mirror of
https://github.com/patriciogonzalezvivo/thebookofshaders
synced 2024-11-01 21:40:27 +00:00
28 lines
582 B
GLSL
28 lines
582 B
GLSL
#ifdef GL_ES
|
|
precision mediump float;
|
|
#endif
|
|
|
|
#define PI 3.14159265359
|
|
|
|
uniform vec2 u_resolution;
|
|
uniform float u_time;
|
|
|
|
float plot(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;
|
|
|
|
// Step will return 0.0 unless the value is over 0.5,
|
|
// in that case it will return 1.0
|
|
float y = step(0.5,st.x);
|
|
|
|
vec3 color = vec3(y);
|
|
|
|
float pct = plot(st,y);
|
|
color = (1.0-pct)*color+pct*vec3(0.0,1.0,0.0);
|
|
|
|
gl_FragColor = vec4(color,1.0);
|
|
} |