phaser/Phaser/system/QuadTree.ts

/// <reference path="../Game.ts" />
/// <reference path="LinkedList.ts" />

/**
 * A fairly generic quad tree structure for rapid overlap checks.
 * QuadTree is also configured for single or dual list operation.
 * You can add items either to its A list or its B list.
 * When you do an overlap check, you can compare the A list to itself,
 * or the A list against the B list.  Handy for different things!
 */

/**
*   Phaser
*/

module Phaser {

    export class QuadTree extends Rectangle {

        /**
         * Instantiate a new Quad Tree node.
         * 
         * @param	X			The X-coordinate of the point in space.
         * @param	Y			The Y-coordinate of the point in space.
         * @param	Width		Desired width of this node.
         * @param	Height		Desired height of this node.
         * @param	Parent		The parent branch or node.  Pass null to create a root.
         */
        constructor(X: number, Y: number, Width: number, Height: number, Parent: QuadTree = null) {

            super(X, Y, Width, Height);

            //console.log('-------- QuadTree',X,Y,Width,Height);

            this._headA = this._tailA = new LinkedList();
            this._headB = this._tailB = new LinkedList();

            //Copy the parent's children (if there are any)
            if (Parent != null)
            {
                //console.log('Parent not null');
                var iterator: LinkedList;
                var ot: LinkedList;

                if (Parent._headA.object != null)
                {
                    iterator = Parent._headA;
                    //console.log('iterator set to parent headA');

                    while (iterator != null)
                    {
                        if (this._tailA.object != null)
                        {
                            ot = this._tailA;
                            this._tailA = new LinkedList();
                            ot.next = this._tailA;
                        }

                        this._tailA.object = iterator.object;
                        iterator = iterator.next;
                    }
                }

                if (Parent._headB.object != null)
                {
                    iterator = Parent._headB;
                    //console.log('iterator set to parent headB');

                    while (iterator != null)
                    {
                        if (this._tailB.object != null)
                        {
                            ot = this._tailB;
                            this._tailB = new LinkedList();
                            ot.next = this._tailB;
                        }

                        this._tailB.object = iterator.object;
                        iterator = iterator.next;
                    }
                }
            }
            else
            {
                QuadTree._min = (this.width + this.height) / (2 * QuadTree.divisions);
            }

            this._canSubdivide = (this.width > QuadTree._min) || (this.height > QuadTree._min);

            //console.log('canSubdivided', this._canSubdivide);

            //Set up comparison/sort helpers
            this._northWestTree = null;
            this._northEastTree = null;
            this._southEastTree = null;
            this._southWestTree = null;
            this._leftEdge = this.x;
            this._rightEdge = this.x + this.width;
            this._halfWidth = this.width / 2;
            this._midpointX = this._leftEdge + this._halfWidth;
            this._topEdge = this.y;
            this._bottomEdge = this.y + this.height;
            this._halfHeight = this.height / 2;
            this._midpointY = this._topEdge + this._halfHeight;

        }

        /**
         * Flag for specifying that you want to add an object to the A list.
         */
        public static A_LIST: number = 0;

        /**
         * Flag for specifying that you want to add an object to the B list.
         */
        public static B_LIST: number = 1;

        /**
         * Controls the granularity of the quad tree.  Default is 6 (decent performance on large and small worlds).
         */
        public static divisions: number;

        /**
         * Whether this branch of the tree can be subdivided or not.
         */
        private _canSubdivide: bool;

        /**
         * Refers to the internal A and B linked lists,
         * which are used to store objects in the leaves.
         */
        private _headA: LinkedList;

        /**
         * Refers to the internal A and B linked lists,
         * which are used to store objects in the leaves.
         */
        private _tailA: LinkedList;

        /**
         * Refers to the internal A and B linked lists,
         * which are used to store objects in the leaves.
         */
        private _headB: LinkedList;

        /**
         * Refers to the internal A and B linked lists,
         * which are used to store objects in the leaves.
         */
        private _tailB: LinkedList;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private static _min: number;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _northWestTree: QuadTree;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _northEastTree: QuadTree;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _southEastTree: QuadTree;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _southWestTree: QuadTree;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _leftEdge: number;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _rightEdge: number;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _topEdge: number;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _bottomEdge: number;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _halfWidth: number;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _halfHeight: number;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _midpointX: number;

        /**
         * Internal, governs and assists with the formation of the tree.
         */
        private _midpointY: number;

        /**
         * Internal, used to reduce recursive method parameters during object placement and tree formation.
         */
        private static _object;

        /**
         * Internal, used to reduce recursive method parameters during object placement and tree formation.
         */
        private static _objectLeftEdge: number;

        /**
         * Internal, used to reduce recursive method parameters during object placement and tree formation.
         */
        private static _objectTopEdge: number;

        /**
         * Internal, used to reduce recursive method parameters during object placement and tree formation.
         */
        private static _objectRightEdge: number;

        /**
         * Internal, used to reduce recursive method parameters during object placement and tree formation.
         */
        private static _objectBottomEdge: number;

        /**
         * Internal, used during tree processing and overlap checks.
         */
        private static _list: number;

        /**
         * Internal, used during tree processing and overlap checks.
         */
        private static _useBothLists: bool;

        /**
         * Internal, used during tree processing and overlap checks.
         */
        private static _processingCallback;

        /**
         * Internal, used during tree processing and overlap checks.
         */
        private static _notifyCallback;

        /**
         * Internal, used during tree processing and overlap checks.
         */
        private static _iterator: LinkedList;

        /**
         * Internal, helpers for comparing actual object-to-object overlap - see <code>overlapNode()</code>.
         */
        private static _objectHullX: number;

        /**
         * Internal, helpers for comparing actual object-to-object overlap - see <code>overlapNode()</code>.
         */
        private static _objectHullY: number;

        /**
         * Internal, helpers for comparing actual object-to-object overlap - see <code>overlapNode()</code>.
         */
        private static _objectHullWidth: number;

        /**
         * Internal, helpers for comparing actual object-to-object overlap - see <code>overlapNode()</code>.
         */
        private static _objectHullHeight: number;

        /**
         * Internal, helpers for comparing actual object-to-object overlap - see <code>overlapNode()</code>.
         */
        private static _checkObjectHullX: number;

        /**
         * Internal, helpers for comparing actual object-to-object overlap - see <code>overlapNode()</code>.
         */
        private static _checkObjectHullY: number;

        /**
         * Internal, helpers for comparing actual object-to-object overlap - see <code>overlapNode()</code>.
         */
        private static _checkObjectHullWidth: number;

        /**
         * Internal, helpers for comparing actual object-to-object overlap - see <code>overlapNode()</code>.
         */
        private static _checkObjectHullHeight: number;

        /**
         * Clean up memory.
         */
        public destroy() {

            this._tailA.destroy();
            this._tailB.destroy();
            this._headA.destroy();
            this._headB.destroy();

            this._tailA = null;
            this._tailB = null;
            this._headA = null;
            this._headB = null;

            if (this._northWestTree != null)
            {
                this._northWestTree.destroy();
            }

            if (this._northEastTree != null)
            {
                this._northEastTree.destroy();
            }

            if (this._southEastTree != null)
            {
                this._southEastTree.destroy();
            }

            if (this._southWestTree != null)
            {
                this._southWestTree.destroy();
            }

            this._northWestTree = null;
            this._northEastTree = null;
            this._southEastTree = null;
            this._southWestTree = null;

            QuadTree._object = null;
            QuadTree._processingCallback = null;
            QuadTree._notifyCallback = null;

        }

        /**
         * Load objects and/or groups into the quad tree, and register notify and processing callbacks.
         * 
         * @param ObjectOrGroup1	Any object that is or extends GameObject or Group.
         * @param ObjectOrGroup2	Any object that is or extends GameObject or Group.  If null, the first parameter will be checked against itself.
         * @param NotifyCallback	A function with the form <code>myFunction(Object1:GameObject,Object2:GameObject)</code> that is called whenever two objects are found to overlap in world space, and either no ProcessCallback is specified, or the ProcessCallback returns true. 
         * @param ProcessCallback	A function with the form <code>myFunction(Object1:GameObject,Object2:GameObject):bool</code> that is called whenever two objects are found to overlap in world space.  The NotifyCallback is only called if this function returns true.  See GameObject.separate(). 
         */
        public load(ObjectOrGroup1: Basic, ObjectOrGroup2: Basic = null, NotifyCallback = null, ProcessCallback = null) {

            //console.log('quadtree load', QuadTree.divisions, ObjectOrGroup1, ObjectOrGroup2);

            this.add(ObjectOrGroup1, QuadTree.A_LIST);

            if (ObjectOrGroup2 != null)
            {
                this.add(ObjectOrGroup2, QuadTree.B_LIST);
                QuadTree._useBothLists = true;
            }
            else
            {
                QuadTree._useBothLists = false;
            }

            QuadTree._notifyCallback = NotifyCallback;
            QuadTree._processingCallback = ProcessCallback;

            //console.log('use both', QuadTree._useBothLists);
            //console.log('------------ end of load');

        }

        /**
         * Call this function to add an object to the root of the tree.
         * This function will recursively add all group members, but
         * not the groups themselves.
         * 
         * @param	ObjectOrGroup	GameObjects are just added, Groups are recursed and their applicable members added accordingly.
         * @param	List			A <code>uint</code> flag indicating the list to which you want to add the objects.  Options are <code>QuadTree.A_LIST</code> and <code>QuadTree.B_LIST</code>.
         */
        public add(ObjectOrGroup: Basic, List: number) {

            QuadTree._list = List;

            if (ObjectOrGroup.isGroup == true)
            {
                var i: number = 0;
                var basic: Basic;
                var members = <Group> ObjectOrGroup['members'];
                var l: number = ObjectOrGroup['length'];

                while (i < l)
                {
                    basic = members[i++];

                    if ((basic != null) && basic.exists)
                    {
                        if (basic.isGroup)
                        {
                            this.add(basic, List);
                        }
                        else
                        {
                            QuadTree._object = basic;

                            if (QuadTree._object.exists && QuadTree._object.allowCollisions)
                            {
                                QuadTree._objectLeftEdge = QuadTree._object.x;
                                QuadTree._objectTopEdge = QuadTree._object.y;
                                QuadTree._objectRightEdge = QuadTree._object.x + QuadTree._object.width;
                                QuadTree._objectBottomEdge = QuadTree._object.y + QuadTree._object.height;
                                this.addObject();
                            }
                        }
                    }
                }
            }
            else
            {
                QuadTree._object = ObjectOrGroup;

                //console.log('add - not group:', ObjectOrGroup.name);

                if (QuadTree._object.exists && QuadTree._object.allowCollisions)
                {
                    QuadTree._objectLeftEdge = QuadTree._object.x;
                    QuadTree._objectTopEdge = QuadTree._object.y;
                    QuadTree._objectRightEdge = QuadTree._object.x + QuadTree._object.width;
                    QuadTree._objectBottomEdge = QuadTree._object.y + QuadTree._object.height;
                    //console.log('object properties', QuadTree._objectLeftEdge, QuadTree._objectTopEdge, QuadTree._objectRightEdge, QuadTree._objectBottomEdge);
                    this.addObject();
                }
            }
        }

        /**
         * Internal function for recursively navigating and creating the tree
         * while adding objects to the appropriate nodes.
         */
        private addObject() {

            //console.log('addObject');

            //If this quad (not its children) lies entirely inside this object, add it here
            if (!this._canSubdivide || ((this._leftEdge >= QuadTree._objectLeftEdge) && (this._rightEdge <= QuadTree._objectRightEdge) && (this._topEdge >= QuadTree._objectTopEdge) && (this._bottomEdge <= QuadTree._objectBottomEdge)))
            {
                //console.log('add To List');
                this.addToList();
                return;
            }

            //See if the selected object fits completely inside any of the quadrants
            if ((QuadTree._objectLeftEdge > this._leftEdge) && (QuadTree._objectRightEdge < this._midpointX))
            {
                if ((QuadTree._objectTopEdge > this._topEdge) && (QuadTree._objectBottomEdge < this._midpointY))
                {
                    //console.log('Adding NW tree');

                    if (this._northWestTree == null)
                    {
                        this._northWestTree = new QuadTree(this._leftEdge, this._topEdge, this._halfWidth, this._halfHeight, this);
                    }

                    this._northWestTree.addObject();
                    return;
                }

                if ((QuadTree._objectTopEdge > this._midpointY) && (QuadTree._objectBottomEdge < this._bottomEdge))
                {
                    //console.log('Adding SW tree');

                    if (this._southWestTree == null)
                    {
                        this._southWestTree = new QuadTree(this._leftEdge, this._midpointY, this._halfWidth, this._halfHeight, this);
                    }

                    this._southWestTree.addObject();
                    return;
                }
            }

            if ((QuadTree._objectLeftEdge > this._midpointX) && (QuadTree._objectRightEdge < this._rightEdge))
            {
                if ((QuadTree._objectTopEdge > this._topEdge) && (QuadTree._objectBottomEdge < this._midpointY))
                {
                    //console.log('Adding NE tree');

                    if (this._northEastTree == null)
                    {
                        this._northEastTree = new QuadTree(this._midpointX, this._topEdge, this._halfWidth, this._halfHeight, this);
                    }

                    this._northEastTree.addObject();
                    return;
                }

                if ((QuadTree._objectTopEdge > this._midpointY) && (QuadTree._objectBottomEdge < this._bottomEdge))
                {
                    //console.log('Adding SE tree');

                    if (this._southEastTree == null)
                    {
                        this._southEastTree = new QuadTree(this._midpointX, this._midpointY, this._halfWidth, this._halfHeight, this);
                    }

                    this._southEastTree.addObject();
                    return;
                }
            }

            //If it wasn't completely contained we have to check out the partial overlaps
            if ((QuadTree._objectRightEdge > this._leftEdge) && (QuadTree._objectLeftEdge < this._midpointX) && (QuadTree._objectBottomEdge > this._topEdge) && (QuadTree._objectTopEdge < this._midpointY))
            {
                if (this._northWestTree == null)
                {
                    this._northWestTree = new QuadTree(this._leftEdge, this._topEdge, this._halfWidth, this._halfHeight, this);
                }

                //console.log('added to north west partial tree');
                this._northWestTree.addObject();
            }

            if ((QuadTree._objectRightEdge > this._midpointX) && (QuadTree._objectLeftEdge < this._rightEdge) && (QuadTree._objectBottomEdge > this._topEdge) && (QuadTree._objectTopEdge < this._midpointY))
            {
                if (this._northEastTree == null)
                {
                    this._northEastTree = new QuadTree(this._midpointX, this._topEdge, this._halfWidth, this._halfHeight, this);
                }

                //console.log('added to north east partial tree');
                this._northEastTree.addObject();
            }

            if ((QuadTree._objectRightEdge > this._midpointX) && (QuadTree._objectLeftEdge < this._rightEdge) && (QuadTree._objectBottomEdge > this._midpointY) && (QuadTree._objectTopEdge < this._bottomEdge))
            {
                if (this._southEastTree == null)
                {
                    this._southEastTree = new QuadTree(this._midpointX, this._midpointY, this._halfWidth, this._halfHeight, this);
                }

                //console.log('added to south east partial tree');
                this._southEastTree.addObject();
            }

            if ((QuadTree._objectRightEdge > this._leftEdge) && (QuadTree._objectLeftEdge < this._midpointX) && (QuadTree._objectBottomEdge > this._midpointY) && (QuadTree._objectTopEdge < this._bottomEdge))
            {
                if (this._southWestTree == null)
                {
                    this._southWestTree = new QuadTree(this._leftEdge, this._midpointY, this._halfWidth, this._halfHeight, this);
                }

                //console.log('added to south west partial tree');
                this._southWestTree.addObject();
            }

        }

        /**
         * Internal function for recursively adding objects to leaf lists.
         */
        private addToList() {

            //console.log('Adding to List');

            var ot: LinkedList;

            if (QuadTree._list == QuadTree.A_LIST)
            {
                //console.log('A LIST');
                if (this._tailA.object != null)
                {
                    ot = this._tailA;
                    this._tailA = new LinkedList();
                    ot.next = this._tailA;
                }

                this._tailA.object = QuadTree._object;
            }
            else
            {
                //console.log('B LIST');
                if (this._tailB.object != null)
                {
                    ot = this._tailB;
                    this._tailB = new LinkedList();
                    ot.next = this._tailB;
                }

                this._tailB.object = QuadTree._object;
            }

            if (!this._canSubdivide)
            {
                return;
            }

            if (this._northWestTree != null)
            {
                this._northWestTree.addToList();
            }

            if (this._northEastTree != null)
            {
                this._northEastTree.addToList();
            }

            if (this._southEastTree != null)
            {
                this._southEastTree.addToList();
            }

            if (this._southWestTree != null)
            {
                this._southWestTree.addToList();
            }

        }

        /**
         * <code>QuadTree</code>'s other main function.  Call this after adding objects
         * using <code>QuadTree.load()</code> to compare the objects that you loaded.
         *
         * @return	Whether or not any overlaps were found.
         */
        public execute(): bool {

            //console.log('quadtree execute');

            var overlapProcessed: bool = false;
            var iterator: LinkedList;

            if (this._headA.object != null)
            {
                //console.log('---------------------------------------------------');
                //console.log('headA iterator');

                iterator = this._headA;

                while (iterator != null)
                {
                    QuadTree._object = iterator.object;

                    if (QuadTree._useBothLists)
                    {
                        QuadTree._iterator = this._headB;
                    }
                    else
                    {
                        QuadTree._iterator = iterator.next;
                    }

                    if (QuadTree._object.exists && (QuadTree._object.allowCollisions > 0) && (QuadTree._iterator != null) && (QuadTree._iterator.object != null) && QuadTree._iterator.object.exists && this.overlapNode())
                    {
                        //console.log('headA iterator overlapped true');
                        overlapProcessed = true;
                    }

                    iterator = iterator.next;

                }
            }

            //Advance through the tree by calling overlap on each child
            if ((this._northWestTree != null) && this._northWestTree.execute())
            {
                //console.log('NW quadtree execute');
                overlapProcessed = true;
            }

            if ((this._northEastTree != null) && this._northEastTree.execute())
            {
                //console.log('NE quadtree execute');
                overlapProcessed = true;
            }

            if ((this._southEastTree != null) && this._southEastTree.execute())
            {
                //console.log('SE quadtree execute');
                overlapProcessed = true;
            }

            if ((this._southWestTree != null) && this._southWestTree.execute())
            {
                //console.log('SW quadtree execute');
                overlapProcessed = true;
            }

            return overlapProcessed;

        }

        /**
         * An private for comparing an object against the contents of a node.
         * 
         * @return	Whether or not any overlaps were found.
         */
        private overlapNode(): bool {

            //console.log('overlapNode');

            //Walk the list and check for overlaps
            var overlapProcessed: bool = false;
            var checkObject;

            while (QuadTree._iterator != null)
            {
                if (!QuadTree._object.exists || (QuadTree._object.allowCollisions <= 0))
                {
                    //console.log('break 1');
                    break;
                }

                checkObject = QuadTree._iterator.object;

                if ((QuadTree._object === checkObject) || !checkObject.exists || (checkObject.allowCollisions <= 0))
                {
                    //console.log('break 2');
                    QuadTree._iterator = QuadTree._iterator.next;
                    continue;
                }

                //calculate bulk hull for QuadTree._object
                QuadTree._objectHullX = (QuadTree._object.x < QuadTree._object.last.x) ? QuadTree._object.x : QuadTree._object.last.x;
                QuadTree._objectHullY = (QuadTree._object.y < QuadTree._object.last.y) ? QuadTree._object.y : QuadTree._object.last.y;
                QuadTree._objectHullWidth = QuadTree._object.x - QuadTree._object.last.x;
                QuadTree._objectHullWidth = QuadTree._object.width + ((QuadTree._objectHullWidth > 0) ? QuadTree._objectHullWidth : -QuadTree._objectHullWidth);
                QuadTree._objectHullHeight = QuadTree._object.y - QuadTree._object.last.y;
                QuadTree._objectHullHeight = QuadTree._object.height + ((QuadTree._objectHullHeight > 0) ? QuadTree._objectHullHeight : -QuadTree._objectHullHeight);

                //calculate bulk hull for checkObject
                QuadTree._checkObjectHullX = (checkObject.x < checkObject.last.x) ? checkObject.x : checkObject.last.x;
                QuadTree._checkObjectHullY = (checkObject.y < checkObject.last.y) ? checkObject.y : checkObject.last.y;
                QuadTree._checkObjectHullWidth = checkObject.x - checkObject.last.x;
                QuadTree._checkObjectHullWidth = checkObject.width + ((QuadTree._checkObjectHullWidth > 0) ? QuadTree._checkObjectHullWidth : -QuadTree._checkObjectHullWidth);
                QuadTree._checkObjectHullHeight = checkObject.y - checkObject.last.y;
                QuadTree._checkObjectHullHeight = checkObject.height + ((QuadTree._checkObjectHullHeight > 0) ? QuadTree._checkObjectHullHeight : -QuadTree._checkObjectHullHeight);

                //check for intersection of the two hulls
                if ((QuadTree._objectHullX + QuadTree._objectHullWidth > QuadTree._checkObjectHullX) && (QuadTree._objectHullX < QuadTree._checkObjectHullX + QuadTree._checkObjectHullWidth) && (QuadTree._objectHullY + QuadTree._objectHullHeight > QuadTree._checkObjectHullY) && (QuadTree._objectHullY < QuadTree._checkObjectHullY + QuadTree._checkObjectHullHeight))
                {
                    //console.log('intersection!');

                    //Execute callback functions if they exist
                    if ((QuadTree._processingCallback == null) || QuadTree._processingCallback(QuadTree._object, checkObject))
                    {
                        overlapProcessed = true;
                    }

                    if (overlapProcessed && (QuadTree._notifyCallback != null))
                    {
                        QuadTree._notifyCallback(QuadTree._object, checkObject);
                    }
                }

                QuadTree._iterator = QuadTree._iterator.next;

            }

            return overlapProcessed;

        }
    }

}