C# Class Cyclyc.Framework.ParticleSystem

ParticleSystem is an abstract class that provides the basic functionality to create a particle effect. Different subclasses will have different effects, such as fire, explosions, and plumes of smoke. To use these subclasses, simply call AddParticles, and pass in where the particles should exist

Inheritance: Microsoft.Xna.Framework.DrawableGameComponent

Show file Open project: JoeOsborn/Cyclyc

Protected Properties

Property	Type	Description
maxAcceleration	float
maxBlue	float
maxGreen	float
maxInitialSpeed	float
maxLifetime	float
maxNumParticles	int
maxRed	float
maxRotationSpeed	float
maxScale	float
minAcceleration	float
minBlue	float
minGreen	float
minInitialSpeed	float
minLifetime	float
minNumParticles	int
minRed	float
minRotationSpeed	float
minScale	float
spriteBlendMode	SpriteBlendMode
textureFilename	string

Public Methods

Method	Description
AddParticles ( Vector2 where ) : void	AddParticles's job is to add an effect somewhere on the screen. If there aren't enough particles in the freeParticles queue, it will use as many as it can. This means that if there not enough particles available, calling AddParticles will have no effect.
Draw ( GameTime gameTime ) : void	overriden from DrawableGameComponent, Draw will use ParticleSampleGame's sprite batch to render all of the active particles.
Initialize ( ) : void	override the base class's Initialize to do some additional work; we want to call InitializeConstants to let subclasses set the constants that we'll use. also, the particle array and freeParticles queue are set up here.
Update ( GameTime gameTime ) : void	overriden from DrawableGameComponent, Update will update all of the active particles.

Protected Methods

Method	Description
InitializeConstants ( ) : void	this abstract function must be overriden by subclasses of ParticleSystem. It's here that they should set all the constants marked in the region "constants to be set by subclasses", which give each ParticleSystem its specific flavor.
InitializeParticle ( Particle p, Vector2 where ) : void	InitializeParticle randomizes some properties for a particle, then calls initialize on it. It can be overriden by subclasses if they want to modify the way particles are created. For example, SmokePlumeParticleSystem overrides this function make all particles accelerate to the right, simulating wind.
LoadContent ( ) : void	Override the base class LoadContent to load the texture. once it's loaded, calculate the origin.
ParticleSystem ( Game1 game, int howManyEffects ) : System	Constructs a new ParticleSystem. it is tempting to set the value of howManyEffects very high. However, this value should be set to the minimum possible, because it has a large impact on the amount of memory required, and slows down the Update and Draw functions.
PickRandomAngle ( ) : float	PickRandomDirection is used by InitializeParticles to decide which direction particles will move. The default implementation is a random vector in a circular pattern.
PickRandomDirection ( ) : Vector2

Method Details

AddParticles() public method

AddParticles's job is to add an effect somewhere on the screen. If there aren't enough particles in the freeParticles queue, it will use as many as it can. This means that if there not enough particles available, calling AddParticles will have no effect.

public AddParticles ( Vector2 where ) : void
where	Vector2	where the particle effect should be created
return	void

Draw() public method

overriden from DrawableGameComponent, Draw will use ParticleSampleGame's sprite batch to render all of the active particles.

public Draw ( GameTime gameTime ) : void
gameTime	Microsoft.Xna.Framework.GameTime
return	void

Initialize() public method

override the base class's Initialize to do some additional work; we want to call InitializeConstants to let subclasses set the constants that we'll use. also, the particle array and freeParticles queue are set up here.

public Initialize ( ) : void
return	void

InitializeConstants() protected abstract method

this abstract function must be overriden by subclasses of ParticleSystem. It's here that they should set all the constants marked in the region "constants to be set by subclasses", which give each ParticleSystem its specific flavor.

protected abstract InitializeConstants ( ) : void
return	void

InitializeParticle() protected method

InitializeParticle randomizes some properties for a particle, then calls initialize on it. It can be overriden by subclasses if they want to modify the way particles are created. For example, SmokePlumeParticleSystem overrides this function make all particles accelerate to the right, simulating wind.

protected InitializeParticle ( Particle p, Vector2 where ) : void
p	Particle	the particle to initialize
where	Vector2	the position on the screen that the particle should be ///
return	void

LoadContent() protected method

Override the base class LoadContent to load the texture. once it's loaded, calculate the origin.

protected LoadContent ( ) : void
return	void

ParticleSystem() protected method

Constructs a new ParticleSystem.

it is tempting to set the value of howManyEffects very high. However, this value should be set to the minimum possible, because it has a large impact on the amount of memory required, and slows down the Update and Draw functions.

protected ParticleSystem ( Game1 game, int howManyEffects ) : System
game	Game1	The host for this particle system. The game keeps the /// content manager and sprite batch for us.
howManyEffects	int	the maximum number of particle effects that /// are expected on screen at once.
return	System

PickRandomAngle() protected method

PickRandomDirection is used by InitializeParticles to decide which direction particles will move. The default implementation is a random vector in a circular pattern.

protected PickRandomAngle ( ) : float
return	float

PickRandomDirection() protected method

protected PickRandomDirection ( ) : Vector2
return	Vector2

Update() public method

overriden from DrawableGameComponent, Update will update all of the active particles.

public Update ( GameTime gameTime ) : void
gameTime	Microsoft.Xna.Framework.GameTime
return	void

Property Details

maxAcceleration protected property

protected float maxAcceleration
return	float

maxBlue protected property

protected float maxBlue
return	float

maxGreen protected property

protected float maxGreen
return	float

maxInitialSpeed protected property

protected float maxInitialSpeed
return	float

maxLifetime protected property

protected float maxLifetime
return	float

maxNumParticles protected property

protected int maxNumParticles
return	int

maxRed protected property

protected float maxRed
return	float

maxRotationSpeed protected property

protected float maxRotationSpeed
return	float

maxScale protected property

protected float maxScale
return	float

minAcceleration protected property

minAcceleration and maxAcceleration are used to control the acceleration of the particles. The particle's acceleration will be a random number between these two. By default, the direction of acceleration is the same as the direction of the initial velocity.

protected float minAcceleration
return	float

minBlue protected property

protected float minBlue
return	float

minGreen protected property

protected float minGreen
return	float

minInitialSpeed protected property

minInitialSpeed and maxInitialSpeed are used to control the initial velocity of the particles. The particle's initial speed will be a random number between these two. The direction is determined by the function PickRandomDirection, which can be overriden.

protected float minInitialSpeed
return	float

minLifetime protected property

minLifetime and maxLifetime are used to control the lifetime. Each particle's lifetime will be a random number between these two. Lifetime is used to determine how long a particle "lasts." Also, in the base implementation of Draw, lifetime is also used to calculate alpha and scale values to avoid particles suddenly "popping" into view

protected float minLifetime
return	float

minNumParticles protected property

minNumParticles and maxNumParticles control the number of particles that are added when AddParticles is called. The number of particles will be a random number between minNumParticles and maxNumParticles.

protected int minNumParticles
return	int

minRed protected property

protected float minRed
return	float

minRotationSpeed protected property

minRotationSpeed and maxRotationSpeed control the particles' angular velocity: the speed at which particles will rotate. Each particle's rotation speed will be a random number between minRotationSpeed and maxRotationSpeed. Use smaller numbers to make particle systems look calm and wispy, and large numbers for more violent effects.

protected float minRotationSpeed
return	float

minScale protected property

to get some additional variance in the appearance of the particles, we give them all random scales. the scale is a value between minScale and maxScale, and is additionally affected by the particle's lifetime to avoid particles "popping" into view.

protected float minScale
return	float

spriteBlendMode protected property

different effects can use different blend modes. fire and explosions work well with additive blending, for example.

protected SpriteBlendMode spriteBlendMode
return	SpriteBlendMode

textureFilename protected property

this controls the texture that the particle system uses. It will be used as an argument to ContentManager.Load.

protected string textureFilename
return	string