1 /* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
2 /* cairo - a vector graphics library with display and print output
3 *
4 * Copyright © 2011 Intel Corporation
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it either under the terms of the GNU Lesser General Public
8 * License version 2.1 as published by the Free Software Foundation
9 * (the "LGPL") or, at your option, under the terms of the Mozilla
10 * Public License Version 1.1 (the "MPL"). If you do not alter this
11 * notice, a recipient may use your version of this file under either
12 * the MPL or the LGPL.
13 *
14 * You should have received a copy of the LGPL along with this library
15 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
17 * You should have received a copy of the MPL along with this library
18 * in the file COPYING-MPL-1.1
19 *
20 * The contents of this file are subject to the Mozilla Public License
21 * Version 1.1 (the "License"); you may not use this file except in
22 * compliance with the License. You may obtain a copy of the License at
23 * http://www.mozilla.org/MPL/
24 *
25 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
26 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
27 * the specific language governing rights and limitations.
28 *
29 * The Original Code is the cairo graphics library.
30 *
31 * The Initial Developer of the Original Code is University of Southern
32 * California.
33 *
34 * Contributor(s):
35 * Chris Wilson <chris@chris-wilson.co.uk>
36 */
37
38 #include "cairoint.h"
39 #include "cairo-clip-inline.h"
40 #include "cairo-clip-private.h"
41 #include "cairo-error-private.h"
42 #include "cairo-freed-pool-private.h"
43 #include "cairo-gstate-private.h"
44 #include "cairo-path-fixed-private.h"
45 #include "cairo-pattern-private.h"
46 #include "cairo-composite-rectangles-private.h"
47 #include "cairo-region-private.h"
48
49 static cairo_bool_t
can_convert_to_polygon(const cairo_clip_t * clip)50 can_convert_to_polygon (const cairo_clip_t *clip)
51 {
52 cairo_clip_path_t *clip_path = clip->path;
53 cairo_antialias_t antialias = clip_path->antialias;
54
55 while ((clip_path = clip_path->prev) != NULL) {
56 if (clip_path->antialias != antialias)
57 return FALSE;
58 }
59
60 return TRUE;
61 }
62
63 cairo_int_status_t
_cairo_clip_get_polygon(const cairo_clip_t * clip,cairo_polygon_t * polygon,cairo_fill_rule_t * fill_rule,cairo_antialias_t * antialias)64 _cairo_clip_get_polygon (const cairo_clip_t *clip,
65 cairo_polygon_t *polygon,
66 cairo_fill_rule_t *fill_rule,
67 cairo_antialias_t *antialias)
68 {
69 cairo_status_t status;
70 cairo_clip_path_t *clip_path;
71
72 if (_cairo_clip_is_all_clipped (clip)) {
73 _cairo_polygon_init (polygon, NULL, 0);
74 return CAIRO_INT_STATUS_SUCCESS;
75 }
76
77 /* If there is no clip, we need an infinite polygon */
78 assert (clip && (clip->path || clip->num_boxes));
79
80 if (clip->path == NULL) {
81 *fill_rule = CAIRO_FILL_RULE_WINDING;
82 *antialias = CAIRO_ANTIALIAS_DEFAULT;
83 return _cairo_polygon_init_box_array (polygon,
84 clip->boxes,
85 clip->num_boxes);
86 }
87
88 /* check that residual is all of the same type/tolerance */
89 if (! can_convert_to_polygon (clip))
90 return CAIRO_INT_STATUS_UNSUPPORTED;
91
92 if (clip->num_boxes < 2)
93 _cairo_polygon_init_with_clip (polygon, clip);
94 else
95 _cairo_polygon_init_with_clip (polygon, NULL);
96
97 clip_path = clip->path;
98 *fill_rule = clip_path->fill_rule;
99 *antialias = clip_path->antialias;
100
101 status = _cairo_path_fixed_fill_to_polygon (&clip_path->path,
102 clip_path->tolerance,
103 polygon);
104 if (unlikely (status))
105 goto err;
106
107 if (clip->num_boxes > 1) {
108 status = _cairo_polygon_intersect_with_boxes (polygon, fill_rule,
109 clip->boxes, clip->num_boxes);
110 if (unlikely (status))
111 goto err;
112 }
113
114 polygon->limits = NULL;
115 polygon->num_limits = 0;
116
117 while ((clip_path = clip_path->prev) != NULL) {
118 cairo_polygon_t next;
119
120 _cairo_polygon_init (&next, NULL, 0);
121 status = _cairo_path_fixed_fill_to_polygon (&clip_path->path,
122 clip_path->tolerance,
123 &next);
124 if (likely (status == CAIRO_STATUS_SUCCESS))
125 status = _cairo_polygon_intersect (polygon, *fill_rule,
126 &next, clip_path->fill_rule);
127 _cairo_polygon_fini (&next);
128 if (unlikely (status))
129 goto err;
130
131 *fill_rule = CAIRO_FILL_RULE_WINDING;
132 }
133
134 return CAIRO_STATUS_SUCCESS;
135
136 err:
137 _cairo_polygon_fini (polygon);
138 return status;
139 }
140
141 cairo_bool_t
_cairo_clip_is_polygon(const cairo_clip_t * clip)142 _cairo_clip_is_polygon (const cairo_clip_t *clip)
143 {
144 if (_cairo_clip_is_all_clipped (clip))
145 return TRUE;
146
147 /* If there is no clip, we need an infinite polygon */
148 if (clip == NULL)
149 return FALSE;
150
151 if (clip->path == NULL)
152 return TRUE;
153
154 /* check that residual is all of the same type/tolerance */
155 return can_convert_to_polygon (clip);
156 }
157