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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
/* -*- 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/. */
// Helper functions.
float hardlight(float dest, float src) {
if (src <= 0.5) {
return dest * (2.0 * src);
} else {
// Note: we substitute (2*src-1) into the screen formula below.
return 2.0 * dest + 2.0 * src - 1.0 - 2.0 * dest * src;
}
}
float dodge(float dest, float src) {
if (dest == 0.0) {
return 0.0;
} else if (src == 1.0) {
return 1.0;
} else {
return min(1.0, dest / (1.0 - src));
}
}
float burn(float dest, float src) {
if (dest == 1.0) {
return 1.0;
} else if (src == 0.0) {
return 0.0;
} else {
return 1.0 - min(1.0, (1.0 - dest) / src);
}
}
float darken(float dest) {
if (dest <= 0.25) {
return ((16.0 * dest - 12.0) * dest + 4.0) * dest;
} else {
return sqrt(dest);
}
}
float softlight(float dest, float src) {
if (src <= 0.5) {
return dest - (1.0 - 2.0 * src) * dest * (1.0 - dest);
} else {
return dest + (2.0 * src - 1.0) * (darken(dest) - dest);
}
}
float Lum(float3 c) {
return dot(float3(0.3, 0.59, 0.11), c);
}
float3 ClipColor(float3 c) {
float L = Lum(c);
float n = min(min(c.r, c.g), c.b);
float x = max(max(c.r, c.g), c.b);
if (n < 0.0) {
c = L + (((c - L) * L) / (L - n));
}
if (x > 1.0) {
c = L + (((c - L) * (1.0 - L)) / (x - L));
}
return c;
}
float3 SetLum(float3 c, float L) {
float d = L - Lum(c);
return ClipColor(float3(
c.r + d,
c.g + d,
c.b + d));
}
float Sat(float3 c) {
return max(max(c.r, c.g), c.b) - min(min(c.r, c.g), c.b);
}
// To use this helper, re-arrange rgb such that r=min, g=mid, and b=max.
float3 SetSatInner(float3 c, float s) {
if (c.b > c.r) {
c.g = (((c.g - c.r) * s) / (c.b - c.r));
c.b = s;
} else {
c.gb = float2(0.0, 0.0);
}
return float3(0.0, c.g, c.b);
}
float3 SetSat(float3 c, float s) {
if (c.r <= c.g) {
if (c.g <= c.b) {
c.rgb = SetSatInner(c.rgb, s);
} else if (c.r <= c.b) {
c.rbg = SetSatInner(c.rbg, s);
} else {
c.brg = SetSatInner(c.brg, s);
}
} else if (c.r <= c.b) {
c.grb = SetSatInner(c.grb, s);
} else if (c.g <= c.b) {
c.gbr = SetSatInner(c.gbr, s);
} else {
c.bgr = SetSatInner(c.bgr, s);
}
return c;
}
float3 BlendMultiply(float3 dest, float3 src) {
return dest * src;
}
float3 BlendScreen(float3 dest, float3 src) {
return dest + src - (dest * src);
}
float3 BlendOverlay(float3 dest, float3 src) {
return float3(
hardlight(src.r, dest.r),
hardlight(src.g, dest.g),
hardlight(src.b, dest.b));
}
float3 BlendDarken(float3 dest, float3 src) {
return min(dest, src);
}
float3 BlendLighten(float3 dest, float3 src) {
return max(dest, src);
}
float3 BlendColorDodge(float3 dest, float3 src) {
return float3(
dodge(dest.r, src.r),
dodge(dest.g, src.g),
dodge(dest.b, src.b));
}
float3 BlendColorBurn(float3 dest, float3 src) {
return float3(
burn(dest.r, src.r),
burn(dest.g, src.g),
burn(dest.b, src.b));
}
float3 BlendHardLight(float3 dest, float3 src) {
return float3(
hardlight(dest.r, src.r),
hardlight(dest.g, src.g),
hardlight(dest.b, src.b));
}
float3 BlendSoftLight(float3 dest, float3 src) {
return float3(
softlight(dest.r, src.r),
softlight(dest.g, src.g),
softlight(dest.b, src.b));
}
float3 BlendDifference(float3 dest, float3 src) {
return abs(dest - src);
}
float3 BlendExclusion(float3 dest, float3 src) {
return dest + src - 2.0 * dest * src;
}
float3 BlendHue(float3 dest, float3 src) {
return SetLum(SetSat(src, Sat(dest)), Lum(dest));
}
float3 BlendSaturation(float3 dest, float3 src) {
return SetLum(SetSat(dest, Sat(src)), Lum(dest));
}
float3 BlendColor(float3 dest, float3 src) {
return SetLum(src, Lum(dest));
}
float3 BlendLuminosity(float3 dest, float3 src) {
return SetLum(dest, Lum(src));
}
|
