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
|
#include <u.h>
#include <libc.h>
#include <thread.h>
#include <draw.h>
#include <memdraw.h>
#include <geometry.h>
#include "libobj/obj.h"
#include "graphics.h"
#include "internal.h"
/*
* see also “The Importance of Being Linear”, Gritz and d'Eon, GPU Gems 3, Ch. 24, December 2007
*/
/*
* generated with:
* % seq 0 255 | awk '{$0 = $0/255; if($0 > 0.04045) $0 = (($0+0.055)/1.055)^2.4; else $0 = $0/12.92; printf("\t0x%02X,%s", int($0*255+0.5), NR%8 == 0? "\n": "")}'
*/
static uchar srgb2lineartab[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
0x02, 0x02, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x04, 0x04, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05,
0x05, 0x06, 0x06, 0x06, 0x06, 0x07, 0x07, 0x07,
0x08, 0x08, 0x08, 0x08, 0x09, 0x09, 0x09, 0x0A,
0x0A, 0x0A, 0x0B, 0x0B, 0x0C, 0x0C, 0x0C, 0x0D,
0x0D, 0x0D, 0x0E, 0x0E, 0x0F, 0x0F, 0x10, 0x10,
0x11, 0x11, 0x11, 0x12, 0x12, 0x13, 0x13, 0x14,
0x14, 0x15, 0x16, 0x16, 0x17, 0x17, 0x18, 0x18,
0x19, 0x19, 0x1A, 0x1B, 0x1B, 0x1C, 0x1D, 0x1D,
0x1E, 0x1E, 0x1F, 0x20, 0x20, 0x21, 0x22, 0x23,
0x23, 0x24, 0x25, 0x25, 0x26, 0x27, 0x28, 0x29,
0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2D, 0x2E, 0x2F,
0x30, 0x31, 0x32, 0x33, 0x33, 0x34, 0x35, 0x36,
0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E,
0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
0x47, 0x48, 0x49, 0x4A, 0x4C, 0x4D, 0x4E, 0x4F,
0x50, 0x51, 0x52, 0x54, 0x55, 0x56, 0x57, 0x58,
0x5A, 0x5B, 0x5C, 0x5D, 0x5F, 0x60, 0x61, 0x63,
0x64, 0x65, 0x67, 0x68, 0x69, 0x6B, 0x6C, 0x6D,
0x6F, 0x70, 0x72, 0x73, 0x74, 0x76, 0x77, 0x79,
0x7A, 0x7C, 0x7D, 0x7F, 0x80, 0x82, 0x83, 0x85,
0x86, 0x88, 0x8A, 0x8B, 0x8D, 0x8E, 0x90, 0x92,
0x93, 0x95, 0x97, 0x98, 0x9A, 0x9C, 0x9D, 0x9F,
0xA1, 0xA3, 0xA4, 0xA6, 0xA8, 0xAA, 0xAB, 0xAD,
0xAF, 0xB1, 0xB3, 0xB5, 0xB7, 0xB8, 0xBA, 0xBC,
0xBE, 0xC0, 0xC2, 0xC4, 0xC6, 0xC8, 0xCA, 0xCC,
0xCE, 0xD0, 0xD2, 0xD4, 0xD6, 0xD8, 0xDA, 0xDC,
0xDE, 0xE0, 0xE2, 0xE5, 0xE7, 0xE9, 0xEB, 0xED,
0xEF, 0xF2, 0xF4, 0xF6, 0xF8, 0xFA, 0xFD, 0xFF,
};
/*
* generated with:
* % seq 0 255 | awk '{$0 = $0/255.0; if($0 > 0.0031308) $0 = 1.055*$0^(1.0/2.4)-0.055; else $0 = $0*12.92; printf("\t0x%02X,%s", int($0*255+0.5), NR%8 == 0? "\n": "")}'
*/
static uchar linear2srgbtab[] = {
0x00, 0x0D, 0x16, 0x1C, 0x22, 0x26, 0x2A, 0x2E,
0x32, 0x35, 0x38, 0x3B, 0x3D, 0x40, 0x42, 0x45,
0x47, 0x49, 0x4B, 0x4D, 0x4F, 0x51, 0x53, 0x55,
0x56, 0x58, 0x5A, 0x5C, 0x5D, 0x5F, 0x60, 0x62,
0x63, 0x65, 0x66, 0x68, 0x69, 0x6A, 0x6C, 0x6D,
0x6E, 0x70, 0x71, 0x72, 0x73, 0x75, 0x76, 0x77,
0x78, 0x79, 0x7A, 0x7C, 0x7D, 0x7E, 0x7F, 0x80,
0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88,
0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90,
0x91, 0x92, 0x93, 0x94, 0x94, 0x95, 0x96, 0x97,
0x98, 0x99, 0x9A, 0x9B, 0x9B, 0x9C, 0x9D, 0x9E,
0x9F, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA3, 0xA4,
0xA5, 0xA6, 0xA7, 0xA7, 0xA8, 0xA9, 0xAA, 0xAA,
0xAB, 0xAC, 0xAD, 0xAD, 0xAE, 0xAF, 0xAF, 0xB0,
0xB1, 0xB2, 0xB2, 0xB3, 0xB4, 0xB4, 0xB5, 0xB6,
0xB6, 0xB7, 0xB8, 0xB9, 0xB9, 0xBA, 0xBB, 0xBB,
0xBC, 0xBD, 0xBD, 0xBE, 0xBE, 0xBF, 0xC0, 0xC0,
0xC1, 0xC2, 0xC2, 0xC3, 0xC4, 0xC4, 0xC5, 0xC5,
0xC6, 0xC7, 0xC7, 0xC8, 0xC8, 0xC9, 0xCA, 0xCA,
0xCB, 0xCB, 0xCC, 0xCD, 0xCD, 0xCE, 0xCE, 0xCF,
0xD0, 0xD0, 0xD1, 0xD1, 0xD2, 0xD2, 0xD3, 0xD4,
0xD4, 0xD5, 0xD5, 0xD6, 0xD6, 0xD7, 0xD7, 0xD8,
0xD8, 0xD9, 0xDA, 0xDA, 0xDB, 0xDB, 0xDC, 0xDC,
0xDD, 0xDD, 0xDE, 0xDE, 0xDF, 0xDF, 0xE0, 0xE0,
0xE1, 0xE2, 0xE2, 0xE3, 0xE3, 0xE4, 0xE4, 0xE5,
0xE5, 0xE6, 0xE6, 0xE7, 0xE7, 0xE8, 0xE8, 0xE9,
0xE9, 0xEA, 0xEA, 0xEB, 0xEB, 0xEC, 0xEC, 0xED,
0xED, 0xEE, 0xEE, 0xEE, 0xEF, 0xEF, 0xF0, 0xF0,
0xF1, 0xF1, 0xF2, 0xF2, 0xF3, 0xF3, 0xF4, 0xF4,
0xF5, 0xF5, 0xF6, 0xF6, 0xF6, 0xF7, 0xF7, 0xF8,
0xF8, 0xF9, 0xF9, 0xFA, 0xFA, 0xFB, 0xFB, 0xFB,
0xFC, 0xFC, 0xFD, 0xFD, 0xFE, 0xFE, 0xFF, 0xFF,
};
/*
* Equations 5.32 and 5.30 from “Display Encoding”, Real-Time Rendering 4th ed. § 5.6
*/
//static double
//_srgb2linear(double c)
//{
// if(c > 0.04045)
// return pow((c + 0.055)/1.055, 2.4);
// return c/12.92;
//}
//
//static double
//_linear2srgb(double c)
//{
// if(c > 0.0031308)
// return 1.055*pow(c, 1.0/2.4) - 0.055;
// return 12.92*c;
//}
static double
_srgb2linear(double c)
{
c = fclamp(c, 0, 1);
return srgb2lineartab[(int)(c*255)]/255.0;
}
static double
_linear2srgb(double c)
{
c = fclamp(c, 0, 1);
return linear2srgbtab[(int)(c*255)]/255.0;
}
Color
srgb2linear(Color c)
{
c.r = _srgb2linear(c.r);
c.g = _srgb2linear(c.g);
c.b = _srgb2linear(c.b);
return c;
}
Color
linear2srgb(Color c)
{
c.r = _linear2srgb(c.r);
c.g = _linear2srgb(c.g);
c.b = _linear2srgb(c.b);
return c;
}
ulong
rgba2xrgb(ulong c)
{
return (c & 0xFF)<<24|(c>>24 & 0xFF)<<16|
(c>>16 & 0xFF)<<8|(c>>8 & 0xFF);
}
|
