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
|
uniform sampler2D texture_data;
uniform vec4 shift_color;
vec3 rgb_to_hsl(vec3 rgb) {
vec3 ret;
float min = min(min(rgb.r, rgb.g), rgb.b);
float max = max(max(rgb.r, rgb.g), rgb.b);
float lum = (max + min) / 2.0;
ret.z = lum;
if (max == min) {
ret.x = ret.y = 0.0;
} else {
float chroma = max - min;
ret.y = chroma / (1.0 - abs(2.0 * lum - 1.0));
if (max == rgb.r) {
ret.x = (rgb.g - rgb.b) / chroma + (rgb.g < rgb.b ? 6.0 : 0.0);
} else if (max == rgb.g) {
ret.x = (rgb.b - rgb.r) / chroma + 2.0;
} else {
ret.x = (rgb.r - rgb.g) / chroma + 4.0;
}
ret.x /= 6.0;
}
return ret;
}
float hue_to_rgb(float p, float q, float t) {
if (t < 0.0) t += 1.0;
if (t > 1.0) t -= 1.0;
if (t < 1.0/6.0) return p + (q - p) * 6.0 * t;
if (t < 1.0/2.0) return q;
if (t < 2.0/3.0) return p + (q - p) * (2.0/3.0 - t) * 6.0;
return p;
}
vec3 hsl_to_rgb(vec3 hsl) {
vec3 ret;
if (hsl.y == 0.0) {
ret.r = ret.g = ret.b = hsl.z;
} else {
float q = hsl.z < 0.5 ? hsl.z * (1.0 + hsl.y) : hsl.z + hsl.y - hsl.z * hsl.y;
float p = 2.0 * hsl.z - q;
ret.r = hue_to_rgb(p, q, hsl.x + 1.0/3.0);
ret.g = hue_to_rgb(p, q, hsl.x);
ret.b = hue_to_rgb(p, q, hsl.x - 1.0/3.0);
}
return ret;
}
void main()
{
vec2 tcfull = vec2(vertex_texcoord.x, 1.0 - vertex_texcoord.y);
vec4 texel = texture(texture_data, tcfull);
vec3 hsl = rgb_to_hsl(texel.xyz);
vec3 shift_hsl = rgb_to_hsl(shift_color.xyz);
hsl.x = shift_hsl.x;
texel.xyz = hsl_to_rgb(hsl);
frag_color = texel;
}
|
