return new TxQuad(tx, x1, y1, x1 + width, y1 + height);
 	}
@@ -65,7 +65,7 @@ public class TxQuad {
 	 * @param x2 right bottom X (0-1)
 	 * @param y2 right bottom Y (0-1)
 	 */
-	public TxQuad(GLTexture tx, double x1, double y1, double x2, double y2)
+	public TxQuad(ITexture tx, double x1, double y1, double x2, double y2)
 	{
 		this(tx, Rect.make(x1, y1, x2, y2));
 	}
@@ -75,7 +75,7 @@ public class TxQuad {
 	 * @param tx Texture
 	 * @param uvs Rect of texture UVs (0-1); will be frozen.
 	 */
-	public TxQuad(GLTexture tx, Rect uvs)
+	public TxQuad(ITexture tx, Rect uvs)
 	{
 		this.tx = tx;
 		this.uvs = uvs.freeze();

src/mightypork/rogue/RogueApp.java

@@ -3,6 +3,7 @@ package mightypork.rogue;
 
 import java.io.File;
 
+import mightypork.gamecore.backend.lwjgl.LwjglBackend;
 import mightypork.gamecore.core.config.Config;
 import mightypork.gamecore.core.events.MainLoopRequest;
 import mightypork.gamecore.core.events.ShudownRequest;
@@ -45,6 +46,8 @@ public final class RogueApp extends BaseApp implements ViewportChangeListener, S
 	{
 		super(workdir, singleInstance);
 		
+		setBackend(new LwjglBackend(this));
+		
 		AppInitOptions opt = getInitOptions();
 		
 		opt.addRoutes(new RogueRoutes());

src/mightypork/rogue/RogueResources.java

@@ -7,7 +7,7 @@ import mightypork.gamecore.resources.fonts.FontRegistry;
 import mightypork.gamecore.resources.fonts.Glyphs;
 import mightypork.gamecore.resources.fonts.impl.LazyFont;
 import mightypork.gamecore.resources.textures.FilterMode;
-import mightypork.gamecore.resources.textures.GLTexture;
+import mightypork.gamecore.resources.textures.ITexture;
 import mightypork.gamecore.resources.textures.QuadGrid;
 import mightypork.gamecore.resources.textures.TextureRegistry;
 import mightypork.gamecore.resources.textures.WrapMode;
@@ -76,7 +76,7 @@ public class RogueResources implements ResourceSetup {
 	@Override
 	public void addTextures(TextureRegistry textures)
 	{
-		GLTexture texture;
+		ITexture texture;
 		QuadGrid grid;
 		
 		// gui