From:	"Alexei A. Frounze" <dummy_addressee AT hotmail DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: MISSION: Making worlds fastest pixel drawing possible
Date:	Tue, 16 Jan 2001 18:15:44 -0500
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References:	<942h1e$5qq$1 AT tron DOT sci DOT fi>
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To:	djgpp AT delorie DOT com
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Reply-To:	djgpp AT delorie DOT com

macro is a good thing.

though precalculated addresses for x,y pair can slow down things on decent
CPUs. On 286 and 386 this could be a good thing but not now on Pentiums.

I also see segment register reload in your code. This thing also slows down.

Btw, globalBuffer[x][y] <- is the same crap as "something + (y<<10)+(y<<8)"
because the compiler has to translate those [x][y] into an address anyway.

So your code is even worse than something like "screen[(y<<8)+(y<<6)+x] =
color".

Take care
--
Alexei A. Frounze
alexfru [AT] chat [DOT] ru
frounze [AT] ece [DOT] rochester [DOT] edu
http://alexfru.chat.ru
http://members.xoom.com/alexfru/
http://welcome.to/pmode/

"Traveler" <traveler AT netti DOT fi> wrote in message
news:942h1e$5qq$1 AT tron DOT sci DOT fi...
>
> Contents:
> - Fastest possible way to draw pixel´s (well, maybe the near pointer hack
> mentioned in DJGPP FAQ is faster :)). Drawing developed as a macro
(becourse
> jumping to function and back again takes more time than drawing the damn
> pixel !). Screen coordinates pre-calculated in the global table.
>
> Feedback needed about the following subjects:
> 1) Is it necessary to save ES segment register (the macro currently does
not
> do it, but it seems to work fine, no crashes, etc...) ?
> 2) Is the assembly command "les    %0,%%edi" faster than the currently
used
>  "movw    %0,%%es;movl %1,%%edi" pair ?
>
> "Traveler 2001AD"
> traveler AT netti DOT fi
> Dark DOT Angel AT saunalahti DOT fi
>
>
>
>
>

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