Sender:	mike AT Home-51 DOT inp DOT nsk DOT su
To:	djgpp AT delorie DOT com
Subject:	Re: Direct Access vs. Far vs. Near
References:	<19971101224800 DOT RAA21869 AT ladder01 DOT news DOT aol DOT com>
From:	Michael Bukin <bukinm AT inp DOT nsk DOT su>
Date:	03 Nov 1997 08:16:25 +0600
In-Reply-To:	eggbrains@aol.com's message of 1 Nov 1997 22:48:02 GMT
Message-ID:	<m3lnz6bu2u.fsf@H-Bukin.inp.nsk.su>
Lines:	36

eggbrains AT aol DOT com (Egg brains) writes:

> 
> okay, anyway, in my program (a start of a graphics lib -- yes, i know about
>  Allegro)  i draw pixles to the screen (what else).  when i directly wrote to
>  the screen ie:
> 
> vga = (unsigned char*)MK_FP(0xA000, 0);
> vga[where]=color;
> 
> i can draw about 1.6 million pixels per second, however, when using Farnspoke,
>  i can draw up to 3+ million pixels per second... why is it so much faster?
> 

Try assembler for the first. Or
*((unsigned char*) MK_FP (0xA000, where)) = color;

Make sure you use the same video mode for both methods.

> would using the near access go faster yet?

Most probably not.

> 
> anyway, using the Far mode, how would i make selectors to sprites? would i make
>  the sprites by define an array (with malloc/new etc...) and then make a
>  selctor to it?  what about if I change the size/location? i will need to make
>  a new selector right? an since you can't delete selectors if i re-size it
>  enough will i run out of memmory?

You need not make selector for memory allocated with malloc/new, I don't
know where the selector is, but looking into libc references, _my_ds ()
is a good candidate and alternatively you can get it
from %%ds with inline assembly.

BTW, Allegro has selector in BITMAP structure, so it is all there, I think.

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