129 lines
3.4 KiB
HLSL
129 lines
3.4 KiB
HLSL
#ifndef GRIFFIN_CG_INCLUDED
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#define GRIFFIN_CG_INCLUDED
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float2 GradientNoise_dir(float2 p)
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{
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p = p % 289;
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float x = (34 * p.x + 1) * p.x % 289 + p.y;
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x = (34 * x + 1) * x % 289;
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x = frac(x / 41) * 2 - 1;
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return normalize(float2(x - floor(x + 0.5), abs(x) - 0.5));
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}
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float GradientNoise(float2 p)
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{
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float2 ip = floor(p);
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float2 fp = frac(p);
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float d00 = dot(GradientNoise_dir(ip), fp);
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float d01 = dot(GradientNoise_dir(ip + float2(0, 1)), fp - float2(0, 1));
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float d10 = dot(GradientNoise_dir(ip + float2(1, 0)), fp - float2(1, 0));
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float d11 = dot(GradientNoise_dir(ip + float2(1, 1)), fp - float2(1, 1));
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fp = fp * fp * fp * (fp * (fp * 6 - 15) + 10);
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return lerp(lerp(d00, d01, fp.y), lerp(d10, d11, fp.y), fp.x);
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}
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float InverseLerpUnclamped(float a, float b, float value)
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{
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//adding a==b check if needed
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return (value - a) / (b - a + 0.0000001);
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}
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float RandomValue(float seed)
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{
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return frac(sin(dot(float2(seed, seed+1), float2(12.9898, 78.233)))*43758.5453);
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}
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float RandomValue(float u, float v)
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{
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return frac(sin(dot(float2(u, v), float2(12.9898, 78.233)))*43758.5453);
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}
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float2 VoronoiRandomVector (float2 UV, float offset)
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{
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float2x2 m = float2x2(15.27, 47.63, 99.41, 89.98);
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UV = frac(sin(mul(UV, m)) * 46839.32);
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return float2(sin(UV.y*+offset)*0.5+0.5, cos(UV.x*offset)*0.5+0.5);
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}
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float Voronoi(float2 UV, float AngleOffset, float CellDensity)
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{
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float2 g = floor(UV * CellDensity);
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float2 f = frac(UV * CellDensity);
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float t = 8.0;
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float3 res = float3(8.0, 0.0, 0.0);
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float noiseValue = 0;
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for(int y=-1; y<=1; y++)
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{
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for(int x=-1; x<=1; x++)
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{
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float2 lattice = float2(x,y);
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float2 offset = VoronoiRandomVector(lattice + g, AngleOffset);
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float d = distance(lattice + offset, f);
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if(d < res.x)
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{
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res = float3(d, offset.x, offset.y);
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noiseValue = res.x;
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}
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}
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}
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return noiseValue;
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}
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inline float ValueNoiseInterpolate (float a, float b, float t)
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{
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return (1.0-t)*a + (t*b);
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}
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inline float ValueNoise (float2 uv)
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{
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float2 i = floor(uv);
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float2 f = frac(uv);
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f = f * f * (3.0 - 2.0 * f);
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uv = abs(frac(uv) - 0.5);
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float2 c0 = i + float2(0.0, 0.0);
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float2 c1 = i + float2(1.0, 0.0);
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float2 c2 = i + float2(0.0, 1.0);
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float2 c3 = i + float2(1.0, 1.0);
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float r0 = RandomValue(c0.x, c0.y);
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float r1 = RandomValue(c1.x, c1.y);
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float r2 = RandomValue(c2.x, c2.y);
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float r3 = RandomValue(c3.x, c3.y);
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float bottomOfGrid = ValueNoiseInterpolate(r0, r1, f.x);
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float topOfGrid = ValueNoiseInterpolate(r2, r3, f.x);
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float t = ValueNoiseInterpolate(bottomOfGrid, topOfGrid, f.y);
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return t;
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}
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float4 MoveTowards(float4 current, float4 target, float maxDistanceDelta)
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{
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float4 a = target - current;
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float magnitude = length(a);
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if (magnitude <= maxDistanceDelta || magnitude == 0)
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{
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return target;
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}
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return current + a / magnitude * maxDistanceDelta;
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}
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// Encoding/decoding [0..1) floats into 8 bit/channel RG. Note that 1.0 will not be encoded properly.
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inline float2 GriffinEncodeFloatRG(float v)
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{
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float2 kEncodeMul = float2(1.0, 255.0);
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float kEncodeBit = 1.0 / 255.0;
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float2 enc = kEncodeMul * v;
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enc = frac(enc);
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enc.x -= enc.y * kEncodeBit;
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return enc;
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}
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inline float GriffinDecodeFloatRG(float2 enc)
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{
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float2 kDecodeDot = float2(1.0, 1 / 255.0);
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return dot(enc, kDecodeDot);
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}
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#endif //GRIFFIN_CG_INCLUDED |