/* * The Mana Client * Copyright (C) 2006-2009 The Mana World Development Team * Copyright (C) 2009-2010 The Mana Developers * * This file is part of The Mana Client. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <cmath> /** * Returns a random numeric value that is larger than or equal min and smaller * than max */ enum ChangeFunc { FUNC_NONE = 0, FUNC_SINE, FUNC_SAW, FUNC_TRIANGLE, FUNC_SQUARE }; template <typename T> struct ParticleEmitterProp { ParticleEmitterProp(): minVal(0), maxVal(0), changeFunc(FUNC_NONE), changeAmplitude(0), changePeriod(0), changePhase(0) { } void set(T min, T max) { minVal = min; maxVal = max; } void set(T val) { set(val, val); } void setFunction(ChangeFunc func, T amplitude, int period, int phase) { changeFunc = func; changeAmplitude = amplitude; changePeriod = period; changePhase = phase; } T value(int tick) { tick += changePhase; T val = (T) (minVal + (maxVal - minVal) * (rand() / ((double) RAND_MAX + 1))); switch (changeFunc) { case FUNC_SINE: val += (T) std::sin(M_PI * 2 * ((double)(tick % changePeriod) / (double)changePeriod)) * changeAmplitude; break; case FUNC_SAW: val += (T) (changeAmplitude * ((double)(tick % changePeriod) / (double)changePeriod)) * 2 - changeAmplitude; break; case FUNC_TRIANGLE: if ((tick % changePeriod) * 2 < changePeriod) { val += changeAmplitude - (T)((tick % changePeriod) / (double)changePeriod) * changeAmplitude * 4; } else { val += changeAmplitude * -3 + (T)((tick % changePeriod) / (double)changePeriod) * changeAmplitude * 4; // I have no idea why this works but it does } break; case FUNC_SQUARE: if ((tick % changePeriod) * 2 < changePeriod) val += changeAmplitude; else val -= changeAmplitude; break; case FUNC_NONE: default: //nothing break; } return val; } T minVal; T maxVal; ChangeFunc changeFunc; T changeAmplitude; int changePeriod; int changePhase; };