| 1 | /* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield |
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| 2 | * |
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| 3 | * This library is open source and may be redistributed and/or modified under |
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| 4 | * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or |
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| 5 | * (at your option) any later version. The full license is in LICENSE file |
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| 6 | * included with this distribution, and on the openscenegraph.org website. |
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| 7 | * |
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| 8 | * This library is distributed in the hope that it will be useful, |
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| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 11 | * OpenSceneGraph Public License for more details. |
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| 12 | */ |
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| 13 | |
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| 14 | #ifndef OSGPARTICLE_CONSTANTRATECOUNTER |
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| 15 | #define OSGPARTICLE_CONSTANTRATECOUNTER 1 |
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| 16 | |
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| 17 | #include <osgParticle/Counter> |
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| 18 | |
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| 19 | #include <osg/Object> |
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| 20 | #include <osg/Math> |
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| 21 | |
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| 22 | namespace osgParticle |
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| 23 | { |
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| 24 | |
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| 25 | class ConstantRateCounter: public Counter { |
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| 26 | public: |
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| 27 | ConstantRateCounter(): |
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| 28 | Counter(), |
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| 29 | _minimumNumberOfParticlesToCreate(0), |
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| 30 | _numberOfParticlesPerSecondToCreate(0), |
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| 31 | _carryOver(0) |
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| 32 | { |
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| 33 | } |
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| 34 | |
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| 35 | ConstantRateCounter(const ConstantRateCounter& copy, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY): |
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| 36 | Counter(copy, copyop), |
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| 37 | _minimumNumberOfParticlesToCreate(copy._minimumNumberOfParticlesToCreate), |
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| 38 | _numberOfParticlesPerSecondToCreate(copy._numberOfParticlesPerSecondToCreate), |
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| 39 | _carryOver(copy._carryOver) |
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| 40 | { |
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| 41 | } |
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| 42 | |
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| 43 | |
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| 44 | META_Object(osgParticle, ConstantRateCounter); |
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| 45 | |
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| 46 | void setMinimumNumberOfParticlesToCreate(int minNumToCreate) { _minimumNumberOfParticlesToCreate = minNumToCreate; } |
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| 47 | int getMinimumNumberOfParticlesToCreate() const { return _minimumNumberOfParticlesToCreate; } |
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| 48 | |
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| 49 | void setNumberOfParticlesPerSecondToCreate(double numPerSecond) { _numberOfParticlesPerSecondToCreate = numPerSecond; } |
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| 50 | double getNumberOfParticlesPerSecondToCreate() const { return _numberOfParticlesPerSecondToCreate; } |
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| 51 | |
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| 52 | /// Return the number of particles to be created in this frame |
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| 53 | virtual int numParticlesToCreate(double dt) const |
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| 54 | { |
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| 55 | double v = (dt*_numberOfParticlesPerSecondToCreate); |
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| 56 | int i = (int)(v); |
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| 57 | _carryOver += (v-(double)i); |
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| 58 | if (_carryOver>1.0) |
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| 59 | { |
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| 60 | ++i; |
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| 61 | _carryOver -= 1.0; |
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| 62 | } |
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| 63 | return osg::maximum(_minimumNumberOfParticlesToCreate, i); |
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| 64 | } |
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| 65 | |
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| 66 | protected: |
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| 67 | virtual ~ConstantRateCounter() {} |
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| 68 | |
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| 69 | int _minimumNumberOfParticlesToCreate; |
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| 70 | double _numberOfParticlesPerSecondToCreate; |
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| 71 | mutable double _carryOver; |
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| 72 | }; |
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| 73 | |
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| 74 | } |
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| 75 | |
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| 76 | |
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| 77 | #endif |
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