fingerprints

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vec2 hash2( vec2 p )
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{
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    p = vec2( dot(p,vec2(63.31,127.63)), dot(p,vec2(395.467,213.799)) );
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    return -1.0 + 2.0*fract(sin(p)*43141.59265);
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}
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void main(void)
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{
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    float invzoom = 64.;
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    vec2 uv = invzoom*((gl_FragCoord.xy-0.5*resolution.xy)/resolution.x);
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    float bounds = smoothstep(9.,10.,length(uv*vec2(0.74,0.55)));
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    float a=0.;
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    vec2 h = vec2(floor(7.*time), 0.);
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    for(int i=0; i<50; i++){
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        float s=sign(h.x);
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        h = hash2(h)*vec2(15.,20.);
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        a += s*atan(uv.x-h.x, uv.y-h.y);
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    }
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    uv += 20.*abs(hash2(h));
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    a+=atan(uv.y, uv.x);
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    float w = 0.8;
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    float p=(1.-bounds)*w; 
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    float s = min(0.3,p);
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    float l = length(uv)+0.319*a; 
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    float m = mod(l,2.);
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    float v = (1.-smoothstep(2.-s,2.,m))*smoothstep(p,p+s,m);
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    glFragColor = vec4(v,v,v,1.);
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}
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