Method Update

trinity/Particle/Tr2GpuParticleSystem.cpp:318–375

-------------------------------------------------------------------------------------- Description: Updates particle system. Optionally clears the system, emits new particles, runs physics simulation does sorting. Arguments: time - Current time originShift - world origin shif compared to previous frame --------------------------------------------------------------------------------------

//   originShift - world origin shif compared to previous frame
// --------------------------------------------------------------------------------------
void Tr2GpuParticleSystem::Update( Be::Time time, const Vector3& originShift, Tr2RenderContext& renderContext )
{
	if( !CheckEffect( m_emit ) || !CheckEffect( m_update ) || !CheckEffect( m_clear ) || !CheckEffect( m_setDrawParameters ) )
	{
		return;
	}

	float dt = ( m_previousTime == Be::Time( -1 ) || !m_enableUpdate ) ? 0 : TimeAsFloat( time - m_previousTime );
	dt = std::min( dt, MAXIMUM_FRAME_TIME );
	m_previousTime = time;

	if( m_clearRequested )
	{
		if( !DoClear( renderContext ) )
		{
			return;
		}
		m_clearRequested = false;
		m_turbulenceOffset = Vector3( 0.f, 0.f, 0.f );
	}

	m_turbulenceOffset -= originShift;
	m_turbulenceOffset /= MAX_TURBULENCE_LENGTH;
	m_turbulenceOffset.x -= floor( m_turbulenceOffset.x );
	m_turbulenceOffset.y -= floor( m_turbulenceOffset.y );
	m_turbulenceOffset.z -= floor( m_turbulenceOffset.z );
	m_turbulenceOffset *= MAX_TURBULENCE_LENGTH;

	m_turbulenceAnimation.z += dt * TURBULENCE_ANIMATION_SPEED;

	ExpireEmitterParams( dt );
	if( m_enableEmit )
	{
		UpdateEmitterParams( renderContext );
		EmitParticles( renderContext );
	}
	m_emitRequests.Clear();

	if( m_liveTime <= 0.f )
	{
		// no particles left alive
		return;
	}

	RunSimulation( dt, originShift, renderContext );

	m_liveTime -= dt;

	if( m_enableSort )
	{
		Sort( renderContext );
	}

	// prepare draw arguments for Render
	Tr2Renderer::RunComputeShader( m_setDrawParameters, 1, 1, 1, renderContext );

	UpdateLiveCount( renderContext );
}