From:	"Alexei A. Frounze" <alex DOT fru AT mtu-net DOT ru>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Z-Buffered Bitmaps
Date:	Thu, 25 May 2000 00:55:08 +0400
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You don't really need any Z-buffers. At least Z-buffer is a computer gfx
term usually used in 3d gfx. 

What you need is a list of all your bitmaps (pointers to the images) plus a
Z(depth) coordinate. Then you just use painter algorithm, i.e. back to front
bitblitting to the screen buffer. It's recommended to make all these blits
in a virtual screen and flip it to your display only when you have finished
back to fron drawings.

This is a basic idea. For modern fast computers (any Pentium) this should
not be a problem. Old ones are slow for such a simple approach. Some extra
stuff is needed for speeding up your code for those computers.

Best regards.
Alexei A. Frounze
-----------------------------------------
Homepage: http://alexfru.chat.ru
Mirror:   http://members.xoom.com/alexfru

Robert Boles wrote:
> 
> Hello,
> Is there any way to to make Z-Buffered bitmaps in Allegro.
> 
> For example: I wish to blit several bitmaps to a back buffer, and then blit
> this buffer to the screen.
> 
> Typical double buffered graphics. However, I have no way of easily bliting
> the bitmaps in the right order (it is a muli-threaded application). Each
> thread blits to the back buffer. I do have a depth assigned to each of the
> bitmaps, so a Z-Buffered blit to the back buffer would make my life easy.
> 
> Any libraries would be great.
> 
> Any help is greatly appreciated.

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