/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library 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
 * OpenSceneGraph Public License for more details.
*/

#include <osgParticle/ExplosionDebrisEffect>
#include <osgParticle/ModularEmitter>
#include <osgParticle/ModularProgram>
#include <osgParticle/RandomRateCounter>
#include <osgParticle/SectorPlacer>
#include <osgParticle/RadialShooter>
#include <osgParticle/AccelOperator>
#include <osgParticle/FluidFrictionOperator>
#include <osgParticle/ParticleSystemUpdater>

#include <osg/Geode>

using namespace osgParticle;

ExplosionDebrisEffect::ExplosionDebrisEffect(bool automaticSetup):
    ParticleEffect(automaticSetup)
{
    setDefaults();

    _position.set(0.0f,0.0f,0.0f);
    _scale = 1.0f;
    _intensity = 1.0f;

    _emitterDuration = 0.1;
    _defaultParticleTemplate.setLifeTime(1.0+0.6*_scale);

    if (_automaticSetup) buildEffect();
}

ExplosionDebrisEffect::ExplosionDebrisEffect(const osg::Vec3& position, float scale, float intensity)
{
    setDefaults();

    _position = position;
    _scale = scale;
    _intensity = intensity;

    _emitterDuration = 0.1;
    _defaultParticleTemplate.setLifeTime(1.0+0.6*_scale);

    if (_automaticSetup) buildEffect();
}

ExplosionDebrisEffect::ExplosionDebrisEffect(const ExplosionDebrisEffect& copy, const osg::CopyOp& copyop):
    ParticleEffect(copy,copyop)
{
    if (_automaticSetup) buildEffect();
}

void ExplosionDebrisEffect::setDefaults()
{
    ParticleEffect::setDefaults();

    _textureFileName = "Images/particle.rgb";
    _emitterDuration = 0.1;

    // set up unit particle.
    _defaultParticleTemplate.setLifeTime(1.0+0.6*_scale);
    _defaultParticleTemplate.setSizeRange(osgParticle::rangef(0.75f, 3.0f));
    _defaultParticleTemplate.setAlphaRange(osgParticle::rangef(0.0f, 1.0f));
    _defaultParticleTemplate.setColorRange(osgParticle::rangev4(
                            osg::Vec4(0.5f, 0.5f, 0.0f, 1.0f),
                            osg::Vec4(0.2f, 0.2f, 0.2f, 0.5f)));

}


void ExplosionDebrisEffect::setUpEmitterAndProgram()
{
    // set up particle system
    if (!_particleSystem)
    {
        _particleSystem = new osgParticle::ParticleSystem;
    }

    if (_particleSystem.valid())
    {
        _particleSystem->setDefaultAttributes(_textureFileName, false, false);

        osgParticle::Particle& ptemplate = _particleSystem->getDefaultParticleTemplate();

        float radius = 0.05f*_scale;
        float density = 1000.0f; // 1000.0kg/m^3

        ptemplate.setLifeTime(_defaultParticleTemplate.getLifeTime());

        // the following ranges set the envelope of the respective
        // graphical properties in time.
        ptemplate.setSizeRange(osgParticle::rangef(radius*_defaultParticleTemplate.getSizeRange().minimum,
                                                   radius*_defaultParticleTemplate.getSizeRange().maximum));
        ptemplate.setAlphaRange(_defaultParticleTemplate.getAlphaRange());
        ptemplate.setColorRange(_defaultParticleTemplate.getColorRange());

        // these are physical properties of the particle
        ptemplate.setRadius(radius);
        ptemplate.setMass(density*radius*radius*radius*osg::PI*4.0f/3.0f);

    }


    // set up emitter
    if (!_emitter)
    {
        _emitter = new osgParticle::ModularEmitter;
        _emitter->setCounter(new osgParticle::RandomRateCounter);
        _emitter->setPlacer(new osgParticle::SectorPlacer);
        _emitter->setShooter(new osgParticle::RadialShooter);
    }

    if (_emitter.valid())
    {
        _emitter->setParticleSystem(_particleSystem.get());
        _emitter->setReferenceFrame(_useLocalParticleSystem?
                                    osgParticle::ParticleProcessor::ABSOLUTE_RF:
                                    osgParticle::ParticleProcessor::RELATIVE_RF);

        _emitter->setStartTime(_startTime);
        _emitter->setLifeTime(_emitterDuration);
        _emitter->setEndless(false);

        osgParticle::RandomRateCounter* counter = dynamic_cast<osgParticle::RandomRateCounter*>(_emitter->getCounter());
        if (counter)
        {
            counter->setRateRange(2000*_intensity,2000*_intensity);
        }

        osgParticle::SectorPlacer* placer = dynamic_cast<osgParticle::SectorPlacer*>(_emitter->getPlacer());
        if (placer)
        {
            placer->setCenter(_position);
            placer->setRadiusRange(0.0f*_scale,0.25f*_scale);
        }

        osgParticle::RadialShooter* shooter = dynamic_cast<osgParticle::RadialShooter*>(_emitter->getShooter());
        if (shooter)
        {
            shooter->setThetaRange(0.0f, osg::PI_2);
            shooter->setInitialSpeedRange(1.0f*_scale,5.0f*_scale);
        }
    }

    // set up program.
    if (!_program)
    {
        _program = new osgParticle::FluidProgram;
    }

    if (_program.valid())
    {
        _program->setParticleSystem(_particleSystem.get());
        _program->setWind(_wind);
    }

}

