mirror of
https://github.com/Ttanasart-pt/Pixel-Composer.git
synced 2024-12-25 14:36:13 +01:00
100 lines
2.7 KiB
GLSL
100 lines
2.7 KiB
GLSL
//Caustic noise by jaybird
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varying vec2 v_vTexcoord;
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varying vec4 v_vColour;
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uniform float seed;
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uniform float progress;
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uniform float detail;
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uniform vec2 u_resolution;
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uniform vec2 position;
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uniform vec2 scale;
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#region noise
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vec4 mod289(vec4 x) { return x - floor(x / 289.0) * 289.0; }
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vec4 permute(vec4 x) { return mod289((x * 34.0 + 1.0) * x); }
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vec4 snoise(vec3 v) {
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const vec2 C = vec2(1.0 / 6.0, 1.0 / 3.0);
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// First corner
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vec3 i = floor(v + dot(v, vec3(C.y)));
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vec3 x0 = v - i + dot(i, vec3(C.x));
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// Other corners
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vec3 g = step(x0.yzx, x0.xyz);
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vec3 l = 1.0 - g;
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vec3 i1 = min(g.xyz, l.zxy);
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vec3 i2 = max(g.xyz, l.zxy);
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vec3 x1 = x0 - i1 + C.x;
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vec3 x2 = x0 - i2 + C.y;
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vec3 x3 = x0 - 0.5;
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// Permutations
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vec4 p =
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permute(permute(permute(i.z + vec4(0.0, i1.z, i2.z, 1.0))
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+ i.y + vec4(0.0, i1.y, i2.y, 1.0))
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+ i.x + vec4(0.0, i1.x, i2.x, 1.0));
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// Gradients: 7x7 points over a square, mapped onto an octahedron.
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// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
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vec4 j = p - 49.0 * floor(p / 49.0); // mod(p,7*7)
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vec4 x_ = floor(j / 7.0);
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vec4 y_ = floor(j - 7.0 * x_);
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vec4 x = (x_ * 2.0 + 0.5) / 7.0 - 1.0;
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vec4 y = (y_ * 2.0 + 0.5) / 7.0 - 1.0;
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vec4 h = 1.0 - abs(x) - abs(y);
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vec4 b0 = vec4(x.xy, y.xy);
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vec4 b1 = vec4(x.zw, y.zw);
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vec4 s0 = floor(b0) * 2.0 + 1.0;
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vec4 s1 = floor(b1) * 2.0 + 1.0;
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vec4 sh = -step(h, vec4(0.0));
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vec4 a0 = b0.xzyw + s0.xzyw * sh.xxyy;
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vec4 a1 = b1.xzyw + s1.xzyw * sh.zzww;
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vec3 g0 = vec3(a0.xy, h.x);
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vec3 g1 = vec3(a0.zw, h.y);
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vec3 g2 = vec3(a1.xy, h.z);
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vec3 g3 = vec3(a1.zw, h.w);
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// Compute noise and gradient at P
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vec4 m = max(0.6 - vec4(dot(x0, x0), dot(x1, x1), dot(x2, x2), dot(x3, x3)), 0.0);
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vec4 m2 = m * m;
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vec4 m3 = m2 * m;
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vec4 m4 = m2 * m2;
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vec3 grad =
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-6.0 * m3.x * x0 * dot(x0, g0) + m4.x * g0 +
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-6.0 * m3.y * x1 * dot(x1, g1) + m4.y * g1 +
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-6.0 * m3.z * x2 * dot(x2, g2) + m4.z * g2 +
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-6.0 * m3.w * x3 * dot(x3, g3) + m4.w * g3;
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vec4 px = vec4(dot(x0, g0), dot(x1, g1), dot(x2, g2), dot(x3, g3));
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return 42.0 * vec4(grad, dot(m4, px));
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}
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#endregion
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void main() {
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vec2 p = v_vTexcoord - .5;
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p.x *= (u_resolution.x / u_resolution.y);
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p = (p + position) * scale / 2.;
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vec3 pos = vec3(p.x, progress, p.y);
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vec4 n = snoise( pos );
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pos -= 0.07 * n.xyz;
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n = snoise( pos );
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pos -= 0.07 * n.xyz;
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n = snoise( pos );
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// noise [-1..+1] -> color
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float intensity = exp(n.w * 3. - 1.5);
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gl_FragColor = vec4(vec3(intensity), 1.);
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}
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