gojs
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Interactive diagrams, charts, and graphs, such as trees, flowcharts, orgcharts, UML, BPMN, or business diagrams
955 lines (954 loc) • 39.9 kB
JavaScript
/*
* Copyright (C) 1998-2020 by Northwoods Software Corporation. All Rights Reserved.
*/
import * as go from '../release/go-module.js';
/**
* @hidden
*/
class QuadNode {
constructor(bounds, parent, level) {
this.objects = [];
this.treeObjects = [];
this.totalObjects = 0; // total in this node + in all children (recursively)
this.nodes = [null, null, null, null];
this.bounds = bounds;
this.parent = parent;
this.level = level;
}
split() {
const w2 = this.bounds.width / 2;
const h2 = this.bounds.height / 2;
const x = this.bounds.x;
const y = this.bounds.y;
this.nodes[0] = new QuadNode(new go.Rect(x + w2, y, w2, h2), this, this.level + 1);
this.nodes[1] = new QuadNode(new go.Rect(x, y, w2, h2), this, this.level + 1);
this.nodes[2] = new QuadNode(new go.Rect(x, y + h2, w2, h2), this, this.level + 1);
this.nodes[3] = new QuadNode(new go.Rect(x + w2, y + h2, w2, h2), this, this.level + 1);
}
clear() {
this.treeObjects = [];
this.objects = [];
this.totalObjects = 0;
for (let i = 0; i < this.nodes.length; i++) {
const n = this.nodes[i];
if (n !== null) {
n.clear();
this.nodes[i] = null;
}
}
}
}
/**
* Object to be contained by the {@link Quadtree} class. This object needs
* to have rectangular bounds (described by an {@link Rect} object), as well
* as something (of any type) associated with it.
*/
class TreeObject {
constructor(bounds, obj) {
this.bounds = bounds;
this.obj = obj;
}
}
/**
* Implementation of the quadtree data structure using the {@link Rect} class.
* Each Quadtree has defined bounds found at {@link #bounds}, an array
* of member rectangles, and an array of child nodes
* (Quadtrees themselves). If the Quadtree has no
* children, the nodes array will have four nulls. To construct a Quadtree, you
* can call its constructor with no arguments. Then, to insert a rectangle, call
* {@link #add}. This tree supports adding points (rectangles with 0
* width and height), segments (rectangles with either 0 width or 0 height), and
* rectangles with nonzero widths and heights.
*
* Quadtrees can be used to calculate intersections extremely quickly between a
* given rectangle and all of the rectangles in the quadtree. Use of this data
* structure prevents having to do precise intersection calculations for every
* rectangle in the tree. To calculate all of the rectangular intersections for
* a given rectangle, use {@link #intersecting}.
*
* Other common operations are detailed below.
* @category Layout Extension
*/
export class Quadtree {
/**
* In most cases, simply calling this constructor with no arguments will produce the desired behaviour.
* @constructor
* @param {number=} nodeCapacity The node capacity of this quadtree. This is the number of objects a node can contain before it splits. Defaults to 1.
* @param {number=} maxLevel The maximum depth the Quadtree will allow before it will no longer split. Defaults to Infinity (no maximum depth).
* @param {Rect=} bounds The bounding box surrounding the entire Quadtree. If the bounds are unset or a node is inserted outside of the bounds, the tree will automatically grow.
*/
constructor(nodeCapacity, maxLevel, bounds) {
/** @hidden @internal */ this._nodeCapacity = 1;
/** @hidden @internal */ this._maxLevels = Infinity;
/** @hidden @internal */ this._treeObjectMap = new go.Map();
// we can avoid unnecessary work when adding objects if there are no objects with 0 width or height.
// Note that after being set to true, these flags are not ever set again to false, even if all objects
// with zero width/height are removed (assumption was made that this should almost never matter)
/** @hidden @internal */ this._hasZeroWidthObject = false;
/** @hidden @internal */ this._hasZeroHeightObject = false;
if (nodeCapacity) {
this._nodeCapacity = nodeCapacity;
}
if (maxLevel) {
this._maxLevels = maxLevel;
}
if (bounds === undefined) {
bounds = new go.Rect();
}
this._root = new QuadNode(bounds, null, 0);
}
/**
* Gets the node capacity of this quadtree. This is the number of objects a node can contain before it splits.
*/
get nodeCapacity() { return this._nodeCapacity; }
/**
* Gets the maximum depth the Quadtree will allow before it will no longer split..
*/
get maxLevels() { return this._maxLevels; }
/**
* Gets the boundaries of the node. All nodes should be square.
*/
get bounds() { return this._root.bounds; }
/**
* Gets the root node of the tree
*/
get root() { return this._root; }
/**
* Clears the Quadtree, removing all objects and children nodes. Keeps the current bounds of the root node.
* @this {Quadtree}
* @return {void}
*/
clear() {
this._root.clear();
this._treeObjectMap.clear();
}
/**
* @hidden @internal
* Returns a list of possible quadrants that the given rect could be in
* @this {Quadtree}
* @param {Rect} rect the rectangle to test
* @return {Array<number>}
*/
_getQuadrants(rect, node) {
const quadrants = [];
const horizontalMidpoint = node.bounds.x + (node.bounds.width / 2);
const verticalMidpoint = node.bounds.y + (node.bounds.height / 2);
const topQuadrant = rect.y <= verticalMidpoint;
const bottomQuadrant = rect.y + rect.height >= verticalMidpoint;
if (rect.x <= horizontalMidpoint) {
if (topQuadrant) {
quadrants.push(1);
}
if (bottomQuadrant) {
quadrants.push(2);
}
}
if (rect.x + rect.width >= horizontalMidpoint) {
if (topQuadrant) {
quadrants.push(0);
}
if (bottomQuadrant) {
quadrants.push(3);
}
}
return quadrants;
}
/**
* @hidden @internal
* Determine which node the rect belongs to. -1 means rect
* cannot completely fit within a child node and is part of
* the parent node. This function avoids some additional
* calculations by assuming that the rect is contained entirely
* within the parent node's bounds.
* @this {Quadtree}
* @param {Rect} rect the rect to test
* @return {number}
*/
_getIndex(rect, node) {
let index = -1;
if (node.bounds === undefined) { // the quadtree is empty
return index;
}
const horizontalMidpoint = node.bounds.x + (node.bounds.width / 2);
const verticalMidpoint = node.bounds.y + (node.bounds.height / 2);
const topQuadrant = rect.y <= verticalMidpoint && rect.y + rect.height <= verticalMidpoint;
const bottomQuadrant = rect.y >= verticalMidpoint;
if (rect.x + rect.width <= horizontalMidpoint) {
if (topQuadrant) {
index = 1;
}
else if (bottomQuadrant) {
index = 2;
}
}
else if (rect.x >= horizontalMidpoint) {
if (topQuadrant) {
index = 0;
}
else if (bottomQuadrant) {
index = 3;
}
}
return index;
}
/**
* Insert the object into the quadtree. If the node
* exceeds the capacity, it will split and add all
* objects to their corresponding nodes. If the object is
* outside the bounds of the tree's root node, the tree
* will grow to accomodate it. Possibly restructures the
* tree if a more efficient configuration can be found with
* the new dimensions. Bounds can be given either as a
* single {@link Rect} or as any combination of arguments
* which is valid for the {@link Rect} constructor.
* @this {Quadtree}
* @param {T} obj the object to insert
* @param {Rect|Point|number} x The Rect bounds of the object, or top-left Point, or x value.
* @param {Point|Size|number} y Bottom-right Point or Size or y value.
* @param {number} w Width to be used if x,y are specified;
* must be non-negative.
* @param {number} h Height to be used if x,y are specified;
* @return {void}
*/
add(obj, x, y, w, h) {
let bounds;
if (!(obj instanceof TreeObject) && (x === undefined || x === null)) {
throw new Error('Invalid bounds for added object');
}
if (x instanceof go.Rect) {
bounds = x.copy();
}
else {
bounds = new go.Rect(x, y, w, h);
}
let treeObj;
if (obj instanceof TreeObject) {
treeObj = obj;
obj = treeObj.obj;
bounds = treeObj.bounds;
}
else {
treeObj = new TreeObject(bounds, obj);
}
if (isNaN(bounds.x) || bounds.x === Infinity ||
isNaN(bounds.y) || bounds.y === Infinity ||
isNaN(bounds.width) || bounds.width === Infinity ||
isNaN(bounds.height) || bounds.height === Infinity) {
throw new Error('Invalid rectangle, contains NaN or Infinity properties');
}
this._hasZeroWidthObject = this._hasZeroWidthObject || bounds.width === 0;
this._hasZeroHeightObject = this._hasZeroHeightObject || bounds.height === 0;
// initialize bounds of tree as the max width or height of the first object added
if (this._root.bounds.width === 0 || this._root.bounds.height === 0) {
const len = Math.max(bounds.width, bounds.height);
this._root.bounds = new go.Rect(bounds.x, bounds.y, len, len);
}
// fixes quadtree having a width and height of 0 if the first object added is a point
// this will only be called after a second object is added, the new width/height is the maximum distance between them
if (this._root.bounds !== undefined && (this._root.bounds.width === 0 || this._root.bounds.height === 0)) {
const len = Math.max(Math.abs(bounds.x - this._root.bounds.x), Math.abs(bounds.y - this._root.bounds.y));
this._root.bounds = new go.Rect(Math.min(this._root.bounds.x, bounds.x), Math.min(this._root.bounds.y, bounds.y), len, len);
}
// map the object to its corresponding TreeObject (so that the bounds of this object can be retrieved later)
this._treeObjectMap.add(obj, treeObj);
// grow as many times as necessary to fit the new object
while (!this._root.bounds.containsRect(bounds)) {
const old = this._root;
this.walk(n => n.level++, old);
const intersectsTopBound = bounds.y < this._root.bounds.y;
const intersectsBottomBound = bounds.y + bounds.height > this._root.bounds.y + this._root.bounds.height;
const intersectsRightBound = bounds.x + bounds.width > this._root.bounds.x + this._root.bounds.width;
const intersectsLeftBound = bounds.x < this._root.bounds.x;
if ((intersectsTopBound && intersectsRightBound) || (intersectsTopBound && !intersectsLeftBound)) {
/* _______
* | 1 | 0 |
* |___|___|
* |old| 3 |
* |___|___|
*/
const newBounds = new go.Rect(this._root.bounds.x, this._root.bounds.y - this._root.bounds.height, this._root.bounds.width * 2, this._root.bounds.height * 2);
this._root = new QuadNode(newBounds, null, 0);
this._root.split();
this._root.nodes[2] = old;
this._root.totalObjects = old.totalObjects;
old.parent = this._root;
this._restructure(old);
this._restructureLevels(old);
if (this._hasZeroHeightObject) {
this._fixTopObjectPlacement(old);
}
}
else if (intersectsTopBound && intersectsLeftBound) {
/* _______
* | 1 | 0 |
* |___|___|
* | 2 |old|
* |___|___|
*/
const newBounds = new go.Rect(this._root.bounds.x - this._root.bounds.width, this._root.bounds.y - this._root.bounds.height, this._root.bounds.width * 2, this._root.bounds.height * 2);
this._root = new QuadNode(newBounds, null, 0);
this._root.split();
this._root.nodes[3] = old;
this._root.totalObjects = old.totalObjects;
old.parent = this._root;
this._restructure(old);
this._restructureLevels(old);
if (this._hasZeroWidthObject) {
this._fixLeftObjectPlacement(old);
}
if (this._hasZeroHeightObject) {
this._fixTopObjectPlacement(old);
}
}
else if ((intersectsBottomBound && intersectsRightBound) || ((intersectsRightBound || intersectsBottomBound) && !intersectsLeftBound)) {
/* _______
* |old| 0 |
* |___|___|
* | 2 | 3 |
* |___|___|
*/
const newBounds = new go.Rect(this._root.bounds.x, this._root.bounds.y, this._root.bounds.width * 2, this._root.bounds.height * 2);
this._root = new QuadNode(newBounds, null, 0);
this._root.split();
this._root.nodes[1] = old;
this._root.totalObjects = old.totalObjects;
old.parent = this._root;
this._restructure(old);
this._restructureLevels(old);
}
else if ((intersectsBottomBound && intersectsLeftBound) || intersectsLeftBound) {
/* _______
* | 1 |old|
* |___|___|
* | 2 | 3 |
* |___|___|
*/
const newBounds = new go.Rect(this._root.bounds.x - this._root.bounds.width, this._root.bounds.y, this._root.bounds.width * 2, this._root.bounds.height * 2);
this._root = new QuadNode(newBounds, null, 0);
this._root.split();
this._root.nodes[0] = old;
this._root.totalObjects = old.totalObjects;
old.parent = this._root;
this._restructure(old);
this._restructureLevels(old);
if (this._hasZeroWidthObject) {
this._fixLeftObjectPlacement(old);
}
}
}
// add the object to the tree
this._addHelper(this._root, treeObj);
}
/**
* @hidden @internal
* Helper function to recursively perform the add operation
* on the tree.
* @this {Quadtree}
* @param {QuadNode<T>} root the current node being operated on
* @param {TreeObject<T>} treeObj the object being added
* @return {void}
*/
_addHelper(root, treeObj) {
root.totalObjects++;
if (root.nodes[0]) {
const index = this._getIndex(treeObj.bounds, root);
if (index !== -1) {
const selected = root.nodes[index];
if (selected !== null) {
this._addHelper(selected, treeObj);
return;
}
}
}
root.treeObjects.push(treeObj);
root.objects.push(treeObj.obj);
if (root.treeObjects.length > this._nodeCapacity && root.level < this._maxLevels) {
if (!root.nodes[0]) {
root.split();
}
let i = 0;
while (i < root.treeObjects.length) {
const index = this._getIndex(root.treeObjects[i].bounds, root);
if (index !== -1 && !(root.treeObjects[i].bounds.width === 0 || root.treeObjects[i].bounds.height === 0)) {
root.objects.splice(i, 1);
const selected = root.nodes[index];
if (selected !== null) {
this._addHelper(selected, root.treeObjects.splice(i, 1)[0]);
}
}
else {
i++;
}
}
}
}
/**
* @hidden @internal
* Recursively moves objects placed on the right side of a vertical border
* between two nodes to the left side of the vertical border. This allows
* them to be located by {@link #_getIndex}. This function is called
* after an {@link #add} call grows the Quadtree, but only if there
* are 0 width objects in the tree.
* @this {Quadtree}
* @param {QuadNode<T>} root the current root node being operated on
* @return {void}
*/
_fixLeftObjectPlacement(root) {
const nw = root.nodes[1];
if (nw !== null) { // if root is split
this._fixLeftObjectPlacement(nw); // NW
const sw = root.nodes[2];
if (sw !== null) {
this._fixLeftObjectPlacement(sw); // SW
}
}
const toRemove = [];
const toAdd = [];
for (let i = 0; i < root.objects.length; i++) {
const obj = root.treeObjects[i];
if (obj.bounds.width === 0 && obj.bounds.x === root.bounds.x) {
toRemove.push(i);
toAdd.push(obj);
}
}
this._removeFromOwner(root, toRemove);
for (const obj of toAdd) {
this.add(obj.obj, obj.bounds);
}
}
/**
* @hidden @internal
* Recursively moves objects placed on the bottom side of a horizontal border
* between two nodes to the top side of the vertical border. This allows
* them to be located by {@link #_getIndex}. This function is called
* after an {@link #add} call grows the Quadtree, but only if there
* are 0 height objects in the tree.
* @this {Quadtree}
* @param {QuadNode<T>} root the current root node being operated on
* @return {void}
*/
_fixTopObjectPlacement(root) {
const ne = root.nodes[0];
if (ne !== null) { // if root is split
this._fixTopObjectPlacement(ne); // NE
const nw = root.nodes[1];
if (nw !== null) {
this._fixTopObjectPlacement(nw); // NW
}
}
const toRemove = [];
const toAdd = [];
for (let i = 0; i < root.objects.length; i++) {
const obj = root.treeObjects[i];
if (obj.bounds.height === 0 && obj.bounds.y === root.bounds.y) {
toRemove.push(i);
toAdd.push(obj);
}
}
this._removeFromOwner(root, toRemove);
for (const obj of toAdd) {
this.add(obj);
}
}
/**
* @hidden @internal
* Moves all objects from a leaf node to its parent and unsplits.
* Used after growing the tree when level>max level.
* @this {Quadtree}
* @param {QuadNode<T>} node the leaf node to restructure
* @return {void}
*/
_restructureLevels(node) {
if (node && this._maxLevels < Infinity && node.nodes[0] !== null) {
if (node.level >= this._maxLevels) {
for (let i = 0; i < node.nodes.length; i++) {
const selected = node.nodes[i];
if (selected !== null) {
node.objects.push.apply(node.objects, selected.objects);
node.treeObjects.push.apply(node.treeObjects, selected.treeObjects);
selected.clear();
node.nodes[i] = null;
}
}
}
else {
for (let i = 0; i < node.nodes.length; i++) {
const selected = node.nodes[i];
if (selected !== null) {
this._restructureLevels(selected);
}
}
}
}
}
/**
* Return the node that contains the given object.
* @this {Quadtree}
* @param {T} obj the object to find
* @return {QuadNode<T>} the node containing the given object, null if the object is not found
*/
find(obj) {
const treeObj = this._treeObjectMap.get(obj);
if (treeObj) {
return this._findHelper(this._root, treeObj);
}
return null;
}
_findHelper(root, treeObj) {
for (const object of root.treeObjects) {
if (object === treeObj) {
return root;
}
}
const index = this._getIndex(treeObj.bounds, root);
const selected = index === -1 ? null : root.nodes[index];
if (selected !== null) {
const result = this._findHelper(selected, treeObj);
if (result) {
return result;
}
}
return null;
}
/**
* Convenience method, calls {@link #find} and returns a boolean
* indicating whether or not the tree contains the given object
* @this {Quadtree}
* @param {T} obj the object to check for
* @return {boolean} whether or not the given object is present in the tree
*/
has(obj) {
return !!this.find(obj);
}
/**
* Checks if any of the objects in the tree have the given boundaries
* @this {Quadtree}
* @param {Rect} bounds the rectangle to check for
* @return {Rect} the actual bounds object stored in the tree
*/
findBounds(bounds) {
if (bounds) {
return this._findBoundsHelper(this._root, bounds);
}
return null;
}
_findBoundsHelper(root, bounds) {
for (const object of root.treeObjects) {
if (bounds.equalsApprox(object.bounds)) {
return bounds;
}
}
const index = this._getIndex(bounds, root);
const selected = index === -1 ? null : root.nodes[index];
if (selected !== null) {
return this._findBoundsHelper(selected, bounds);
}
return null;
}
/**
* Remove the given object from the tree, restructuring to
* get rid of empty nodes that are unneeded.
* @this {Quadtree}
* @param {T} obj the object to remove
* @return {boolean} whether or not the deletion was successful. False when the object is not in the tree.
*/
remove(obj) {
const treeObj = this._treeObjectMap.get(obj);
if (treeObj) {
const owner = this._findHelper(this._root, treeObj);
if (owner) {
owner.treeObjects.splice(owner.treeObjects.indexOf(treeObj), 1);
owner.objects.splice(owner.objects.indexOf(obj), 1);
owner.totalObjects--;
this._treeObjectMap.remove(obj);
let parent = owner.parent;
while (parent) {
parent.totalObjects--;
parent = parent.parent;
}
if (owner.nodes[0] && owner.totalObjects <= this._nodeCapacity) {
this._addChildObjectsToNode(owner, owner);
for (let i = 0; i < owner.nodes.length; i++) {
const selected = owner.nodes[i];
if (selected !== null) {
selected.clear();
}
owner.nodes[i] = null;
}
}
this._restructure(owner);
return true;
}
}
return false;
}
/**
* Removes multiple objects at the given indices from the given owner. Similar
* to the normal remove function, but much faster when the owner and indices are
* already known.
* @this {Quadtree}
* @param {QuadNode<T>} owner the node to remove objects from
* @param {Array<number>} indexes the indices to remove. Should be given in ascending order.
*/
_removeFromOwner(owner, indexes) {
if (indexes.length === 0) {
return;
}
for (let i = indexes.length - 1; i >= 0; i--) {
this._treeObjectMap.remove(owner.objects[indexes[i]]);
owner.treeObjects.splice(indexes[i], 1);
owner.objects.splice(indexes[i], 1);
}
owner.totalObjects -= indexes.length;
let parent = owner.parent;
while (parent) {
parent.totalObjects -= indexes.length;
parent = parent.parent;
}
if (owner.nodes[0] && owner.totalObjects <= this._nodeCapacity) {
this._addChildObjectsToNode(owner, owner);
for (let i = 0; i < owner.nodes.length; i++) {
const selected = owner.nodes[i];
if (selected !== null) {
selected.clear();
}
owner.nodes[i] = null;
}
}
this._restructure(owner);
}
/**
* @hidden @internal
* Recursively adds all objects from children of the given
* root tree to the given owner tree
* Used internally by {@link #remove}
* @this {Quadtree}
* @param {Quadtree} owner the tree to add objects to
* @return {void}
*/
_addChildObjectsToNode(owner, root) {
for (const node of root.nodes) {
if (node) {
owner.treeObjects.push.apply(owner.treeObjects, node.treeObjects);
owner.objects.push.apply(owner.objects, node.objects);
this._addChildObjectsToNode(owner, node);
}
}
}
/**
* @hidden @internal
* Recursively combines parent nodes that should be split, all the way
* up the tree. Starts from the given node.
* @this {Quadtree}
* @return {void}
*/
_restructure(root) {
const parent = root.parent;
if (parent) {
// if none of the child nodes have any objects, the parent should not be split
let childrenHaveNoObjects = true;
for (const node of parent.nodes) {
if (node !== null && node.totalObjects > 0) {
childrenHaveNoObjects = false;
break;
}
}
// unsplit children and move nodes to parent
if (parent.totalObjects <= this._nodeCapacity || childrenHaveNoObjects) {
for (let i = 0; i < parent.nodes.length; i++) {
const selected = parent.nodes[i];
if (selected !== null) {
parent.objects.push.apply(parent.objects, selected.objects);
parent.treeObjects.push.apply(parent.treeObjects, selected.treeObjects);
selected.clear();
parent.nodes[i] = null;
}
}
this._restructure(parent);
}
}
}
/**
* Can be called as either (obj, x, y) or (obj, point). Translate
* the given object to given x and y coordinates or to a given {@link Point}.
* @this {Quadtree}
* @param {T} obj the object to move
* @param {number|Point} x the x coordinate or Point to move the object to
* @param {number} y the y coordinate to move the object to
* @return {boolean} whether or not the move was successful. False if the object was not in the tree.
*/
move(obj, x, y) {
const treeObj = this._treeObjectMap.get(obj);
if (treeObj && this.remove(obj)) {
if (x instanceof go.Point) {
treeObj.bounds.x = x.x;
treeObj.bounds.y = x.y;
}
else if (y !== undefined) {
treeObj.bounds.x = x;
treeObj.bounds.y = y;
}
else {
throw new Error('Please provide the position as either a Point or two numbers');
}
this.add(treeObj);
return true;
}
return false;
}
/**
* Can be called as either (obj, width, height) or (obj, size). Resize
* the given object to given width and height or to a given {@link Size}.
* @this {Quadtree}
* @param {T} obj the object to resize
* @param {number|Size} width the width or Size to resize the object to
* @param {number} height the height to resize the object to
* @return {boolean} whether or not the resize was successful. False if the object was not in the tree.
*/
resize(obj, width, height) {
const treeObj = this._treeObjectMap.get(obj);
if (treeObj && this.remove(obj)) {
if (width instanceof go.Size) {
treeObj.bounds.width = width.width;
treeObj.bounds.height = width.height;
}
else if (height !== undefined) {
treeObj.bounds.width = width;
treeObj.bounds.height = height;
}
else {
throw new Error('Please provide the size as either a Size or two numbers');
}
this.add(treeObj);
return true;
}
return false;
}
/**
* Updates the given object to have the bounds given, provided as either a
* {@link Rect} or x, y, width, and height.
* @this {Quadtree}
* @param obj the object to change the bounds of
* @param x the x-coordinate or Rect to set the object to
* @param y the y-coordinate to set the object to, unnecessary if a Rect was given
* @param width the width to set the object to, unnecessary if a Rect was given
* @param height the height to set the object to, unnecessary if a Rect was given
*/
setTo(obj, x, y, width, height) {
const treeObj = this._treeObjectMap.get(obj);
if (treeObj && this.remove(obj)) {
if (x instanceof go.Rect) {
treeObj.bounds.set(x);
}
else if (y !== undefined && width !== undefined && height !== undefined) {
treeObj.bounds.setTo(x, y, width, height);
}
else {
throw new Error('Please provide new bounds as either a Rect or combination of four numbers (x, y, width, height)');
}
this.add(treeObj);
return true;
}
return false;
}
/**
* Return all objects that intersect (wholly or partially) with
* the given {@link Rect} or {@link Point}. Touching edges and
* objects overlapping by 1e-7 or less (to account for floating
* point error) are both not considered intersections.
* @this {Quadtree}
* @param {Rect|Point} rect the Rect or Point to check intersections for. If a point is given, a Rect with size (0, 0) is created for intersection calculations.
* @return {Array<T>} array containing all intersecting objects
*/
intersecting(rect) {
if (rect instanceof go.Point) {
rect = new go.Rect(rect.x, rect.y, 0, 0);
}
const returnObjects = [];
this._intersectingHelper(rect, this._root, returnObjects);
return returnObjects;
}
_intersectingHelper(rect, root, returnObjects) {
const index = this._getIndex(rect, root);
const selected = index === -1 ? null : root.nodes[index];
if (selected !== null) {
this._intersectingHelper(rect, selected, returnObjects);
}
else if (root.nodes[0] !== null) {
const quadrants = this._getQuadrants(rect, root);
for (const quadrant of quadrants) {
const node = root.nodes[quadrant];
if (node !== null) {
this._intersectingHelper(rect, node, returnObjects);
}
}
}
for (const obj of root.treeObjects) {
if (Quadtree._rectsIntersect(obj.bounds, rect)) {
returnObjects.push(obj.obj);
}
}
}
/**
* @hidden @internal
* Similar as {@link Rect.intersectsRect}, but doesn't count edges as intersections.
* Also accounts for floating error (by returning false more often) up to an error of 1e-7.
* Used by {@link #intersecting}.
* @this {Quadtree}
* @param {Rect} r1 first rectangle
* @param {Rect} r2 second rectangle
* @return {boolean} whether or not the two rectangles intersect
*/
static _rectsIntersect(r1, r2) {
return !(r2.left + 1e-7 >= r1.right || r2.right - 1e-7 <= r1.left || r2.top + 1e-7 >= r1.bottom || r2.bottom - 1e-7 <= r1.top);
}
/**
* Return all objects that fully contain the given {@link Rect} or {@link Point}.
* @this {Quadtree}
* @param {Rect|Point} rect the Rect or Point to check containing for. If a point is given, a Rect with size (0, 0) is created for containment calculations.
* @return {Array<T>} array containing all containing objects
*/
containing(rect) {
if (rect instanceof go.Point) {
rect = new go.Rect(rect.x, rect.y, 0, 0);
}
const returnObjects = [];
this._containingHelper(rect, this._root, returnObjects);
return returnObjects;
}
_containingHelper(rect, root, returnObjects) {
const index = this._getIndex(rect, root);
const selected = index === -1 ? null : root.nodes[index];
if (selected !== null) {
this._containingHelper(rect, selected, returnObjects);
}
else if (root.nodes[0]) {
const quadrants = this._getQuadrants(rect, root);
for (const quadrant of quadrants) {
const node = root.nodes[quadrant];
if (node !== null) {
this._containingHelper(rect, node, returnObjects);
}
}
}
for (const obj of root.treeObjects) {
if (obj.bounds.containsRect(rect)) {
returnObjects.push(obj.obj);
}
}
}
/**
* Returns the square of the distance from the centers of the given objects
* @this {Quadtree}
* @param {T} obj1
* @param {T} obj2
* @return {number} square of the distance between the centers of obj1 and obj2
*/
distanceSquared(obj1, obj2) {
const owner1 = this.find(obj1);
const owner2 = this.find(obj2);
if (owner1 !== null && owner2 !== null) {
const treeObj1 = this._treeObjectMap.get(obj1);
const treeObj2 = this._treeObjectMap.get(obj2);
if (treeObj1 !== null && treeObj2 !== null) {
return treeObj1.bounds.center.distanceSquaredPoint(treeObj2.bounds.center);
}
}
return -1;
}
/**
* Recursively traverses the tree (depth first) and executes the
* given callback on each node.
* @this {Quadtree}
* @param {function} callback the callback to execute on each node. Takes the form of (n: Quadtree) => void
* @param {boolean} root whether or not to execute the callback on the root node as well. Defaults to true
* @return {void}
*/
walk(callback, node = this._root, root = true) {
if (root) {
root = false;
callback(node);
}
for (const n of node.nodes) {
if (n) {
callback(n);
this.walk(callback, n, root);
}
}
}
/**
* Visits every object stored in the tree (depth first)
* @this {Quadtree}
* @param {function} callback the callback to execute on each object.
* @return {void}
*/
forEach(callback) {
this.walk((n) => {
for (const obj of n.objects) {
callback(obj);
}
});
}
/**
* Finds the most furthest object in each direction stored in the tree.
* Bounds are tested using the center x and y coordinate.
* @this {Quadtree}
* @return {Array<T>} maximum and minimum objects in the tree, in the format [min x, max x, min y, max y].
*/
findExtremeObjects() {
const [extremes0, extremes1, extremes2, extremes3] = this._findExtremeObjectsHelper();
return [
extremes0 !== null ? extremes0.obj : null,
extremes1 !== null ? extremes1.obj : null,
extremes2 !== null ? extremes2.obj : null,
extremes3 !== null ? extremes3.obj : null
];
}
/**
* @hidden @internal
* Recursive helper function for {@link #findExtremeObjects}
* @this {Quadtree}
* @param {QuadNode<T>} root the current root node being searched
* @return {Array<TreeObject<T>>} maximum and minimum objects in the tree, in the format [min x, max x, min y, max y].
*/
_findExtremeObjectsHelper(root = this._root) {
let minX = null;
let maxX = null;
let minY = null;
let maxY = null;
if (root.nodes[0]) { // if root is split
for (const node of root.nodes) {
if (node !== null) {
const [extremes0, extremes1, extremes2, extremes3] = this._findExtremeObjectsHelper(node);
if (minX == null || (extremes0 !== null && extremes0.bounds.centerX < minX.bounds.centerX)) {
minX = extremes0;
}
if (maxX === null || (extremes1 !== null && extremes1.bounds.centerX > maxX.bounds.centerX)) {
maxX = extremes1;
}
if (minY === null || (extremes2 !== null && extremes2.bounds.centerY < minY.bounds.centerY)) {
minY = extremes2;
}
if (maxY === null || (extremes3 !== null && extremes3.bounds.centerY > maxY.bounds.centerY)) {
maxY = extremes3;
}
}
}
}
for (const obj of root.treeObjects) {
if (!minX || obj.bounds.centerX < minX.bounds.centerX) {
minX = obj;
}
if (!maxX || obj.bounds.centerX > maxX.bounds.centerX) {
maxX = obj;
}
if (!minY || obj.bounds.centerY < minY.bounds.centerY) {
minY = obj;
}
if (!maxY || obj.bounds.centerY > maxY.bounds.centerY) {
maxY = obj;
}
}
return [minX, maxX, minY, maxY];
}
}