Method UpdateSimulation

trinity/Particle/Tr2ParticleSystem.cpp:555–806

-------------------------------------------------------------------------------------- Description: Updates per-particle data (age, positions, etc.), removes dead particles, emits new particles with "emit during lifetime" and "emit on death" emitters. This function can be called asyncronously. Arguments: arguments - Child emitter update arguments dt - simulation time interval --------------------

//   dt - simulation time interval
// --------------------------------------------------------------------------------------
void Tr2ParticleSystem::UpdateSimulation( const ITr2GenericEmitter::UpdateArguments& arguments, float dt )
{
	// Update lifetime and remove dead particles
	if( m_applyAging && HasElement( Tr2ParticleElementDeclarationName::LIFETIME ) )
	{
		float* lifetime = nullptr;
		unsigned lifetimeStride;
		GetElementStream( Tr2ParticleElementDeclarationName::LIFETIME, lifetime, lifetimeStride );

		float* position = nullptr;
		unsigned positionStride;
		GetElementStream( Tr2ParticleElementDeclarationName::POSITION, position, positionStride );

		float* velocity = nullptr;
		unsigned velocityStride;
		GetElementStream( Tr2ParticleElementDeclarationName::VELOCITY, velocity, velocityStride );

		if( m_insertDeleteMutex )
		{
			m_insertDeleteMutex->Acquire();
		}

		for( unsigned i = 0; i < m_aliveCount; ++i )
		{
			lifetime[0] += dt / lifetime[1];
			if( lifetime[0] >= 1.0f )
			{
				if( m_emissionOnDeathEmitter )
				{
					m_emissionOnDeathEmitter->SpawnParticles( arguments,
															  reinterpret_cast<Vector3*>( position ),
															  reinterpret_cast<Vector3*>( velocity ) );
				}

				m_aliveCount -= 1;
				if( i < m_aliveCount )
				{
					for( unsigned j = 0; j < Tr2ParticleElementData::COUNT; ++j )
					{
						std::copy( m_buffers[j] + m_aliveCount * m_vertexSizes[j],
								   m_buffers[j] + ( m_aliveCount + 1 ) * m_vertexSizes[j],
								   m_buffers[j] + i * m_vertexSizes[j] );
					}
				}

				--i;
			}
			else
			{
				lifetime += lifetimeStride;
				if( position )
				{
					position += positionStride;
				}
				if( velocity )
				{
					velocity += velocityStride;
				}