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https://github.com/patriciogonzalezvivo/thebookofshaders
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27 lines
625 B
GLSL
27 lines
625 B
GLSL
// Author @patriciogv ( patriciogonzalezvivo.com ) - 2015
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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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float box(vec2 _st, vec2 _size){
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_size = vec2(0.5) - _size*0.5;
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vec2 uv = smoothstep(_size,
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_size+vec2(0.0001),
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_st);
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uv *= smoothstep(_size,
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_size+vec2(0.0001),
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vec2(1.0)-_st);
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return uv.x*uv.y;
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}
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void main(){
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vec2 st = gl_FragCoord.xy/u_resolution.xy;
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float pct = box(st, vec2(0.9,0.3)) + box(st, vec2(0.3,0.9));
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gl_FragColor = vec4( vec3(1.-pct),pct );
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}
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