Box2D.java

/**
 * Copyright (c) 2009, iPlant Collaborative, Texas Advanced Computing Center This software is licensed
 * under the CC-GNU GPL version 2.0 or later. License: http://creativecommons.org/licenses/GPL/2.0/
 */

package org.iplantc.phyloviewer.shared.math;

import com.google.gwt.user.client.rpc.IsSerializable;

public class Box2D implements IsSerializable
{
	private Vector2 min;
	private Vector2 max;

	private static Vector2 getDefaultMinValue()
	{
		return new Vector2(Double.MAX_VALUE, Double.MAX_VALUE);
	}
	
	private static Vector2 getDefaultMaxValue()
	{
		return new Vector2(Double.MIN_VALUE, Double.MIN_VALUE);
	}
	
	/**
	 * Create a box with invalid min and max corners.
	 */
	public Box2D()
	{
		min = getDefaultMinValue();
		max =getDefaultMaxValue();
	}

	/**
	 * Create a bounding box.
	 * 
	 * @param Lower left corner of box.
	 * @param Upper right corner of box.
	 */
	public Box2D(Vector2 min, Vector2 max)
	{
		setMin(min);
		setMax(max);
	}

	
	/**
	 * Clone this box
	 */
	public Box2D clone()
	{
		Vector2 min = this.getMin();
		if(min == null)
		{
			min = getDefaultMinValue();
		}
		else
		{
			min = min.clone();
		}
		
		Vector2 max = this.getMax();
		if(max == null)
		{
			max = getDefaultMaxValue();
		}
		else
		{
			max = max.clone();
		}

		return new Box2D(min, max);
	}

	public Boolean valid()
	{
		return max.getX() >= min.getX() && max.getY() >= min.getY();
	}

	public Vector2 getMin()
	{
		return min;
	}

	public void setMin(Vector2 min)
	{
		if(min == this.max)
		{
			// we don't want these to be the same object, or mutators with change both at once
			min = new Vector2(min.getX(), min.getY());
		}

		this.min = min;
	}

	public Vector2 getMax()
	{
		return max;
	}

	public void setMax(Vector2 max)
	{
		if(max == this.min)
		{
			// we don't want these to be the same object, or mutators with change both at once
			max = new Vector2(max.getX(), max.getY());
		}

		this.max = max;
	}

	public void expandBy(Vector2 v)
	{
		if(v.getX() < min.getX())
			min.setX(v.getX());
		if(v.getX() > max.getX())
			max.setX(v.getX());

		if(v.getY() < min.getY())
			min.setY(v.getY());
		if(v.getY() > max.getY())
			max.setY(v.getY());
	}

	public void expandBy(Box2D bb)
	{
		if(false == bb.valid())
			return;

		if(bb.getMin().getX() < min.getX())
			min.setX(bb.getMin().getX());
		if(bb.getMax().getX() > max.getX())
			max.setX(bb.getMax().getX());

		if(bb.getMin().getY() < min.getY())
			min.setY(bb.getMin().getY());
		if(bb.getMax().getY() > max.getY())
			max.setY(bb.getMax().getY());
	}

	public void expandBy(double d)
	{
		min.setX(min.getX() - d);
		min.setY(min.getY() - d);
		max.setX(max.getX() + d);
		max.setY(max.getY() + d);
	}

	// Return true if the given box intersects this one.
	public boolean intersects(Box2D bb)
	{
		return Math.max(min.getX(), bb.getMin().getX()) <= Math.min(max.getX(), bb.getMax().getX())
				&& Math.max(min.getY(), bb.getMin().getY()) <= Math.min(max.getY(), bb.getMax().getY());
	}

	public boolean contains(Vector2 position)
	{
		return this.valid()
				&& (position.getX() >= this.getMin().getX() && position.getX() <= this.getMax().getX()
						&& position.getY() >= this.getMin().getY() && position.getY() <= this.getMax()
						.getY());
	}

	public Vector2 getCenter()
	{
		double x = (min.getX() + max.getX()) / 2.0;
		double y = (min.getY() + max.getY()) / 2.0;
		return new Vector2(x, y);
	}

	public double getWidth()
	{
		return max.getX() - min.getX();
	}

	public double getHeight()
	{
		return max.getY() - min.getY();
	}

	public String toString()
	{
		return "[" + min.toString() + ", " + max.toString() + "]";
	}

	/**
	 * @return the box defined by the given corners (any two opposite corners of the box)
	 */
	public static Box2D createBox(Vector2 v0, Vector2 v1)
	{
		Box2D box = new Box2D(v0, v0);
		box.expandBy(v1);
		return box;
	}

	public String toJSON()
	{
		return "{\"min\":" + min.toJSON() + ",\"max\":" + max.toJSON() + "}";
	}
}