101 lines
No EOL
2.6 KiB
Text
101 lines
No EOL
2.6 KiB
Text
#include "snoise.msl"
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/*
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contributors: Isaac Cohen
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description: https://github.com/cabbibo/glsl-curl-noise/blob/master/curl.msl
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use: curl(<float3|float4> pos)
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examples:
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- /shaders/generative_curl.frag
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*/
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#ifndef FNC_CURL
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#define FNC_CURL
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#ifndef CURL_FNC
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float2 curl( float2 p ) {
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const float e = .1;
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float2 dx = float2( e , 0.0 );
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float2 dy = float2( 0.0 , e );
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float2 p_x0 = snoise2( p - dx );
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float2 p_x1 = snoise2( p + dx );
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float2 p_y0 = snoise2( p - dy );
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float2 p_y1 = snoise2( p + dy );
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float x = p_x1.y + p_x0.y;
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float y = p_y1.x - p_y0.x;
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const float divisor = 1.0 / ( 2.0 * e );
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#ifndef CURL_UNNORMALIZED
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return normalize( float2(x, y) * divisor );
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#else
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return float2(x, y) * divisor;
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#endif
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}
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#else
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float2 curl( float2 p ) {
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float2 e = float2(0.1, 0.0);
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float3 pos = float3(p, 0.0);
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float2 C = float2( (CURL_FNC(pos+e.yxy)-CURL_FNC(pos-e.yxy))/(2.0*e.x),
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-(CURL_FNC(pos+e.xyy)-CURL_FNC(pos-e.xyy))/(2.0*e.x));
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#ifndef CURL_UNNORMALIZED
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return normalize(C);
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#else
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float divisor = 1.0 / (2.0 * e.x);
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return C * divisor;
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#endif
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}
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#endif
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float3 curl( float3 p ){
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const float e = .1;
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float3 dx = float3( e , 0.0 , 0.0 );
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float3 dy = float3( 0.0 , e , 0.0 );
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float3 dz = float3( 0.0 , 0.0 , e );
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float3 p_x0 = snoise3( p - dx );
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float3 p_x1 = snoise3( p + dx );
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float3 p_y0 = snoise3( p - dy );
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float3 p_y1 = snoise3( p + dy );
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float3 p_z0 = snoise3( p - dz );
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float3 p_z1 = snoise3( p + dz );
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float x = p_y1.z - p_y0.z - p_z1.y + p_z0.y;
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float y = p_z1.x - p_z0.x - p_x1.z + p_x0.z;
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float z = p_x1.y - p_x0.y - p_y1.x + p_y0.x;
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const float divisor = 1.0 / ( 2.0 * e );
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#ifndef CURL_UNNORMALIZED
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return normalize( float3( x , y , z ) * divisor );
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#else
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return float3( x , y , z ) * divisor;
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#endif
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}
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float3 curl( float4 p ){
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const float e = .1;
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float4 dx = float4( e , 0.0 , 0.0 , 1.0 );
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float4 dy = float4( 0.0 , e , 0.0 , 1.0 );
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float4 dz = float4( 0.0 , 0.0 , e , 1.0 );
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float3 p_x0 = snoise3( p - dx );
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float3 p_x1 = snoise3( p + dx );
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float3 p_y0 = snoise3( p - dy );
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float3 p_y1 = snoise3( p + dy );
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float3 p_z0 = snoise3( p - dz );
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float3 p_z1 = snoise3( p + dz );
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float x = p_y1.z - p_y0.z - p_z1.y + p_z0.y;
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float y = p_z1.x - p_z0.x - p_x1.z + p_x0.z;
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float z = p_x1.y - p_x0.y - p_y1.x + p_y0.x;
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const float divisor = 1.0 / ( 2.0 * e );
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#ifndef CURL_UNNORMALIZED
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return normalize( float3( x , y , z ) * divisor );
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#else
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return float3( x , y , z ) * divisor;
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#endif
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}
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#endif |