#pragma glslify:sdTriangle=require('../../includes/sdf/2d/equilateral-triangle')
#pragma glslify:sigmoid=require('../../includes/math/sigmoid')
#pragma glslify:opRotate=require('../../includes/ops/rotate')
uniform float time;
uniform float seed;
uniform vec2 resolution;
const float TILE = 28.;
const float BORDER = .05;
vec3 palette(float t){
vec3 a=vec3(0.37,0.19,0.6);
vec3 b=vec3(0.43,0.31,0.19);
vec3 c=vec3(0.22,0.27,0.82);
vec3 d=vec3(0.11,0.95,0.76);
return a+b*cos(6.28318*(c*t+d));
}
vec2 roundToTriangleCenter(vec2 uv) {
float x = floor(uv.x);
float y = floor(uv.y);
vec2 localPos = fract(uv);
bool inTopTriangle = localPos.x + localPos.y < 1.0;
vec2 triangleCenter = inTopTriangle
? vec2(0.5, 0.5)
: vec2(1.0, 1.0);
vec2 gridOffset = vec2(x, y);
return gridOffset + triangleCenter;
}
float isBorder(vec2 uv, float threshold) {
uv = abs(fract(uv));
float b = 1.;
b *= uv.x < BORDER ? 0. : 1.;
b *= uv.x > 2.-BORDER ? 0. : 1.;
b *= uv.y < BORDER ? 0. : 1.;
b *= uv.y > 2.-BORDER ? 0. : 1.;
b *= uv.x + uv.y < 1.-BORDER || uv.x + uv.y > 1.+BORDER ? 1. : 0.;
return 1.-b;
}
vec3 tripulse(vec2 uv, float t){
vec2 uv0=uv;
uv += vec2(0.,0.1);
uv += vec2(1.,0.)*sin(t+uv.y*5.)*0.04;
float d = sdTriangle(uv);
vec3 color = palette(pow(sigmoid(d*3.+0.5),1.));
color *= pow(smoothstep(0.,1.,fract(d*7.-t)),1.5);
color *= clamp(0.,1.,pow(1.-d,2.));
return color;
}
void main(){
vec2 uv=gl_FragCoord.xy/resolution.xy;
float t=time*.7;
uv-=vec2(0.5);
uv*=max(vec2(resolution.x/resolution.y,1.),vec2(1.,resolution.y/resolution.x));
vec2 cUv = roundToTriangleCenter(uv*TILE);
vec3 color = vec3(0);
color += tripulse(cUv / TILE, t);
color *= 1.-isBorder(uv * TILE, 0.2);
gl_FragColor=vec4(color,1.);
}
