00001 00002 /* 00003 pbrt source code Copyright(c) 1998-2010 Matt Pharr and Greg Humphreys. 00004 00005 This file is part of pbrt. 00006 00007 pbrt is free software; you can redistribute it and/or modify 00008 it under the terms of the GNU General Public License as published by 00009 the Free Software Foundation; either version 2 of the License, or 00010 (at your option) any later version. Note that the text contents of 00011 the book "Physically Based Rendering" are *not* licensed under the 00012 GNU GPL. 00013 00014 pbrt is distributed in the hope that it will be useful, 00015 but WITHOUT ANY WARRANTY; without even the implied warranty of 00016 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00017 GNU General Public License for more details. 00018 00019 You should have received a copy of the GNU General Public License 00020 along with this program. If not, see <http://www.gnu.org/licenses/>. 00021 00022 */ 00023 00024 #if defined(_MSC_VER) 00025 #pragma once 00026 #endif 00027 00028 #ifndef PBRT_FILTERS_GAUSSIAN_H 00029 #define PBRT_FILTERS_GAUSSIAN_H 00030 00031 // filters/gaussian.h* 00032 #include "filter.h" 00033 00034 // Gaussian Filter Declarations 00035 class GaussianFilter : public Filter { 00036 public: 00037 // GaussianFilter Public Methods 00038 GaussianFilter(float xw, float yw, float a) 00039 : Filter(xw, yw), alpha(a), expX(expf(-alpha * xWidth * xWidth)), 00040 expY(expf(-alpha * yWidth * yWidth)) { } 00041 float Evaluate(float x, float y) const; 00042 private: 00043 // GaussianFilter Private Data 00044 const float alpha; 00045 const float expX, expY; 00046 00047 // GaussianFilter Utility Functions 00048 float Gaussian(float d, float expv) const { 00049 return max(0.f, float(expf(-alpha * d * d) - expv)); 00050 } 00051 }; 00052 00053 00054 GaussianFilter *CreateGaussianFilter(const ParamSet &ps); 00055 00056 #endif // PBRT_FILTERS_GAUSSIAN_H