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Removed Particle::Shape support for QUAD_TRIANGLESTRIP, HEXAGON, USER as these are unlikely to be used as their implementation prevents refactoring to use vertex array code paths

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This commit is contained in:
Robert Osfield
2016-08-25 15:13:36 +01:00
parent c637010c9d
commit 56ed225f17
6 changed files with 54 additions and 194 deletions
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73
examples/osgparticleshader/osgparticleshader.cpp
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@@ -44,15 +44,15 @@ void createFountainEffect( osgParticle::ModularEmitter* emitter, osgParticle::Mo
// Emit specific number of particles every frame
osg::ref_ptr<osgParticle::RandomRateCounter> rrc = new osgParticle::RandomRateCounter;
rrc->setRateRange( 500, 2000 );
// Accelerate particles in the given gravity direction.
osg::ref_ptr<osgParticle::AccelOperator> accel = new osgParticle::AccelOperator;
accel->setToGravity();
// Multiply each particle's velocity by a damping constant.
osg::ref_ptr<osgParticle::DampingOperator> damping = new osgParticle::DampingOperator;
damping->setDamping( 0.9f );
// Bounce particles off objects defined by one or more domains.
// Supported domains include triangle, rectangle, plane, disk and sphere.
// Since a bounce always happens instantaneously, it will not work correctly with unstable delta-time.
@@ -63,12 +63,12 @@ void createFountainEffect( osgParticle::ModularEmitter* emitter, osgParticle::Mo
bounce->setResilience( 0.35 );
bounce->addDiskDomain( osg::Vec3(0.0f, 0.0f, -2.0f), osg::Z_AXIS, 8.0f );
bounce->addPlaneDomain( osg::Plane(osg::Z_AXIS, 5.0f) );
// Kill particles going inside/outside of specified domains.
osg::ref_ptr<osgParticle::SinkOperator> sink = new osgParticle::SinkOperator;
sink->setSinkStrategy( osgParticle::SinkOperator::SINK_OUTSIDE );
sink->addSphereDomain( osg::Vec3(), 20.0f );
emitter->setCounter( rrc.get() );
program->addOperator( accel.get() );
program->addOperator( damping.get() );
@@ -79,48 +79,33 @@ void createFountainEffect( osgParticle::ModularEmitter* emitter, osgParticle::Mo
int main( int argc, char** argv )
{
osg::ArgumentParser arguments( &argc, argv );
std::string textureFile("Images/smoke.rgb");
while ( arguments.read("--texture", textureFile) ) {}
float pointSize = 20.0f;
while ( arguments.read("--point", pointSize) ) {}
double visibilityDistance = -1.0f;
while ( arguments.read("--visibility", visibilityDistance) ) {}
bool customShape = false;
while ( arguments.read("--enable-custom") ) { customShape = true; }
bool useShaders = true;
while ( arguments.read("--disable-shaders") ) { useShaders = false; }
/***
Customize particle template and system attributes
***/
osg::ref_ptr<osgParticle::ParticleSystem> ps = new osgParticle::ParticleSystem;
ps->getDefaultParticleTemplate().setLifeTime( 5.0f );
if ( customShape )
{
// osgParticle now supports making use of customized drawables. The draw() method will be executed
// and display lists will be called for each particle. It is always a huge consumption of memory, and
// hardly to use shaders to render them, so please be careful using this feature.
ps->getDefaultParticleTemplate().setShape( osgParticle::Particle::USER );
ps->getDefaultParticleTemplate().setDrawable( new osg::ShapeDrawable(new osg::Box(osg::Vec3(), 1.0f)) );
useShaders = false;
}
else
{
// The shader only supports rendering points at present.
ps->getDefaultParticleTemplate().setShape( osgParticle::Particle::POINT );
}
// The shader only supports rendering points at present.
ps->getDefaultParticleTemplate().setShape( osgParticle::Particle::POINT );
// Set the visibility distance of particles, due to their Z-value in the eye coordinates.
// Particles that are out of the distance (or behind the eye) will not be rendered.
ps->setVisibilityDistance( visibilityDistance );
if ( useShaders )
{
// Set using local GLSL shaders to render particles.
@@ -133,52 +118,52 @@ int main( int argc, char** argv )
// The default methods uses glBegin()/glEnd() pairs. Fortunately the GLBeginEndAdapter does improve the
// process, which mimics the immediate mode with glDrawArrays().
ps->setDefaultAttributes( textureFile, true, false, 0 );
// Without the help of shaders, we have to sort particles to make the visibility distance work. Sorting is
// also useful in rendering transparent particles in back-to-front order.
if ( visibilityDistance>0.0 )
ps->setSortMode( osgParticle::ParticleSystem::SORT_BACK_TO_FRONT );
}
// At last, to make the point sprite work, we have to set the points size and the sprite attribute.
osg::StateSet* stateset = ps->getOrCreateStateSet();
stateset->setAttribute( new osg::Point(pointSize) );
stateset->setTextureAttributeAndModes( 0, new osg::PointSprite, osg::StateAttribute::ON );
/***
Construct other particle system elements, including the emitter and program
***/
osg::ref_ptr<osgParticle::ModularEmitter> emitter = new osgParticle::ModularEmitter;
emitter->setParticleSystem( ps.get() );
osg::ref_ptr<osgParticle::ModularProgram> program = new osgParticle::ModularProgram;
program->setParticleSystem( ps.get() );
createFountainEffect( emitter.get(), program.get() );
/***
Add the entire particle system to the scene graph
***/
osg::ref_ptr<osg::MatrixTransform> parent = new osg::MatrixTransform;
parent->addChild( emitter.get() );
parent->addChild( program.get() );
// The updater can receive particle systems as child drawables now. The addParticleSystem() method
// is still usable, with which we should define another geode to contain a particle system.
osg::ref_ptr<osgParticle::ParticleSystemUpdater> updater = new osgParticle::ParticleSystemUpdater;
//updater->addDrawable( ps.get() );
osg::ref_ptr<osg::Group> root = new osg::Group;
root->addChild( parent.get() );
root->addChild( updater.get() );
// FIXME 2010.9.19: the updater can't be a drawable; otehrwise the ParticleEffect will not work properly. why?
updater->addParticleSystem( ps.get() );
osg::ref_ptr<osg::Geode> geode = new osg::Geode;
geode->addDrawable( ps.get() );
root->addChild( geode.get() );
/***
Start the viewer
***/
@@ -188,7 +173,7 @@ int main( int argc, char** argv )
viewer.addEventHandler( new osgViewer::WindowSizeHandler );
viewer.setSceneData( root.get() );
viewer.setCameraManipulator( new osgGA::TrackballManipulator );
// A floating error of delta-time should be explained here:
// The particles emitter, program and updater all use a 'dt' to compute the time value in every frame.
// Because the 'dt' is a double value, it is not suitable to keep three copies of it separately, which
@@ -197,7 +182,7 @@ int main( int argc, char** argv )
// Now we make use of the getDeltaTime() of ParticleSystem to maintain and dispatch the delta time. But..
// it is not the best solution so far, since there are still very few particles acting unexpectedly.
return viewer.run();
// FIXME 2010.9.19: At present, getDeltaTime() is not used and the implementations in the updater and processors still
// use a (t - _t0) as the delta time, which is of course causing floating errors. ParticleEffect will not work if we
// replace the delta time with getDeltaTime()... Need to find a solution.