# naucoin/VTKSlicerWidgets

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 /*========================================================================= Program: Visualization Toolkit Module: vtkPerlinNoise.cxx Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen All rights reserved. See Copyright.txt or http://www.kitware.com/Copyright.htm for details. This software is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the above copyright notice for more information. =========================================================================*/ #include "vtkPerlinNoise.h" #include "vtkObjectFactory.h" #include vtkStandardNewMacro(vtkPerlinNoise); // These functions are from Greg Ward's recursive implementation in // Graphics Gems II. I've kept the names the same for instructional // purposes, and only changed things where optimizations could be made. static double hermite(double p0, double p1, double r0, double r1, double t) { double tt = t*t; return (p0*((2.0*t - 3.0)*tt + 1.0) + p1*(-2.0*t + 3.0)*tt + r0*((t-2.0)*t+1.0)*t + r1*(t-1.0)*tt); } // assumes 32 bit ints, but so it seems does VTK static double frand(int s) { s = (s<<13) ^ s; s = (s*(s*s*15731 + 789221)+1376312589)&VTK_INT_MAX; return 1.0 - double(s)/(VTK_INT_MAX/2 + 1); } static void rand3abcd(int x, int y, int z, double outv[4]) { outv[0] = frand(67*x + 59*y + 71*z); outv[1] = frand(73*x + 79*y + 83*z); outv[2] = frand(89*x + 97*y + 101*z); outv[3] = frand(103*x + 107*y + 109*z); } static void interpolate(double f[4], int i, int n, int xlim[3][2], double xarg[2]) { double f0[4], f1[4]; if (n == 0) { rand3abcd(xlim[0][i&1], xlim[1][(i>>1) & 1], xlim[2][i>>2], f); return; } n--; interpolate(f0, i, n, xlim, xarg); interpolate(f1, i | (1<Frequency[0] = 1.0; this->Frequency[1] = 1.0; this->Frequency[2] = 1.0; this->Phase[0] = 0.0; this->Phase[1] = 0.0; this->Phase[2] = 0.0; this->Amplitude = 1.0; } double vtkPerlinNoise::EvaluateFunction(double x[3]) { double xd[3]; double noise[4]; xd[0] = x[0]*this->Frequency[0] - this->Phase[0]*2.0; xd[1] = x[1]*this->Frequency[1] - this->Phase[1]*2.0; xd[2] = x[2]*this->Frequency[2] - this->Phase[2]*2.0; perlinNoise(xd, noise); return noise[3]*this->Amplitude; } // Evaluate PerlinNoise gradient. void vtkPerlinNoise::EvaluateGradient(double* vtkNotUsed(x), // Was x[3] double n[3]) { // contrary to the paper, the vector computed as a byproduct of // the Perlin Noise computation isn't a gradient; it's a tangent. // Doing this right will take some work. n[0] = 0.0; n[1] = 0.0; n[2] = 0.0; } void vtkPerlinNoise::PrintSelf(ostream& os, vtkIndent indent) { this->Superclass::PrintSelf(os,indent); os << indent << "Amplitude: " << this->Amplitude << "\n"; os << indent << "Frequency: (" << this->Frequency[0] << ", " << this->Frequency[1] << ", " << this->Frequency[2] << ")\n"; os << indent << "Phase: (" << this->Phase[0] << ", " << this->Phase[1] << ", " << this->Phase[2] << ")\n"; }