Message-ID: <199807221249190710.00A6C5C4@pogwizd.tcs.uni.wroc.pl>
In-Reply-To: <p6tsojuilqz.fsf@SunKEDR30.inp.nsk.su>
References: <6onnuh$12p$2 AT oravannahka DOT Helsinki DOT FI>
 <199807212300450430 DOT 00099FEB AT pogwizd DOT tcs DOT uni DOT wroc DOT pl>
 <p6tsojuilqz DOT fsf AT SunKEDR30 DOT inp DOT nsk DOT su>
Date: Wed, 22 Jul 1998 12:49:19 +0200
From: "Pawel Kowalski" <pk AT tcs DOT uni DOT wroc DOT pl>
To: M DOT A DOT Bukin AT inp DOT nsk DOT su, djgpp AT delorie DOT com
Subject: Re: Allegro and blitting to screen
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On 98-07-22, at 08:57, M DOT A DOT Bukin AT inp DOT nsk DOT su wrote: 

>"Pawel Kowalski" <pk AT tcs DOT uni DOT wroc DOT pl> writes:
>
>> I tried Allegro demo to find out what's faster: page flipping of double buffer.
>> I was almost sure that the firtst technique is ~1/4 faster. Well, ...:
>> 640x480x8       DB - 106fps, PF - 59fps
>> 800x600x8       DB - 66fps, PF - 60fps
>> 1024x768x8      DB - 39fps, PF - 60fps
>> Why PF fps is always the same?
>
>  For smooth animation page-flipping waits for vertical retrace before
>switching pages.  When using double-buffering there is no vsync, otherwise
>you may see both old and new frames if the whole screen can not be copied
>during vertical retrace.
>
>> I tried removing vsync_in() from 
>> vesa_scroll(int, int) (djgpp/vesa.c) but with no effect...
>
>  Remove vsync() call in demo game not in library sources.

There's no vsync() call in demo game.

Pawel Kowalski