From 9edf5074230d714b5a25ded5652877a1bac46d1e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Hru=C5=A1ka?= <ondra@ondrovo.com>
Date: Sun, 12 Nov 2017 17:19:46 +0100
Subject: [PATCH] initial work

---
 main.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 main.c

diff --git a/main.c b/main.c
new file mode 100644
index 0000000..665cb5e
--- /dev/null
+++ b/main.c
@@ -0,0 +1,100 @@
+#include <X11/Xlib.h>
+#include <X11/X.h>
+#include <X11/Xutil.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+
+typedef struct RGB_struct {
+  uint8_t b;
+  uint8_t g;
+  uint8_t r;
+} RGB;
+
+int main()
+{
+  Display *display = XOpenDisplay(NULL);
+  Window root = DefaultRootWindow(display);
+
+  XWindowAttributes gwa;
+
+  XGetWindowAttributes(display, root, &gwa);
+  uint32_t width = gwa.width;
+  uint32_t height = gwa.height;
+
+  // The first image, to measure the screen
+  XImage *image = XGetImage(display, root, 0, 0, width, height, AllPlanes, ZPixmap);   
+  uint8_t array[width * height * 3];
+  const uint32_t red_mask = image->red_mask;
+  const uint32_t green_mask = image->green_mask;
+  const uint32_t blue_mask = image->blue_mask;
+  
+  printf("mask: %p %p %p\nbyte_order: %d\nunit: %d\nbit_order: %d\npad: %d\ndepth: %d\nBPL: %d\nbPPx: %d\n", 
+         red_mask, green_mask, blue_mask, image->byte_order, image->bitmap_unit, 
+         image->bitmap_bit_order, image->bitmap_pad, image->depth, image->bytes_per_line, image->bits_per_pixel);
+
+  union Color {
+    uint32_t hex;
+    RGB rgb;
+    
+    struct {
+      uint8_t b;
+      uint8_t g;
+      uint8_t r;
+    };
+  };
+  
+  const uint32_t xnum = 32;
+  const uint32_t ynum = 24;
+  const uint32_t xstep = width/xnum;
+  const uint32_t ystep = height/ynum;
+  
+  union Color *C;
+  while (XGetSubImage(display, root, 0, 0, width, height, AllPlanes, ZPixmap, image, 0, 0)) {
+    //color.hex = XGetPixel(image, 40,40);
+    
+    printf("\033[2J\033[H");
+    for (int i = 0; i < ynum; i++) {
+      printf("\n");
+      for (int j = 0; j < xnum; j++) {
+        C = ((union Color*)image->data + i*ystep*width + j*xstep);
+        printf("\x1b[48;2;%d;%d;%dm  \x1b[m", C->r, C->g, C->b);
+      }
+    }
+    
+    usleep(50000);
+  }
+
+  return 0;
+}
+
+#if 0
+typedef struct _XImage {
+	int width, height;		/* size of image */
+	int xoffset;			/* number of pixels offset in X direction */
+	int format;			/* XYBitmap, XYPixmap, ZPixmap */
+	char *data;			/* pointer to image data */
+	int byte_order;			/* data byte order, LSBFirst, MSBFirst */
+	int bitmap_unit;		/* quant. of scanline 8, 16, 32 */
+	int bitmap_bit_order;		/* LSBFirst, MSBFirst */
+	int bitmap_pad;			/* 8, 16, 32 either XY or ZPixmap */
+	int depth;			/* depth of image */
+	int bytes_per_line;		/* accelerator to next scanline */
+	int bits_per_pixel;		/* bits per pixel (ZPixmap) */
+	unsigned long red_mask;		/* bits in z arrangement */
+	unsigned long green_mask;
+	unsigned long blue_mask;
+	XPointer obdata;		/* hook for the object routines to hang on */
+	struct funcs {			/* image manipulation routines */
+		struct _XImage *(*create_image)();
+		int (*destroy_image)();
+		unsigned long (*get_pixel)();
+		int (*put_pixel)();
+		struct _XImage *(*sub_image)();
+		int (*add_pixel)();
+	} f;
+} XImage;
+#endif
+