Date: Thu, 26 Dec 1996 12:33:10 +0200 (EET)
From: Indrek Mandre <indrek AT warp DOT edu DOT ee>
To: tangchis AT iscs DOT nus DOT sg
cc: djgpp AT delorie DOT com
Subject: Re: Which is faster? Allegro or Sandmann's LFB
In-Reply-To: <59s2q3$84l@nuscc.nus.sg>
Message-ID: <Pine.LNX.3.91.961226115107.161A-100000@warp.edu.ee>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII


On 25 Dec 1996 tangchis AT iscs DOT nus DOT sg wrote:
> Hi!
> 
> I was wondering .. which is faster for graphics programming which requires
> a high frame rate and uses double buffering in RAM for page-flipping? I
> havn't tried Allegro yet, but I managed to write some routines based on
> Charles Sandmann's (thanks!) VBE.ZIP, using a linear frame buffer under
> VBE 2.0. 
> 
> I was hoping to avoid having to use univbe to invoke VBE 2.0, and am
> thinking of switching to Allegro's graphics library.

 If you want to avoid using univbe then you have to use svgalib. Svgalib
uses your card directly and it supports most of the cards. It cointains
two libraries:
  low level vga library, which helps you to set modes, virtual screens, 
pages, get linear framebuffer, and other low level  stuff. It supports 
modes from 1 bits to 24 bits.
  Other library vgagl is for graphics making. It supports double buffering,
blittings all kind for different modes, palette stuff and too many other
features here to describe.
For some cards they even support card's acceleration.
The best part is that svgalib is originally under Linux - your programmes
will work under Linux.
Bad things: It doesn't support yet mach64.
Svgalib was ported from Linux to DJGPP by Mihai Cartoaje.
You can get it from his home page:
        http://wwwbacc.ift.ulaval.ca/~moisemih/svgalib.zip

> 
> I use 640x480x8bpp mode and managed to get about 15-17 fps on a Pentium
> 133 for a totally unoptimised example that moved 640x480 different pixels
> every frame from double buffer to video mem and also 2 lines that moved up
> and down and across the screen. The double buffer is also cleared after
> every frame.

I don't know about double buffering but with page flipping
I got 30 fps under my Cx486DX2/66 (800x600x256). I made scrolling background 
from tiles (size 50x50).

Indrek
indrek AT warp DOT edu DOT ee