oops ... those should be bitwise '&', not logical '&&' ...
--
-Richard M. Hartman
[EMAIL PROTECTED]
186,000 mi./sec ... not just a good idea, it's the LAW!
> -----Original Message-----
> From: Richard Hartman
> Sent: Thursday, November 18, 1999 1:44 PM
> To: '[EMAIL PROTECTED]'
> Subject: RE: the BitBlt OR transparent bitmaps
>
>
> The best way to do transparancies is with masking.
>
> I don't know if the PalmOS supports masking, so you'd
> probably have to implement it yourself.
>
> The basic idea is that you create two bitmaps, one
> with your image and the other with a mask designating
> which parts of the final image should come from your
> bitmap and which parts should come from the background
> that you are drawing it onto.
>
> If I remember correctly, the equation for masking,
> assuming monochrome background & bitmap, looks something
> like this:
>
> *pFinal = (*pBitmap && *pMask) | (*pBackground && ~(*pMask));
>
> (This, of course, ignores the finer points of positioning
> bitmaps at anywhere other than byte boundries on the
> target screen, etc.)
>
> --
> -Richard M. Hartman
> [EMAIL PROTECTED]
>
> 186,000 mi./sec ... not just a good idea, it's the LAW!
>
>
> > -----Original Message-----
> > From: David Korus [mailto:[EMAIL PROTECTED]]
> > Sent: Thursday, November 18, 1999 12:35 PM
> > To: '[EMAIL PROTECTED]'
> > Subject: the BitBlt OR transparent bitmaps
> >
> >
> > 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
> >
>
