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
|
/* Shared code for cairo based loaders like svgload and pdfload.
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/vips.h>
#include <vips/internal.h>
/* Convert from Cairo-style premultiplied BGRA to RGBA.
*
* See also openslide's argb2rgba().
*/
void
vips__premultiplied_bgra2rgba(guint32 *restrict p, int n)
{
int x;
for (x = 0; x < n; x++) {
guint32 bgra = GUINT32_FROM_BE(p[x]);
guint8 a = bgra & 0xff;
guint32 rgba;
if (a == 0 ||
a == 255)
rgba =
(bgra & 0x00ff00ff) |
(bgra & 0x0000ff00) << 16 |
(bgra & 0xff000000) >> 16;
else
/* Undo premultiplication.
*/
rgba =
((255 * ((bgra >> 8) & 0xff) / a) << 24) |
((255 * ((bgra >> 16) & 0xff) / a) << 16) |
((255 * ((bgra >> 24) & 0xff) / a) << 8) |
a;
p[x] = GUINT32_TO_BE(rgba);
}
}
/* Unpremultiplied RGBA (vips convention) to cairo-style premul BGRA.
*/
void
vips__rgba2bgra_premultiplied(guint32 *restrict p, int n)
{
int x;
for (x = 0; x < n; x++) {
guint32 rgba = GUINT32_FROM_BE(p[x]);
guint8 a = rgba & 0xff;
guint32 bgra;
if (a == 0)
bgra = 0;
else if (a == 255)
bgra = (rgba & 0x00ff00ff) |
(rgba & 0x0000ff00) << 16 |
(rgba & 0xff000000) >> 16;
else {
int r = (rgba >> 24) & 0xff;
int g = (rgba >> 16) & 0xff;
int b = (rgba >> 8) & 0xff;
r = ((r * a) + 128) >> 8;
g = ((g * a) + 128) >> 8;
b = ((b * a) + 128) >> 8;
bgra = (b << 24) | (g << 16) | (r << 8) | a;
}
p[x] = GUINT32_TO_BE(bgra);
}
}
/* Convert from PDFium-style BGRA to RGBA.
*/
void
vips__bgra2rgba(guint32 *restrict p, int n)
{
int x;
for (x = 0; x < n; x++) {
guint32 bgra = GUINT32_FROM_BE(p[x]);
guint rgba;
/* Leave G and A, swap R and B.
*/
rgba =
(bgra & 0x00ff00ff) |
(bgra & 0x0000ff00) << 16 |
(bgra & 0xff000000) >> 16;
p[x] = GUINT32_TO_BE(rgba);
}
}
|
