1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
/* cairo - a vector graphics library with display and print output
*
* Copyright © 2002 University of Southern California
* 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 University of Southern
* California.
*
* Contributor(s):
* Carl D. Worth <cworth@cworth.org>
*/
#include "cairoint.h"
static cairo_color_t const cairo_color_white = {
1.0, 1.0, 1.0, 1.0,
0xffff, 0xffff, 0xffff, 0xffff
};
static cairo_color_t const cairo_color_black = {
0.0, 0.0, 0.0, 1.0,
0x0, 0x0, 0x0, 0xffff
};
static cairo_color_t const cairo_color_transparent = {
0.0, 0.0, 0.0, 0.0,
0x0, 0x0, 0x0, 0x0
};
static cairo_color_t const cairo_color_magenta = {
1.0, 0.0, 1.0, 1.0,
0xffff, 0x0, 0xffff, 0xffff
};
const cairo_color_t *
_cairo_stock_color (cairo_stock_t stock)
{
switch (stock) {
case CAIRO_STOCK_WHITE:
return &cairo_color_white;
case CAIRO_STOCK_BLACK:
return &cairo_color_black;
case CAIRO_STOCK_TRANSPARENT:
return &cairo_color_transparent;
}
ASSERT_NOT_REACHED;
/* If the user can get here somehow, give a color that indicates a
* problem. */
return &cairo_color_magenta;
}
void
_cairo_color_init (cairo_color_t *color)
{
*color = cairo_color_white;
}
void
_cairo_color_init_rgb (cairo_color_t *color,
double red, double green, double blue)
{
_cairo_color_init_rgba (color, red, green, blue, 1.0);
}
/* We multiply colors by (0x10000 - epsilon), such that we get a uniform
* range even for 0xffff. In other words, (1.0 - epsilon) would convert
* to 0xffff, not 0xfffe.
*/
#define CAIRO_COLOR_ONE_MINUS_EPSILON (65536.0 - 1e-5)
static void
_cairo_color_compute_shorts (cairo_color_t *color)
{
color->red_short = color->red * color->alpha * CAIRO_COLOR_ONE_MINUS_EPSILON;
color->green_short = color->green * color->alpha * CAIRO_COLOR_ONE_MINUS_EPSILON;
color->blue_short = color->blue * color->alpha * CAIRO_COLOR_ONE_MINUS_EPSILON;
color->alpha_short = color->alpha * CAIRO_COLOR_ONE_MINUS_EPSILON;
}
void
_cairo_color_init_rgba (cairo_color_t *color,
double red, double green, double blue,
double alpha)
{
color->red = red;
color->green = green;
color->blue = blue;
color->alpha = alpha;
_cairo_color_compute_shorts (color);
}
void
_cairo_color_multiply_alpha (cairo_color_t *color,
double alpha)
{
color->alpha *= alpha;
_cairo_color_compute_shorts (color);
}
void
_cairo_color_get_rgba (cairo_color_t *color,
double *red,
double *green,
double *blue,
double *alpha)
{
*red = color->red;
*green = color->green;
*blue = color->blue;
*alpha = color->alpha;
}
void
_cairo_color_get_rgba_premultiplied (cairo_color_t *color,
double *red,
double *green,
double *blue,
double *alpha)
{
*red = color->red * color->alpha;
*green = color->green * color->alpha;
*blue = color->blue * color->alpha;
*alpha = color->alpha;
}
|
