*Bounding box of a gradient masked movie clip

1

I have a movie clip with a gradient mask.
now I would like to have the bounding box of this movie clip reduced to the visible(masked) area,
so that I can get its x and y positions.

is it even possible?


mc1.cacheAsBitmap = true;
mc2.cacheAsBitmap = true;
mc1.setMask("mc2");

mc1 and mc2 are the same size and the shape of the mask is constantly changing.