/**
* SpriteSheet by Grant Skinner. Dec 5, 2010
* Visit www.gskinner.com/blog for documentation, updates and more free code.
*
*
* Copyright (c) 2010 Grant Skinner
* 
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
* 
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
**/

(function(window) {

/**
* Constructs a new SpriteSheet object.
* @param image The Image, Canvas, or Video instance to use as a sprite sheet.
* @param frameWidth The width in pixels of each frame on the sprite sheet.
* @param frameHeight The height in pixels of each frame on the sprite sheet.
* @param frameData Defines named frames and frame sequences. See the frameData property for more information.
* @class Encapsulates the properties associated with a sprite sheet. A sprite sheet is a series of images (usually animation frames) combined into a single image on a regular grid. For example, an animation consisting of 8 100x100 images could be combined into a 400x200 sprite sheet (4 frames across by 2 high).
* The simplest form of sprite sheet has values for the image, frameWidth, and frameHeight properties, but does not include frameData. It will then play all of the frames in the animation and loop if the loop property is true. In this simple mode, you can also set the totalFrames property if you have extraneous frames in your sprite sheet (for example, a 2x4 frame sprite sheet, with only 7 frames used).<br/><br/>
* More complex sprite sheets include a frameData property, which provides named frames and animations which can be played and sequenced together. See frameData for more information.
**/
function SpriteSheet(image, frameWidth, frameHeight, frameData) {
  this.init(image, frameWidth, frameHeight, frameData);
}
var p = SpriteSheet.prototype;
	
	
// public properties:
	/** The Image, Canvas, or Video instance to use as a sprite sheet. **/
	p.image = null;
	/** The width in pixels of each frame on the sprite sheet image. **/
	p.frameWidth = 0;
	/** The height in pixels of each frame on the sprite sheet image. **/
	p.frameHeight = 0;
	/** Defines named frames and frame sequences. Frame data is specified as a generic object, where each property name will be used to define a new named frame or sequence. Named frames specify a frame number. Sequences are defined using an array of 2 or 3 values: the start frame, the end frame, and optionally the name of the next sequence to play.<br/><br/>For example, examine the following frame data:<br/>{walk:[0,20], shoot:[21,25,"walk"], crouch:[26,30,false], stand:31}<br/>This will create 3 sequences and a named frame. The first sequence will be named "walk", and will loop frames 0 to 20 inclusive. The second sequence will be named "shoot", and will play frames 21 to 25 then play the walk sequence. The third sequence "crouch" will play frames 26 to 30 then pause on frame 30, due to false being passed as the next sequence. The named frame "stand" will display frame 31. **/
	p.frameData = null;
	/** The loop property is only used if no frameData is specified, and indicates whether all frames (as specified with totalFrames) should loop. If false, the animation will play to totalFrames, then pause. **/
	p.loop = true;
	/** Specifies the total number of frames in the sprite sheet if no frameData is specified. This is useful for excluding extraneous frames (for example, if you have 7 frames in a 2x4 sprite sheet). The total frames will be automatically calculated by BitmapSequence based on frame and image dimensions if totalFrames is 0. **/
	p.totalFrames = 0;
	
// constructor:
	/** @private **/
	p.init = function(image, frameWidth, frameHeight, frameData) {
		this.image = image;
		this.frameWidth = frameWidth;
		this.frameHeight = frameHeight;
		this.frameData = frameData;
	}
	
// public methods:
	/**
	* Returns a string representation of this object.
	**/
	p.toString = function() {
		return "[SpriteSheet]";
	}
	
	/**
	* Returns a clone of this object.
	**/
	p.clone = function() {
		var o = new SpriteSheet(this.image, this.frameWidth, this.frameHeight, this.frameData);
		o.loop = this.loop;
		o.totalFrames = this.totalFrames;
		return o;
	}
	
window.SpriteSheet = SpriteSheet;
}(window));