Hello, I am trying to figure out a decent way of obtaining a objects delta speed horizontally and vertically when its running a MoveBy/To action. As of right now I am using a update loop and calculating the distance the moving object has moved to, every .01 seconds like this:

	trackDistance:function()
	{
		if (this.prevX != -1)
		{
			this.moveX = (this.x - this.prevX);
			this.moveY = (this.y - this.prevY);
		}
		else if (this.prevX == this.x)
		{
			this.moveX = this.moveY = 0;
			this.unschedule(this.trackDistance);
		}
		
		this.prevX = this.x;
		this.prevY = this.y;
	},

This works relatively well, however the program cannot keep up when the objects are moving at high speeds, or if there is any lag. Is there any way to better approach this situation?