Point3d.as

/*
   CASA Lib for ActionScript 3.0
   Copyright (c) 2010, Aaron Clinger & Contributors of CASA Lib
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 */
package utils.geom
{

	import utils.math.Percent;

	import utils.number.interpolate;

	/**
	   Stores location of a point in a three-dimensional coordinate system, where x represents the horizontal axis, y represents the vertical axis, z represents the axis that is vertically perpendicular to the x/y axis or depth.

	   @author Aaron Clinger
	   @author David Bliss
	   @author Mike Creighton
	   @version 09/23/08
	 */
	public class Point3d
	{
		protected var _x:Number;
		protected var _y:Number;
		protected var _z:Number;


		/**
		   Creates a new Point3d.

		   @param x: The horizontal coordinate of the point.
		   @param y: The vertical coordinate of the point.
		   @param z: The depth coordinate of the point.
		 */
		public function Point3d(x:Number = 0, y:Number = 0, z:Number = 0)
		{
			this.x = x;
			this.y = y;
			this.z = z;
		}

		/**
		   The horizontal coordinate of the point.
		 */
		public function get x():Number
		{
			return this._x;
		}

		public function set x(position:Number):void
		{
			this._x = position;
		}

		/**
		   The vertical coordinate of the point.
		 */
		public function get y():Number
		{
			return this._y;
		}

		public function set y(position:Number):void
		{
			this._y = position;
		}

		/**
		   The depth coordinate of the point.
		 */
		public function get z():Number
		{
			return this._z;
		}

		public function set z(position:Number):void
		{
			this._z = position;
		}

		/**
		   Adds the coordinates of another Point3d to the coordinates of this point to create a new Point3d.

		   @param point: The point to be added.
		   @return The new point.
		 */
		public function add(point:Point3d):Point3d
		{
			return new Point3d(this.x + point.x, this.y + point.y, this.z + point.z);
		}

		/**
		   Subtracts the coordinates of another Point3d from the coordinates of this point to create a new Point3d.

		   @param point: The point to be subtracted.
		   @return The new point.
		 */
		public function subtract(point:Point3d):Point3d
		{
			return new Point3d(this.x - point.x, this.y - point.y, this.z - point.z);
		}

		/**
		   Offsets the Point object by the specified amount.

		   @param xOffset: The amount by which to offset the horizontal coordinate.
		   @param yOffset: The amount by which to offset the vertical coordinate.
		   @param zOffset: The amount by which to offset the depth coordinate.
		 */
		public function offset(xOffset:Number, yOffset:Number, zOffset:Number):void
		{
			this.x += xOffset;
			this.y += yOffset;
			this.z += zOffset;
		}

		/**
		   Determines if the point specified in the <code>point</code> parameter is equal to this point object.

		   @param point: A Point3d object.
		   @return Returns <code>true</code> if shape's location is identical; otherwise <code>false</code>.
		 */
		public function equals(point:Point3d):Boolean
		{
			return this.x == point.x && this.y == point.y && this.z == point.z;
		}

		/**
		   Creates a copy of this Point3d object.

		   @return A new Point3d with the same values as this point.
		 */
		public function clone():Point3d
		{
			return new Point3d(this.x, this.y, this.z);
		}

		/**
		   Determines the distance between the first and second points in 3D space.

		   @param firstPoint: The first Point3d.
		   @param secondPoint: The second Point3d.
		   @return Distance between the two points.
		 */
		public static function distance(firstPoint:Point3d, secondPoint:Point3d):Number
		{
			var x:Number = secondPoint.x - firstPoint.x;
			var y:Number = secondPoint.y - firstPoint.y;
			var z:Number = secondPoint.z - firstPoint.z;

			return Math.sqrt(x * x + y * y + z * z);
		}

		/**
		   Determines a point between two specified points.

		   @param firstPoint: The first Point3d.
		   @param secondPoint: The second Point3d.
		   @param amount: The level of interpolation between the two points. If <code>0%</code>, <code>firstPoint</code> is returned; if <code>100%</code>, <code>secondPoint</code> is returned.
		   @return The new, interpolated point.
		 */
		public static function interpolate(firstPoint:Point3d, secondPoint:Point3d, amount:Percent):Point3d
		{
			var x:Number = utils.number.interpolate(amount, firstPoint.x, secondPoint.x);
			var y:Number = utils.number.interpolate(amount, firstPoint.y, secondPoint.y);
			var z:Number = utils.number.interpolate(amount, firstPoint.z, secondPoint.z);

			return new Point3d(x, y, z);
		}
	}
}