Package tripleplay.particle.effect

Class Drag

java.lang.Object

tripleplay.particle.Effector

tripleplay.particle.effect.Drag

public class Drag
extends Effector

Applies friction (drag) to particles.

Constructor Summary

Constructors

Constructor	Description
Drag(float drag)	Creates a drag effector with uniform x and y drag.
Drag(float dragX, float dragY)	Creates a drag effector with the specified x and y drag.

Method Summary

Modifier and Type	Method	Description
void	apply(int index, float[] data, int start, float now, float dt)	Applies this effector to the indexth particle in the supplied buffer.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Drag

public Drag(float drag)

Creates a drag effector with uniform x and y drag.

Parameters:

drag - the fraction of the velocity to preserve on each frame (0 to 1).

Drag

public Drag(float dragX,
 float dragY)

Creates a drag effector with the specified x and y drag.

Parameters:

dragX - the fraction of the x velocity to preserve on each frame (0 to 1).

dragY - the fraction of the y velocity to preserve on each frame (0 to 1).

Method Details

apply

public void apply(int index,
 float[] data,
 int start,
 float now,
 float dt)

Description copied from class: Effector

Applies this effector to the indexth particle in the supplied buffer. The effector must use the ParticleBuffer offsets to extract fields from data, for example: float x = data[start+ParticleBuffer.POS_X].

Specified by:

apply in class Effector

Parameters:

index - the index of the particle, which can be used to index into other per-particle data arrays.

data - the particle field data.

start - the offset into data at which the particle's fields start.

now - the number of seconds elapsed since the emitter came into being. Can be used to compute a particle's age.

dt - the amount of time (in fractions of a second) that has elapsed since the last update.