>I have a graph which I've drawn on the screen on a black background.  I
>would like to paint a black rectangle over top of it but only have the
>rectangle darken, not obliterate, the existing graph.  I tried using
>PAINTRECT with the foreground color set to black and the penmode set to the
>_blend color mode but it did not work.  Any help would be appreciated.
>TIA
>
>____________
>Mark Goodes (Toronto, Canada)

Mark,

When I can't figure out how to do something correctly in FB, I cheat. :)
Can you just use the darker color to paint the rect opaquely and then
redraw that part of the graph in a darker color too right over it to
simulate transparency?

Maybe you could have another darker color graph pre-drawn on the black
background using an offscreen port, and then use COPYBITS to move that
square back where you need it? :)

You could also step through your squares, get the color of the pixel there,
and then reset the pixel's color by a set amount to darken each one (that
isn't black). Would be slow for big squares though I guess.

Hey, might work. :)

Good luck,

Robert Covington