An interesting solution to your problem is to draw to an offscreen window
and then use:
WinCopyRectangle (WinHandle srcWin, WinHandle dstWin,
RectanglePtr srcRect, SWord destX,
SWord destY, ScrOperation mode)
..and set mode to be "scrOR"
Not sure what this does in grayscale mode, but in black and white this
should work.
I discovered this function when I wanted to do XOR graphics a while ago
(but I didn't discover it until _after_ I had worked around my problem
(doh!)). Thus, I've never actually tried it. Your mileage may vary.
---
--On Thu, Nov 18, 1999 12:34 PM -0800 David Korus <[EMAIL PROTECTED]> wrote:
> Hi all,
> I'm trying to do some graphics for a game, mainly trying to draw
> bitmaps with transparency. First of all, is there a function somewhere
> that can draw bitmaps with transparency? Say for example not overwriting
> any white pixels.
>
> Our other alternative is to use a BitBlt from the bitmap to the
> screen memory. Do any of you know of any BitBlt or RasterOps type code
> that I could use? I looked in the palm docs as well as the 6800 docs and
> couldn't find any functions that could do a BitBlt for me. There are
> plenty of mem-copy type operations, but I can't find any that work on
> non-byte aligned memory.
>
> It really seems like someone must have written some code to work
> with transparency before. I'm really not looking forward to writing my
> own BitBlt function...
>
>
> David Korus
