Pixel-Composer/shaders/sh_gradient_display/sh_gradient_display.fsh
2024-02-12 16:25:23 +07:00

136 lines
3.7 KiB
GLSL

varying vec2 v_vTexcoord;
varying vec4 v_vColour;
#define TAU 6.283185307179586
#region //////////////////////////////////// GRADIENT ////////////////////////////////////
#define GRADIENT_LIMIT 128
uniform int gradient_blend;
uniform vec4 gradient_color[GRADIENT_LIMIT];
uniform float gradient_time[GRADIENT_LIMIT];
uniform int gradient_keys;
vec3 linearToGamma(vec3 c) { return pow(c, vec3( 2.2)); }
vec3 gammaToLinear(vec3 c) { return pow(c, vec3(1. / 2.2)); }
vec3 rgbMix(vec3 c1, vec3 c2, float t) { #region
vec3 k1 = linearToGamma(c1);
vec3 k2 = linearToGamma(c2);
return gammaToLinear(mix(k1, k2, t));
} #endregion
vec3 rgb2oklab(vec3 c) { #region
const mat3 kCONEtoLMS = mat3(
0.4121656120, 0.2118591070, 0.0883097947,
0.5362752080, 0.6807189584, 0.2818474174,
0.0514575653, 0.1074065790, 0.6302613616);
c = pow(c, vec3(2.2));
c = pow( kCONEtoLMS * c, vec3(1.0 / 3.0) );
return c;
} #endregion
vec3 oklab2rgb(vec3 c) { #region
const mat3 kLMStoCONE = mat3(
4.0767245293, -1.2681437731, -0.0041119885,
-3.3072168827, 2.6093323231, -0.7034763098,
0.2307590544, -0.3411344290, 1.7068625689);
c = kLMStoCONE * (c * c * c);
c = pow(c, vec3(1. / 2.2));
return c;
} #endregion
vec3 oklabMax(vec3 c1, vec3 c2, float t) { #region
vec3 k1 = rgb2oklab(c1);
vec3 k2 = rgb2oklab(c2);
return oklab2rgb(mix(k1, k2, t));
} #endregion
vec3 rgb2hsv(vec3 c) { #region
vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
float d = q.x - min(q.w, q.y);
float e = 0.0000000001;
return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
} #endregion
vec3 hsv2rgb(vec3 c) { #region
vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
} #endregion
float hueDist(float a0, float a1, float t) { #region
float da = fract(a1 - a0);
float ds = fract(2. * da) - da;
return a0 + ds * t;
} #endregion
vec3 hsvMix(vec3 c1, vec3 c2, float t) { #region
vec3 h1 = rgb2hsv(c1);
vec3 h2 = rgb2hsv(c2);
vec3 h = vec3(0.);
h.x = h.x + hueDist(h1.x, h2.x, t);
h.y = mix(h1.y, h2.y, t);
h.z = mix(h1.z, h2.z, t);
return hsv2rgb(h);
} #endregion
vec4 gradientEval(in float prog) { #region
vec4 col = vec4(0.);
for(int i = 0; i < GRADIENT_LIMIT; i++) {
if(gradient_time[i] == prog) {
col = gradient_color[i];
break;
} else if(gradient_time[i] > prog) {
if(i == 0)
col = gradient_color[i];
else {
float t = (prog - gradient_time[i - 1]) / (gradient_time[i] - gradient_time[i - 1]);
vec3 c0 = gradient_color[i - 1].rgb;
vec3 c1 = gradient_color[i].rgb;
float a = mix(gradient_color[i - 1].a, gradient_color[i].a, t);
if(gradient_blend == 0)
col = vec4(mix(c0, c1, t), a);
else if(gradient_blend == 1)
col = gradient_color[i - 1];
else if(gradient_blend == 2)
col = vec4(hsvMix(c0, c1, t), a);
else if(gradient_blend == 3)
col = vec4(oklabMax(c0, c1, t), a);
else if(gradient_blend == 4)
col = vec4(rgbMix(c0, c1, t), a);
}
break;
}
if(i >= gradient_keys - 1)
return gradient_color[gradient_keys - 1];
}
return col;
} #endregion
#endregion //////////////////////////////////// GRADIENT ////////////////////////////////////
void main() {
vec4 col = gradientEval(v_vTexcoord.x);
gl_FragColor = vec4(col.rgb, 1.);
}