mirror of
https://github.com/Ttanasart-pt/Pixel-Composer.git
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120 lines
3.4 KiB
GLSL
120 lines
3.4 KiB
GLSL
//
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// Description : Array and textureless GLSL 2D/3D/4D simplex
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// noise functions.
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// Author : Ian McEwan, Ashima Arts.
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// Maintainer : stegu
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// Lastmod : 20201014 (stegu)
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// License : Copyright (C) 2011 Ashima Arts. All rights reserved.
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// Distributed under the MIT License. See LICENSE file.
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// https://github.com/ashima/webgl-noise
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// https://github.com/stegu/webgl-noise
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//
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varying vec2 v_vTexcoord;
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varying vec4 v_vColour;
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uniform vec2 scale;
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uniform vec3 position;
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uniform int iteration;
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vec3 mod289(vec3 x) { return x - floor(x * (1.0 / 289.0)) * 289.0; }
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vec4 mod289(vec4 x) { return x - floor(x * (1.0 / 289.0)) * 289.0; }
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vec4 permute(vec4 x) { return mod289(((x * 34.0) + 10.0) * x); }
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vec4 taylorInvSqrt(vec4 r) { return 1.79284291400159 - 0.85373472095314 * r; }
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float snoise(vec3 vec) {
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vec3 v = vec * 4.;
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const vec2 C = vec2(1.0 / 6.0, 1.0 / 3.0);
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const vec4 D = vec4(0.0, 0.5, 1.0, 2.0);
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// First corner
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vec3 i = floor(v + dot(v, C.yyy));
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vec3 x0 = v - i + dot(i, C.xxx);
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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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// x0 = x0 - 0.0 + 0.0 * C.xxx;
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// x1 = x0 - i1 + 1.0 * C.xxx;
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// x2 = x0 - i2 + 2.0 * C.xxx;
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// x3 = x0 - 1.0 + 3.0 * C.xxx;
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vec3 x1 = x0 - i1 + C.xxx;
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vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
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vec3 x3 = x0 - D.yyy; // -1.0+3.0*C.x = -0.5 = -D.y
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// Permutations
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i = mod289(i);
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vec4 p = permute( permute( permute(
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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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float n_ = 0.142857142857; // 1.0/7.0
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vec3 ns = n_ * D.wyz - D.xzx;
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vec4 j = p - 49.0 * floor(p * ns.z * ns.z); // mod(p,7*7)
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vec4 x_ = floor(j * ns.z);
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vec4 y_ = floor(j - 7.0 * x_ ); // mod(j,N)
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vec4 x = x_ * ns.x + ns.yyyy;
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vec4 y = y_ * ns.x + ns.yyyy;
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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 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
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//vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
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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 p0 = vec3(a0.xy, h.x);
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vec3 p1 = vec3(a0.zw, h.y);
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vec3 p2 = vec3(a1.xy, h.z);
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vec3 p3 = vec3(a1.zw, h.w);
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//Normalise gradients
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vec4 norm = taylorInvSqrt(vec4(dot(p0, p0), dot(p1, p1), dot(p2, p2), dot(p3, p3)));
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p0 *= norm.x;
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p1 *= norm.y;
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p2 *= norm.z;
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p3 *= norm.w;
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// Mix final noise value
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vec4 m = max(0.5 - vec4(dot(x0, x0), dot(x1, x1), dot(x2, x2), dot(x3, x3)), 0.0);
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m = m * m;
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float n = 105.0 * dot( m * m, vec4( dot(p0, x0), dot(p1, x1), dot(p2, x2), dot(p3, x3) ) );
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n = mix(0.0, 0.5 + 0.5 * n, smoothstep(0.0, 0.003, vec.z));
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return n;
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}
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void main() {
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vec2 p = ((v_vTexcoord + position.xy) / scale) * 2.0 - 1.0;
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float _z = 1. + position.z;
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vec3 xyz = vec3(p, _z);
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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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for(int i = 0; i < iteration; i++) {
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n += snoise(xyz) * amp;
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amp *= .5;
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xyz *= 2.;
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}
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gl_FragColor = vec4(vec3(n), 1.);
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} |