mirror of
https://github.com/Ttanasart-pt/Pixel-Composer.git
synced 2024-11-13 05:53:53 +01:00
81 lines
2.1 KiB
GLSL
81 lines
2.1 KiB
GLSL
varying vec2 v_vTexcoord;
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varying vec4 v_vColour;
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uniform vec2 dimension;
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uniform float seed;
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uniform float scale;
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uniform int iteration;
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uniform float flowRate;
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uniform int externalForceType;
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uniform float externalForce;
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uniform float externalForceDir;
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#region ///////////////////// PERLIN START /////////////////////
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float random (in vec2 st) { return smoothstep(0., 1., abs(fract(sin(dot(st.xy + vec2(21.456, 46.856), vec2(12.989, 78.233))) * (43758.545 + seed)) * 2. - 1.)); }
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vec2 random2 (in vec2 st) { float a = random(st) * 6.28319; return vec2(cos(a), sin(a)); }
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float noise (in vec2 st) {
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vec2 cellMin = floor(st);
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vec2 cellMax = floor(st) + vec2(1., 1.);
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vec2 f = fract(st);
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vec2 u = f * f * (3.0 - 2.0 * f);
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vec2 _a = vec2(cellMin.x, cellMin.y);
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vec2 _b = vec2(cellMax.x, cellMin.y);
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vec2 _c = vec2(cellMin.x, cellMax.y);
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vec2 _d = vec2(cellMax.x, cellMax.y);
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vec2 ai = f - vec2(0., 0.);
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vec2 bi = f - vec2(1., 0.);
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vec2 ci = f - vec2(0., 1.);
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vec2 di = f - vec2(1., 1.);
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vec2 a2 = random2(_a);
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vec2 b2 = random2(_b);
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vec2 c2 = random2(_c);
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vec2 d2 = random2(_d);
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float l1 = mix(dot(ai, a2), dot(bi, b2), u.x);
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float l2 = mix(dot(ci, c2), dot(di, d2), u.x);
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return mix(l1, l2, u.y) + 0.5;
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}
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float perlin ( vec2 st ) {
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float amp = pow(2., float(iteration) - 1.) / (pow(2., float(iteration)) - 1.);
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float n = 0.;
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vec2 pos = st;
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for(int i = 0; i < iteration; i++) {
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n += noise(pos) * amp;
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amp *= .5;
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pos *= 2.;
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}
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return n;
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}
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#endregion ///////////////////// PERLIN END /////////////////////
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void main() {
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vec2 tx = 1. / dimension;
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float x0 = perlin((v_vTexcoord + vec2(-tx.x, 0.)) * scale);
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float x1 = perlin((v_vTexcoord + vec2( tx.x, 0.)) * scale);
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float y0 = perlin((v_vTexcoord + vec2(0., -tx.y)) * scale);
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float y1 = perlin((v_vTexcoord + vec2(0., tx.y)) * scale);
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vec2 flow = vec2(x1 - x0, y1 - y0);
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if(externalForceType == 0)
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flow += externalForce * (v_vTexcoord - 0.5);
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if(externalForceType == 1)
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flow += externalForce * vec2(cos(externalForceDir), sin(externalForceDir));
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gl_FragColor = texture2D( gm_BaseTexture, v_vTexcoord - flow * flowRate );
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}
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