From:	William Lachance <billl AT synapse DOT net>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: A couple of Qs:
Date:	Thu, 13 Feb 1997 02:46:46 -0800
Organization:	Synapse Internet <www.synapse.net>
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Tony O'Bryan wrote:
> 
> On Wed, 12 Feb 1997 01:26:17 GMT, demandrd AT compusmart DOT ab DOT ca (Demandred) wrote:
> 
> >2.  When using Allegro's draw_rle_sprite() can one pass in negative
> >BITMAP coordinates, that is, does it clip the sprite for you if it's
> >upper left-hand corner is at, say (-5,-27)?
> 
> No.  The only thing to be done with an RLE sprite is to quickly place it onto a
> bitmap.  No special processing (clipping, stretching, rotating, etc) can be
> performed on them.  

Uh, actually you can. RLE sprites clip just as well as regular sprites.. 
you're probably thinking about compiled sprites.

> There is a trick, though, to simulate clipping with RLE sprites.  Create a
> hidden background screen that is larger than your display area.   If you're
> using tiles, one extra tile width to the left and right and one extra tile
> height at the top and bottom of your hidden background screen will suffice.

Not a bad plan when dealing with compiled sprites..

Bill Lachance
billl AT synapse DOT net

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