#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <X11/Xlib.h>
#include <X11/keysymdef.h>
#include <X11/extensions/Xrender.h>

int
main (int argc,
	  char** argv)
{
	Display* pDisplay = NULL;
	XEvent event;
	Bool bKeepGoing = True;
	Bool bGotEvent = False;
	int iEventBase;
	int iErrorBase;
	int iMajorVersion;
	int iMinorVersion;
	XSetWindowAttributes values;
	Window window;
	XRenderPictFormat* pPictFormat = NULL;
	XRenderPictureAttributes pictAttribs;
	XRenderColor colorRed = {0xffff, 0x000, 0x000, 0x7fff};
	XRenderColor colorGreen = {0x000, 0xffff, 0x000, 0x7fff};
	XRenderColor colorBlue = {0x000, 0x000, 0xffff, 0x7fff};
	Picture redFillPict;
	Picture greenFillPict;
	Picture blueFillPict;
	Picture destPict;
	int iWindowAttribsMask;
	XTrapezoid trapezoid;

	trapezoid.top = 20;
	trapezoid.bottom = 100;
	trapezoid.left.p1.x = 40;
	trapezoid.left.p1.y = 20;
	trapezoid.left.p2.x = 20;
	trapezoid.left.p2.y = 100;
	trapezoid.right.p1.x = 60;
	trapezoid.right.p1.y = 20;
	trapezoid.right.p2.x = 200;
	trapezoid.right.p2.y = 200;

	/* connect to display */
	pDisplay = XOpenDisplay (NULL);
	if (!pDisplay)
	{
		printf ("Could not open display\n");
		return 1;
	}

	/* check for Xrender-extension */
	if (!XRenderQueryExtension (pDisplay, &iEventBase, &iErrorBase))
	{
		XCloseDisplay (pDisplay);
		printf ("Xrender-extension not found\n");
		return 2;
	}

	/* see which version is available */
	XRenderQueryVersion (pDisplay, &iMajorVersion, &iMinorVersion);
	printf ("Found Xrender %d.%d\n", iMajorVersion, iMinorVersion);

	/* make behaviour synchronous */
	XSynchronize (pDisplay, True);

	/* create and open window */
	values.background_pixel = WhitePixel (pDisplay, 0);
	values.event_mask = KeyPressMask;
	iWindowAttribsMask = CWEventMask | CWBackPixel;
	window = XCreateWindow (pDisplay,
							RootWindow (pDisplay, 0),
							50, 50, 400, 400, 0,
							DefaultDepth (pDisplay, 0),
							InputOutput,
							DefaultVisual (pDisplay, 0),
							iWindowAttribsMask,
							&values);
	XMapWindow (pDisplay, window);

	/* now the guessing work starts,
	** because Xrender is so "thoroughly" documented :-( */
	pPictFormat = XRenderFindVisualFormat (pDisplay,
										   DefaultVisual (pDisplay, 0));

	printf ("depth %d\n", pPictFormat->depth);

	/* as far as I get it this should give
	** me three colored "infinite pictures" */
	redFillPict = XRenderCreateSolidFill (pDisplay, &colorRed);
	greenFillPict = XRenderCreateSolidFill (pDisplay, &colorGreen);
	blueFillPict = XRenderCreateSolidFill (pDisplay, &colorBlue);

	/* this is my target- or destination-drawable derived from the window...
	** at least I think so */
	/*pictAttribs.repeat = True;*/
	destPict = XRenderCreatePicture (pDisplay,
									 window,
									 pPictFormat,
									 0,
									 &pictAttribs);

	/* the rectangles show up */
	XRenderFillRectangle (pDisplay,
						  PictOpOver,
						  destPict,
						  &colorRed,
						  50,
						  120,
						  325,
						  200);

	XRenderFillRectangle (pDisplay,
						  PictOpOver,
						  destPict,
						  &colorGreen,
						  150,
						  20,
						  200,
						  150);

	XRenderFillRectangle (pDisplay,
						  PictOpOver,
						  destPict,
						  &colorBlue,
						  5,
						  10,
						  250,
						  50);

	/* but this trapezoid does not */
	XRenderCompositeTrapezoids (pDisplay,
								PictOpOver,
								blueFillPict,
								destPict,
								pPictFormat,
								0,
								0,
								&trapezoid,
								1);

	while (bKeepGoing)
	{
		bGotEvent = XCheckWindowEvent (pDisplay,
									   window,
									   KeyPressMask,
									   &event);
		if (bGotEvent)
		{
			switch (event.type)
			{
				case KeyPress :
					if (XLookupKeysym (&event.xkey, 0) == XK_Escape)
						bKeepGoing = False;
				break;
			}
		}
		else
			usleep (10000);

	}

	XRenderFreePicture (pDisplay, redFillPict);
	XRenderFreePicture (pDisplay, greenFillPict);
	XRenderFreePicture (pDisplay, blueFillPict);
	XRenderFreePicture (pDisplay, destPict);
	XUnmapWindow (pDisplay, window);
	XDestroyWindow (pDisplay, window);
	XCloseDisplay (pDisplay);

	return 0;
}