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Mail Archives: djgpp/1997/08/12/19:51:13

Date: Wed, 13 Aug 1997 09:57:47 +1100
From: Bill Currie <billc AT blackmagic DOT tait DOT co DOT nz>
Subject: Re: Optimization and bug smashing.. a lot of other questions too
In-reply-to: <5sntuu$99n@news.service.uci.edu>
To: beppu AT rigel DOT oac DOT uci DOT edu (John Beppu), djgpp AT delorie DOT com
Message-id: <199708122358.LAA03919@teleng1.tait.co.nz gatekeeper.tait.co.nz>
Organization: Tait Electronics Limited
MIME-version: 1.0
Comments: Authenticated sender is <billc AT blackmagic DOT tait DOT co DOT nz>

On 11 Aug 97 at 20:50, John Beppu wrote:
>     The sprites were restructured so that a routine could be written
>     to skip over anything that might be transparent without
>     performing a costly comparison.  A sprite was made up of
>     variable sized structures I call "Scan Lines".  In turn, scan
>     lines are made up of 0 or more variable sized structures I call
>     "line segments".  The following describes the format of these
>     two structures.
> 
>     ; Line Segment
> 
>     byte 0	horizontal offset (# of pixels to /not/ draw)
>     byte 1	# of pixels to draw
>     byte 2+	pixel data
> 
>     ; Scan Line
> 
>     word 0	# of bytes occupied by all data for this
>       scan line (all line segments + the 2 bytes
>   occupied by this one word header).
>     byte 2+	Line Segment data.
> 
>     The hierarchy of their sprite format is:
> 
>     Sprite
>       Scan Line
>         Line Segment
> 
>     Hopefully, my description was not too vague.

Actually, this is very similar to the way id did their sprites (?), 
and definitly the wall textures, in Doom, except the scan lines were 
vertical rather than horizontal. (Info from the `Unoficial Doom 
Specs')
Bill
--
Leave others their otherness.

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