I'm looking for the answers to a coupld of questions about clicking on / selecting a transparent bitmap (or bitmaps!).

I have StretchBlt'd my bitmap and mask to create on-the-fly transparencies with the top-left pixel defining the transparency.

That is all fine.

I want actions to occur when the user clicks on the bitmap.
I can do this using the bounding rectangle, but I'd like to ignore the transparent regions (i.e. just react to clicks on the visible parts).

I'd also like to 'highlight' the bitmap with a border OnMouseOver,
again with a border around the visible regions.

I suspect this involves the use of 'Regions' and masks and such, but I really don't know where to start?

Does anyone?

Thx,

Dan