51 lines
2.4 KiB
C#
51 lines
2.4 KiB
C#
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using static Unity.Mathematics.math;
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namespace Unity.Mathematics
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{
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public static partial class noise
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{
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// Modulo 289 without a division (only multiplications)
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static float mod289(float x) { return x - floor(x * (1.0f / 289.0f)) * 289.0f; }
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static float2 mod289(float2 x) { return x - floor(x * (1.0f / 289.0f)) * 289.0f; }
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static float3 mod289(float3 x) { return x - floor(x * (1.0f / 289.0f)) * 289.0f; }
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static float4 mod289(float4 x) { return x - floor(x * (1.0f / 289.0f)) * 289.0f; }
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// Modulo 7 without a division
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static float3 mod7(float3 x) { return x - floor(x * (1.0f / 7.0f)) * 7.0f; }
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static float4 mod7(float4 x) { return x - floor(x * (1.0f / 7.0f)) * 7.0f; }
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// Permutation polynomial: (34x^2 + x) math.mod 289
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static float permute(float x) { return mod289((34.0f * x + 1.0f) * x); }
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static float3 permute(float3 x) { return mod289((34.0f * x + 1.0f) * x); }
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static float4 permute(float4 x) { return mod289((34.0f * x + 1.0f) * x); }
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static float taylorInvSqrt(float r) { return 1.79284291400159f - 0.85373472095314f * r; }
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static float4 taylorInvSqrt(float4 r) { return 1.79284291400159f - 0.85373472095314f * r; }
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static float2 fade(float2 t) { return t*t*t*(t*(t*6.0f-15.0f)+10.0f); }
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static float3 fade(float3 t) { return t*t*t*(t*(t*6.0f-15.0f)+10.0f); }
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static float4 fade(float4 t) { return t*t*t*(t*(t*6.0f-15.0f)+10.0f); }
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static float4 grad4(float j, float4 ip)
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{
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float4 ones = float4(1.0f, 1.0f, 1.0f, -1.0f);
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float3 pxyz = floor(frac(float3(j) * ip.xyz) * 7.0f) * ip.z - 1.0f;
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float pw = 1.5f - dot(abs(pxyz), ones.xyz);
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float4 p = float4(pxyz, pw);
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float4 s = float4(p < 0.0f);
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p.xyz = p.xyz + (s.xyz*2.0f - 1.0f) * s.www;
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return p;
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}
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// Hashed 2-D gradients with an extra rotation.
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// (The constant 0.0243902439 is 1/41)
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static float2 rgrad2(float2 p, float rot)
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{
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// For more isotropic gradients, math.sin/math.cos can be used instead.
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float u = permute(permute(p.x) + p.y) * 0.0243902439f + rot; // Rotate by shift
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u = frac(u) * 6.28318530718f; // 2*pi
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return float2(cos(u), sin(u));
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}
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}
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}
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