23 lines
791 B
HLSL
23 lines
791 B
HLSL
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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inline float gradientNoise_float(float2 uv, float scale)
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{ return gradientNoise(uv * scale) + 0.5; } |