Pixel-Composer/shaders/sh_gradient/sh_gradient.fsh
2022-11-14 09:16:15 +07:00

111 lines
2.6 KiB
GLSL

//
// Simple passthrough fragment shader
//
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
#define TAU 6.28318
uniform int gradient_blend;
uniform vec4 gradient_color[16];
uniform float gradient_time[16];
uniform int gradient_keys;
uniform int gradient_loop;
uniform vec2 center;
uniform float angle;
uniform float radius;
uniform float shift;
uniform int type;
vec3 rgb2hsv(vec3 c) {
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);
}
vec3 hsv2rgb(vec3 c) {
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);
}
float hueDist(float a0, float a1, float t) {
float da = fract(a1 - a0);
float ds = fract(2. * da) - da;
return a0 + ds * t;
}
vec3 hsvMix(vec3 c1, vec3 c2, float t) {
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);
}
vec4 gradientEval(in float prog) {
vec4 col = vec4(0.);
for(int i = 0; i < 16; 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]);
if(gradient_blend == 0)
col = mix(gradient_color[i - 1], gradient_color[i], t);
else if(gradient_blend == 1)
col = gradient_color[i - 1];
else if(gradient_blend == 2)
col = vec4(hsvMix(gradient_color[i - 1].rgb, gradient_color[i].rgb, t), 1.);
}
break;
}
if(i >= gradient_keys - 1) {
col = gradient_color[gradient_keys - 1];
break;
}
}
return col;
}
void main() {
float prog = 0.;
if(type == 0) {
prog = .5 + (v_vTexcoord.x - center.x) * cos(angle) - (v_vTexcoord.y - center.y) * sin(angle);
} else if(type == 1) {
prog = distance(v_vTexcoord, center) / radius;
} else if(type == 2) {
vec2 _p = v_vTexcoord - center;
float _a = atan(_p.y, _p.x) + angle;
prog = (_a - floor(_a / TAU) * TAU) / TAU;
}
prog = prog + shift;
if(gradient_loop == 1) {
prog = abs(prog);
if(prog > 1.) {
if(prog == floor(prog))
prog = 1.;
else
prog = fract(prog);
}
}
vec4 col = gradientEval(prog);
gl_FragColor = vec4(col.rgb, texture2D( gm_BaseTexture, v_vTexcoord ).a);
}