hoa_video::ParticleEffect Class Reference

particle effect, basically one coherent "effect" like an explosion, or snow falling from the sky. Consists of one or more ParticleSystems. An example of using multiple systems to create one effect would be a campfire where you have fire + smoke + glowing embers. More...

#include <particle_effect.h>

Collaboration diagram for hoa_video::ParticleEffect:

[legend]List of all members.


Public Member Functions
float	GetAge () const
	return the age of the system, i.e. how many seconds it has been since it was created
int32	GetNumParticles () const
	return the number of active particles in this effect
void	GetPosition (float &x, float &y) const
	return the position of the effect into x and y
bool	IsAlive ()
	returns true if the system is alive, i.e. the number of active particles is more than zero. This is used by the particle manager so it knows when to destroy an effect.
void	Move (float x, float y)
	moves the effect to the specified position on the screen, This can be used if you want to move a particle system around on some flight path, or if you want to attach the system to an object. (e.g. smoke to a jet)
void	MoveRelative (float dx, float dy)
	moves the effect dx and dy units relative to its current position
	ParticleEffect ()
	Constructor.
void	SetAttractorPoint (float x, float y)
	set the position of an "attractor point". Any particle systems which use radial acceleration and have user-defined attractor points enabled will have particles move towards this point
void	SetOrientation (float angle)
	set the orientation of the effect (including all systems contained within the effect). This is essentially added to the emitter orientation for each system. For example, if you want to create a particle system for smoke coming out of a jet, set the emitter orientation to zero degrees (right) when you create the effect. Then, at runtime just call SetOrientation() every frame with the angle the jet is facing.
void	Stop (bool kill_immediate=false)
	stops this effect
Private Member Functions
void	_Destroy ()
	destroys the effect. This is private so that only the ParticleManager class can destroy effects.
bool	_Draw ()
	draws the effect. This is private so that only the ParticleManager class can draw effects.
bool	_Update (float frame_time)
	updates the effect. This is private so that only the ParticleManager class can update effects.
Private Attributes
float	_age
	age of the effect (seconds since it was created)
bool	_alive
	is the effect is alive or not
float	_attractor_x
	position of attractor point
float	_attractor_y
const ParticleEffectDef *	_effect_def
	pointer to the effect definition
int32	_num_particles
	number of active particles (this is updated on each call to Update())
float	_orientation
	orientation of the effect (angle in radians)
std::list< ParticleSystem * >	_systems
float	_x
	position of the effect
float	_y
Friends
class	private_video::ParticleManager

Detailed Description

***************************************************************************

Definition at line 68 of file particle_effect.h.

Constructor & Destructor Documentation

hoa_video::ParticleEffect::ParticleEffect ( )

Constructor.

Definition at line 27 of file particle_effect.cpp.

References _age, _alive, _attractor_x, _attractor_y, _effect_def, _orientation, _x, and _y.

Member Function Documentation

void hoa_video::ParticleEffect::_Destroy ( ) [private]

destroys the effect. This is private so that only the ParticleManager class can destroy effects.

Definition at line 132 of file particle_effect.cpp.

References _systems.

bool hoa_video::ParticleEffect::_Draw ( ) [private]

draws the effect. This is private so that only the ParticleManager class can draw effects.

Returns:: success/failure

Definition at line 42 of file particle_effect.cpp.

References _systems, _x, _y, hoa_video::GameVideo::Move(), hoa_video::GameVideo::PopMatrix(), hoa_video::GameVideo::PushMatrix(), hoa_video::VIDEO_DEBUG, and hoa_video::VideoManager.

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bool hoa_video::ParticleEffect::_Update ( float frame_time ) [private]

updates the effect. This is private so that only the ParticleManager class can update effects.

Parameters:

the

new frame time

Returns:: success/failure

Definition at line 79 of file particle_effect.cpp.

References _age, _alive, _attractor_x, _attractor_y, _num_particles, _orientation, _systems, _x, _y, hoa_video::private_video::EffectParameters::attractor_x, hoa_video::private_video::EffectParameters::attractor_y, hoa_video::private_video::EffectParameters::orientation, and hoa_video::VIDEO_DEBUG.

float hoa_video::ParticleEffect::GetAge ( ) const

return the age of the system, i.e. how many seconds it has been since it was created

Returns:: age of the system

Definition at line 258 of file particle_effect.cpp.

References _age.

int32 hoa_video::ParticleEffect::GetNumParticles ( ) const

return the number of active particles in this effect

Returns:: number of particles in the system

Definition at line 236 of file particle_effect.cpp.

References _num_particles.

void hoa_video::ParticleEffect::GetPosition	(	float &	x,
		float &	y
	)			const

return the position of the effect into x and y

Parameters:

	x	parameter to store x value of system in
	y	parameter to store y value of system in

Definition at line 246 of file particle_effect.cpp.

References _x, and _y.

bool hoa_video::ParticleEffect::IsAlive ( )

returns true if the system is alive, i.e. the number of active particles is more than zero. This is used by the particle manager so it knows when to destroy an effect.

Returns:: true if system is alive, false if dead

Definition at line 197 of file particle_effect.cpp.

References _alive.

void hoa_video::ParticleEffect::Move	(	float	x,
		float	y
	)

moves the effect to the specified position on the screen, This can be used if you want to move a particle system around on some flight path, or if you want to attach the system to an object. (e.g. smoke to a jet)

Parameters:

	x	movement of system in x direction
	y	movement of system in y direction

Definition at line 149 of file particle_effect.cpp.

References _x, and _y.

Referenced by hoa_video::private_video::ParticleManager::AddEffect().

void hoa_video::ParticleEffect::MoveRelative	(	float	dx,
		float	dy
	)

moves the effect dx and dy units relative to its current position

Parameters:

	dx	x offset to move to from current x position
	dy	y offset to move to from current y position

Definition at line 161 of file particle_effect.cpp.

References _x, and _y.

void hoa_video::ParticleEffect::SetAttractorPoint	(	float	x,
		float	y
	)

set the position of an "attractor point". Any particle systems which use radial acceleration and have user-defined attractor points enabled will have particles move towards this point

Note:: a positive radial acceleration will move a particle away from the attractor, and negative will move it towards it.

Parameters:

	x	x coordiante of gravitation point
	y	y coordiante of gravitation point

Definition at line 185 of file particle_effect.cpp.

References _attractor_x, and _attractor_y.

void hoa_video::ParticleEffect::SetOrientation ( float angle )

set the orientation of the effect (including all systems contained within the effect). This is essentially added to the emitter orientation for each system. For example, if you want to create a particle system for smoke coming out of a jet, set the emitter orientation to zero degrees (right) when you create the effect. Then, at runtime just call SetOrientation() every frame with the angle the jet is facing.

Parameters:

angle

rotation of particle system

Definition at line 173 of file particle_effect.cpp.

References _orientation.

void hoa_video::ParticleEffect::Stop ( bool kill_immediate = false )

stops this effect

Parameters:

kill_immediate

If this is true, the effect is immediately killed. If it isn't true, then we stop the effect from emitting new particles, and allow it to live until all the active particles fizzle out.

Definition at line 209 of file particle_effect.cpp.

References _alive, and _systems.