pjs/gfx/thebes/cairo-gdk-utils.h

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* 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/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Novell code.
*
* The Initial Developer of the Original Code is Novell.
* Portions created by the Initial Developer are Copyright (C) 2006
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* rocallahan@novell.com
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
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* ***** END LICENSE BLOCK ***** */
#ifndef CAIROGDKUTILS_H_
#define CAIROGDKUTILS_H_
#include "cairo.h"
#include <gdk/gdk.h>
CAIRO_BEGIN_DECLS
/**
* This callback encapsulates GDK-based rendering. We assume that the
* execution of the callback is equivalent to compositing some RGBA image of
* size (bounds_width, bounds_height) onto the drawable at offset (offset_x,
* offset_y), clipped to the union of the clip_rects if num_rects is greater
* than zero. This includes the assumption that the same RGBA image
* is composited if you call the callback multiple times with the same closure,
* display and visual during a single cairo_draw_with_gdk call.
*
* @return True when able to draw, False otherwise
*/
typedef cairo_bool_t (* cairo_gdk_drawing_callback)
(void *closure,
cairo_surface_t *surface,
short offset_x, short offset_y,
GdkRectangle * clip_rects, unsigned int num_rects);
/**
* This type specifies whether the native drawing callback draws all pixels
* in its bounds opaquely, independent of the contents of the target drawable,
* or whether it leaves pixels transparent/translucent or depends on the
* existing contents of the target drawable in some way.
*/
typedef enum _cairo_gdk_drawing_opacity {
CAIRO_GDK_DRAWING_OPAQUE,
CAIRO_GDK_DRAWING_TRANSPARENT
} cairo_gdk_drawing_opacity_t;
/**
* This type encodes the capabilities of the native drawing callback.
*
* If CAIRO_GDK_DRAWING_SUPPORTS_CLIP_RECT is set, then 'num_rects' can be
* zero or one in the call to the callback. Otherwise 'num_rects' will be
* zero.
*/
typedef enum {
CAIRO_GDK_DRAWING_SUPPORTS_CLIP_RECT = 0x02,
} cairo_gdk_drawing_support_t;
/**
* Draw GDK output into any cairo context. All cairo transforms and effects
* are honored, including the current operator. This is equivalent to a
* cairo_set_source_surface and then cairo_paint.
* @param cr the context to draw into
* @param drawable a GDK Drawable that we're targetting
* @param callback the code to perform GDK rendering
* @param closure associated data
* @param width the width of the putative image drawn by the callback
* @param height the height of the putative image drawn by the callback
* @param is_opaque set to CAIRO_GDK_DRAWING_IS_OPAQUE to indicate
* that all alpha values of the putative image will be 1.0; the pixels drawn into
* the Drawable must not depend on the prior contents of the Drawable
* in any way
* @param capabilities the capabilities of the callback as described above.
* @param result if non-NULL, we *may* fill in the struct with information about
* the rendered image. 'surface' may be filled in with a surface representing
* the image, similar to the target of 'cr'. If 'uniform_alpha' is True then
* every pixel of the image has the same alpha value 'alpha'. If
* 'uniform_color' is True then every pixel of the image has the same RGB
* color (r, g, b). If the image has uniform color and alpha (or alpha is zero,
* in which case the color is always uniform) then we won't bother returning
* a surface for it.
*/
void cairo_draw_with_gdk (cairo_t *cr,
cairo_gdk_drawing_callback callback,
void * closure,
unsigned int width, unsigned int height,
cairo_gdk_drawing_opacity_t is_opaque,
cairo_gdk_drawing_support_t capabilities,
cairo_gdk_drawing_result_t *result);
CAIRO_END_DECLS
#endif /*CAIROGDKUTILS_H_*/