Re: [AD] C/Asm integration (was [AD] Improvement on alphablending...)

[George Foot <gfoot@xxxxxxxxxx>]

On Sat, Aug 04, 2001 at 08:15:32PM -0400, Bob wrote:
> George Foot wrote:
> > There are basically two ways around this -- either we set our
> > segment limit to -1, which means disabled, or we ask DPMI for
> > another selector we can use to access the memory we want.  (Or
> > for the VGA memory at 0xa0000 we can use the DOS selector, which
> > djgpp already obtains.)
> 
> So uhm, what do I do to make the C line blender code work with the 
> assembler primitives?

I might be misunderstanding the problem but AFAICS there are two
options -- either the buffers are in the main segment (so you
have to copy from source and dest to there, and copy back to
dest afterwards) or they're not (so you have to pass the
segments through along with the
pointers-which-aren't-really-pointers).

As a compromise, you could copy the source into the main segment
(if it's not there already) and use bmp_select on the dest
bitmap, then require the blender to use bmp_read and bmp_write
macros to access the dest buffer.

But as I said I might be misunderstanding -- I'm not really sure
what these blenders are.  Are they user-supplied?

George

-- 
Random project update:
07/06/2001: Libnet 0.10.9 uploaded -- 13 months after 0.10.8!  Oops.
        http://www.canvaslink.com/libnet/  (try changes-0.10.9.txt)