101 lines
No EOL
2.5 KiB
GLSL
101 lines
No EOL
2.5 KiB
GLSL
#include "snoise.glsl"
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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.glsl
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use: curl(<vec3|vec4> 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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vec2 curl( vec2 p ) {
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const float e = .1;
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vec2 dx = vec2( e , 0.0 );
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vec2 dy = vec2( 0.0 , e );
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vec2 p_x0 = snoise2( p - dx );
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vec2 p_x1 = snoise2( p + dx );
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vec2 p_y0 = snoise2( p - dy );
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vec2 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( vec2(x, y) * divisor );
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#else
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return vec2(x, y) * divisor;
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#endif
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}
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#else
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vec2 curl( vec2 p ) {
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vec2 e = vec2(0.1, 0.0);
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vec3 pos = vec3(p, 0.0);
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vec2 C = vec2( (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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vec3 curl( vec3 p ){
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const float e = .1;
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vec3 dx = vec3( e , 0.0 , 0.0 );
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vec3 dy = vec3( 0.0 , e , 0.0 );
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vec3 dz = vec3( 0.0 , 0.0 , e );
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vec3 p_x0 = snoise3( p - dx );
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vec3 p_x1 = snoise3( p + dx );
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vec3 p_y0 = snoise3( p - dy );
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vec3 p_y1 = snoise3( p + dy );
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vec3 p_z0 = snoise3( p - dz );
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vec3 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( vec3( x , y , z ) * divisor );
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#else
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return vec3( x , y , z ) * divisor;
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#endif
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}
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vec3 curl( vec4 p ){
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const float e = .1;
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vec4 dx = vec4( e , 0.0 , 0.0 , 1.0 );
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vec4 dy = vec4( 0.0 , e , 0.0 , 1.0 );
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vec4 dz = vec4( 0.0 , 0.0 , e , 1.0 );
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vec3 p_x0 = snoise3( p - dx );
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vec3 p_x1 = snoise3( p + dx );
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vec3 p_y0 = snoise3( p - dy );
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vec3 p_y1 = snoise3( p + dy );
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vec3 p_z0 = snoise3( p - dz );
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vec3 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( vec3( x , y , z ) * divisor );
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#else
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return vec3( x , y , z ) * divisor;
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#endif
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}
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#endif |