42 lines
No EOL
1.1 KiB
Text
42 lines
No EOL
1.1 KiB
Text
/*
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contributors: Inigo Quiles
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description: generate the SDF of a cylinder
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use:
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- <float> cylinderSDF( <float3> pos, <float2|float> h [, <float> r] )
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- <float> cylinderSDF( <float3> p, <float3> a, <float3> b, <float> r)
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*/
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#ifndef FNC_CYLINDERSDF
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#define FNC_CYLINDERSDF
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// vertical
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float cylinderSDF( float3 p, float2 h ) {
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float2 d = abs(float2(length(p.xz),p.y)) - h;
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return min(max(d.x,d.y),0.0) + length(max(d,0.0));
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}
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float cylinderSDF( float3 p, float h ) {
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return cylinderSDF( p, float2(h) );
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}
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float cylinderSDF( float3 p, float h, float r ) {
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float2 d = abs(float2(length(p.xz),p.y)) - float2(h,r);
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return min(max(d.x,d.y),0.0) + length(max(d,0.0));
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}
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// arbitrary orientation
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float cylinderSDF(float3 p, float3 a, float3 b, float r) {
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float3 pa = p - a;
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float3 ba = b - a;
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float baba = dot(ba,ba);
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float paba = dot(pa,ba);
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float x = length(pa*baba-ba*paba) - r*baba;
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float y = abs(paba-baba*0.5)-baba*0.5;
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float x2 = x*x;
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float y2 = y*y*baba;
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float d = (max(x,y)<0.0)?-min(x2,y2):(((x>0.0)?x2:0.0)+((y>0.0)?y2:0.0));
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return sign(d)*sqrt(abs(d))/baba;
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}
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#endif |