KhaParticle

Author: Sidar Talei

Simple particle system for kha

How to use:

For now simply copy the files to your Source folder

var img:Image = Loader.the.getImage("particle");

p = new ParticleSystem(1000, img);
var e:RadialEmitter = new RadialEmitter();

e.rate = 100; 			//particles per second
e.speed = 0; 			//particle velocity
e.duration = 1;			//Duration of emission
e.loop = true;			//If true emission continues after duration
e.amountPerRate = 1;	//Amount of particles per rate
e.maxLife = 2;			//Maximum life of a particles in seconds
e.lifeVariation = 1;	//[0-1]Random life between 0 and maxlife
e.edgeSpawn = true; 	//Spawns at the edge of the emitter
						//property of RadialEmitter
e.maxRotationVel = 10;	//Rotation speed.

p.setEmitter(e);
p.start();				//Start processing particles.

Adding burst:

var b:BurstProp = new BurstProp();
b.amount = 100; //Amount to emit 
b.time = .5;	//Every half a second
e.addBurst(b);	//Add to the emitter

Adding modifiers:

//Add color change over life time
var c:ColorModifier = new ColorModifier();
//Color and position -> [0-1]
c.pushColor(0xFFFFFF00, 0);
c.pushColor(0xFFFF00FF, 1);
p.addModifier(c);

//Add Fader over life time
p.addModifier(new FadeModifier(FadeType.FADE_OUT)); //fades out

//Add gravity 
p.addModifier(new GravityModfier(0,250)); // adds 250 to y over time

//Scale Up over life time. min,max,Multiplier 1;
p.addModifier(new ScaleModifier(ScaleType.SCALE_DOWN, 0, 1, 1));

• Modifiers can be used with multiple ParticleSystem objects

Updating & Rendering

ParticleSystems need to be updated:

function update() : Void
{
	p.update();
}

function render(painter:Painter) : Void
{	
	p.render(painter);
}

Notes

• If you want to change the position of the emitter simply change the x and y value on the particle system object. This will automatically update the position of the emitter as well.
• ScaleModifier can make use of a Spline curve (kha.scene.Spline) but currently it's pretty heavy. When using lots of particles avoid using a spline. Eventually most basic modifiers will have the option to include a curve over life time.