Path: chuka.playstation.co.uk!scea!greg_labrec@interactive.sony.com
From: mperdue@iquest.net (Mario Perdue)
Newsgroups: scea.yaroze.programming.2d_graphics
Subject: Re: Sprite Help. Warning lots of code
Date: Tue, 03 Jun 1997 14:12:04 GMT
Organization: SCEA Net Yaroze News
Lines: 140
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Hi Mark,

Let's take a look at what you have.

On 2 Jun 1997 23:59:09 GMT, "Mark Cooke" <spider@best.com> wrote:
>// 2D Display Playstation Sprite
>
>#include <libps.h>
>#include "pad.h"
>
>GsOT WorldOT[2]; // How Many sprites in world & where draw
>GsOT_TAG OTtag[2][1<<1];
>int activeBuffer; // Which buffer are we drawing to?
>
>#define SPRITE_CNT 7 
>PACKET GpuPacketArea[2][1*sizeof(GsSPRITE)];

I think this line came from one of my examples. I thought I fixed
that. I'd try using a multiple of 24 (the average packet size) here.
Since you're not too worried about space yet, make it large; 2400
should do.
	PACKET GpuPacketArea[2][2400];
	or
	PACKET GpuPacketArea[2][100*24];


>#define OUR_SPRITE_ADDRESS 0x80090000
>GsSPRITE ourSprite; // Guess what this is?
>GsIMAGE  ourSpriteInfo;
>
>void main()
>{
>  int i;
>  int padData;
>  RECT rect;
>  u_short texturePage;
>  int hsync = 0;
>
>  SetVideoMode( MODE_NTSC ); // For American TV's
>
>  ResetGraph(0);
>
>  GsInitGraph(320, 240, 4, 0, 0); // 320x240, GPU Doublebuffer, No dither
>                                  // 16-bit color
>  GsDefDispBuff(0, 0, 0, 240);    // Front Buffer starts at 0,0
>                                  // Back  Buffer starts at 0,240 
>  // Initialize the ordering table  
>
>  PadInit();
>  
>  for (i = 0; i < 2; i++)
>  {
>    WorldOT[i].length = 1;
>    WorldOT[i].org = OTtag[i];
>  }
>
>  ourSprite.r = 128;
>  ourSprite.g = 128;
>  ourSprite.b = 128;
>  ourSprite.scalex = ONE;
>  ourSprite.scaley = ONE;
>  ourSprite.rotate = 0;
>
>  ourSprite.tpage = GetTPage(1, 0, 320, 0);
>  ourSprite.attribute |= 1 << 25; 
>  ourSprite.x = 0;
>  ourSprite.y = 0;
>  ourSprite.w = 128;
>  ourSprite.h = 240;
>  ourSprite.u = 0;
>  ourSprite.v = 0;
>
>  setRECT( &rect, 960, 0, 128, 240 );
>
>  GsGetTimInfo( (u_long *)(OUR_SPRITE_ADDRESS+4), &ourSpriteInfo);
>
>  rect.x = ourSpriteInfo.px;
>  rect.y = ourSpriteInfo.py;
>  rect.w = ourSpriteInfo.pw;
>  rect.h = ourSpriteInfo.ph;
>
>  LoadImage(&rect, ourSpriteInfo.pixel);
>
>  if ((ourSpriteInfo.pmode >> 3) & 0x01)
>  {
>    rect.x = ourSpriteInfo.cx;
>    rect.y = ourSpriteInfo.cy;
>    rect.w = ourSpriteInfo.cw;
>    rect.h = ourSpriteInfo.ch;
>
>    LoadImage( &rect, ourSpriteInfo.clut);
>  }

It looks like you're OK to here. The next two lines are wrong. Both
should be performed inside the while loop. Get rid of them here.

>  DrawSync(0);
>  activeBuffer = GsGetActiveBuff();


>  while (1)
>  {
>    padData = PadRead(); 
>    if (padData & PADselect)
>      break;

Get the active buffer before you do anything with the frame buffer.

   activeBuffer = GsGetActiveBuff();

>    GsSetWorkBase((PACKET *)GpuPacketArea[activeBuffer]);
>    GsClearOt(0,0,&WorldOT[activeBuffer]);
>    GsSortSprite(&ourSprite, &WorldOT[activeBuffer], 3);

Wait for all drawing to stop before waiting for VSync.
   DrawSync(0);

>    hsync = VSync(0);
>    ResetGraph(1);
>    GsSwapDispBuff();
>    GsSortClear(0,0,4,&WorldOT[activeBuffer]);

You need to do the GsDrawOt(). Remove the comment.
>    //GsDrawOt(&WorldOT[activeBuffer]);

Get rid of this. The active buffer is read at the beginning of the
loop.
>    activeBuffer ^= 1;
>  }

Get rid of the ResetGraph() here.

>  ResetGraph(3);

> }

I hope that helps.

Mario