gfx/thebes/src/cairo-gdk-utils.c

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
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   8  * http://www.mozilla.org/MPL/
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  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is Novell code.
  16  *
  17  * The Initial Developer of the Original Code is Novell.
  18  * Portions created by the Initial Developer are Copyright (C) 2006
  19  * the Initial Developer. All Rights Reserved.
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  21  * Contributor(s):
  22  *   rocallahan@novell.com
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  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either the GNU General Public License Version 2 or later (the "GPL"), or
  26  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include "cairo-gdk-utils.h"
  39
  40 #include <stdlib.h>
  41
  42 #if   HAVE_STDINT_H
  43 #include <stdint.h>
  44 #elif HAVE_INTTYPES_H
  45 #include <inttypes.h>
  46 #elif HAVE_SYS_INT_TYPES_H
  47 #include <sys/int_types.h>
  48 #endif
  49
  50
  51 /* We have three basic strategies available:
  52    1) 'direct': cr targets a native surface, and other conditions are met: we can
  53       pass the underlying drawable directly to the callback
  54    2) 'opaque': the image is opaque: we can create a temporary cairo native surface,
  55       pass its underlying drawable to the callback, and paint the result
  56       using cairo
  57    3) 'default': create a temporary cairo native surface, fill with black, pass its
  58       underlying drawable to the callback, copy the results to a cairo
  59       image surface, repeat with a white background, update the on-black
  60       image alpha values by comparing the two images, then paint the on-black
  61       image using cairo
  62    Sure would be nice to have an X extension to do 3 for us on the server...
  63 */
  64
  65 static cairo_bool_t
  66 _convert_coord_to_short (double coord, short *v)
  67 {
  68     *v = (short)coord;
  69     /* XXX allow some tolerance here? */
  70     return *v == coord;
  71 }
  72
  73 static cairo_bool_t
  74 _convert_coord_to_unsigned_short (double coord, unsigned short *v)
  75 {
  76     *v = (unsigned short)coord;
  77     /* XXX allow some tolerance here? */
  78     return *v == coord;
  79 }
  80
  81
  82 void cairo_draw_with_gdk (cairo_t *cr,
  83                            cairo_gdk_drawing_callback callback,
  84                            void * closure,
  85                            unsigned int width, unsigned int height,
  86                            cairo_gdk_drawing_opacity_t is_opaque,
  87                            cairo_gdk_drawing_support_t capabilities,
  88                            cairo_gdk_drawing_result_t *result)
  89 {
  90     double device_offset_x, device_offset_y;
  91     short offset_x = 0, offset_y = 0;
  92     //cairo_surface_t * target = cairo_get_group_target (cr);
  93     cairo_surface_t * target = cairo_get_target (cr);
  94     cairo_matrix_t matrix;
  95
  96     cairo_surface_get_device_offset (target, &device_offset_x, &device_offset_y);
  97     cairo_get_matrix (cr, &matrix);
  98
  99     _convert_coord_to_short (matrix.x0 + device_offset_x, &offset_x);
 100     _convert_coord_to_short (matrix.y0 + device_offset_y, &offset_y);
 101
 102     cairo_surface_flush (target);
 103     callback (closure, target, offset_x, offset_y, NULL, 0);
 104     cairo_surface_mark_dirty (target);
 105 }
 106
 107