mirror of
https://github.com/patriciogonzalezvivo/thebookofshaders
synced 2024-11-11 13:10:57 +00:00
36 lines
917 B
GLSL
36 lines
917 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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uniform vec2 u_resolution;
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uniform float u_time;
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// YUV to RGB matrix
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mat3 yuv2rgb = mat3(1.0, 0.0, 1.13983,
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1.0, -0.39465, -0.58060,
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1.0, 2.03211, 0.0);
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// RGB to YUV matrix
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mat3 rgb2yuv = mat3(0.2126, 0.7152, 0.0722,
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-0.09991, -0.33609, 0.43600,
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0.615, -0.5586, -0.05639);
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void main(){
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vec2 st = gl_FragCoord.xy/u_resolution;
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vec3 color = vec3(0.0);
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// UV values goes from -1 to 1
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// So we need to remap st (0.0 to 1.0)
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st -= 0.5; // becomes -0.5 to 0.5
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st *= 2.0; // becomes -1.0 to 1.0
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// we pass st as the y & z values of
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// a three dimensional vector to be
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// properly multiply by a 3x3 matrix
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color = yuv2rgb * vec3(0.5, st.x, st.y);
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gl_FragColor = vec4(color,1.0);
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}
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