mirror of
https://github.com/patriciogonzalezvivo/thebookofshaders
synced 2024-11-09 19:10:24 +00:00
28 lines
582 B
GLSL
28 lines
582 B
GLSL
#ifdef GL_ES
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precision mediump float;
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#endif
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#define PI 3.14159265359
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uniform vec2 u_resolution;
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uniform float u_time;
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float plot(vec2 st, float pct){
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return smoothstep( pct-0.02, pct, st.y) -
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smoothstep( pct, pct+0.02, st.y);
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}
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void main() {
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vec2 st = gl_FragCoord.xy/u_resolution;
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// Step will return 0.0 unless the value is over 0.5,
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// in that case it will return 1.0
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float y = step(0.5,st.x);
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vec3 color = vec3(y);
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float pct = plot(st,y);
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color = (1.0-pct)*color+pct*vec3(0.0,1.0,0.0);
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gl_FragColor = vec4(color,1.0);
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} |