Particle engine crashing fix (for torque 1.2)

I've just discovered a problem in torque 1.2 - when i have a lot of particles in a mission, ending the mission crashes the engine - while removing the particle objects, the particle engine still tries to use them.


Note: this patch requires the improved particle emitters patch
You can find it here..
www.garagegames.com/index.php?sec=mg&mod=resource&page=view&qid=4096


It's easier to reproduce on slow cpus or with a lot of particles.

The fix is ugly, but it works, thanks to Ben Garney for the idea.

First in particleEmitter.cc, in method ParticleEmitterNode::onRemove() add the line marked with comment (fixed)

void ParticleEmitterNode::onRemove()
{
   removeFromScene();
   if (isClientObject()) {
      mEmitter->LinkObject = NULL;	// (fixed)
      mEmitter->deleteWhenEmpty();
      mEmitter = NULL;
   }
   Parent::onRemove();
}

this will clean the reference from the emitter to the node, when the node no longer exists.

the following things are not nice at all - we replace the datablock pointers with SimObjectPtr-s, so we will now, when they are no longer available.

In particleEmitter.h replace the definition of mDataBlock in class ParticleEmitterNode with

SimObjectPtr<ParticleEmitterNodeData> mDataBlock;

(original is like: ParticleEmitterNodeData* mDataBlock)

In particleEngine.h replace the definition of mDataBlock in class ParticleEmitter with

SimObjectPtr<ParticleEmitterData> mDataBlock;

(original is like: ParticleEmitterData* mDataBlock)

In particleEngine.cc replace the definition of dataBlock in struct Particle with

SimObjectPtr<ParticleData> dataBlock;

(original is like: ParticleData* dataBlock)

And now the fix:

Still in particelEngine.cc in method PEngine::updateSingleParticle add the following check after the asserts:

if (particle->dataBlock.isNull() || !emitter.getDataBlock()) return; // (fixed)

It's all - now it's not crashing - at least, i can't reproduce it :)

I hope I helped you, have a great time using Torque :)