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.org * 00021 ***************************************************************************/ 00022 00023 // gaussianspd.cpp* 00024 #include "gaussianspd.h" 00025 00026 using namespace lux; 00027 00028 void GaussianSPD::init(float mean, float width, float refl) { 00029 mu = mean; 00030 wd = width; 00031 r0 = refl; 00032 00033 float scale2 = float(-0.5 / (width * width)); 00034 00035 lambdaMin = GAUSS_CACHE_START; 00036 lambdaMax = GAUSS_CACHE_END; 00037 delta = (GAUSS_CACHE_END - GAUSS_CACHE_START) / (GAUSS_CACHE_SAMPLES-1); 00038 invDelta = 1.f / delta; 00039 nSamples = GAUSS_CACHE_SAMPLES; 00040 00041 AllocateSamples(GAUSS_CACHE_SAMPLES); 00042 00043 // Fill samples with Gaussian curve 00044 for(int i=0; i<GAUSS_CACHE_SAMPLES; i++) { 00045 float w = (GAUSS_CACHE_START + (delta*i)); 00046 float x = w - mu; 00047 samples[i] = refl * expf(x * x * scale2); 00048 } 00049 00050 Clamp(); 00051 }