Lucas de Vries
23 lines
534 B
Plaintext
23 lines
534 B
Plaintext
#define pi 3.141592653589793238462643383279
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#define twopi (pi * 2.0)
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varying vec2 rcoords;
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uniform float progress;
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const float maxRad = 0.8;
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const float minRad = 0.4;
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void main() {
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float r = length(rcoords);
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if(r < minRad || r > maxRad)
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discard;
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float ang = (atan(rcoords.y, rcoords.x) + pi) / twopi;
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if(ang > progress)
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discard;
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float alpha = abs(r - (minRad + (maxRad - minRad) / 2.0));
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alpha /= (maxRad - minRad);
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alpha = 1.0 - alpha;
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gl_FragColor.rgb = gl_Color.rgb;
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gl_FragColor.a = alpha;
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}
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