/**
* @author Richard Davey <rich@photonstorm.com>
* @copyright 2016 Photon Storm Ltd.
* @license {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/
/**
* The CanvasPool is a global static object, that allows Phaser to recycle and pool Canvas DOM elements.
*
* @class Phaser.CanvasPool
* @static
*/
Phaser.CanvasPool = {
/**
* Creates a new Canvas DOM element, or pulls one from the pool if free.
*
* @method Phaser.CanvasPool.create
* @static
* @param {any} parent - The parent of the canvas element.
* @param {number} width - The width of the canvas element.
* @param {number} height - The height of the canvas element.
* @return {HTMLCanvasElement} The canvas element.
*/
create: function (parent, width, height) {
var idx = Phaser.CanvasPool.getFirst();
var canvas;
if (idx === -1)
{
var container = {
parent: parent,
canvas: document.createElement('canvas')
};
Phaser.CanvasPool.pool.push(container);
canvas = container.canvas;
}
else
{
Phaser.CanvasPool.pool[idx].parent = parent;
canvas = Phaser.CanvasPool.pool[idx].canvas;
}
if (width !== undefined)
{
canvas.width = width;
canvas.height = height;
}
return canvas;
},
/**
* Gets the first free canvas index from the pool.
*
* @static
* @method Phaser.CanvasPool.getFirst
* @return {number}
*/
getFirst: function () {
var pool = Phaser.CanvasPool.pool;
for (var i = 0; i < pool.length; i++)
{
if (!pool[i].parent)
{
return i;
}
}
return -1;
},
/**
* Looks up a canvas based on its parent, and if found puts it back in the pool, freeing it up for re-use.
* The canvas has its width and height set to 1, and its parent attribute nulled.
*
* @static
* @method Phaser.CanvasPool.remove
* @param {any} parent - The parent of the canvas element.
*/
remove: function (parent) {
var pool = Phaser.CanvasPool.pool;
for (var i = 0; i < pool.length; i++)
{
if (pool[i].parent === parent)
{
pool[i].parent = null;
pool[i].canvas.width = 1;
pool[i].canvas.height = 1;
}
}
},
/**
* Looks up a canvas based on its type, and if found puts it back in the pool, freeing it up for re-use.
* The canvas has its width and height set to 1, and its parent attribute nulled.
*
* @static
* @method Phaser.CanvasPool.removeByCanvas
* @param {HTMLCanvasElement} canvas - The canvas element to remove.
*/
removeByCanvas: function (canvas) {
var pool = Phaser.CanvasPool.pool;
for (var i = 0; i < pool.length; i++)
{
if (pool[i].canvas === canvas)
{
pool[i].parent = null;
pool[i].canvas.width = 1;
pool[i].canvas.height = 1;
}
}
},
/**
* Gets the total number of used canvas elements in the pool.
*
* @static
* @method Phaser.CanvasPool.getTotal
* @return {number} The number of in-use (parented) canvas elements in the pool.
*/
getTotal: function () {
var pool = Phaser.CanvasPool.pool;
var c = 0;
for (var i = 0; i < pool.length; i++)
{
if (pool[i].parent)
{
c++;
}
}
return c;
},
/**
* Gets the total number of free canvas elements in the pool.
*
* @static
* @method Phaser.CanvasPool.getFree
* @return {number} The number of free (un-parented) canvas elements in the pool.
*/
getFree: function () {
var pool = Phaser.CanvasPool.pool;
var c = 0;
for (var i = 0; i < pool.length; i++)
{
if (!pool[i].parent)
{
c++;
}
}
return c;
}
};
/**
* The pool into which the canvas elements are placed.
*
* @property pool
* @type Array
* @static
*/
Phaser.CanvasPool.pool = [];
