Particle emitter. More...

#include <ParticleEmitter.h>

Public Member Functions
	CParticleEmitter (const CParticleEmitterTypePtr &type)

void	SetPosition (const CVector3D &pos)
	Set the position to be used for emission of new particles. More...

CVector3D	GetPosition () const

CBoundingBoxAligned	GetParticleBounds ()
	Get the bounding box of the center points of particles at their current positions. More...

void	AddParticle (const SParticle &particle)
	Push a new particle onto the ring buffer. More...

void	UpdateArrayData ()
	Update particle and vertex array data. More...

void	Bind (const CShaderProgramPtr &shader)
	Bind rendering state (textures and blend modes). More...

void	RenderArray (const CShaderProgramPtr &shader)
	Draw the vertex array. More...

void	Unattach (const CParticleEmitterPtr &self)
	Stop this emitter emitting new particles, and pass responsibility for rendering to the CParticleManager. More...

void	SetEntityVariable (const std::string &name, float value)

Public Attributes
CParticleEmitterTypePtr	m_Type

bool	m_Active
	Whether this emitter is still emitting new particles. More...

CVector3D	m_Pos

std::map< std::string, float >	m_EntityVariables

std::vector< SParticle >	m_Particles

size_t	m_NextParticleIdx

float	m_LastUpdateTime

float	m_EmissionRoundingError

Private Attributes
CBoundingBoxAligned	m_ParticleBounds
	Bounding box of the current particle center points. More...

VertexIndexArray	m_IndexArray

VertexArray	m_VertexArray

VertexArray::Attribute	m_AttributePos

VertexArray::Attribute	m_AttributeAxis

VertexArray::Attribute	m_AttributeUV

VertexArray::Attribute	m_AttributeColor

Detailed Description

Particle emitter.

Emitters store particle data in two forms:

m_Particles contains the raw data used for the CPU particle simulation.
m_VertexArray contains the data required for rendering. Particles are rendered as billboard quads, so the vertex array contains four vertices per particle with different UV coordinates. The billboard position computation is performed by a vertex shader.

The number of particles is a constant for the entire life of the emitter, to simplify the updating and rendering. m_Particles acts like a ring buffer, so we don't have to worry about dynamically allocating particles. If particles have variable lifetimes, they'll exist in the array with alpha=0 until they're overwritten by a new particle after the maximum lifetime.

(It's quite likely this could be made more efficient, if the overhead of any added complexity is not high.)

Definition at line 65 of file ParticleEmitter.h.

Constructor & Destructor Documentation

CParticleEmitter::CParticleEmitter ( const CParticleEmitterTypePtr & type )

Definition at line 30 of file ParticleEmitter.cpp.

Member Function Documentation

void CParticleEmitter::AddParticle ( const SParticle & particle )

Push a new particle onto the ring buffer.

(May overwrite an old particle.)

Definition at line 217 of file ParticleEmitter.cpp.

void CParticleEmitter::Bind ( const CShaderProgramPtr & shader )

Bind rendering state (textures and blend modes).

Definition at line 167 of file ParticleEmitter.cpp.

CBoundingBoxAligned CParticleEmitter::GetParticleBounds ( )

inline

Get the bounding box of the center points of particles at their current positions.

Definition at line 86 of file ParticleEmitter.h.

CVector3D CParticleEmitter::GetPosition ( ) const

inline

Definition at line 78 of file ParticleEmitter.h.

void CParticleEmitter::RenderArray ( const CShaderProgramPtr & shader )

Draw the vertex array.

Definition at line 183 of file ParticleEmitter.cpp.

void CParticleEmitter::SetEntityVariable	(	const std::string &	name,
		float	value
	)

Definition at line 227 of file ParticleEmitter.cpp.

void CParticleEmitter::SetPosition ( const CVector3D & pos )

inline

Set the position to be used for emission of new particles.

Definition at line 73 of file ParticleEmitter.h.

void CParticleEmitter::Unattach ( const CParticleEmitterPtr & self )

Stop this emitter emitting new particles, and pass responsibility for rendering to the CParticleManager.

This should be called before dropping the last shared_ptr to this object so that it will carry on rendering (until all particles have dissipated) even when it's no longer attached to a model.

Parameters

self	the shared_ptr you're about to drop

Definition at line 211 of file ParticleEmitter.cpp.

void CParticleEmitter::UpdateArrayData ( )

Update particle and vertex array data.

Must be called before RenderArray.

Definition at line 83 of file ParticleEmitter.cpp.

Member Data Documentation

bool CParticleEmitter::m_Active

Whether this emitter is still emitting new particles.

Definition at line 122 of file ParticleEmitter.h.

VertexArray::Attribute CParticleEmitter::m_AttributeAxis

private

Definition at line 142 of file ParticleEmitter.h.

VertexArray::Attribute CParticleEmitter::m_AttributeColor

private

Definition at line 144 of file ParticleEmitter.h.

VertexArray::Attribute CParticleEmitter::m_AttributePos

private

Definition at line 141 of file ParticleEmitter.h.

VertexArray::Attribute CParticleEmitter::m_AttributeUV

private

Definition at line 143 of file ParticleEmitter.h.

float CParticleEmitter::m_EmissionRoundingError

Definition at line 132 of file ParticleEmitter.h.

std::map<std::string, float> CParticleEmitter::m_EntityVariables

Definition at line 126 of file ParticleEmitter.h.

VertexIndexArray CParticleEmitter::m_IndexArray

private

Definition at line 138 of file ParticleEmitter.h.

float CParticleEmitter::m_LastUpdateTime

Definition at line 131 of file ParticleEmitter.h.

size_t CParticleEmitter::m_NextParticleIdx

Definition at line 129 of file ParticleEmitter.h.

CBoundingBoxAligned CParticleEmitter::m_ParticleBounds

private

Bounding box of the current particle center points.

Definition at line 136 of file ParticleEmitter.h.

std::vector<SParticle> CParticleEmitter::m_Particles

Definition at line 128 of file ParticleEmitter.h.

CVector3D CParticleEmitter::m_Pos

Definition at line 124 of file ParticleEmitter.h.

CParticleEmitterTypePtr CParticleEmitter::m_Type

Definition at line 119 of file ParticleEmitter.h.

VertexArray CParticleEmitter::m_VertexArray

private

Definition at line 140 of file ParticleEmitter.h.

The documentation for this class was generated from the following files:

/home/sathyam/0ad.svn/source/graphics/ParticleEmitter.h
/home/sathyam/0ad.svn/source/graphics/ParticleEmitter.cpp

Public Member Functions

Public Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation