CCClippingNode.js

/****************************************************************************
 Copyright (c) 2008-2010 Ricardo Quesada
 Copyright (c) 2011-2012 cocos2d-x.org
 Copyright (c) 2013-2014 Chukong Technologies Inc.
 Copyright (c) 2012 Pierre-David Bélanger

 http://www.cocos2d-x.org

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/**
 * the value of stencil bits.
 * @type Number
 */
cc.stencilBits = -1;

/**
 * <p>
 *     cc.ClippingNode is a subclass of cc.Node.                                                            <br/>
 *     It draws its content (children) clipped using a stencil.                                               <br/>
 *     The stencil is an other cc.Node that will not be drawn.                                               <br/>
 *     The clipping is done using the alpha part of the stencil (adjusted with an alphaThreshold).
 * </p>
 * @class
 * @extends cc.Node
 * @param {cc.Node} [stencil=null]
 *
 * @property {Number}   alphaThreshold  - Threshold for alpha value.
 * @property {Boolean}  inverted        - Indicate whether in inverted mode.
 * @property {cc.Node}  stencil         - he cc.Node to use as a stencil to do the clipping.
 */
cc.ClippingNode = cc.Node.extend(/** @lends cc.ClippingNode# */{
    alphaThreshold: 0,
    inverted: false,

    _stencil: null,
    _className: "ClippingNode",

    /**
     * Constructor function, override it to extend the construction behavior, remember to call "this._super()" in the extended "ctor" function.
     * @param {cc.Node} [stencil=null]
     */
    ctor: function (stencil) {
        stencil = stencil || null;
        cc.Node.prototype.ctor.call(this);
        this._stencil = stencil;
        this.alphaThreshold = 1;
        this.inverted = false;
        this._renderCmd.initStencilBits();
    },

    /**
     * Initialization of the node, please do not call this function by yourself, you should pass the parameters to constructor to initialize it
.
     * @function
     * @param {cc.Node} [stencil=null]
     */
    init: function (stencil) {
        this._stencil = stencil;
        this.alphaThreshold = 1;
        this.inverted = false;
        this._renderCmd.initStencilBits();
        return true;
    },

    /**
     * <p>
     *     Event callback that is invoked every time when node enters the 'stage'.                                   <br/>
     *     If the CCNode enters the 'stage' with a transition, this event is called when the transition starts.        <br/>
     *     During onEnter you can't access a "sister/brother" node.                                                    <br/>
     *     If you override onEnter, you must call its parent's onEnter function with this._super().
     * </p>
     * @function
     */
    onEnter: function () {
        cc.Node.prototype.onEnter.call(this);
        this._stencil.onEnter();
    },

    /**
     * <p>
     *     Event callback that is invoked when the node enters in the 'stage'.                                                        <br/>
     *     If the node enters the 'stage' with a transition, this event is called when the transition finishes.                       <br/>
     *     If you override onEnterTransitionDidFinish, you shall call its parent's onEnterTransitionDidFinish with this._super()
     * </p>
     * @function
     */
    onEnterTransitionDidFinish: function () {
        cc.Node.prototype.onEnterTransitionDidFinish.call(this);
        this._stencil.onEnterTransitionDidFinish();
    },

    /**
     * <p>
     *     callback that is called every time the node leaves the 'stage'.  <br/>
     *     If the node leaves the 'stage' with a transition, this callback is called when the transition starts. <br/>
     *     If you override onExitTransitionDidStart, you shall call its parent's onExitTransitionDidStart with this._super()
     * </p>
     * @function
     */
    onExitTransitionDidStart: function () {
        this._stencil.onExitTransitionDidStart();
        cc.Node.prototype.onExitTransitionDidStart.call(this);
    },

    /**
     * <p>
     * callback that is called every time the node leaves the 'stage'. <br/>
     * If the node leaves the 'stage' with a transition, this callback is called when the transition finishes. <br/>
     * During onExit you can't access a sibling node.                                                             <br/>
     * If you override onExit, you shall call its parent's onExit with this._super().
     * </p>
     * @function
     */
    onExit: function () {
        this._stencil.onExit();
        cc.Node.prototype.onExit.call(this);
    },

    /**
     * <p>
     * The alpha threshold.                                                                                   <br/>
     * The content is drawn only where the stencil have pixel with alpha greater than the alphaThreshold.     <br/>
     * Should be a float between 0 and 1.                                                                     <br/>
     * This default to 1 (so alpha test is disabled).
     * </P>
     * @return {Number}
     */
    getAlphaThreshold: function () {
        return this.alphaThreshold;
    },

    /**
     * set alpha threshold.
     * @param {Number} alphaThreshold
     */
    setAlphaThreshold: function (alphaThreshold) {
        this.alphaThreshold = alphaThreshold;
    },

    /**
     * <p>
     *     Inverted. If this is set to YES,                                                                 <br/>
     *     the stencil is inverted, so the content is drawn where the stencil is NOT drawn.                 <br/>
     *     This default to NO.
     * </p>
     * @return {Boolean}
     */
    isInverted: function () {
        return this.inverted;
    },

    /**
     * set whether or not invert of stencil
     * @param {Boolean} inverted
     */
    setInverted: function (inverted) {
        this.inverted = inverted;
    },

    /**
     * The cc.Node to use as a stencil to do the clipping.                                   <br/>
     * The stencil node will be retained. This default to nil.
     * @return {cc.Node}
     */
    getStencil: function () {
        return this._stencil;
    },

    /**
     * Set stencil.
     * @function
     * @param {cc.Node} stencil
     */
    setStencil: function (stencil) {
        if(this._stencil === stencil)
            return;
        this._renderCmd.setStencil(stencil);
    },

    _createRenderCmd: function(){
            return new cc.ClippingNode.WebGLRenderCmd(this);
    }
});

var _p = cc.ClippingNode.prototype;

// Extended properties
cc.defineGetterSetter(_p, "stencil", _p.getStencil, _p.setStencil);
/** @expose */
_p.stencil;

/**
 * Creates and initializes a clipping node with an other node as its stencil. <br/>
 * The stencil node will be retained.
 * @deprecated since v3.0, please use "new cc.ClippingNode(stencil)" instead
 * @param {cc.Node} [stencil=null]
 * @return {cc.ClippingNode}
 * @example
 * //example
 * new cc.ClippingNode(stencil);
 */
cc.ClippingNode.create = function (stencil) {
    return new cc.ClippingNode(stencil);
};