mirror of
https://github.com/patriciogonzalezvivo/thebookofshaders
synced 2024-11-03 23:15:23 +00:00
45 lines
932 B
GLSL
45 lines
932 B
GLSL
// Author @patriciogv - 2015
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// http://patriciogonzalezvivo.com
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#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 sampler2D u_tex0;
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uniform vec2 u_tex0Resolution;
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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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// Based on Asalga shader
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// https://www.shadertoy.com/view/4ss3WX
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void main () {
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vec2 st = gl_FragCoord.xy/u_resolution.xy;
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float time = u_time*0.1;
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// move to the center
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st = st - 0.5;
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// cartesian to polar coordinates
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float r = length(st);
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float a = atan(st.y, st.x);
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// Repeat side acoriding to angle
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float sides = 10.;
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float ma = mod(a, TWO_PI/sides);
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ma = abs(ma - PI/sides);
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// polar to cartesian coordinates
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st = r * vec2(cos(ma), sin(ma));
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st = fract(st+time);
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vec4 color = vec4(st.x,st.y,0.0,1.0);
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color = texture2D(u_tex0,st);
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gl_FragColor = color;
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}
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