64 lines
1.4 KiB
GLSL
64 lines
1.4 KiB
GLSL
#pragma map iChannel0=builtin:RGBA Noise Medium
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const float tau = 6.28318530717958647692;
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// Gamma correction
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#define GAMMA (2.2)
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vec3 ToLinear( in vec3 col )
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{
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// simulate a monitor, converting colour values into light values
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return pow( col, vec3(GAMMA) );
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}
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vec3 ToGamma( in vec3 col )
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{
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// convert back into colour values, so the correct light will come out of the monitor
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return pow( col, vec3(1.0/GAMMA) );
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}
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vec4 Noise( in ivec2 x )
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{
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return texture( iChannel0, (vec2(x)+0.5)/256.0, -100.0 );
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}
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vec4 Rand( in int x )
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{
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vec2 uv;
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uv.x = (float(x)+0.5)/256.0;
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uv.y = (floor(uv.x)+0.5)/256.0;
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return texture( iChannel0, uv, -100.0 );
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}
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void mainImage( out vec4 fragColor, in vec2 fragCoord )
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{
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vec3 ray;
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ray.xy = 2.0*(fragCoord.xy-iResolution.xy*.5)/iResolution.x;
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ray.z = 1.0;
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float offset = iTime*.5;
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float speed2 = (cos(offset)+1.0)*2.0;
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float speed = speed2+.1;
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offset += sin(offset)*.96;
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offset *= 2.0;
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vec3 col = vec3(0);
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vec3 stp = ray/max(abs(ray.x),abs(ray.y));
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vec3 pos = 2.0*stp+.5;
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for ( int i=0; i < 20; i++ )
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{
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float z = Noise(ivec2(pos.xy)).x;
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z = fract(z-offset);
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float d = 50.0*z-pos.z;
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float w = pow(max(0.0,1.0-8.0*length(fract(pos.xy)-.5)),2.0);
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vec3 c = max(vec3(0),vec3(1.0-abs(d+speed2*.5)/speed,1.0-abs(d)/speed,1.0-abs(d-speed2*.5)/speed));
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col += 1.5*(1.0-z)*c*w;
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pos += stp;
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}
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fragColor = vec4(ToGamma(col),1.0);
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}
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