/*
*   --------------------------------------------------
*   Class:         Point2DClass.as
*   --------------------------------------------------
*   Version:       1.0
*   --------------------------------------------------
*   Latest update: August 1, 2003
*   --------------------------------------------------
*   Adapted for Flash MX by Richard Wright - June 2003
*                           [wisolutions2002@shaw.ca]
*   --------------------------------------------------
*   Copyright (c) 2000-2002, Kevin Lindsey
*                            [http://www.kevlindev.com/]
*
*   All rights reserved.
*
*   Redistribution and use in source and binary forms, with or without
*   modification, are permitted provided that the following conditions are met:
*
*      - Redistributions of source code must retain the above copyright notice,
*         this list of conditions and the following disclaimer.
*
*       - Redistributions in binary form must reproduce the above copyright
*         notice, this list of conditions and the following disclaimer in the
*         documentation and/or other materials provided with the distribution.
*
*       - Neither the name of this software nor the names of its contributors
*         may be used to endorse or promote products derived from this software
*         without specific prior written permission.
*
*   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
*   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
*   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
*   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
*   ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
*   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
*   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
*   ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
*   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
*   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*   -----------------------------------------------------------
*   Functions:
*       - class
*       1. Point2D(x,y)
*          - prototypes
*          Point2D.prototype.
*             2.   init(x,y)
*             3.   adds(that)
*             4.   addEquals(that)
*             5.   scalarAdd(scalar)
*             6.   scalarAddEquals(scalar)
*             7.   subtract(that)
*             8.   subtractEquals(that)
*             9.   scalarSubtract(scalar)
*             10.  scalarSubtractEquals(scalar)
*             11.  multiply(scalar)
*             12.  multiplyEquals(scalar)
*             13.  divide(scalar)
*             14.  divideEquals(scalar)
*          - comparison methods
*             15.  eqs(that)
*             16.  lessThan(that)
*             17.  lessThanEq(that)
*             18.  greaterThan(that)
*             19.  greaterThanEq(that)
*          - utility methods
*             20.  lerp(that,t)
*             21.  distanceFrom(that)
*             22.  min(that)
*             23.  max(that)
*             24.  toString()
*         - get/set methods
*             25.  setXY(x,y)
*             26.  setFromPoint(that)
*             27.  swap(that)
*   ------------------------------------------------------
*   Updates may be available at:
*                    http://members.shaw.ca/flashmath101/as/
*   -----------------------------------------------------
*/

/*****
*
*   Point2D
*
*****/

/*****
*
*   1. constructor
*
*****/
function Point2D(x, y) {
    if ( arguments.length > 0 ) {
        this.init(x, y);
    }
}


/*****
*
*   2. init
*
*****/
Point2D.prototype.init = function(x, y) {
    this.x = x;
    this.y = y;
};


/*****
*
*   3. adds
*
*****/
Point2D.prototype.adds = function(that) {
    return new Point2D(this.x+that.x, this.y+that.y);
};


/*****
*
*   4. addEquals
*
*****/
Point2D.prototype.addEquals = function(that) {
    this.x += that.x;
    this.y += that.y;

    return this;
};


/*****
*
*   5. scalarAdd
*
*****/
Point2D.prototype.scalarAdd = function(scalar) {
    return new Point2D(this.x+scalar, this.y+scalar);
};


/*****
*
*   6. scalarAddEquals
*
*****/
Point2D.prototype.scalarAddEquals = function(scalar) {
    this.x += scalar;
    this.y += scalar;

    return this;
};


/*****
*
*   7. subtract
*
*****/
Point2D.prototype.subtract = function(that) {
    return new Point2D(this.x-that.x, this.y-that.y);
};


/*****
*
*   8. subtractEquals
*
*****/
Point2D.prototype.subtractEquals = function(that) {
    this.x -= that.x;
    this.y -= that.y;

    return this;
};


/*****
*
*   9. scalarSubtract
*
*****/
Point2D.prototype.scalarSubtract = function(scalar) {
    return new Point2D(this.x-scalar, this.y-scalar);
};


/*****
*
*   10. scalarSubtractEquals
*
*****/
Point2D.prototype.scalarSubtractEquals = function(scalar) {
    this.x -= scalar;
    this.y -= scalar;

    return this;
};


/*****
*
*   11. multiply
*
*****/
Point2D.prototype.multiply = function(scalar) {
    return new Point2D(this.x*scalar, this.y*scalar);
};


/*****
*
*   12. multiplyEquals
*
*****/
Point2D.prototype.multiplyEquals = function(scalar) {
    this.x *= scalar;
    this.y *= scalar;

    return this;
};


/*****
*
*   13. divide
*
*****/
Point2D.prototype.divide = function(scalar) {
    return new Point2D(this.x/scalar, this.y/scalar);
};


/*****
*
*   14. divideEquals
*
*****/
Point2D.prototype.divideEquals = function(scalar) {
    this.x /= scalar;
    this.y /= scalar;

    return this;
};


/*****
*
*   comparison methods
*
*****/

/*****
*
*   15. eqs - equal
*
*****/
Point2D.prototype.eqs = function(that) {
    return ( this.x == that.x && this.y == that.y );
};


/*****
*
*   16. lessThan - less than
*
*****/
Point2D.prototype.lessThan = function(that) {
    return ( this.x < that.x && this.y < that.y );
};


/*****
*
*   17. lessThanEq - less than or equal
*
*****/
Point2D.prototype.lessThanEq = function(that) {
    return ( this.x <= that.x && this.y <= that.y );
};


/*****
*
*   18. greaterThan - greater than
*
*****/
Point2D.prototype.greaterThan = function(that) {
    return ( this.x > that.x && this.y > that.y );
};


/*****
*
*   19. greaterThanEq - greater than or equal
*
*****/
Point2D.prototype.greaterThanEq = function(that) {
    return ( this.x >= that.x && this.y >= that.y );
};


/*****
*
*   utility methods
*
*****/

/*****
*
*   20. lerp
*
*****/
Point2D.prototype.lerp = function(that, t) {
    return new Point2D(
        this.x + (that.x - this.x) * t,
        this.y + (that.y - this.y) * t
    );
};


/*****
*
*   21. distanceFrom
*
*****/
Point2D.prototype.distanceFrom = function(that) {
    var dx = this.x - that.x;
    var dy = this.y - that.y;

    return Math.sqrt(dx*dx + dy*dy);
};


/*****
*
*   22. min
*
*****/
Point2D.prototype.min = function(that) {
    return new Point2D(
        Math.min( this.x, that.x ),
        Math.min( this.y, that.y )
    );
};


/*****
*
*   23. max
*
*****/
Point2D.prototype.max = function(that) {
    return new Point2D(
        Math.max( this.x, that.x ),
        Math.max( this.y, that.y )
    );
};


/*****
*
*   24. toString
*
*****/
Point2D.prototype.toString = function() {
    return this.x + "," + this.y;
};


/*****
*
*   get/set methods
*
*****/

/*****
*
*   25. setXY
*
*****/
Point2D.prototype.setXY = function(x, y) {
    this.x = x;
    this.y = y;
};


/*****
*
*   26. setFromPoint
*
*****/
Point2D.prototype.setFromPoint = function(that) {
    this.x = that.x;
    this.y = that.y;
};


/*****
*
*   27. swap
*
*****/
Point2D.prototype.swap = function(that) {
    var x = this.x;
    var y = this.y;

    this.x = that.x;
    this.y = that.y;

    that.x = x;
    that.y = y;
};