[cairo] win32 port leaks

Oleg Smolsky oleg.smolsky at pacific-simulators.co.nz
Sun Feb 20 16:35:12 PST 2005


Hello Owen,

Owen Taylor wrote on Monday, 21 February 2005:
>> as Hans Breuer mentioned this in
>> http://lists.freedesktop.org/archives/cairo/2005-February/003014.html
>> 
>> The current CVS version of cairo leaks GDI objects (bitmaps and
>> DCs) on win32. Below, are the descriptions of two bugs:
OT> I'm confused ... is there anything different here than in Hans's
OT> message? (I want to get his patch in the next day or two)
Probably quite similar, at least as far a the first bug goes. I was
unable to apply the original patch - the CVS version must've
evolved...

Anyway, my version is attached, so you can do a diff.

Best regards,
Oleg.
-------------- next part --------------
/* Cairo - a vector graphics library with display and print output
*
* Copyright © 2005 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is Red Hat, Inc.
*
* Contributor(s):
*	Owen Taylor <otaylor at redhat.com>
*/

#include <stdio.h>

#include "cairo-win32-private.h"

static const cairo_surface_backend_t cairo_win32_surface_backend;

/**
* _cairo_win32_print_gdi_error:
* @context: context string to display along with the error
* 
* Helper function to dump out a human readable form of the
* current error code.
*
* Return value: A Cairo status code for the error code
**/
cairo_status_t
_cairo_win32_print_gdi_error (const char *context)
{
	void *lpMsgBuf;
	DWORD last_error = GetLastError ();

	if (!FormatMessageA (FORMAT_MESSAGE_ALLOCATE_BUFFER | 
		FORMAT_MESSAGE_FROM_SYSTEM,
		NULL,
		last_error,
		MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
		(LPTSTR) &lpMsgBuf,
		0, NULL)) {
			fprintf (stderr, "%s: Unknown GDI error", context);
		} else {
			fprintf (stderr, "%s: %s", context, (char *)lpMsgBuf);

			LocalFree (lpMsgBuf);
		}

		/* We should switch off of last_status, but we'd either return
		* CAIRO_STATUS_NO_MEMORY or CAIRO_STATUS_UNKNOWN_ERROR and there
		* is no CAIRO_STATUS_UNKNOWN_ERROR.
		*/

		return CAIRO_STATUS_NO_MEMORY;
}

void
cairo_set_target_win32 (cairo_t *cr,
						HDC      hdc)
{
	cairo_surface_t *surface;

	if (cr->status && cr->status != CAIRO_STATUS_NO_TARGET_SURFACE)
		return;

	surface = cairo_win32_surface_create (hdc);
	if (surface == NULL) {
		cr->status = CAIRO_STATUS_NO_MEMORY;
		return;
	}

	cairo_set_target_surface (cr, surface);

	/* cairo_set_target_surface takes a reference, so we must destroy ours */
	cairo_surface_destroy (surface);
}

static cairo_status_t
_create_dc_and_bitmap (cairo_win32_surface_t *surface,
					   HDC			   original_dc,
					   cairo_format_t  format,
					   int             width,
					   int             height,
					   char          **bits_out,
					   int            *rowstride_out)
{
	cairo_status_t status;

	BITMAPINFO *bitmap_info = NULL;
	struct {
		BITMAPINFOHEADER bmiHeader;
		RGBQUAD bmiColors[2];
	} bmi_stack;
	void *bits;

	int num_palette = 0;	/* Quiet GCC */
	int i;

	switch (format) {
	case CAIRO_FORMAT_ARGB32:
	case CAIRO_FORMAT_RGB24:
		num_palette = 0;
		break;

	case CAIRO_FORMAT_A8:
		num_palette = 256;
		break;

	case CAIRO_FORMAT_A1:
		num_palette = 2;
		break;
	}

	if (num_palette > 2) {
		bitmap_info = malloc (sizeof (BITMAPINFOHEADER) + num_palette * sizeof (RGBQUAD));
		if (!bitmap_info)
			return CAIRO_STATUS_NO_MEMORY;
	} else {
		bitmap_info = (BITMAPINFO *)&bmi_stack;
	}

	bitmap_info->bmiHeader.biSize = sizeof (BITMAPINFOHEADER);
	bitmap_info->bmiHeader.biWidth = width;
	bitmap_info->bmiHeader.biHeight = - height; /* top-down */
	bitmap_info->bmiHeader.biSizeImage = 0;
	bitmap_info->bmiHeader.biXPelsPerMeter = 72. / 0.0254; /* unused here */
	bitmap_info->bmiHeader.biYPelsPerMeter = 72. / 0.0254; /* unused here */
	bitmap_info->bmiHeader.biPlanes = 1;

	switch (format) {
	case CAIRO_FORMAT_ARGB32:
	case CAIRO_FORMAT_RGB24:
		bitmap_info->bmiHeader.biBitCount = 32;
		bitmap_info->bmiHeader.biCompression = BI_RGB;
		bitmap_info->bmiHeader.biClrUsed = 0;	/* unused */
		bitmap_info->bmiHeader.biClrImportant = 0;
		break;

	case CAIRO_FORMAT_A8:
		bitmap_info->bmiHeader.biBitCount = 8;
		bitmap_info->bmiHeader.biCompression = BI_RGB;
		bitmap_info->bmiHeader.biClrUsed = 256;
		bitmap_info->bmiHeader.biClrImportant = 0;

		for (i = 0; i < 256; i++) {
			bitmap_info->bmiColors[i].rgbBlue = i;
			bitmap_info->bmiColors[i].rgbGreen = i;
			bitmap_info->bmiColors[i].rgbRed = i;
			bitmap_info->bmiColors[i].rgbReserved = 0;
		}

		break;

	case CAIRO_FORMAT_A1:
		bitmap_info->bmiHeader.biBitCount = 1;
		bitmap_info->bmiHeader.biCompression = BI_RGB;
		bitmap_info->bmiHeader.biClrUsed = 2;
		bitmap_info->bmiHeader.biClrImportant = 0;

		for (i = 0; i < 2; i++) {
			bitmap_info->bmiColors[i].rgbBlue = i * 255;
			bitmap_info->bmiColors[i].rgbGreen = i * 255;
			bitmap_info->bmiColors[i].rgbRed = i * 255;
			bitmap_info->bmiColors[i].rgbReserved = 0;
			break;
		}
	}

    surface->dc = CreateCompatibleDC(original_dc);
	if (!surface->dc)
		goto FAIL;

	surface->delete_dc = TRUE;

    surface->bitmap = CreateDIBSection (surface->dc,
										bitmap_info,
										DIB_RGB_COLORS,
										&bits,
										NULL, 0);
	if (!surface->bitmap)
		goto FAIL;

	if (!(surface->old_bitmap = SelectObject(surface->dc, surface->bitmap)))
		goto FAIL;

	if (bitmap_info && num_palette > 2)
		free (bitmap_info);

	if (bits_out)
		*bits_out = bits;

	if (rowstride_out) {
		/* Windows bitmaps are padded to 16-bit (word) boundaries */
		switch (format) {
	case CAIRO_FORMAT_ARGB32:
	case CAIRO_FORMAT_RGB24:
		*rowstride_out = 4 * width;
		break;

	case CAIRO_FORMAT_A8:
		*rowstride_out = (width + 1) & -2;
		break;

	case CAIRO_FORMAT_A1:
		*rowstride_out = ((width + 15) & -16) / 8;
		break;
		}
	}

	return CAIRO_STATUS_SUCCESS;

FAIL:
	status = _cairo_win32_print_gdi_error ("_create_dc_and_bitmap");

	if (bitmap_info && num_palette > 2)
		free (bitmap_info);

	if (surface->bitmap) {
		if (surface->old_bitmap)
			SelectObject(surface->dc, surface->old_bitmap);
		DeleteObject(surface->bitmap);
		surface->bitmap = NULL;
		surface->old_bitmap = NULL;
	}

	if (surface->dc)
	{
		DeleteDC(surface->dc);
		surface->dc = NULL;
	}

	return status;
}

static cairo_surface_t *
_cairo_win32_surface_create_for_dc (HDC             original_dc,
									cairo_format_t  format,
									int	            drawable,
									int	            width,
									int	            height)
{
	cairo_win32_surface_t *surface;
	char *bits;
	int rowstride;

	surface = malloc (sizeof (cairo_win32_surface_t));
	if (!surface)
		return NULL;

	if (_create_dc_and_bitmap(surface, original_dc,
							  format, width, height, &bits, &rowstride) != CAIRO_STATUS_SUCCESS)
		goto FAIL;

	surface->image = cairo_image_surface_create_for_data (bits, format, width, height, rowstride);
	if (!surface->image)
		goto FAIL;

	surface->format = format;

	surface->clip_rect.x = 0;
	surface->clip_rect.y = 0;
	surface->clip_rect.width = width;
	surface->clip_rect.height = height;

	surface->set_clip = 0;
	surface->saved_clip = NULL;

	_cairo_surface_init (&surface->base, &cairo_win32_surface_backend);

	return (cairo_surface_t *)surface;

FAIL:
	if (surface->bitmap) {
		if (surface->old_bitmap)
			SelectObject(surface->dc, surface->old_bitmap);
		DeleteObject(surface->bitmap);
		surface->bitmap = NULL;
		surface->old_bitmap = NULL;
	}
	
	if (surface->dc) 
	{
		DeleteDC(surface->dc);
		surface->dc = NULL;
	}
	if (surface)
		free (surface);

	return NULL;

}

static cairo_surface_t *
_cairo_win32_surface_create_similar (void	    *abstract_src,
									 cairo_format_t  format,
									 int	     drawable,
									 int	     width,
									 int	     height)
{
	cairo_win32_surface_t *src = abstract_src;

	return _cairo_win32_surface_create_for_dc (src->dc, format, drawable,
		width, height);
}

/**
* _cairo_win32_surface_create_dib:
* @format: format of pixels in the surface to create 
* @width: width of the surface, in pixels
* @height: height of the surface, in pixels
* 
* Creates a device-independent-bitmap surface not associated with
* any particular existing surface or device context. The created
* bitmap will be unititialized.
* 
* Return value: the newly created surface, or %NULL if it couldn't
*   be created (probably because of lack of memory)
**/
cairo_surface_t *
_cairo_win32_surface_create_dib (cairo_format_t format,
								 int	        width,
								 int	        height)
{
	return _cairo_win32_surface_create_for_dc (NULL, format, TRUE,
		width, height);
}

static void
_cairo_win32_surface_destroy (void *abstract_surface)
{
	cairo_win32_surface_t *surface = abstract_surface;

	if (surface->image)
		cairo_surface_destroy (surface->image);

	if (surface->saved_clip)
		DeleteObject (surface->saved_clip);

	if (surface->bitmap) {
		if (surface->old_bitmap)
			surface->bitmap = SelectObject(surface->dc, surface->old_bitmap);
		DeleteObject(surface->bitmap);
		surface->bitmap = NULL;
	}

	if (surface->delete_dc)
		DeleteDC(surface->dc);
	free (surface);
}

static double
_cairo_win32_surface_pixels_per_inch (void *abstract_surface)
{
	/* XXX: We should really get this value from somewhere */
	return 96.0;
}

static cairo_status_t
_cairo_win32_surface_get_subimage (cairo_win32_surface_t  *surface,
								   int                     x,
								   int                     y,
								   int                     width,
								   int                     height,
								   cairo_win32_surface_t **local_out)
{
	cairo_win32_surface_t *local;
	cairo_status_t status;

	local = 
		(cairo_win32_surface_t *) _cairo_win32_surface_create_similar (surface,
		surface->format,
		0,
		width, height);
	if (!local)
		return CAIRO_STATUS_NO_MEMORY;

	if (!BitBlt (local->dc, 
		0, 0,
		width, height,
		surface->dc,
		x, y,
		SRCCOPY))
		goto FAIL;

	*local_out = local;

	return CAIRO_STATUS_SUCCESS;

FAIL:
	status = _cairo_win32_print_gdi_error ("_cairo_win32_surface_get_subimage");

	if (local)
		cairo_surface_destroy (&local->base);

	return status;
}

static cairo_status_t
_cairo_win32_surface_acquire_source_image (void                    *abstract_surface,
										   cairo_image_surface_t  **image_out,
										   void                   **image_extra)
{
	cairo_win32_surface_t *surface = abstract_surface;
	cairo_win32_surface_t *local = NULL;
	cairo_status_t status;

	if (surface->image) {
		*image_out = (cairo_image_surface_t *)surface->image;
		*image_extra = NULL;

		return CAIRO_STATUS_SUCCESS;
	}

	status = _cairo_win32_surface_get_subimage (abstract_surface, 0, 0,
		surface->clip_rect.width,
		surface->clip_rect.height, &local);
	if (CAIRO_OK (status)) {
		cairo_surface_set_filter (&local->base, surface->base.filter);
		cairo_surface_set_matrix (&local->base, &surface->base.matrix);
		cairo_surface_set_repeat (&local->base, surface->base.repeat);

		*image_out = (cairo_image_surface_t *)local->image;
		*image_extra = local;
	}

	return status;
}

static void
_cairo_win32_surface_release_source_image (void                   *abstract_surface,
										   cairo_image_surface_t  *image,
										   void                   *image_extra)
{
	cairo_win32_surface_t *local = image_extra;

	if (local)
		cairo_surface_destroy ((cairo_surface_t *)local);
}

static cairo_status_t
_cairo_win32_surface_acquire_dest_image (void                    *abstract_surface,
										 cairo_rectangle_t       *interest_rect,
										 cairo_image_surface_t  **image_out,
										 cairo_rectangle_t       *image_rect,
										 void                   **image_extra)
{
	cairo_win32_surface_t *surface = abstract_surface;
	cairo_win32_surface_t *local = NULL;
	cairo_status_t status;
	RECT clip_box;
	int x1, y1, x2, y2;

	if (surface->image) {
		image_rect->x = 0;
		image_rect->y = 0;
		image_rect->width = surface->clip_rect.width;
		image_rect->height = surface->clip_rect.height;

		*image_out = (cairo_image_surface_t *)surface->image;
		*image_extra = NULL;

		return CAIRO_STATUS_SUCCESS;
	}

	if (GetClipBox (surface->dc, &clip_box) == ERROR)
		return _cairo_win32_print_gdi_error ("_cairo_win3_surface_acquire_dest_image");

	x1 = clip_box.left;
	x2 = clip_box.right;
	y1 = clip_box.top;
	y2 = clip_box.bottom;

	if (interest_rect->x > x1)
		x1 = interest_rect->x;
	if (interest_rect->y > y1)
		y1 = interest_rect->y;
	if (interest_rect->x + interest_rect->width < x2)
		x2 = interest_rect->x + interest_rect->width;
	if (interest_rect->y + interest_rect->height < y2)
		y2 = interest_rect->y + interest_rect->height;

	if (x1 >= x2 || y1 >= y2) {
		*image_out = NULL;
		*image_extra = NULL;

		return CAIRO_STATUS_SUCCESS;
	}

	status = _cairo_win32_surface_get_subimage (abstract_surface, 
		x1, y1, x2 - x1, y2 - y1,
		&local);
	if (CAIRO_OK (status)) {
		*image_out = (cairo_image_surface_t *)local->image;
		*image_extra = local;

		image_rect->x = x1;
		image_rect->y = y1;
		image_rect->width = x2 - x1;
		image_rect->height = y2 - y1;
	}

	return status;
}

static void
_cairo_win32_surface_release_dest_image (void                   *abstract_surface,
										 cairo_rectangle_t      *interest_rect,
										 cairo_image_surface_t  *image,
										 cairo_rectangle_t      *image_rect,
										 void                   *image_extra)
{
	cairo_win32_surface_t *surface = abstract_surface;
	cairo_win32_surface_t *local = image_extra;

	if (!local)
		return;

	if (!BitBlt (surface->dc,
		image_rect->x, image_rect->y,
		image_rect->width, image_rect->height,
		local->dc,
		0, 0,
		SRCCOPY))
		_cairo_win32_print_gdi_error ("_cairo_win32_surface_release_dest_image");

	cairo_surface_destroy ((cairo_surface_t *)local);
}

static cairo_status_t
_cairo_win32_surface_clone_similar (void             *surface,
									cairo_surface_t  *src,
									cairo_surface_t **clone_out)
{
	return CAIRO_INT_STATUS_UNSUPPORTED;
}

static cairo_status_t
_cairo_win32_surface_set_matrix (void           *abstract_surface, 
								 cairo_matrix_t *matrix)
{
	cairo_win32_surface_t *surface = abstract_surface;

	if (surface->image)
		cairo_surface_set_matrix (surface->image, matrix);

	return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_win32_surface_set_filter (void           *abstract_surface, 
								 cairo_filter_t  filter)
{
	cairo_win32_surface_t *surface = abstract_surface;

	if (surface->image)
		cairo_surface_set_filter (surface->image, filter);

	return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_win32_surface_set_repeat (void *abstract_surface, 
								 int   repeat)
{
	cairo_win32_surface_t *surface = abstract_surface;

	if (surface->image)
		cairo_surface_set_repeat (surface->image, repeat);

	return CAIRO_STATUS_SUCCESS;
}

static cairo_int_status_t
_cairo_win32_surface_composite (cairo_operator_t	operator,
								cairo_pattern_t       	*pattern,
								cairo_surface_t	        *generic_mask,
								void			*abstract_dst,
								int			src_x,
								int			src_y,
								int			mask_x,
								int			mask_y,
								int			dst_x,
								int			dst_y,
								unsigned int		width,
								unsigned int		height)
{
	cairo_win32_surface_t *dst = abstract_dst;
	cairo_win32_surface_t *src;
	cairo_win32_surface_t *mask = (cairo_win32_surface_t *)generic_mask;
	int alpha;
	int integer_transform;
	int itx, ity;

	if (pattern->type != CAIRO_PATTERN_SURFACE ||
		pattern->extend != CAIRO_EXTEND_NONE ||
		pattern->u.surface.surface->backend != dst->base.backend ||
		mask)
		return CAIRO_INT_STATUS_UNSUPPORTED;

	src = (cairo_win32_surface_t *)pattern->u.surface.surface;

	integer_transform = _cairo_matrix_is_integer_translation (&pattern->matrix, &itx, &ity);
	if (!integer_transform)
		return CAIRO_INT_STATUS_UNSUPPORTED;

	alpha = (pattern->color.alpha_short) >> 8;

    if (alpha == 255 &&
	src->format == dst->format &&
		(operator == CAIRO_OPERATOR_SRC ||
		(src->format == CAIRO_FORMAT_RGB24 && operator == CAIRO_OPERATOR_OVER))) {

			if (!BitBlt (dst->dc,
				dst_x, dst_y,
				width, height,
				src->dc,
				src_x + itx, src_y + ity,
				SRCCOPY))
				return _cairo_win32_print_gdi_error ("_cairo_win32_surface_composite");

			return CAIRO_STATUS_SUCCESS;

		} else if (integer_transform &&
			(src->format == CAIRO_FORMAT_RGB24 || src->format == CAIRO_FORMAT_ARGB32) &&
			dst->format == CAIRO_FORMAT_RGB24 &&
			!src->base.repeat &&
			operator == CAIRO_OPERATOR_OVER) {

				BLENDFUNCTION blend_function;

				blend_function.BlendOp = AC_SRC_OVER;
				blend_function.BlendFlags = 0;
				blend_function.SourceConstantAlpha = alpha;
				blend_function.AlphaFormat = src->format == CAIRO_FORMAT_ARGB32 ? AC_SRC_ALPHA : 0;

				fprintf (stderr, "AlphaBlend\n");

				if (!AlphaBlend (dst->dc,
					dst_x, dst_y,
					width, height,
					src->dc,
					src_x + itx, src_y + ity,
					width, height,
					blend_function))
					return _cairo_win32_print_gdi_error ("_cairo_win32_surface_composite");

				return CAIRO_STATUS_SUCCESS;
			}

			return CAIRO_INT_STATUS_UNSUPPORTED;
}

static cairo_int_status_t
_cairo_win32_surface_fill_rectangles (void			*abstract_surface,
									  cairo_operator_t		operator,
									  const cairo_color_t	*color,
									  cairo_rectangle_t		*rects,
									  int			num_rects)
{
	cairo_win32_surface_t *surface = abstract_surface;
	cairo_status_t status;
	COLORREF new_color;
	HBRUSH new_brush;
	int i;

	/* If we have a local image, use the fallback code; it will be as fast
	* as calling out to GDI.
	*/
	if (surface->image)
		return CAIRO_INT_STATUS_UNSUPPORTED;

	/* We could support possibly support more operators for color->alpha = 0xffff.
	* for CAIRO_OPERATOR_SRC, alpha doesn't matter since we know the destination
	* image doesn't have alpha. (surface->pixman_image is non-NULL for all
	* surfaces with alpha.)
	*/
	if (operator != CAIRO_OPERATOR_SRC)
		return CAIRO_INT_STATUS_UNSUPPORTED;

	new_color = RGB (color->red_short >> 8, color->green_short >> 8, color->blue_short >> 8);

	new_brush = CreateSolidBrush (new_color);
	if (!new_brush)
		return _cairo_win32_print_gdi_error ("_cairo_win32_surface_fill_rectangles");

	for (i = 0; i < num_rects; i++) {
		RECT rect;

		rect.left = rects[i].x;
		rect.top = rects[i].y;
		rect.right = rects[i].x + rects[i].width;
		rect.bottom = rects[i].y + rects[i].height;

		if (!FillRect (surface->dc, &rect, new_brush))
			goto FAIL;
	}

	DeleteObject (new_brush);

	return CAIRO_STATUS_SUCCESS;

FAIL:
	status = _cairo_win32_print_gdi_error ("_cairo_win32_surface_fill_rectangles");

	DeleteObject (new_brush);

	return status;
}

static cairo_int_status_t
_cairo_win32_surface_composite_trapezoids (cairo_operator_t	operator,
										   cairo_pattern_t	*pattern,
										   void			*abstract_dst,
										   int			src_x,
										   int			src_y,
										   int			dst_x,
										   int			dst_y,
										   unsigned int		width,
										   unsigned int		height,
										   cairo_trapezoid_t	*traps,
										   int			num_traps)

{
	return CAIRO_INT_STATUS_UNSUPPORTED;
}

static cairo_int_status_t
_cairo_win32_surface_copy_page (void *abstract_surface)
{
    return CAIRO_INT_STATUS_UNSUPPORTED;
}

static cairo_int_status_t
_cairo_win32_surface_show_page (void *abstract_surface)
{
    return CAIRO_INT_STATUS_UNSUPPORTED;
}

static cairo_int_status_t
_cairo_win32_surface_set_clip_region (void              *abstract_surface,
									  pixman_region16_t *region)
{
	cairo_win32_surface_t *surface = abstract_surface;
	cairo_status_t status;

	/* If we are in-memory, then we set the clip on the image surface
	* as well as on the underlying GDI surface.
	*/
	if (surface->image)
		_cairo_surface_set_clip_region (surface->image, region);

	/* The semantics we want is that any clip set by Cairo combines
	* is intersected with the clip on device context that the
	* surface was created for. To implement this, we need to
	* save the original clip when first setting a clip on surface.
	*/

	if (region == NULL) {
		/* Clear any clip set by Cairo, return to the original */

		if (surface->set_clip) {
			if (SelectClipRgn (surface->dc, surface->saved_clip) == ERROR)
				return _cairo_win32_print_gdi_error ("_cairo_win32_surface_set_clip_region");

			if (surface->saved_clip) {
				DeleteObject (surface->saved_clip);
				surface->saved_clip = NULL;
			}

			surface->set_clip = 0;
		}


		return CAIRO_STATUS_SUCCESS;

	} else {
		pixman_box16_t *boxes = pixman_region_rects (region);
		int num_boxes = pixman_region_num_rects (region);
		pixman_box16_t *extents = pixman_region_extents (region);
		RGNDATA *data;
		size_t data_size;
		RECT *rects;
		int i;
		HRGN gdi_region;

		/* Create a GDI region for the cairo region */

		data_size = sizeof (RGNDATAHEADER) + num_boxes * sizeof (RECT);
		data = malloc (data_size);
		if (!data)
			return CAIRO_STATUS_NO_MEMORY;
		rects = (RECT *)data->Buffer;

		data->rdh.dwSize = sizeof (RGNDATAHEADER);
		data->rdh.iType = RDH_RECTANGLES;
		data->rdh.nCount = num_boxes;
		data->rdh.nRgnSize = num_boxes * sizeof (RECT);
		data->rdh.rcBound.left = extents->x1;
		data->rdh.rcBound.top = extents->y1;
		data->rdh.rcBound.right = extents->x2;
		data->rdh.rcBound.bottom = extents->y2;

		for (i = 0; i < num_boxes; i++) {
			rects[i].left = boxes[i].x1;
			rects[i].top = boxes[i].y1;
			rects[i].right = boxes[i].x2;
			rects[i].bottom = boxes[i].y2;
		}

		gdi_region = ExtCreateRegion (NULL, data_size, data);
		free (data);

		if (!gdi_region)
			return CAIRO_STATUS_NO_MEMORY;

		if (surface->set_clip) {
			/* Combine the new region with the original clip */

			if (surface->saved_clip) {
				if (CombineRgn (gdi_region, gdi_region, surface->saved_clip, RGN_AND) == ERROR)
					goto FAIL;
			}

			if (SelectClipRgn (surface->dc, gdi_region) == ERROR)
				goto FAIL;

		} else {
			/* Save the the current region */

			surface->saved_clip = CreateRectRgn (0, 0, 0, 0);
			if (!surface->saved_clip) {
				goto FAIL;	    }

			/* This function has no error return! */
			if (GetClipRgn (surface->dc, surface->saved_clip) == 0) { /* No clip */
				DeleteObject (surface->saved_clip);
				surface->saved_clip = NULL;
			}

			if (ExtSelectClipRgn (surface->dc, gdi_region, RGN_AND) == ERROR)
				goto FAIL;

			surface->set_clip = 1;
		}

		DeleteObject (gdi_region);
		return CAIRO_STATUS_SUCCESS;

FAIL:
		status = _cairo_win32_print_gdi_error ("_cairo_win32_surface_set_clip_region");
		DeleteObject (gdi_region);
		return status;
	}
}

static cairo_status_t
_cairo_win32_surface_show_glyphs (cairo_font_t          *font,
								  cairo_operator_t      operator,
								  cairo_pattern_t	*pattern,
								  void			*abstract_surface,
								  int			source_x,
								  int			source_y,
								  int			dest_x,
								  int			dest_y,
								  unsigned int		width,
								  unsigned int		height,
								  const cairo_glyph_t	*glyphs,
								  int			num_glyphs)
{
	return CAIRO_INT_STATUS_UNSUPPORTED;  
}

cairo_surface_t *
cairo_win32_surface_create (HDC hdc)
{
	cairo_win32_surface_t *surface;
	RECT rect;

	/* Try to figure out the drawing bounds for the Device context
	*/
	if (GetClipBox (hdc, &rect) == ERROR) {
		_cairo_win32_print_gdi_error ("cairo_win32_surface_create");
		return NULL;
	}

	surface = malloc (sizeof (cairo_win32_surface_t));
	if (!surface)
		return NULL;

	surface->image = NULL;
	surface->format = CAIRO_FORMAT_RGB24;

	surface->dc = hdc;
	surface->delete_dc = FALSE;
	surface->bitmap = NULL;

	surface->clip_rect.x = rect.left;
	surface->clip_rect.y = rect.top;
	surface->clip_rect.width = rect.right - rect.left;
	surface->clip_rect.height = rect.bottom - rect.top;

	surface->set_clip = 0;
	surface->saved_clip = NULL;

	_cairo_surface_init (&surface->base, &cairo_win32_surface_backend);

	return (cairo_surface_t *)surface;
}

/**
* _cairo_surface_is_win32:
* @surface: a #cairo_surface_t
* 
* Checks if a surface is an #cairo_win32_surface_t
* 
* Return value: True if the surface is an win32 surface
**/
int
_cairo_surface_is_win32 (cairo_surface_t *surface)
{
	return surface->backend == &cairo_win32_surface_backend;
}

static const cairo_surface_backend_t cairo_win32_surface_backend = {
	_cairo_win32_surface_create_similar,
		_cairo_win32_surface_destroy,
		_cairo_win32_surface_pixels_per_inch,
		_cairo_win32_surface_acquire_source_image,
		_cairo_win32_surface_release_source_image,
		_cairo_win32_surface_acquire_dest_image,
		_cairo_win32_surface_release_dest_image,
		_cairo_win32_surface_clone_similar,
		_cairo_win32_surface_set_matrix,
		_cairo_win32_surface_set_filter,
		_cairo_win32_surface_set_repeat,
		_cairo_win32_surface_composite,
		_cairo_win32_surface_fill_rectangles,
		_cairo_win32_surface_composite_trapezoids,
		_cairo_win32_surface_copy_page,
		_cairo_win32_surface_show_page,
		_cairo_win32_surface_set_clip_region,
		_cairo_win32_surface_show_glyphs
};


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