#include <X11/Xlib.h>

  #include <stdio.h>

  #include <stdlib.h>		/* getenv(), etc. */
  #include <unistd.h>		/* sleep(), etc.  */

  Window create_simple_window(Display* display, int width, int height, int x, int y)
  {
    int screen_num = DefaultScreen(display);
    int win_border_width = 2;
    Window win;
  
    win = XCreateSimpleWindow(display, RootWindow(display, screen_num), x, y, width, height, win_border_width, BlackPixel(display, screen_num), WhitePixel(display, screen_num));

    XMapWindow(display, win);
    XFlush(display);

    return win;
  }

  GC create_gc(Display* display, Window win, int reverse_video)

  {

    GC gc;
    unsigned long valuemask = 0;		/* which values in 'values' to  */
  					/* check when creating the GC.  */
    XGCValues values;			/* initial values for the GC.   */
    unsigned int line_width = 2;		/* line width for the GC.       */
    int line_style = LineSolid;		/* style for lines drawing and  */
    int cap_style = CapButt;		/* style of the line's edje and */
    int join_style = JoinBevel;		/*  joined lines.		*/
    int screen_num = DefaultScreen(display);
  
    gc = XCreateGC(display, win, valuemask, &values);
    if (gc < 0) {
  	fprintf(stderr, "XCreateGC: \n");
    }
  
    if (reverse_video)
    {
      XSetForeground(display, gc, WhitePixel(display, screen_num));
      XSetBackground(display, gc, BlackPixel(display, screen_num));
    }
    else
    {
      XSetForeground(display, gc, BlackPixel(display, screen_num));
      XSetBackground(display, gc, WhitePixel(display, screen_num));
    }
  
    XSetLineAttributes(display, gc, line_width, line_style, cap_style, join_style);
    XSetFillStyle(display, gc, FillSolid);
  
    return gc;
  }

  int main(int argc, char* argv[])
  {
    Display* display;		/* pointer to X Display structure.           */
    int screen_num;		/* number of screen to place the window on.  */
    Window win;			/* pointer to the newly created window.      */
    unsigned int display_width,
                 display_height;	/* height and width of the X display.        */
    unsigned int width, height;	/* height and width for the new window.      */
    char *display_name = getenv("DISPLAY");  /* address of the X display.      */
    GC gc;			/* GC (graphics context) used for drawing    */
  				/*  in our window.			     */
    Colormap screen_colormap;     /* color map to use for allocating colors.   */
    XColor red, brown, blue, yellow, green;
  				/* used for allocation of the given color    */
  				/* map entries.                              */
    Status rc;			/* return status of various Xlib functions.  */
  	int initOffsetBMP;
  	XColor col;

    display = XOpenDisplay(display_name);
    if (display == NULL) {
      fprintf(stderr, "%s: cannot connect to X server '%s'\n",
              argv[0], display_name);
      exit(1);
    }
  
    screen_num = DefaultScreen(display);
    display_width = DisplayWidth(display, screen_num);
    display_height = DisplayHeight(display, screen_num);
  
    width = display_width;
    height = display_height;
    printf("window width - '%d'; height - '%d'\n", width, height);
  
    win = create_simple_window(display, width, height, 0, 0);
  
    gc = create_gc(display, win, 0);
    XSync(display, False);
    screen_colormap = DefaultColormap(display, DefaultScreen(display));
  
    rc = XAllocNamedColor(display, screen_colormap, "red", &red, &red);
    if (rc == 0) {
      fprintf(stderr, "XAllocNamedColor - failed to allocated 'red' color.\n");
      exit(1);
    }
    rc = XAllocNamedColor(display, screen_colormap, "brown", &brown, &brown);
    if (rc == 0) {
      fprintf(stderr, "XAllocNamedColor - failed to allocated 'brown' color.\n");
      exit(1);
    }
    rc = XAllocNamedColor(display, screen_colormap, "blue", &blue, &blue);
    if (rc == 0) {
      fprintf(stderr, "XAllocNamedColor - failed to allocated 'blue' color.\n");
      exit(1);
    }
    rc = XAllocNamedColor(display, screen_colormap, "yellow", &yellow, &yellow);
    if (rc == 0) {
      fprintf(stderr, "XAllocNamedColor - failed to allocated 'yellow' color.\n");
      exit(1);
    }
    rc = XAllocNamedColor(display, screen_colormap, "green", &green, &green);
    if (rc == 0) {
      fprintf(stderr, "XAllocNamedColor - failed to allocated 'green' color.\n");
      exit(1);
    }
    
    /* draw one pixel near each corner of the window */
    /* draw the pixels in a red color. */
    XSetForeground(display, gc, red.pixel);
    XDrawPoint(display, win, gc, 5, 5);
    XDrawPoint(display, win, gc, 5, height-5);
    XDrawPoint(display, win, gc, width-5, 5);
    XDrawPoint(display, win, gc, width-5, height-5);

  
  	FILE* home = NULL;
  	char buffer[4];
  	home = fopen("home.bmp", "r");
  	if(home == NULL)
  		return 0;
  
  	fseek(home, 0x0A, SEEK_SET);
  	buffer[0] = getc(home);
  	buffer[1] = getc(home);
  	buffer[2] = getc(home);
  	buffer[3] = getc(home);
  	printf("Pixel array offset %02x %02x %02x %02x\n", buffer[0], buffer[1], buffer[2], buffer[3]);

  	initOffsetBMP = buffer[0] + (buffer[1] >> 8) + (buffer[2] >> 16) + (buffer[3] >> 24);

  
  	fseek(home, 0x12, SEEK_SET);

  	buffer[0] = getc(home);
  	buffer[1] = getc(home);
  	buffer[2] = getc(home);
  	buffer[3] = getc(home);
  	printf("Width %02x %02x %02x %02x\n", buffer[0], buffer[1], buffer[2], buffer[3]);

  
  	//fseek(home, 0x12, SEEK_SET);

  	buffer[0] = getc(home);
  	buffer[1] = getc(home);
  	buffer[2] = getc(home);
  	buffer[3] = getc(home);
  	printf("Height %02x %02x %02x %02x\n", buffer[0], buffer[1], buffer[2], buffer[3]);

  
  	fseek(home, 0x1C, SEEK_SET);

  	buffer[0] = getc(home);
  	buffer[1] = getc(home);
  	printf("Bits Per Pixel %02x %02x\n", buffer[0], buffer[1]);

  
  	if(buffer[1] != 0 || buffer[0] != 0x18)
  	{
  		printf("Could not read BMP\n");
  		return 1;
  	}
  
  

  	fseek(home, initOffsetBMP, SEEK_SET);

  	col.flags= DoRed | DoGreen | DoBlue;

  	int i;
  	for(i=0; i<76800; i++)
  	{
  		col.red = buffer[2] * 257;
  		col.green = buffer[1] * 257;
  		col.blue = buffer[0] * 257;
  
  		if(XAllocColor(display, screen_colormap, &col) == 0)
  			printf("Failed to allocate color\n");

  		buffer[0] = getc(home);
  		buffer[1] = getc(home);
  		buffer[2] = getc(home);
  		printf("Alloc X %03d Y %03d R %02x G %02x B %02x\n", i%width, i/width, buffer[0], buffer[1], buffer[2]);
  	}
  
  
  	fseek(home, initOffsetBMP, SEEK_SET);
  	
  	for(i=0; i<76800; i++)
  	{
  		col.red = buffer[2] * 257;
  		col.green = buffer[1] * 257;
  		col.blue = buffer[0] * 257;
  

  		if(XSetForeground(display, gc, col.pixel) == 0)
  			printf("Failed to set foreground\n");
  		if(XDrawPoint(display,win,gc,i%width,height-1-(i/width)) == 0)
  			printf("Failed to draw point\n");
  		buffer[0] = getc(home);
  		buffer[1] = getc(home);
  		buffer[2] = getc(home);

  		printf("Disp X %03d Y %03d R %02x G %02x B %02x\n", i%width, i/width, buffer[0], buffer[1], buffer[2]);

  	}

    /* draw two intersecting lines, one horizontal and one vertical, */
    /* which intersect at point "50,100".                            */
    /* draw the line in a brown color. */
    //XSetForeground(display, gc, brown.pixel);
    //XDrawLine(display, win, gc, 50, 0, 50, 200);
    //XDrawLine(display, win, gc, 0, 100, 200, 100);
  
    /* flush all pending requests to the X server. */
    XFlush(display);
  
    /* make a delay for a short period. */
    sleep(4);
  
    /* close the connection to the X server. */
    XCloseDisplay(display);
    return(0);
  }