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
|
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef GFX_COLOR_H
#define GFX_COLOR_H
#include "mozilla/Attributes.h" // for MOZ_ALWAYS_INLINE
#include "mozilla/EndianUtils.h" // for mozilla::NativeEndian::swapToBigEndian
/**
* GFX_BLOCK_RGB_TO_FRGB(from,to)
* sizeof(*from) == sizeof(char)
* sizeof(*to) == sizeof(uint32_t)
*
* Copy 4 pixels at a time, reading blocks of 12 bytes (RGB x4)
* and writing blocks of 16 bytes (FRGB x4)
*/
#define GFX_BLOCK_RGB_TO_FRGB(from,to) \
PR_BEGIN_MACRO \
uint32_t m0 = ((uint32_t*)from)[0], \
m1 = ((uint32_t*)from)[1], \
m2 = ((uint32_t*)from)[2], \
rgbr = mozilla::NativeEndian::swapToBigEndian(m0), \
gbrg = mozilla::NativeEndian::swapToBigEndian(m1), \
brgb = mozilla::NativeEndian::swapToBigEndian(m2), \
p0, p1, p2, p3; \
p0 = 0xFF000000 | ((rgbr) >> 8); \
p1 = 0xFF000000 | ((rgbr) << 16) | ((gbrg) >> 16); \
p2 = 0xFF000000 | ((gbrg) << 8) | ((brgb) >> 24); \
p3 = 0xFF000000 | (brgb); \
to[0] = p0; to[1] = p1; to[2] = p2; to[3] = p3; \
PR_END_MACRO
/**
* Fast approximate division by 255. It has the property that
* for all 0 <= n <= 255*255, GFX_DIVIDE_BY_255(n) == n/255.
* But it only uses two adds and two shifts instead of an
* integer division (which is expensive on many processors).
*
* equivalent to ((v)/255)
*/
#define GFX_DIVIDE_BY_255(v) \
(((((unsigned)(v)) << 8) + ((unsigned)(v)) + 255) >> 16)
/**
* Fast premultiply
*
* equivalent to (((c)*(a))/255)
*/
uint8_t MOZ_ALWAYS_INLINE gfxPreMultiply(uint8_t c, uint8_t a) {
return GFX_DIVIDE_BY_255((c)*(a));
}
/**
* Pack the 4 8-bit channels (A,R,G,B)
* into a 32-bit packed NON-premultiplied pixel.
*/
uint32_t MOZ_ALWAYS_INLINE
gfxPackedPixelNoPreMultiply(uint8_t a, uint8_t r, uint8_t g, uint8_t b) {
return (((a) << 24) | ((r) << 16) | ((g) << 8) | (b));
}
/**
* Pack the 4 8-bit channels (A,R,G,B)
* into a 32-bit packed premultiplied pixel.
*/
uint32_t MOZ_ALWAYS_INLINE
gfxPackedPixel(uint8_t a, uint8_t r, uint8_t g, uint8_t b) {
if (a == 0x00)
return 0x00000000;
else if (a == 0xFF) {
return gfxPackedPixelNoPreMultiply(a, r, g, b);
} else {
return ((a) << 24) |
(gfxPreMultiply(r,a) << 16) |
(gfxPreMultiply(g,a) << 8) |
(gfxPreMultiply(b,a));
}
}
#endif /* _GFX_COLOR_H */
|
