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34 lines
670 B
GLSL
34 lines
670 B
GLSL
// Author: Inigo Quiles
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// Title: Parabola
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#ifdef GL_ES
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precision mediump float;
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#endif
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uniform vec2 u_resolution;
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uniform float u_time;
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// Function from Iñigo Quiles
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// www.iquilezles.org/www/articles/functions/functions.htm
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float parabola( float x, float k ){
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return pow( 4.0*x*(1.0-x), k );
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}
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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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float y = parabola(st.x,1.0);
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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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}
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