Tween.java

package it.marteEngine.tween;

/**
 * Tween can change Entity status
 * 
 * @author Gornova
 */
public abstract class Tween {

	public enum TweenerMode {
		ONESHOT, LOOPING, PERSIST
	};

	protected String name = null;
	protected TweenerMode mode = TweenerMode.PERSIST;

	protected Tweener parent = null;
	protected boolean active = true;
	protected boolean finished = false;

	protected float t = 0f;

	/** how much time proceeded */
	private float time = 0f;
	/** when is this tweener done */
	protected float target = 0f;
	/** do we use delta timing or frame counting */
	protected boolean deltaTiming = false;

	/** which easing function does this Tween use */
	protected int easingFunction = Ease.NONE;

	public Tween(float duration, TweenerMode type, int easingType,
			boolean active) {
		this(duration, type, easingType, false, active);
	}

	public Tween(float duration, TweenerMode type, int easingType,
			boolean deltaTiming, boolean active) {
		this.target = duration;
		this.active = active;
		this.deltaTiming = deltaTiming;
		this.easingFunction = easingType;
	}

	public void update(int delta) {
		if (this.deltaTiming)
			time += delta;
		else
			time++;
		t = time / target;
		if (easingFunction != Ease.NONE && t > 0 && t < 1)
			t = Ease.ease(easingFunction, t);
		if (time > target) {
			t = 1;
			this.finished = true;
		}
	}

	/**
	 * Start tween
	 */
	public void start() {
		active = true;
		time = 0;
		if (target == 0)
			active = false;
	}

	/**
	 * Pause tween
	 */
	public void pause() {
		active = false;
	}

	/**
	 * Reset tween to initial position
	 * 
	 * @return void
	 */
	public void reset() {
		time = 0;
		active = false;
	}

	/**
	 * internal function, called by the Tweener if this Tween is finished
	 */
	public void finish() {
		switch (this.mode) {
		case PERSIST:
			time = target;
			active = false;
			break;
		case ONESHOT:
			time = target;
			active = false;
			if (parent != null)
				parent.remove(this);
			break;
		case LOOPING:
			time %= target;
			t = time / target;
			break;
		}
		finished = false;
	}

	public float getValue() {
		return t; // after the ease function has been applied
	}

	/**
	 * how many percent is this tween done? value between 0 and 1
	 * 
	 * @return a value between 0 and 1 where 1 means hundred percent
	 */
	public float getPercentage() {
		return time / target;
	}

	/**
	 * sets the progress of this tween.
	 * 
	 * @param val
	 *            must be a value between 0 and 1.
	 */
	public void setPercentage(float val) {
		time = target * val;
	}

	/**
	 * @return true if tween is active
	 */
	public boolean isActive() {
		return active;
	}

	public TweenerMode getMode() {
		return mode;
	}

	public void setMode(TweenerMode mode) {
		this.mode = mode;
	}

	public Tweener getParent() {
		return parent;
	}

	public void setParent(Tweener parent) {
		this.parent = parent;
	}

	public void setActive(boolean active) {
		this.active = active;
	}

	public boolean isFinished() {
		return finished;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

}