From:	gregorio AT jet DOT es (Grzegorz Adam Hankiewicz)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Extracting a pixel from an Allegro BITMAP
Date:	Fri, 09 Jan 1998 12:57:38 GMT
Organization:	Gogosoftware
Lines:	21
Message-ID:	<34b61e19.6803419@news.jet.es>
References:	<19980109085201 DOT DAA02949 AT ladder02 DOT news DOT aol DOT com>
NNTP-Posting-Host:	infon308.jet.es
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

>       a_pixel = double_buffer[(y<<8) + (y<<6) + (x>>2)];
>     - or -
>      double_buffer [(y<<8) + (y<<6) + (x>>2)] = a_pixel;
>
>   How can I do that with an Allegro BITMAP?

Try this:

a_pixel=bitmap->line[y][x];
or
bitmap->line[y][x]=a_pixel;

This only works if bitmap is a memory bitmap, not a svga screen or
something like that.

Read in the Allegro documentation the section "Direct access to video
memory" for more information about accessing the memory and bitmap
structures.

- Grzegorz Adam Hankiewicz - gregorio AT jet DOT es - http://web.jet.es/gregorio
- Gogosoftware - http://web.jet.es/gregorio/gogosoftware

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