From:	"Arthur" <arfa AT clara DOT net>
To:	<djgpp AT delorie DOT com>
Subject:	RE: Bad Flicker
Date:	Sat, 17 Oct 1998 14:58:06 +0100
Message-ID:	<000401bdf9d6$2a525bc0$764e08c3@arthur>
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Reply-To:	djgpp AT delorie DOT com

> Use a double buffer in your program..
>
> blit everything to a seperate bitmap(the size of your screen) and when
> everything is drawn there, then blit the seperate bitmap to the screen.
>
> like:
>
> BITMAP *buffer=create_bitmap(320, 200);
>
> do
>     {
>     x=x+1;
>     blit(happyface, buffer, 0, 0, x, y, 20, 100);
>     blit(bird, buffer, 0, 0, x, y, 10, 10);
>
>     blit(buffer, screen, 0, 0, 0, 0, 320, 200);
>     clear(buffer);
>     }while(whatever)
>
> doing this eliminates the flicker...try it.
>
> twidler

Do that in 640x480 VESA and you'll die a horrible flickery death, or at
least get shearing. Add a vsync() before blitting the buffer to the screen.
It'll limit your framerate, but there are ways around that. Check out George
Foot's Allegro Vivace tutorial (can't remember the address - George?)

James Arthur
jaa AT arfa DOT clara DOT net
ICQ#15054819

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