mirror of
https://github.com/patriciogonzalezvivo/thebookofshaders
synced 2024-11-05 21:21:06 +00:00
38 lines
782 B
GLSL
38 lines
782 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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#define TWO_PI 6.28318530718
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uniform vec2 u_resolution;
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uniform vec2 u_mouse;
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uniform float u_time;
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// Reference to
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// http://thndl.com/square-shaped-shaders.html
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void main(){
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vec2 st = gl_FragCoord.xy/u_resolution.xy;
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st.x *= u_resolution.x/u_resolution.y;
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vec3 color = vec3(0.0);
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float d = 0.0;
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// Remap the space to -1. to 1.
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st = st *2.-1.;
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// Number of sides of your shape
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int N = 3;
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// Angle and radius from the current pixel
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float a = atan(st.x,st.y)+PI;
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float r = TWO_PI/float(N);
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// Shaping function that modulate the distance
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d = cos(floor(.5+a/r)*r-a)*length(st);
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color = vec3(1.0-smoothstep(.4,.41,d));
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// color = vec3(d);
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gl_FragColor = vec4(color,1.0);
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} |