BitmapData.hitTest Questions

Let me preface this post by saying that I personally think that the BitmapData class is one of the most kick-*** (if not most cryptically documented) class I’ve ever used. It alone makes the upgrade to Flash8 worth it.

Ok, now that I’ve gotten that out of my system:

I’ve been exploring the hitTest method of the BitmapData class and I’ve found the method’s parameters to be a little…odd… Flash doc states:

public hitTest(firstPoint:Point, firstAlphaThreshold:Number,  secondObject:Object, [secondBitmapPoint:Point], [secondAlphaThreshold:Number]) :  Boolean

Now, if I’m testing a BitmapData object against another BitmapData object, why is is necessary for me to include a firstPoint or secondBitmapPoint parameter? I’ve tried excluding them in my code but flash complains about a Type Mismatch.

Anyone know why flash wants these Point params?