PinchZoomExtended.js

PinchZoom.prototype.getContainerCenter = function () {		
    var centerX = this.container.offsetLeft + this.container.offsetWidth / 2;		
    var centerY = this.container.offsetTop + this.container.offsetHeight / 2;		

    return {		
        x: centerX,		
        y: centerY,		
    };	
};

PinchZoom.prototype.zoomTo = function (zoomFactor) {		
    var center = this.getContainerCenter();		
    var startZoomFactor = this.zoomFactor;		
    var updateProgress = (function (progress) {		
        this.scaleTo(startZoomFactor + progress * (zoomFactor - startZoomFactor), center);		
    }).bind(this);		

    this.animate(this.options.animationDuration, updateProgress, this.swing);		
};

PinchZoom.prototype.zoomIn = function () {		
    this.zoomTo(2);		
};

PinchZoom.prototype.zoomOut = function () {		
    // Reset Zoom		
    this.zoomOutAnimation();		
};