89 lines
2.3 KiB
C++
89 lines
2.3 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>
|
|
NzSimplex2D<T>::NzSimplex2D()
|
|
{
|
|
T grad2Temp[][2] = {{1,1},{-1,1},{1,-1},{-1,-1},
|
|
{1,0},{-1,0},{0,1},{0,-1}};
|
|
|
|
for(int i(0) ; i < 8 ; ++i)
|
|
for(int j(0) ; j < 2 ; ++j)
|
|
gradient2[i][j] = grad2Temp[i][j];
|
|
|
|
SkewCoeff2D = 0.5*(sqrt(3.0) - 1.0);
|
|
UnskewCoeff2D = (3.0-sqrt(3.0))/6.;
|
|
}
|
|
|
|
template <typename T>
|
|
T NzSimplex2D<T>::GetValue(T x, T y, T resolution)
|
|
{
|
|
x *= resolution;
|
|
y *= resolution;
|
|
|
|
sum = (x + y) * SkewCoeff2D;
|
|
skewedCubeOrigin.x = this->fastfloor(x + sum);
|
|
skewedCubeOrigin.y = this->fastfloor(y + sum);
|
|
|
|
sum = (skewedCubeOrigin.x + skewedCubeOrigin.y) * UnskewCoeff2D;
|
|
unskewedCubeOrigin.x = skewedCubeOrigin.x - sum;
|
|
unskewedCubeOrigin.y = skewedCubeOrigin.y - sum;
|
|
|
|
unskewedDistToOrigin.x = x - unskewedCubeOrigin.x;
|
|
unskewedDistToOrigin.y = y - unskewedCubeOrigin.y;
|
|
|
|
if(unskewedDistToOrigin.x > unskewedDistToOrigin.y)
|
|
{
|
|
off1.x = 1;
|
|
off1.y = 0;
|
|
}
|
|
else
|
|
{
|
|
off1.x = 0;
|
|
off1.y = 1;
|
|
}
|
|
|
|
d1 = - unskewedDistToOrigin;
|
|
|
|
d2.x = d1.x + off1.x - UnskewCoeff2D;
|
|
d2.y = d1.y + off1.y - UnskewCoeff2D;
|
|
|
|
d3.x = d1.x + 1.0 - 2 * UnskewCoeff2D;
|
|
d3.y = d1.y + 1.0 - 2 * UnskewCoeff2D;
|
|
|
|
ii = skewedCubeOrigin.x & 255;
|
|
jj = skewedCubeOrigin.y & 255;
|
|
|
|
gi0 = this->perm[ii + this->perm[jj ]] & 7;
|
|
gi1 = this->perm[ii + off1.x + this->perm[jj + off1.y]] & 7;
|
|
gi2 = this->perm[ii + 1 + this->perm[jj + 1 ]] & 7;
|
|
|
|
c1 = 0.5 - d1.x * d1.x - d1.y * d1.y;
|
|
c2 = 0.5 - d2.x * d2.x - d2.y * d2.y;
|
|
c3 = 0.5 - d3.x * d3.x - d3.y * d3.y;
|
|
|
|
if(c1 < 0)
|
|
n1 = 0;
|
|
else
|
|
n1 = c1*c1*c1*c1*(gradient2[gi0][0] * d1.x + gradient2[gi0][1] * d1.y);
|
|
|
|
if(c2 < 0)
|
|
n2 = 0;
|
|
else
|
|
n2 = c2*c2*c2*c2*(gradient2[gi1][0] * d2.x + gradient2[gi1][1] * d2.y);
|
|
|
|
if(c3 < 0)
|
|
n3 = 0;
|
|
else
|
|
n3 = c3*c3*c3*c3*(gradient2[gi2][0] * d3.x + gradient2[gi2][1] * d3.y);
|
|
|
|
return (n1+n2+n3)*70;
|
|
}
|
|
|
|
#include <Nazara/Core/DebugOff.hpp>
|