/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* GdkPixbuf library - convert X drawable information to RGB
 *
 * Copyright (C) 1999 Michael Zucchi
 *
 * Authors: Michael Zucchi <zucchi@zedzone.mmc.com.au>
 *          Cody Russell <bratsche@dfw.net>
 * 	    Federico Mena-Quintero <federico@gimp.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/* Ported to Xlib by John Harper <john@dcs.warwick.ac.uk> */


#include <config.h>
#include <stdio.h>
#include <string.h>
#include "gdk-pixbuf-xlib-private.h"
#include <X11/Xlib.h>
#include <X11/Xutil.h>

#if (X_BYTE_ORDER == X_LITTLE_ENDIAN)
#define LITTLE
#endif
#define d(x)



static unsigned int mask_table[] = {
	0x00000000, 0x00000001, 0x00000003, 0x00000007,
	0x0000000f, 0x0000001f, 0x0000003f, 0x0000007f,
	0x000000ff, 0x000001ff, 0x000003ff, 0x000007ff,
	0x00000fff, 0x00001fff, 0x00003fff, 0x00007fff,
	0x0000ffff, 0x0001ffff, 0x0003ffff, 0x0007ffff,
	0x000fffff, 0x001fffff, 0x003fffff, 0x007fffff,
	0x00ffffff, 0x01ffffff, 0x03ffffff, 0x07ffffff,
	0x0fffffff, 0x1fffffff, 0x3fffffff, 0x7fffffff,
	0xffffffff
};


/* color handling */

typedef struct xlib_colormap_struct xlib_colormap;
struct xlib_colormap_struct {
	int size;
	XColor *colors;
	Visual *visual;
	Colormap colormap;
};


/* from gdkvisual.c */
static void
visual_decompose_mask (unsigned long  mask,
		       int   *shift,
		       int   *prec)
{
	*shift = 0;
	*prec = 0;

	while (!(mask & 0x1)) {
		(*shift)++;
		mask >>= 1;
	}

	while (mask & 0x1) {
		(*prec)++;
		mask >>= 1;
	}
}

static int x_error;

static int
handle_x_error (Display *dpy, XErrorEvent *ev)
{
	x_error = 1;
	return 0;
}

static int
drawable_is_pixmap (Drawable d)
{
	/* copied from Imlib */

	XErrorHandler errh;
	XWindowAttributes wa;
	int is_pixmap;

	errh = XSetErrorHandler (handle_x_error);
	x_error = 0;
	XGetWindowAttributes (gdk_pixbuf_dpy, d, &wa);
	XSync (gdk_pixbuf_dpy, False);
	is_pixmap = x_error;
	XSetErrorHandler (errh);

	return is_pixmap;
}



/*
  convert 1 bits-pixel data
  no alpha
*/
static void
rgb1 (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;
	unsigned char *s;
	register unsigned char data;
	unsigned char *o;
	unsigned char *srow = image->data, *orow = pixels;

	d (printf ("1 bits/pixel\n"));

	/* convert upto 8 pixels/time */
	/* its probably not worth trying to make this run very fast, who uses
	   1 bit displays anymore? */
	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = orow;

		for (xx = 0; xx < width; xx ++) {
			data = srow[xx >> 3] >> (7 - (xx & 7)) & 1;
			*o++ = colormap->colors[data].red;
			*o++ = colormap->colors[data].green;
			*o++ = colormap->colors[data].blue;
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 1 bits/pixel data
  with alpha
*/
static void
rgb1a (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;
	unsigned char *s;
	register unsigned char data;
	unsigned char *o;
	unsigned char *srow = image->data, *orow = pixels;
	unsigned int remap[2];

	d (printf ("1 bits/pixel\n"));

	/* convert upto 8 pixels/time */
	/* its probably not worth trying to make this run very fast, who uses
	   1 bit displays anymore? */
	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (xx = 0; xx < 2; xx++) {
#ifdef LITTLE
		remap[xx] = 0xff000000
			| colormap->colors[xx].blue << 16
			| colormap->colors[xx].green << 8
			| colormap->colors[xx].red;
#else
		remap[xx] = 0xff
			| colormap->colors[xx].red << 24
			| colormap->colors[xx].green << 16
			| colormap->colors[xx].blue << 8;
#endif
	}

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = orow;

		for (xx = 0; xx < width; xx ++) {
			data = srow[xx >> 3] >> (7 - (xx & 7)) & 1;
			*o++ = remap[data];
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 8 bits/pixel data
  no alpha
*/
static void
rgb8 (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;
	unsigned int mask;
	register unsigned int data;
	unsigned char *srow = image->data, *orow = pixels;
	register unsigned char *s;
	register unsigned char *o;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	d (printf ("8 bit, no alpha output\n"));

	mask = mask_table[image->depth];

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = orow;
		for (xx = 0; xx < width; xx++) {
			data = *s++ & mask;
			*o++ = colormap->colors[data].red;
			*o++ = colormap->colors[data].green;
			*o++ = colormap->colors[data].blue;
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 8 bits/pixel data
  with alpha
*/
static void
rgb8a (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;
	unsigned int mask;
	register unsigned int data;
	unsigned int remap[256];
	register unsigned char *s;	/* read 2 pixels at once */
	register unsigned int *o;
	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	d (printf ("8 bit, with alpha output\n"));

	mask = mask_table[image->depth];

	for (xx = 0; xx < colormap->size; xx++) {
#ifdef LITTLE
		remap[xx] = 0xff000000
			| colormap->colors[xx].blue << 16
			| colormap->colors[xx].green << 8
			| colormap->colors[xx].red;
#else
		remap[xx] = 0xff
			| colormap->colors[xx].red << 24
			| colormap->colors[xx].green << 16
			| colormap->colors[xx].blue << 8;
#endif
	}

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = (unsigned int *) orow;
		for (xx = 0; xx < width; xx ++) {
			data = *s++ & mask;
			*o++ = remap[data];
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 16 bits/pixel data
  no alpha
  data in lsb format
*/
static void
rgb565lsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

#ifdef LITTLE
	register unsigned int *s;	/* read 2 pixels at once */
#else
	register unsigned char *s;	/* read 2 pixels at once */
#endif
	register unsigned short *o;
	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
#ifdef LITTLE
		s = (unsigned int *) srow;
#else
		s = srow;
#endif
		o = (unsigned short *) orow;
		for (xx = 1; xx < width; xx += 2) {
			register unsigned int data;
#ifdef LITTLE
			data = *s++;
			*o++ = (data & 0xf800) >> 8 | (data & 0xe000) >> 13
				| (data & 0x7e0) << 5 | (data & 0x600) >> 1;
			*o++ = (data & 0x1f) << 3 | (data & 0x1c) >> 2
				| (data & 0xf8000000) >> 16 | (data & 0xe0000000) >> 21;
			*o++ = (data & 0x7e00000) >> 19 | (data & 0x6000000) >> 25
				| (data & 0x1f0000) >> 5 | (data & 0x1c0000) >> 10;
#else
			/* swap endianness first */
			data = s[0] | s[1] << 8 | s[2] << 16 | s[3] << 24;
			s += 4;
			*o++ = (data & 0xf800) | (data & 0xe000) >> 5
				| (data & 0x7e0) >> 3 | (data & 0x600) >> 9;
			*o++ = (data & 0x1f) << 11 | (data & 0x1c) << 6
				| (data & 0xf8000000) >> 24 | (data & 0xe0000000) >> 29;
			*o++ = (data & 0x7e00000) >> 11 | (data & 0x6000000) >> 17
				| (data & 0x1f0000) >> 13 | (data & 0x1c0000) >> 18;
#endif
		}
		/* check for last remaining pixel */
		if (width & 1) {
			register unsigned short data;
#ifdef LITTLE
			data = *((short *) s);
#else
			data = *((short *) s);
			data = ((data >> 8) & 0xff) | ((data & 0xff) << 8);
#endif
			((char *) o)[0] = ((data >> 8) & 0xf8) | ((data >> 13) & 0x7);
			((char *) o)[1] = ((data >> 3) & 0xfc) | ((data >> 9) & 0x3);
			((char *) o)[2] = ((data << 3) & 0xf8) | ((data >> 2) & 0x7);
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 16 bits/pixel data
  no alpha
  data in msb format
*/
static void
rgb565msb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

#ifdef LITTLE
	register unsigned char *s;	/* need to swap data order */
#else
	register unsigned int *s;	/* read 2 pixels at once */
#endif
	register unsigned short *o;
	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
#ifdef LITTLE
		s = srow;
#else
		s = (unsigned int *) srow;
#endif
		o = (unsigned short *) orow;
		for (xx = 1; xx < width; xx += 2) {
			register unsigned int data;
#ifdef LITTLE
			/* swap endianness first */
			data = s[0] | s[1] << 8 | s[2] << 16 | s[3] << 24;
			s += 4;
			*o++ = (data & 0xf800) >> 8 | (data & 0xe000) >> 13
				| (data & 0x7e0) << 5 | (data & 0x600) >> 1;
			*o++ = (data & 0x1f) << 3 | (data & 0x1c) >> 2
				| (data & 0xf8000000) >> 16 | (data & 0xe0000000) >> 21;
			*o++ = (data & 0x7e00000) >> 19 | (data & 0x6000000) >> 25
				| (data & 0x1f0000) >> 5 | (data & 0x1c0000) >> 10;
#else
			data = *s++;
			*o++ = (data & 0xf800) | (data & 0xe000) >> 5
				| (data & 0x7e0) >> 3 | (data & 0x600) >> 9;
			*o++ = (data & 0x1f) << 11 | (data & 0x1c) << 6
				| (data & 0xf8000000) >> 24 | (data & 0xe0000000) >> 29;
			*o++ = (data & 0x7e00000) >> 11 | (data & 0x6000000) >> 17
				| (data & 0x1f0000) >> 13 | (data & 0x1c0000) >> 18;
#endif
		}
		/* check for last remaining pixel */
		if (width & 1) {
			register unsigned short data;
#ifdef LITTLE
			data = *((short *) s);
			data = ((data >> 8) & 0xff) | ((data & 0xff) << 8);
#else
			data = *((short *) s);
#endif
			((char *) o)[0] = ((data >> 8) & 0xf8) | ((data >> 13) & 0x7);
			((char *) o)[1] = ((data >> 3) & 0xfc) | ((data >> 9) & 0x3);
			((char *) o)[2] = ((data << 3) & 0xf8) | ((data >> 2) & 0x7);
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 16 bits/pixel data
  with alpha
  data in lsb format
*/
static void
rgb565alsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

#ifdef LITTLE
	register unsigned short *s;	/* read 1 pixels at once */
#else
	register unsigned char *s;
#endif
	register unsigned int *o;

	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
#ifdef LITTLE
		s = (unsigned short *) srow;
#else
		s = (unsigned char *) srow;
#endif
		o = (unsigned int *) orow;
		for (xx = 0; xx < width; xx ++) {
			register unsigned int data;
			/*  rrrrrggg gggbbbbb -> rrrrrRRR ggggggGG bbbbbBBB aaaaaaaa */
			/*  little endian: aaaaaaaa bbbbbBBB ggggggGG rrrrrRRR */
#ifdef LITTLE
			data = *s++;
			*o++ = (data & 0xf800) >> 8 | (data & 0xe000) >> 13
				| (data & 0x7e0) << 5 | (data & 0x600) >> 1
				| (data & 0x1f) << 19 | (data & 0x1c) << 14
				| 0xff000000;
#else
			/* swap endianness first */
			data = s[0] | s[1] << 8;
			s += 2;
			*o++ = (data & 0xf800) << 16 | (data & 0xe000) << 11
				| (data & 0x7e0) << 13 | (data & 0x600) << 7
				| (data & 0x1f) << 11 | (data & 0x1c) << 6
				| 0xff;
#endif
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 16 bits/pixel data
  with alpha
  data in msb format
*/
static void
rgb565amsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

#ifdef LITTLE
	register unsigned char *s;
#else
	register unsigned short *s;	/* read 1 pixels at once */
#endif
	register unsigned int *o;

	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = (unsigned int *) orow;
		for (xx = 0; xx < width; xx ++) {
			register unsigned int data;
			/*  rrrrrggg gggbbbbb -> rrrrrRRR gggggg00 bbbbbBBB aaaaaaaa */
			/*  little endian: aaaaaaaa bbbbbBBB gggggg00 rrrrrRRR */
#ifdef LITTLE
			/* swap endianness first */
			data = s[0] | s[1] << 8;
			s += 2;
			*o++ = (data & 0xf800) >> 8 | (data & 0xe000) >> 13
				| (data & 0x7e0) << 5 | (data & 0x600) >> 1
				| (data & 0x1f) << 19 | (data & 0x1c) << 14
				| 0xff000000;
#else
			data = *s++;
			*o++ = (data & 0xf800) << 16 | (data & 0xe000) << 11
				| (data & 0x7e0) << 13 | (data & 0x600) << 7
				| (data & 0x1f) << 11 | (data & 0x1c) << 6
				| 0xff;
#endif
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 15 bits/pixel data
  no alpha
  data in lsb format
*/
static void
rgb555lsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

#ifdef LITTLE
	register unsigned int *s;	/* read 2 pixels at once */
#else
	register unsigned char *s;	/* read 2 pixels at once */
#endif
	register unsigned short *o;
	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
#ifdef LITTLE
		s = (unsigned int *) srow;
#else
		s = srow;
#endif
		o = (unsigned short *) orow;
		for (xx = 1; xx < width; xx += 2) {
			register unsigned int data;
#ifdef LITTLE
			data = *s++;
			*o++ = (data & 0x7c00) >> 7 | (data & 0x7000) >> 12
				| (data & 0x3e0) << 6 | (data & 0x380) << 1;
			*o++ = (data & 0x1f) << 3 | (data & 0x1c) >> 2
				| (data & 0x7c000000) >> 15 | (data & 0x70000000) >> 20;
			*o++ = (data & 0x3e00000) >> 18 | (data & 0x3800000) >> 23
				| (data & 0x1f0000) >> 5 | (data & 0x1c0000) >> 10;
#else
			/* swap endianness first */
			data = s[0] | s[1] << 8 | s[2] << 16 | s[3] << 24;
			s += 4;
			*o++ = (data & 0x7c00) << 1 | (data & 0x7000) >> 4
				| (data & 0x3e0) >> 2 | (data & 0x380) >> 7;
			*o++ = (data & 0x1f) << 11 | (data & 0x1c) << 6
				| (data & 0x7c000000) >> 23 | (data & 0x70000000) >> 28;
			*o++ = (data & 0x3e00000) >> 10 | (data & 0x3800000) >> 15
				| (data & 0x1f0000) >> 13 | (data & 0x1c0000) >> 18;
#endif
		}
		/* check for last remaining pixel */
		if (width & 1) {
			register unsigned short data;
#ifdef LITTLE
			data = *((short *) s);
#else
			data = *((short *) s);
			data = ((data >> 8) & 0xff) | ((data & 0xff) << 8);
#endif
			((char *) o)[0] = (data & 0x7c00) >> 7 | (data & 0x7000) >> 12;
			((char *) o)[1] = (data & 0x3e0) >> 2 | (data & 0x380) >> 7;
			((char *) o)[2] = (data & 0x1f) << 3 | (data & 0x1c) >> 2;
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 15 bits/pixel data
  no alpha
  data in msb format
*/
static void
rgb555msb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

#ifdef LITTLE
	register unsigned char *s;	/* read 2 pixels at once */
#else
	register unsigned int *s;	/* read 2 pixels at once */
#endif
	register unsigned short *o;
	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = (unsigned short *) orow;
		for (xx = 1; xx < width; xx += 2) {
			register unsigned int data;
#ifdef LITTLE
			/* swap endianness first */
			data = s[0] | s[1] << 8 | s[2] << 16 | s[3] << 24;
			s += 4;
			*o++ = (data & 0x7c00) >> 7 | (data & 0x7000) >> 12
				| (data & 0x3e0) << 6 | (data & 0x380) << 1;
			*o++ = (data & 0x1f) << 3 | (data & 0x1c) >> 2
				| (data & 0x7c000000) >> 15 | (data & 0x70000000) >> 20;
			*o++ = (data & 0x3e00000) >> 18 | (data & 0x3800000) >> 23
				| (data & 0x1f0000) >> 5 | (data & 0x1c0000) >> 10;
#else
			data = *s++;
			*o++ = (data & 0x7c00) << 1 | (data & 0x7000) >> 4
				| (data & 0x3e0) >> 2 | (data & 0x380) >> 7;
			*o++ = (data & 0x1f) << 11 | (data & 0x1c) << 6
				| (data & 0x7c000000) >> 23 | (data & 0x70000000) >> 28;
			*o++ = (data & 0x3e00000) >> 10 | (data & 0x3800000) >> 15
				| (data & 0x1f0000) >> 13 | (data & 0x1c0000) >> 18;
#endif
		}
		/* check for last remaining pixel */
		if (width & 1) {
			register unsigned short data;
#ifdef LITTLE
			data = *((short *) s);
			data = ((data >> 8) & 0xff) | ((data & 0xff) << 8);
#else
			data = *((short *) s);
#endif
			((char *) o)[0] = (data & 0x7c00) >> 7 | (data & 0x7000) >> 12;
			((char *) o)[1] = (data & 0x3e0) >> 2 | (data & 0x380) >> 7;
			((char *) o)[2] = (data & 0x1f) << 3 | (data & 0x1c) >> 2;
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 15 bits/pixel data
  with alpha
  data in lsb format
*/
static void
rgb555alsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

#ifdef LITTLE
	register unsigned short *s;	/* read 1 pixels at once */
#else
	register unsigned char *s;
#endif
	register unsigned int *o;

	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
#ifdef LITTLE
		s = (unsigned short *) srow;
#else
		s = srow;
#endif
		o = (unsigned int *) orow;
		for (xx = 0; xx < width; xx++) {
			register unsigned int data;
			/*  rrrrrggg gggbbbbb -> rrrrrRRR gggggGGG bbbbbBBB aaaaaaaa */
			/*  little endian: aaaaaaaa bbbbbBBB gggggGGG rrrrrRRR */
#ifdef LITTLE
			data = *s++;
			*o++ = (data & 0x7c00) >> 7 | (data & 0x7000) >> 12
				| (data & 0x3e0) << 6 | (data & 0x380) << 1
				| (data & 0x1f) << 19 | (data & 0x1c) << 14
				| 0xff000000;
#else
			/* swap endianness first */
			data = s[0] | s[1] << 8;
			s += 2;
			*o++ = (data & 0x7c00) << 17 | (data & 0x7000) << 12
				| (data & 0x3e0) << 14 | (data & 0x380) << 9
				| (data & 0x1f) << 11 | (data & 0x1c) << 6
				| 0xff;
#endif
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  convert 15 bits/pixel data
  with alpha
  data in msb format
*/
static void
rgb555amsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

#ifdef LITTLE
	register unsigned short *s;	/* read 1 pixels at once */
#else
	register unsigned char *s;
#endif
	register unsigned int *o;

	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
#ifdef LITTLE
		s = (unsigned short *) srow;
#else
		s = srow;
#endif
		o = (unsigned int *) orow;
		for (xx = 0; xx < width; xx++) {
			register unsigned int data;
			/*  rrrrrggg gggbbbbb -> rrrrrRRR gggggGGG bbbbbBBB aaaaaaaa */
			/*  little endian: aaaaaaaa bbbbbBBB gggggGGG rrrrrRRR */
#ifdef LITTLE
			/* swap endianness first */
			data = s[0] | s[1] << 8;
			s += 2;
			*o++ = (data & 0x7c00) >> 7 | (data & 0x7000) >> 12
				| (data & 0x3e0) << 6 | (data & 0x380) << 1
				| (data & 0x1f) << 19 | (data & 0x1c) << 14
				| 0xff000000;
#else
			data = *s++;
			*o++ = (data & 0x7c00) << 17 | (data & 0x7000) << 12
				| (data & 0x3e0) << 14 | (data & 0x380) << 9
				| (data & 0x1f) << 11 | (data & 0x1c) << 6
				| 0xff;
#endif
		}
		srow += bpl;
		orow += rowstride;
	}
}


static void
rgb888alsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

	unsigned char *s;	/* for byte order swapping */
	unsigned char *o;
	unsigned char *srow = image->data, *orow = pixels;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	d (printf ("32 bits/pixel with alpha\n"));

	/* lsb data */
	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = orow;
		for (xx = 0; xx < width; xx++) {
			*o++ = s[2];
			*o++ = s[1];
			*o++ = s[0];
			*o++ = 0xff;
			s += 4;
		}
		srow += bpl;
		orow += rowstride;
	}
}

static void
rgb888lsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

	unsigned char *srow = image->data, *orow = pixels;
	unsigned char *o, *s;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	d (printf ("32 bit, lsb, no alpha\n"));

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = orow;
		for (xx = 0; xx < width; xx++) {
			*o++ = s[2];
			*o++ = s[1];
			*o++ = s[0];
			s += 4;
		}
		srow += bpl;
		orow += rowstride;
	}
}

static void
rgb888amsb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

	unsigned char *srow = image->data, *orow = pixels;
#ifdef LITTLE
	unsigned int *o;
	unsigned int *s;
#else
	unsigned char *s;	/* for byte order swapping */
	unsigned char *o;
#endif

	d (printf ("32 bit, msb, with alpha\n"));

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	/* msb data */
	for (yy = 0; yy < height; yy++) {
#ifdef LITTLE
		s = (unsigned int *) srow;
		o = (unsigned int *) orow;
#else
		s = srow;
		o = orow;
#endif
		for (xx = 0; xx < width; xx++) {
#ifdef LITTLE
			*o++ = s[1];
			*o++ = s[2];
			*o++ = s[3];
			*o++ = 0xff;
			s += 4;
#else
			*o++ = (*s << 8) | 0xff; /* untested */
			s++;
#endif
		}
		srow += bpl;
		orow += rowstride;
	}
}

static void
rgb888msb (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *colormap)
{
	int xx, yy;
	int width, height;
	int bpl;

	unsigned char *srow = image->data, *orow = pixels;
	unsigned char *s;
	unsigned char *o;

	d (printf ("32 bit, msb, no alpha\n"));

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = orow;
		for (xx = 0; xx < width; xx++) {
			*o++ = s[1];
			*o++ = s[2];
			*o++ = s[3];
			s += 4;
		}
		srow += bpl;
		orow += rowstride;
	}
}

/*
  This should work correctly with any display/any endianness, but will probably
  run quite slow
*/
static void
convert_real_slow (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *cmap, int alpha)
{
	int xx, yy;
	int width, height;
	int bpl;
	unsigned char *srow = image->data, *orow = pixels;
	unsigned char *s;
	unsigned char *o;
	unsigned int pixel;
	Visual *v;
	unsigned char component;
	int i;
	int red_shift, red_prec, green_shift, green_prec, blue_shift, blue_prec;

	width = image->width;
	height = image->height;
	bpl = image->bytes_per_line;
	v = cmap->visual;

	visual_decompose_mask (v->red_mask, &red_shift, &red_prec);
	visual_decompose_mask (v->green_mask, &green_shift, &green_prec);
	visual_decompose_mask (v->blue_mask, &blue_shift, &blue_prec);

	d(printf("rgb  mask/shift/prec = %x:%x:%x %d:%d:%d  %d:%d:%d\n",
		 v->red_mask, v->green_mask, v->blue_mask,
		 red_shift, green_shift, blue_shift,
		 red_prec, green_prec, blue_prec));

	for (yy = 0; yy < height; yy++) {
		s = srow;
		o = orow;
		for (xx = 0; xx < width; xx++) {
			pixel = XGetPixel (image, xx, yy);
			switch (v->class) {
				/* I assume this is right for static & greyscale's too? */
			case StaticGray:
			case GrayScale:
			case StaticColor:
			case PseudoColor:
				*o++ = cmap->colors[pixel].red;
				*o++ = cmap->colors[pixel].green;
				*o++ = cmap->colors[pixel].blue;
				break;
			case TrueColor:
				/* This is odd because it must sometimes shift left (otherwise
				   I'd just shift >> (*_shift - 8 + *_prec + <0-7>). This logic
				   should work for all bit sizes/shifts/etc. */
				component = 0;
				for (i = 24; i < 32; i += red_prec)
					component |= ((pixel & v->red_mask) << (32 - red_shift - red_prec)) >> i;
				*o++ = component;
				component = 0;
				for (i = 24; i < 32; i += green_prec)
					component |= ((pixel & v->green_mask) << (32 - green_shift - green_prec)) >> i;
				*o++ = component;
				component = 0;
				for (i = 24; i < 32; i += blue_prec)
					component |= ((pixel & v->blue_mask) << (32 - blue_shift - blue_prec)) >> i;
				*o++ = component;
				break;
			case DirectColor:
				*o++ = cmap->colors[((pixel & v->red_mask) << (32 - red_shift - red_prec)) >> 24].red;
				*o++ = cmap->colors[((pixel & v->green_mask) << (32 - green_shift - green_prec)) >> 24].green;
				*o++ = cmap->colors[((pixel & v->blue_mask) << (32 - blue_shift - blue_prec)) >> 24].blue;
				break;
			}
			if (alpha)
				*o++ = 0xff;
		}
		srow += bpl;
		orow += rowstride;
	}
}

typedef void (* cfunc) (XImage *image, unsigned char *pixels, int rowstride, xlib_colormap *cmap);

static cfunc convert_map[] = {
	rgb1,rgb1,rgb1a,rgb1a,
	rgb8,rgb8,rgb8a,rgb8a,
	rgb555lsb,rgb555msb,rgb555alsb,rgb555amsb,
	rgb565lsb,rgb565msb,rgb565alsb,rgb565amsb,
	rgb888lsb,rgb888msb,rgb888alsb,rgb888amsb
};

/*
  perform actual conversion

  If we can, try and use the optimised code versions, but as a default
  fallback, and always for direct colour, use the generic/slow but complete
  conversion function.
*/
static void
rgbconvert (XImage *image, unsigned char *pixels, int rowstride, int alpha, xlib_colormap *cmap)
{
	int index = (image->byte_order == MSBFirst) | (alpha != 0) << 1;
	int bank=5;		/* default fallback converter */
	Visual *v = cmap->visual;

	d(printf("masks = %x:%x:%x\n", v->red_mask, v->green_mask, v->blue_mask));
	d(printf("image depth = %d, bpp = %d\n", image->depth, image->bits_per_pixel));

	switch (v->class) {
				/* I assume this is right for static & greyscale's too? */
	case StaticGray:
	case GrayScale:
	case StaticColor:
	case PseudoColor:
		switch (image->bits_per_pixel) {
		case 1:
			bank = 0;
			break;
		case 8:
			bank = 1;
			break;
		}
		break;
	case TrueColor:
		switch (image->depth) {
		case 15:
			if (v->red_mask == 0x7c00 && v->green_mask == 0x3e0 && v->blue_mask == 0x1f
			    && image->bits_per_pixel == 16)
				bank = 2;
			break;
		case 16:
			if (v->red_mask == 0xf800 && v->green_mask == 0x7e0 && v->blue_mask == 0x1f
			    && image->bits_per_pixel == 16)
				bank = 3;
			break;
		case 24:
		case 32:
			if (v->red_mask == 0xff0000 && v->green_mask == 0xff00 && v->blue_mask == 0xff
			    && image->bits_per_pixel == 32)
				bank = 4;
			break;
		}
		break;
	case DirectColor:
		/* always use the slow version */
		break;
	}

	d(printf("converting using conversion function in bank %d\n", bank));

	if (bank==5) {
		convert_real_slow(image, pixels, rowstride, cmap, alpha);
	} else {
		index |= bank << 2;
		(* convert_map[index]) (image, pixels, rowstride, cmap);
	}
}

static int
xlib_window_is_viewable (Window w)
{
	XWindowAttributes wa;

	while (w != 0) {
		Window parent, root, *children;
		int nchildren;

		XGetWindowAttributes (gdk_pixbuf_dpy, w, &wa);
		if (wa.map_state != IsViewable)
			return 0;

		if (!XQueryTree (gdk_pixbuf_dpy, w, &root,
				 &parent, &children, &nchildren))
			return 0;

		if (nchildren > 0)
			XFree (children);

		if (parent == root)
			return 1;

		w = parent;
	}

	return 0;
}

static int
xlib_window_get_origin (Window w, int *x, int *y)
{
	Window child;
	return XTranslateCoordinates (gdk_pixbuf_dpy, w,
				      RootWindow (gdk_pixbuf_dpy,
						  gdk_pixbuf_screen),
				      0, 0, x, y, &child);
}
