Date: Fri, 5 Dec 1997 20:57:56 -0800 (PST)
Message-Id: <199712060457.UAA07849@adit.ap.net>
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To: "Dave" <cgileadi AT itsnet DOT com>, djgpp AT delorie DOT com
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: Allegro graphics speed: 16 bit vs. 8 bit
Precedence: bulk

At 10:44  12/5/1997 -0700, Dave wrote:
>I am thinking about switching to 16 color mode, for the obvious reasons of
>good looks and ease of shading, etc. but I am concerned about the speed
>comparisons.  How does the speed of 15 or 16 bit graphics compare to 8 bit?
>(when blitting to the screen, etc.)
>
>I would imagine that it would take roughly twice the time, since it's double
>the information, but are there any special things it does that I don't know
>about?
Well, some bit-twiddling is also required to set the colors, since there are
5/6 bits per color per pixel. The algorithm for actually figuring out the
16-bit colors may end up being faster or slower too, but that's your code.
>
>Sorry I haven't just run at test, but I am wondering if anyone has a quick
>answer before I spend a couple hours downloading, installing, and writing
>new code for the next addition of Allegro (I'm a student, its the end of the
>semester, and time is non-existent right now).
Performance questions don't tend to be that simple in general :) Testing is
of course the best way to find out. I'd suggest that when you get the time.

Nate Eldredge
eldredge AT ap DOT net