1 /*
2  * Copyright © 2010 Red Hat, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person
5  * obtaining a copy of this software and associated documentation
6  * files (the "Software"), to deal in the Software without
7  * restriction, including without limitation the rights to use, copy,
8  * modify, merge, publish, distribute, sublicense, and/or sell copies
9  * of the Software, and to permit persons to whom the Software is
10  * furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  *
24  * Author: Benjamin Otte <otte@gnome.org>
25  */
26 
27 #include "cairo-test.h"
28 
29 #define RECT 10
30 #define SPACE 5
31 
32 static void
paint_with_alpha(cairo_t * cr)33 paint_with_alpha (cairo_t *cr)
34 {
35     cairo_paint_with_alpha (cr, 0.0);
36 }
37 
38 static void
mask_with_solid(cairo_t * cr)39 mask_with_solid (cairo_t *cr)
40 {
41     cairo_pattern_t *pattern = cairo_pattern_create_rgba (1, 0, 0, 0);
42 
43     cairo_mask (cr, pattern);
44 
45     cairo_pattern_destroy (pattern);
46 }
47 
48 static void
mask_with_empty_gradient(cairo_t * cr)49 mask_with_empty_gradient (cairo_t *cr)
50 {
51     cairo_pattern_t *pattern = cairo_pattern_create_linear (1, 2, 3, 4);
52 
53     cairo_mask (cr, pattern);
54 
55     cairo_pattern_destroy (pattern);
56 }
57 
58 static void
mask_with_gradient(cairo_t * cr)59 mask_with_gradient (cairo_t *cr)
60 {
61     cairo_pattern_t *pattern = cairo_pattern_create_radial (1, 2, 3, 4, 5, 6);
62 
63     cairo_pattern_add_color_stop_rgba (pattern, 0, 1, 0, 0, 0);
64     cairo_pattern_add_color_stop_rgba (pattern, 0, 0, 0, 1, 0);
65 
66     cairo_mask (cr, pattern);
67 
68     cairo_pattern_destroy (pattern);
69 }
70 
71 static void
mask_with_surface(cairo_t * cr)72 mask_with_surface (cairo_t *cr)
73 {
74     cairo_surface_t *surface = cairo_surface_create_similar (cairo_get_target (cr),
75                                                              CAIRO_CONTENT_COLOR_ALPHA,
76                                                              RECT,
77                                                              RECT);
78 
79     cairo_mask_surface (cr, surface, 0, 0);
80 
81     cairo_surface_destroy (surface);
82 }
83 
84 static void
mask_with_alpha_surface(cairo_t * cr)85 mask_with_alpha_surface (cairo_t *cr)
86 {
87     cairo_surface_t *surface = cairo_surface_create_similar (cairo_get_target (cr),
88                                                              CAIRO_CONTENT_ALPHA,
89                                                              RECT / 2,
90                                                              RECT / 2);
91     cairo_pattern_t *pattern = cairo_pattern_create_for_surface (surface);
92     cairo_pattern_set_extend (pattern, CAIRO_EXTEND_REFLECT);
93 
94     cairo_mask (cr, pattern);
95 
96     cairo_pattern_destroy (pattern);
97     cairo_surface_destroy (surface);
98 }
99 
100 static void
mask_with_nonclear_surface(cairo_t * cr)101 mask_with_nonclear_surface (cairo_t *cr)
102 {
103     static unsigned char data[8 * 4] = { 0, };
104     cairo_surface_t *surface = cairo_image_surface_create_for_data (data,
105                                                                     CAIRO_FORMAT_A1,
106                                                                     16, 8, 4);
107 
108     cairo_mask_surface (cr, surface, 0, 0);
109 
110     cairo_surface_destroy (surface);
111 }
112 
113 static void
mask_with_0x0_surface(cairo_t * cr)114 mask_with_0x0_surface (cairo_t *cr)
115 {
116     cairo_surface_t *surface = cairo_surface_create_similar (cairo_get_target (cr),
117                                                              CAIRO_CONTENT_COLOR_ALPHA,
118                                                              0, 0);
119 
120     cairo_mask_surface (cr, surface, 0, 0);
121 
122     cairo_surface_destroy (surface);
123 }
124 
125 static void
mask_with_extend_none(cairo_t * cr)126 mask_with_extend_none (cairo_t *cr)
127 {
128     cairo_surface_t *surface = cairo_surface_create_similar (cairo_get_target (cr),
129                                                              CAIRO_CONTENT_COLOR_ALPHA,
130                                                              RECT,
131                                                              RECT);
132 
133     cairo_mask_surface (cr, surface, 2 * RECT, 2 * RECT);
134 
135     cairo_surface_destroy (surface);
136 }
137 
138 typedef void (* mask_func_t) (cairo_t *);
139 
140 static mask_func_t mask_funcs[] = {
141   paint_with_alpha,
142   mask_with_solid,
143   mask_with_empty_gradient,
144   mask_with_gradient,
145   mask_with_surface,
146   mask_with_alpha_surface,
147   mask_with_nonclear_surface,
148   mask_with_0x0_surface,
149   mask_with_extend_none
150 };
151 
152 static cairo_operator_t operators[] = {
153   CAIRO_OPERATOR_CLEAR,
154   CAIRO_OPERATOR_SOURCE,
155   CAIRO_OPERATOR_OVER,
156   CAIRO_OPERATOR_IN,
157   CAIRO_OPERATOR_DEST_ATOP,
158   CAIRO_OPERATOR_SATURATE,
159   CAIRO_OPERATOR_MULTIPLY
160 };
161 
162 static cairo_test_status_t
draw(cairo_t * cr,int width,int height)163 draw (cairo_t *cr, int width, int height)
164 {
165     unsigned int i, op;
166 
167     /* 565-compatible gray background */
168     cairo_set_source_rgb (cr, 0.51613, 0.55555, 0.51613);
169     cairo_paint (cr);
170 
171     cairo_set_source_rgb (cr, 0.0, 1.0, 0.0); /* green */
172     /* mask with zero-alpha in several ways */
173 
174     cairo_translate (cr, SPACE, SPACE);
175 
176     for (op = 0; op < ARRAY_LENGTH (operators); op++) {
177         cairo_set_operator (cr, operators[op]);
178 
179         for (i = 0; i < ARRAY_LENGTH (mask_funcs); i++) {
180             cairo_save (cr);
181             cairo_translate (cr, i * (RECT + SPACE), op * (RECT + SPACE));
182             cairo_rectangle (cr, 0, 0, RECT, RECT);
183             cairo_clip (cr);
184             mask_funcs[i] (cr);
185             cairo_restore (cr);
186         }
187     }
188 
189     return CAIRO_TEST_SUCCESS;
190 }
191 
192 CAIRO_TEST (zero_mask,
193 	    "Testing that masking with zero alpha works",
194 	    "alpha, mask", /* keywords */
195 	    NULL, /* requirements */
196 	    SPACE + (RECT + SPACE) * ARRAY_LENGTH (mask_funcs),
197 	    SPACE + (RECT + SPACE) * ARRAY_LENGTH (operators),
198 	    NULL, draw)
199