https://github.com/azrafe7/hxaabbtree

Haxe dynamic AABB tree.
https://github.com/azrafe7/hxaabbtree

Last synced: 11 days ago
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Haxe dynamic AABB tree.

• Host: GitHub
• URL: https://github.com/azrafe7/hxaabbtree
• Owner: azrafe7
• License: mit
• Created: 2014-06-07T19:15:09.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2014-06-18T23:27:53.000Z (over 10 years ago)
• Last Synced: 2024-11-05T13:22:38.938Z (about 2 months ago)
• Language: Haxe
• Size: 355 KB
• Stars: 19
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
AABBTree

========

Haxe dynamic [AABB tree](http://en.wikipedia.org/wiki/Bounding_volume_hierarchy) for spatial partitioning and query.

 - fast insertion/removal/update

 - supports both AABB and raycast type of queries (with filtering callbacks)

 - easy to use and highly customizable (fattening factor, pool properties, insert strategies, etc.)

 - extendable debug renderer to visualize build steps

 - no dependencies

Check the [demo](https://dl.dropboxusercontent.com/u/32864004/dev/FPDemo/AABBTreeTest01.swf):

![](screenshot.png)

###AS3 PORT

A port to as3 can be found here: [https://github.com/azrafe7/as3AABBTree](https://github.com/azrafe7/as3AABBTree).

###BASIC USAGE EXAMPLE

```haxe

// instances of this class will be stored in the tree

class Entity

{

	public var id:Int = -1;   // id to interact with the tree

	public var mbr:AABB;      // minimum bounding rect

	public var type:String;

	//...

	public function new(type:String, x:Float, y:Float, width:Float, height:Float)

	{

		this.type = type;

		mbr = new AABB(x, y, width, height);

		//...

	}

}

//...

// create the tree and add a bunch of entities to it

var tree = new AABBTree();

for (i in 0...50) {

	var type = (i % 2 == 0) ? "type_one" : "type_two"; 

	var entity = new Entity(type, some pos and size);

	entity.id = tree.insertLeaf(entity, entity.mbr.x, entity.mbr.y, entity.mbr.width, entity.mbr.height);

}

// update an entity (if its position or size changed)

tree.updateLeaf(entity.id, new pos and size);

// remove an entity

tree.removeLeaf(entity.id);

// get all entities in the tree

var entities = tree.getLeavesData();

// ... or walk through them

for (entity in tree) {

	do some stuff

}

// query the tree for entities overlapping the rect (x:-100, y:-100, w:200, h:200)

var results = tree.query(x, y, w, h);

// query the tree for entities _fully contained_ in the rect (x:-100, y:-100, w:200, h:200)

var results = tree.query(x, y, w, h, true);

// query the tree for entities intersecting the ray from (0, 0) to (100, 100) 

var results = tree.rayCast(0, 0, 100, 100);

// query the tree for entities intersecting the ray from (0, 0) to (100, 100) 

// use a callback for filtering by "type_two" and append results to prevResults array

function rayCallback(entity:Entity, id:Int):HitBehaviour {

	return (entity.type == "type_two") ? HitBehaviour.INCLUDE : HitBehaviour.SKIP;

} 

tree.rayCast(0, 0, 100, 100, prevResults, rayCallback);

```

###VALIDATION CHECKS

By default compiling in DEBUG mode will enable a series of tests to ensure the structure's validity (will affect performance), while in RELEASE mode they won't be executed.

You can disable the validation by passing `-DNO_TREE_CHECKS` to the compiler, or forcefully enable it with `-DTREE_CHECKS`.

The `isValidationEnabled` property will be set consequently.

###CREDITS

The code is heavily inspired by the implementations of a dynamic AABB tree by 

 - Nathanael Presson 	(Bullet Physics - [http://bulletphysics.org](http://bulletphysics.org))

 - Erin Catto 			(Box2D - [http://www.box2d.org](http://www.box2d.org))

###LICENSE

This lib is developed by Giuseppe Di Mauro (azrafe7) and released under the MIT license. See the LICENSE file for details.