JS implementation of a * Seek path algorithm __ static function

Source: Internet
Author: User

JS uses canvas to draw the interface.

Define two classes: node save point and F=g+h value in a * algorithm;

 * node *
 P	: node corresponding coordinates
 * PN	: node's parent
 * g	: a*-g
 * H	: a*-h/
function node (p, PN, G, h) {
	if (!) ( P instanceof Point) | | isNaN (g) | | isNaN (h)) {
		throw new Error ("illegal parameter");
	THIS.G = g;
	This.h = h;
	THIS.F = g + H;
	THIS.P = p;
	This.equals = function (obj) {
		if (!) ( obj instanceof Node)) {return
		Return This.p.equals (OBJ.P);

 * dot
/function point (x, y) {
	if (isNaN (x) | | | isNaN (y)) {
		throw new Error ("illegal parameter");
	this.x = x;
	This.y = y;
	This.equals = function (obj) {
		if (!) ( obj instanceof Point)] {return
		return this.x = = obj.x && This.y = = obj.y;

Algorithm implementation: Explore whether the new node-> is accessed. Skip: (Has been logged.) (Whether an update is required.) Update: "" To join the Open list): "" Until the end of the search to the end or the map says a bit is accessed by the loop.

Seek while
(true) {
	if (openlist.length = 0) {break
	var node = Openlist.shift ();
	if (Node.p.equals (constants). End_point)) {
		rsnode = node;
	var Nodearr = utils.explore (node, constants. Map_array, constants. End_point);
	Closelist.push (node);
	Determine if the node being explored has been accessed  if it has not been accessed, add it to the Open list for
	(var i in Nodearr) {
		var n = nodearr[i];
		Determine if the open list already exists whether the node needs to be updated if
		(Utils.inarray (n, closelist) = = 1) {
			var off = Utils.inarray (n, openlist);
			if (off = = 1) {
				openlist.push (n);
			} Else{
				var u = openlist[off];
				This node has been explored and there is now a better path
				if (U.f > N.f) {
					openlist.splice (off, 0);
					Openlist.push (n);
	}}} Openlist.sort (Utils.sortnode);

Source: http://download.csdn.net/detail/lj745280746/7007935

Reference: Http://wenku.baidu.com/link?url= 0qhr1lg5ngtqast6e4j12zenvc4a5wiybpd3mrfkznvp7z7nukljagegnpdumy-il7dedpjjwbehkjmjiogde5emrulbyhycfd7rw0ubpsc

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