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
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
void rgb_to_hsv(vec4 rgb, out vec4 outcol)
{
float cmax, cmin, h, s, v, cdelta;
vec3 c;
cmax = max(rgb[0], max(rgb[1], rgb[2]));
cmin = min(rgb[0], min(rgb[1], rgb[2]));
cdelta = cmax - cmin;
v = cmax;
if (cmax != 0.0) {
s = cdelta / cmax;
}
else {
s = 0.0;
h = 0.0;
}
if (s == 0.0) {
h = 0.0;
}
else {
c = (vec3(cmax) - rgb.xyz) / cdelta;
if (rgb.x == cmax) {
h = c[2] - c[1];
}
else if (rgb.y == cmax) {
h = 2.0 + c[0] - c[2];
}
else {
h = 4.0 + c[1] - c[0];
}
h /= 6.0;
if (h < 0.0) {
h += 1.0;
}
}
outcol = vec4(h, s, v, rgb.w);
}
void hsv_to_rgb(vec4 hsv, out vec4 outcol)
{
float i, f, p, q, t, h, s, v;
vec3 rgb;
h = hsv[0];
s = hsv[1];
v = hsv[2];
if (s == 0.0) {
rgb = vec3(v, v, v);
}
else {
if (h == 1.0) {
h = 0.0;
}
h *= 6.0;
i = floor(h);
f = h - i;
rgb = vec3(f, f, f);
p = v * (1.0 - s);
q = v * (1.0 - (s * f));
t = v * (1.0 - (s * (1.0 - f)));
if (i == 0.0) {
rgb = vec3(v, t, p);
}
else if (i == 1.0) {
rgb = vec3(q, v, p);
}
else if (i == 2.0) {
rgb = vec3(p, v, t);
}
else if (i == 3.0) {
rgb = vec3(p, q, v);
}
else if (i == 4.0) {
rgb = vec3(t, p, v);
}
else {
rgb = vec3(v, p, q);
}
}
outcol = vec4(rgb, hsv.w);
}
void rgb_to_hsl(vec4 rgb, out vec4 outcol)
{
float cmax, cmin, h, s, l;
cmax = max(rgb[0], max(rgb[1], rgb[2]));
cmin = min(rgb[0], min(rgb[1], rgb[2]));
l = min(1.0, (cmax + cmin) / 2.0);
if (cmax == cmin) {
h = s = 0.0; /* achromatic */
}
else {
float cdelta = cmax - cmin;
s = l > 0.5 ? cdelta / (2.0 - cmax - cmin) : cdelta / (cmax + cmin);
if (cmax == rgb[0]) {
h = (rgb[1] - rgb[2]) / cdelta + (rgb[1] < rgb[2] ? 6.0 : 0.0);
}
else if (cmax == rgb[1]) {
h = (rgb[2] - rgb[0]) / cdelta + 2.0;
}
else {
h = (rgb[0] - rgb[1]) / cdelta + 4.0;
}
}
h /= 6.0;
outcol = vec4(h, s, l, rgb.w);
}
void hsl_to_rgb(vec4 hsl, out vec4 outcol)
{
float nr, ng, nb, chroma, h, s, l;
h = hsl[0];
s = hsl[1];
l = hsl[2];
nr = abs(h * 6.0 - 3.0) - 1.0;
ng = 2.0 - abs(h * 6.0 - 2.0);
nb = 2.0 - abs(h * 6.0 - 4.0);
nr = clamp(nr, 0.0, 1.0);
nb = clamp(nb, 0.0, 1.0);
ng = clamp(ng, 0.0, 1.0);
chroma = (1.0 - abs(2.0 * l - 1.0)) * s;
outcol = vec4((nr - 0.5) * chroma + l, (ng - 0.5) * chroma + l, (nb - 0.5) * chroma + l, hsl.w);
}
/* ** Alpha Handling ** */
void color_alpha_clear(vec4 color, out vec4 result)
{
result = vec4(color.rgb, 1.0);
}
void color_alpha_premultiply(vec4 color, out vec4 result)
{
result = vec4(color.rgb * color.a, color.a);
}
void color_alpha_unpremultiply(vec4 color, out vec4 result)
{
if (color.a == 0.0 || color.a == 1.0) {
result = color;
}
else {
result = vec4(color.rgb / color.a, color.a);
}
}
float linear_rgb_to_srgb(float color)
{
if (color < 0.0031308) {
return (color < 0.0) ? 0.0 : color * 12.92;
}
return 1.055 * pow(color, 1.0 / 2.4) - 0.055;
}
vec3 linear_rgb_to_srgb(vec3 color)
{
return vec3(
linear_rgb_to_srgb(color.r), linear_rgb_to_srgb(color.g), linear_rgb_to_srgb(color.b));
}
float srgb_to_linear_rgb(float color)
{
if (color < 0.04045) {
return (color < 0.0) ? 0.0 : color * (1.0 / 12.92);
}
return pow((color + 0.055) * (1.0 / 1.055), 2.4);
}
vec3 srgb_to_linear_rgb(vec3 color)
{
return vec3(
srgb_to_linear_rgb(color.r), srgb_to_linear_rgb(color.g), srgb_to_linear_rgb(color.b));
}
float get_luminance(vec3 color, vec3 luminance_coefficients)
{
return dot(color, luminance_coefficients);
}
|
