NazaraEngine/include/Nazara/Noise/Simplex3D.inl

158 lines
4.3 KiB
C++

// Copyright (C) 2012 Rémi Bèges
// This file is part of the "Nazara Engine".
// For conditions of distribution and use, see copyright notice in Config.hpp
#include <Nazara/Core/Error.hpp>
#include <Nazara/Noise/Config.hpp>
#include <Nazara/Noise/Debug.hpp>
template <typename T>
NzSimplex3D<T>::NzSimplex3D()
{
SkewCoeff3D = 1/3.;
UnskewCoeff3D = 1/6.;
int grad3Temp[][3] = {{1,1,0},{-1,1,0},{1,-1,0},{-1,-1,0},
{1,0,1},{-1,0,1},{1,0,-1},{-1,0,-1},
{0,1,1},{0,-1,1},{0,1,-1},{0,-1,-1}};
for(int i(0) ; i < 12 ; ++i)
for(int j(0) ; j < 3 ; ++j)
gradient3[i][j] = grad3Temp[i][j];
}
template <typename T>
T NzSimplex3D<T>::GetValue(T x, T y, T z, T res)
{
x /= res;
y /= res;
z /= res;
sum = (x + y + z) * SkewCoeff3D;
skewedCubeOrigin.x = fastfloor(x + sum);
skewedCubeOrigin.y = fastfloor(y + sum);
skewedCubeOrigin.z = fastfloor(z + sum);
sum = (skewedCubeOrigin.x + skewedCubeOrigin.y + skewedCubeOrigin.z) * UnskewCoeff3D;
unskewedCubeOrigin.x = skewedCubeOrigin.x - sum;
unskewedCubeOrigin.y = skewedCubeOrigin.y - sum;
unskewedCubeOrigin.z = skewedCubeOrigin.z - sum;
unskewedDistToOrigin.x = x - unskewedCubeOrigin.x;
unskewedDistToOrigin.y = y - unskewedCubeOrigin.y;
unskewedDistToOrigin.z = z - unskewedCubeOrigin.z;
if(unskewedDistToOrigin.x >= unskewedDistToOrigin.y)
{
if(unskewedDistToOrigin.y >= unskewedDistToOrigin.z)
{
off1.x = 1;
off1.y = 0;
off1.z = 0;
off2.x = 1;
off2.y = 1;
off2.z = 0;
}
else if(unskewedDistToOrigin.x >= unskewedDistToOrigin.z)
{
off1.x = 1;
off1.y = 0;
off1.z = 0;
off2.x = 1;
off2.y = 0;
off2.z = 1;
}
else
{
off1.x = 0;
off1.y = 0;
off1.z = 1;
off2.x = 1;
off2.y = 0;
off2.z = 1;
}
}
else
{
if(unskewedDistToOrigin.y < unskewedDistToOrigin.z)
{
off1.x = 0;
off1.y = 0;
off1.z = 1;
off2.x = 0;
off2.y = 1;
off2.z = 1;
}
else if(unskewedDistToOrigin.x < unskewedDistToOrigin.z)
{
off1.x = 0;
off1.y = 1;
off1.z = 0;
off2.x = 0;
off2.y = 1;
off2.z = 1;
}
else
{
off1.x = 0;
off1.y = 1;
off1.z = 0;
off2.x = 1;
off2.y = 1;
off2.z = 0;
}
}
d1 = unskewedDistToOrigin;
d2.x = d1.x - off1.x + UnskewCoeff3D;
d2.y = d1.y - off1.y + UnskewCoeff3D;
d2.z = d1.z - off1.z + UnskewCoeff3D;
d3.x = d1.x - off2.x + 2*UnskewCoeff3D;
d3.y = d1.y - off2.y + 2*UnskewCoeff3D;
d3.z = d1.z - off2.z + 2*UnskewCoeff3D;
d4.x = d1.x - 1.0 + 3*UnskewCoeff3D;
d4.y = d1.y - 1.0 + 3*UnskewCoeff3D;
d4.z = d1.z - 1.0 + 3*UnskewCoeff3D;
ii = skewedCubeOrigin.x & 255;
jj = skewedCubeOrigin.y & 255;
kk = skewedCubeOrigin.z & 255;
gi0 = perm[ii + perm[jj + perm[kk ]]] % 12;
gi1 = perm[ii + off1.x + perm[jj + off1.y + perm[kk + off1.z]]] % 12;
gi2 = perm[ii + off2.x + perm[jj + off2.y + perm[kk + off2.z]]] % 12;
gi3 = perm[ii + 1 + perm[jj + 1 + perm[kk + 1 ]]] % 12;
c1 = 0.6 - d1.x * d1.x - d1.y * d1.y - d1.z * d1.z;
c2 = 0.6 - d2.x * d2.x - d2.y * d2.y - d2.z * d2.z;
c3 = 0.6 - d3.x * d3.x - d3.y * d3.y - d3.z * d3.z;
c4 = 0.6 - d4.x * d4.x - d4.y * d4.y - d4.z * d4.z;
if(c1 < 0)
n1 = 0;
else
n1 = c1*c1*c1*c1*(gradient3[gi0][0] * d1.x + gradient3[gi0][1] * d1.y + gradient3[gi0][2] * d1.z);
if(c2 < 0)
n2 = 0;
else
n2 = c2*c2*c2*c2*(gradient3[gi1][0] * d2.x + gradient3[gi1][1] * d2.y + gradient3[gi1][2] * d2.z);
if(c3 < 0)
n3 = 0;
else
n3 = c3*c3*c3*c3*(gradient3[gi2][0] * d3.x + gradient3[gi2][1] * d3.y + gradient3[gi2][2] * d3.z);
if(c4 < 0)
n4 = 0;
else
n4 = c4*c4*c4*c4*(gradient3[gi3][0] * d4.x + gradient3[gi3][1] * d4.y + gradient3[gi3][2] * d4.z);
return (n1+n2+n3+n4)*32;
}
#include <Nazara/Core/DebugOff.hpp>