135 lines
No EOL
3.7 KiB
GLSL
135 lines
No EOL
3.7 KiB
GLSL
//noise functions adapted from Keijiro HLSL Simplex Noise
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vec3 mod289(vec3 x)
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{
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return x - floor(x / 289.0) * 289.0;
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}
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vec4 mod289(vec4 x)
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{
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return x - floor(x / 289.0) * 289.0;
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}
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vec4 permute(vec4 x)
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{
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return mod289((x * 34.0 + 1.0) * x);
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}
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vec4 taylorInvSqrt(vec4 r)
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{
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return 1.79284291400159 - r * 0.85373472095314;
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}
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vec3 snoise_grad(vec3 v)
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{
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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, 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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// 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;
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vec3 x3 = x0 - 0.5;
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// Permutations
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i = mod289(i); // Avoid truncation effects in permutation
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vec4 p =
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permute(permute(permute(vec4(i.z) + vec4(0.0, i1.z, i2.z, 1.0))
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+ vec4(i.y) + vec4(0.0, i1.y, i2.y, 1.0))
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+ vec4(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_); // mod(j,N)
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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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//float4 s0 = float4(lessThan(b0, 0.0)) * 2.0 - 1.0;
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//float4 s1 = float4(lessThan(b1, 0.0)) * 2.0 - 1.0;
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vec4 s0 = vec4(floor(b0) * 2.0 + 1.0);
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vec4 s1 = vec4(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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// Normalise gradients
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vec4 norm = taylorInvSqrt(vec4(dot(g0, g0), dot(g1, g1), dot(g2, g2), dot(g3, g3)));
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g0 *= norm.x;
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g1 *= norm.y;
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g2 *= norm.z;
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g3 *= norm.w;
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// Compute gradient of noise function 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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return 42.0 * grad;
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}
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void mainImage( out vec4 fragColor, in vec2 fragCoord )
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{
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vec2 iResolution;
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iResolution.x=7.0;
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iResolution.y=7.0;
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vec2 uv = fragCoord.xy / iResolution.xy;
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vec3 noiseOffset = snoise_grad(vec3(uv*16.-iGlobalTime, iGlobalTime*2.));
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vec3 c = vec3(clamp(1. - length((uv * 2. - 1.)*1.5+noiseOffset.xy*0.3),0.2,1.0))*2.;
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c *= vec3(0.2,0.5,1.0);
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c += (1.-length(uv * 2. - 1.))*0.5;
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c = c+c+c+c;
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c /=3.;
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fragColor = vec4(c,1.0);
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}
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float getProceduralColors(inout vec3 diffuse, inout vec3 specular, inout float shininess)
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{
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vec2 position = _position.xz;
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position += 0.5;
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position.y = 1.0 - position.y;
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vec4 pixelColor;
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mainImage(pixelColor, position * iWorldScale.xz);
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diffuse = pixelColor.rgb; // Return 0.0 and color in diffuse for a lit surface
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// return 0.0;
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specular = pixelColor.rgb; // or return 1.0 and color in specular for unlit surface.
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return 1.0;
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} |