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60 lines
1.4 KiB
GLSL
60 lines
1.4 KiB
GLSL
// Author @patriciogv - 2015
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// Title: Truchet - 10 print
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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 3.14159265358979323846
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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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float random (in vec2 _st) {
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return fract(sin(dot(_st.xy,
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vec2(12.9898,78.233)))*
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43758.5453123);
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}
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vec2 truchetPattern(in vec2 _st, in float _index){
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_index = fract(((_index-0.5)*2.0));
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if (_index > 0.75) {
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_st = vec2(1.0) - _st;
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} else if (_index > 0.5) {
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_st = vec2(1.0-_st.x,_st.y);
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} else if (_index > 0.25) {
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_st = 1.0-vec2(1.0-_st.x,_st.y);
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}
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return _st;
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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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st *= 10.0;
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// st = (st-vec2(5.0))*(abs(sin(u_time*0.2))*5.);
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// st.x += u_time*3.0;
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vec2 ipos = floor(st); // integer
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vec2 fpos = fract(st); // fraction
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vec2 tile = truchetPattern(fpos, random( ipos ));
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float color = 0.0;
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// Maze
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color = smoothstep(tile.x-0.3,tile.x,tile.y)-
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smoothstep(tile.x,tile.x+0.3,tile.y);
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// Circles
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// color = (step(length(tile),0.6) -
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// step(length(tile),0.4) ) +
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// (step(length(tile-vec2(1.)),0.6) -
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// step(length(tile-vec2(1.)),0.4) );
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// Truchet (2 triangles)
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// color = step(tile.x,tile.y);
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gl_FragColor = vec4(vec3(color),1.0);
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}
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