00001 /*************************************************************************** 00002 * Copyright (C) 1998-2009 by authors (see AUTHORS.txt ) * 00003 * * 00004 * This file is part of LuxRender. * 00005 * * 00006 * Lux Renderer is free software; you can redistribute it and/or modify * 00007 * it under the terms of the GNU General Public License as published by * 00008 * the Free Software Foundation; either version 3 of the License, or * 00009 * (at your option) any later version. * 00010 * * 00011 * Lux Renderer is distributed in the hope that it will be useful, * 00012 * but WITHOUT ANY WARRANTY; without even the implied warranty of * 00013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * 00014 * GNU General Public License for more details. * 00015 * * 00016 * You should have received a copy of the GNU General Public License * 00017 * along with this program. If not, see <http://www.gnu.org/licenses/>. * 00018 * * 00019 * This project is based on PBRT ; see http://www.pbrt.org * 00020 * Lux Renderer website : http://www.luxrender.net * 00021 ***************************************************************************/ 00022 00023 #ifndef LUX_GAUSSIAN_H 00024 #define LUX_GAUSSIAN_H 00025 00026 // gaussian.cpp* 00027 #include "filter.h" 00028 #include "paramset.h" 00029 00030 namespace lux 00031 { 00032 00033 // Gaussian Filter Declarations 00034 class GaussianFilter : public Filter { 00035 public: 00036 // GaussianFilter Public Methods 00037 GaussianFilter(float xw, float yw, float a) 00038 : Filter(xw, yw) { 00039 alpha = a; 00040 expX = expf(-alpha * xWidth * xWidth); 00041 expY = expf(-alpha * yWidth * yWidth); 00042 } 00043 virtual ~GaussianFilter() { } 00044 virtual float Evaluate(float x, float y) const; 00045 00046 static Filter *CreateFilter(const ParamSet &ps); 00047 private: 00048 // GaussianFilter Private Data 00049 float alpha; 00050 float expX, expY; 00051 // GaussianFilter Utility Functions 00052 float Gaussian(float d, float expv) const { 00053 return max(0.f, expf(-alpha * d * d) - expv); 00054 } 00055 }; 00056 00057 }//namespace lux 00058 00059 #endif