Pixel-Composer/shaders/sh_grid_tri/sh_grid_tri.fsh
2023-05-29 13:25:16 +02:00

134 lines
3.6 KiB
GLSL

//
// Simple passthrough fragment shader
//
varying vec2 v_vTexcoord;
varying vec4 v_vColour;
#define c30 (1.0 / 0.86602540378)
#define PI 3.14159265359
#define GRADIENT_LIMIT 128
uniform vec2 position;
uniform vec2 dimension;
uniform vec2 scale;
uniform float angle;
uniform float width;
uniform float seed;
uniform int mode;
uniform vec4 gapCol;
uniform int gradient_use;
uniform int gradient_blend;
uniform vec4 gradient_color[GRADIENT_LIMIT];
uniform float gradient_time[GRADIENT_LIMIT];
uniform int gradient_keys;
float random (in vec2 st) {
return fract(sin(dot(st.xy + vec2(85.456034, 64.54065), vec2(12.9898, 78.233))) * (43758.5453123 + seed) );
}
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 < 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]);
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;
}
vec3 triGrid(vec2 p){
float _stx = (p.x + c30 / 2.0 * p.y);
float stx = abs(fract(_stx) - 0.5);
float _sty = (p.x - c30 / 2.0 * p.y);
float sty = abs(fract(_sty) - 0.5);
float sth = abs(fract(p.y * c30) - 0.5);
float sm = 1.;
float n = min(smoothstep(sm, -sm, stx),
min(smoothstep(sm, -sm, sty), smoothstep(sm, -sm, sth))
);
n = (n - .16) / (.35 - .16);
return vec3((floor(_stx) + floor(_sty) + 1.) / 2., floor(p.y * c30), n);
}
void main() {
vec2 pos = (v_vTexcoord - position) * scale, _pos;
float ratio = dimension.x / dimension.y;
_pos.x = pos.x * ratio * cos(angle) - pos.y * sin(angle);
_pos.y = pos.x * ratio * sin(angle) + pos.y * cos(angle);
vec3 tri = triGrid(_pos);
float dist = max(0., tri.z);
bool isGap = dist < width * 2.;
if(mode == 0) {
vec2 uv = fract(tri.xy / scale);
gl_FragColor = isGap? gapCol : vec4(gradientEval(random(uv)).rgb, 1.);
} else if(mode == 1) {
gl_FragColor = vec4(vec3(dist), 1.);
} else if(mode == 2) {
vec2 uv = fract((_pos * vec2(1., c30) - tri.xy) + vec2(0.5, 0.));
gl_FragColor = isGap? gapCol : texture2D( gm_BaseTexture, uv );
} else if(mode == 3) {
vec2 uv = clamp(tri.xy / scale, 0., 1.);
gl_FragColor = isGap? gapCol : texture2D( gm_BaseTexture, uv );
}
}