Path: chuka.playstation.co.uk!scea!greg_labrec@interactive.sony.com
From: mperdue@hrtc.net (Mario Perdue)
Newsgroups: scea.yaroze.programming.2d_graphics
Subject: Re: Backgrounds
Date: Tue, 19 Aug 1997 03:23:51 GMT
Organization: SCEA News Server
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Message-ID: <33f91153.15986403@205.149.189.29>
References: <33F8FC3F.726E@concentric.net>
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Scott,

I just took a quick look and noticed that you don't have a DrawSync()
before your VSync(). Try adding:

DrawSync(0);

just before your VSync() call.

Mario


On Mon, 18 Aug 1997 18:51:59 -0700, Scott Cartier
<dsyaroze@concentric.net> wrote:

>I'm having trouble with my background.  It flickers - like it's
>only being drawn every other frame.  I'm using 640x480 and when 
>I switch to low resolution it works fine.  I'm wondering if 
>there is something obvious I'm doing wrong.  Here's a general
>outline of my program.  Is there anything that jumps out as
>being incorrect (assuming I've initialized the cells and map
>data)?
>
>  #define H_RES 640
>  #define V_RES 480
>
>  u_short backgnd_array[64 * 64];  // Max of 64 by 64 background
>  GsCELL backgnd_cells[2];         // Only 2 cells for now
>  GsMAP backgnd_map;
>  GsBG backgnd;
>  u_long backgnd_workarea[(((H_RES >> 4) + 1) * ((V_RES >> 4) + 1 + 1) *
>6 + 4) * 2 + 2];
>
>  backgnd.attribute = 0;
>  backgnd.x = 0;
>  backgnd.y = 0;
>  backgnd.w = H_RES;
>  backgnd.h = V_RES;
>  backgnd.scrollx = 0;
>  backgnd.scrolly = 0;
>  backgnd.r = backgnd.g = backgnd.b = 0x80;
>  backgnd.map = map;
>  backgnd.mx = backgnd.my = 0;
>  backgnd.scalex = backgnd.scaley = ONE;
>  backgnd.rotate = 0;
>
>  GsInitFixBg16(&backgnd, backgnd_workarea);
>
>  while (pad_state[PAD_SELECT] == 0) {  // Main loop
>
>    activeBuff = GsGetActiveBuff();
>    GsSetWorkBase((PACKET *)GpuPacketArea[activeBuff]);
>    GsClearOt(0, 0, &WorldOT[activeBuff]);
>
>    pad_read();
>
>    GsSortFixBg16(&backgnd,
>backgnd_workarea[activeBuff],                   WorldOT[activeBuff],
>OT_BACKGND);
>
>    cnt = VSync(0);
>    ResetGraph(1);
>    GsSwapDispBuff();
>    GsSortClear(0, 0, 0, &WorldOT[activeBuff]);
>    GsDrawOt(&WorldOT[activeBuff]);
>  }
>
>Scott