Particle emitter. More...

#include <ParticleEmitter.h>

Collaboration diagram for CParticleEmitter:

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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

void	SetRotation (const CQuaternion &rot)
	Set the rotation to be used for emission of new particles (note: depends on particles). More...

const CQuaternion &	GetRotation () const

const CBoundingBoxAligned &	GetParticleBounds () const
	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 (int frameNumber)
	Update particle and vertex array data. More...

void	PrepareForRendering ()
	Make the vertex data available for subsequent binding and rendering. More...

void	UploadData (Renderer::Backend::IDeviceCommandContext *deviceCommandContext)
	Upload the vertex data to the backend. More...

void	Bind (Renderer::Backend::IDeviceCommandContext deviceCommandContext, Renderer::Backend::IShaderProgram shader)
	Bind rendering state (textures and blend modes). More...

void	RenderArray (Renderer::Backend::IDeviceCommandContext *deviceCommandContext)
	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

CQuaternion	m_Rot

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

Renderer::Backend::IVertexInputLayout *	m_VertexInputLayout = nullptr

int	m_LastFrameNumber

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.)

Constructor & Destructor Documentation

◆ CParticleEmitter()

CParticleEmitter::CParticleEmitter ( const CParticleEmitterTypePtr & type )

Member Function Documentation

◆ AddParticle()

void CParticleEmitter::AddParticle ( const SParticle & particle )

Push a new particle onto the ring buffer.

(May overwrite an old particle.)

◆ Bind()

void CParticleEmitter::Bind	(	Renderer::Backend::IDeviceCommandContext *	deviceCommandContext,
		Renderer::Backend::IShaderProgram *	shader
	)

Bind rendering state (textures and blend modes).

◆ GetParticleBounds()

const CBoundingBoxAligned & CParticleEmitter::GetParticleBounds ( ) const

inline

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

◆ GetPosition()

CVector3D CParticleEmitter::GetPosition ( ) const

inline

◆ GetRotation()

const CQuaternion & CParticleEmitter::GetRotation ( ) const

inline

◆ PrepareForRendering()

void CParticleEmitter::PrepareForRendering ( )

Make the vertex data available for subsequent binding and rendering.

◆ RenderArray()

void CParticleEmitter::RenderArray ( Renderer::Backend::IDeviceCommandContext * deviceCommandContext )

Draw the vertex array.

◆ SetEntityVariable()

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

◆ SetPosition()

void CParticleEmitter::SetPosition ( const CVector3D & pos )

inline

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

◆ SetRotation()

void CParticleEmitter::SetRotation ( const CQuaternion & rot )

inline

Set the rotation to be used for emission of new particles (note: depends on particles).

◆ Unattach()

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 std::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 std::shared_ptr you're about to drop

◆ UpdateArrayData()

void CParticleEmitter::UpdateArrayData ( int frameNumber )

Update particle and vertex array data.

Must be called before RenderArray.

If frameNumber is the same as the previous call to UpdateArrayData, then the function will do no work and return immediately.

◆ UploadData()

void CParticleEmitter::UploadData ( Renderer::Backend::IDeviceCommandContext * deviceCommandContext )

Upload the vertex data to the backend.

Member Data Documentation

◆ m_Active

bool CParticleEmitter::m_Active

Whether this emitter is still emitting new particles.

◆ m_AttributeAxis

VertexArray::Attribute CParticleEmitter::m_AttributeAxis

private

◆ m_AttributeColor

VertexArray::Attribute CParticleEmitter::m_AttributeColor

private

◆ m_AttributePos

VertexArray::Attribute CParticleEmitter::m_AttributePos

private

◆ m_AttributeUV

VertexArray::Attribute CParticleEmitter::m_AttributeUV

private

◆ m_EmissionRoundingError

float CParticleEmitter::m_EmissionRoundingError

◆ m_EntityVariables

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

◆ m_IndexArray

VertexIndexArray CParticleEmitter::m_IndexArray

private

◆ m_LastFrameNumber

int CParticleEmitter::m_LastFrameNumber

private

◆ m_LastUpdateTime

float CParticleEmitter::m_LastUpdateTime

◆ m_NextParticleIdx

size_t CParticleEmitter::m_NextParticleIdx

◆ m_ParticleBounds

CBoundingBoxAligned CParticleEmitter::m_ParticleBounds

private

Bounding box of the current particle center points.

◆ m_Particles

std::vector<SParticle> CParticleEmitter::m_Particles

◆ m_Pos

CVector3D CParticleEmitter::m_Pos

◆ m_Rot

CQuaternion CParticleEmitter::m_Rot

◆ m_Type

CParticleEmitterTypePtr CParticleEmitter::m_Type

◆ m_VertexArray

VertexArray CParticleEmitter::m_VertexArray

private

◆ m_VertexInputLayout

Renderer::Backend::IVertexInputLayout* CParticleEmitter::m_VertexInputLayout = nullptr

private

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

/home/docker/jenkins/workspace/technical-docs/source/graphics/ParticleEmitter.h
/home/docker/jenkins/workspace/technical-docs/source/graphics/ParticleEmitter.cpp

Public Member Functions

Public Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ CParticleEmitter()

Member Function Documentation

◆ AddParticle()

◆ Bind()

◆ GetParticleBounds()

◆ GetPosition()

◆ GetRotation()

◆ PrepareForRendering()

◆ RenderArray()

◆ SetEntityVariable()

◆ SetPosition()

◆ SetRotation()

◆ Unattach()

◆ UpdateArrayData()

◆ UploadData()

Member Data Documentation

◆ m_Active

◆ m_AttributeAxis

◆ m_AttributeColor

◆ m_AttributePos

◆ m_AttributeUV

◆ m_EmissionRoundingError

◆ m_EntityVariables

◆ m_IndexArray

◆ m_LastFrameNumber

◆ m_LastUpdateTime

◆ m_NextParticleIdx

◆ m_ParticleBounds

◆ m_Particles

◆ m_Pos

◆ m_Rot

◆ m_Type

◆ m_VertexArray

◆ m_VertexInputLayout