39 lines
No EOL
1.1 KiB
GLSL
39 lines
No EOL
1.1 KiB
GLSL
#include "map.glsl"
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/*
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contributors: ["dahart", "Fabrice NEYRET"]
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description: |
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Is similar to floor() but has a 2-pixel wide gradient between clamped steps
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to allow the edges in the result to be anti-aliased.
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Based on examples https://www.shadertoy.com/view/4l2BRD and https://www.shadertoy.com/view/3tSGWy
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use: <float> aafloor(<float> x)
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option:
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AA_EDGE: in the absence of derivatives you can specify the antialiasing factor
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*/
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#ifndef FNC_AAFLOOR
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#define FNC_AAFLOOR
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#if defined(GL_OES_standard_derivatives)
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#extension GL_OES_standard_derivatives : enable
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#endif
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float aafloor(float x) {
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#if !defined(GL_ES) || __VERSION__ >= 300 || defined(GL_OES_standard_derivatives)
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float afwidth = 2.0 * length(vec2(dFdx(x), dFdy(x)));
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float fx = fract(x);
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float idx = 1. - afwidth;
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return (fx < idx) ? x - fx : map(fx, idx, 1., x-fx, x);
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#elif defined(AA_EDGE)
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float afwidth = AA_EDGE;
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float fx = fract(x);
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float idx = 1. - afwidth;
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return (fx < idx) ? x - fx : map(fx, idx, 1., x-fx, x);
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#else
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return floor(x);
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#endif
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}
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vec2 aafloor(vec2 x) { return vec2(aafloor(x.x), aafloor(x.y)); }
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#endif |