import math from '../math';


/**
 * Generic class to deal with traditional 2D matrix transforms
 *
 * @class
 * @memberof PIXI
 */
class TransformBase
{ 
    constructor()
    {
        /**
         * The global matrix transform. It can be swapped temporarily by some functions like getLocalBounds()
         *
         * @member {PIXI.Matrix}
         */
        this.worldTransform = new math.Matrix();
        /**
         * The local matrix transform
         * 
         * @member {PIXI.Matrix}
         */
        this.localTransform = new math.Matrix();

        this._worldID = 0;
    }

    /**
     * TransformBase does not have decomposition, so this function wont do anything
     */
    updateLocalTransform() { // jshint unused:false

    }

    /**
     * Updates the values of the object and applies the parent's transform.
     * @param  parentTransform {PIXI.TransformBase} The transform of the parent of this object
     *
     */
    updateTransform(parentTransform)
    {
        let pt = parentTransform.worldTransform;
        let wt = this.worldTransform;
        let lt = this.localTransform;

        // concat the parent matrix with the objects transform.
        wt.a  = lt.a  * pt.a + lt.b  * pt.c;
        wt.b  = lt.a  * pt.b + lt.b  * pt.d;
        wt.c  = lt.c  * pt.a + lt.d  * pt.c;
        wt.d  = lt.c  * pt.b + lt.d  * pt.d;
        wt.tx = lt.tx * pt.a + lt.ty * pt.c + pt.tx;
        wt.ty = lt.tx * pt.b + lt.ty * pt.d + pt.ty;

        this._worldID ++;
    }

}

/**
 * Updates the values of the object and applies the parent's transform.
 * @param  parentTransform {PIXI.Transform} The transform of the parent of this object
 *
 */
TransformBase.prototype.updateWorldTransform = TransformBase.prototype.updateTransform;

TransformBase.IDENTITY = new TransformBase();

export default TransformBase;