#ifdef GL_ES precision mediump float; #endif #define PI 3.14159265358979323846 uniform vec2 u_resolution; uniform vec2 u_mouse; uniform float u_time; float random (in vec2 _st) { return fract(sin(dot(_st.xy, vec2(12.9898,78.233)))* 43758.5453123); } float line(vec2 st, float pct) { return smoothstep( pct-0.02, pct, st.y) - smoothstep( pct, pct+0.02, st.y); } void main() { vec2 st = gl_FragCoord.xy/u_resolution.xy; float color = 0.; color = line(st, random(st)); gl_FragColor = vec4(vec3(color),1.0); }