Path: chuka.playstation.co.uk!news
From: Mark Green <mark@antelope.demon.co.uk>
Newsgroups: scee.yaroze.beginners
Subject: Ok, truly stuck again.
Date: Sun, 10 Aug 1997 12:50:15 +0100
Organization: No
Lines: 142
Message-ID: <33EDAAF7.7E00@antelope.demon.co.uk>
NNTP-Posting-Host: antelope.demon.co.uk
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I'm actually going to post my source here because I really can't see
what's wrong (and worse yet I have to post through Netscape to do a file
include, so it'll probably do that stupid post-it-in-html-twice trick,
but I can't get a decent bit of news software and my telnet won't
transmit files.. many apologies in advance if it has done it).
  Basically, this program is supposed to draw a sprite, but it doesn't
work at all.  And I can't see why.  I have checked against the check
program and against shadow's code and it seems to do everything in the
same order.  If I take the GsSortClear() out, it works, but doesn't
clear the screen (of course ;) )
  Any help much appreciated.

Mg

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#include <libps.h>
#include "pad.h"

#define VH_ADDR         0x80100000

/* Reserved memory for building packets for the GPU */
PACKET Packets[2][500];

/* Ordering table for planes */               
GsOT OT[2];
/* Only need a few tags, since we're not using 3D */
GsOT_TAG Tag[2][10];
int frame;

/* Our sprite record */
GsSPRITE oursprite;

/* Where we put the TIM */
u_long *theTIMfile = (u_long *)VH_ADDR;

/* Pointers to the PSX control buffers */                                              
volatile u_char *bb0, *bb1;

GsIMAGE         theimage;

/* God knows what this does, but it works */
static u_long PadRead(long id)
{
	return(~(*(bb0+3) | *(bb0+2) << 8 | *(bb1+3) << 16 | *(bb1+2) << 24));
}


void loadthetexture() {
	RECT		rect;
        int             i;
       
        GsGetTimInfo((u_long *)(VH_ADDR+4),&theimage);
        rect.x = theimage.px;  rect.y = theimage.py;
        rect.w = theimage.pw;  rect.h = theimage.ph;
        LoadImage(&rect, theimage.pixel);
        rect.x = theimage.cx;     rect.y = theimage.cy;
        rect.w = theimage.cw;     rect.h = theimage.ch;
        LoadImage(&rect, theimage.clut);
        DrawSync(0);
}

void setupsprite() {
  u_long tpage;

  tpage = GetTPage(1,0,640,0);

  oursprite.attribute = 1 << 24;
  oursprite.x = 50; oursprite.y = 50;
  oursprite.w = theimage.pw*2; oursprite.h = theimage.ph;
  oursprite.u = 0; oursprite.v = 0;
  oursprite.cx = theimage.cx; oursprite.cy = theimage.cy;
  oursprite.tpage = tpage;
  oursprite.r = oursprite.g = oursprite.b = 128;
  oursprite.scalex = oursprite.scaley = ONE;
  oursprite.mx = oursprite.my = 10;
  oursprite.rotate = 0;
}

main() {

  int t;
  u_long padval;
  /* Set up screen */

  SetVideoMode(MODE_PAL);
  GetPadBuf(&bb0, &bb1);
  GsInitGraph(320,256,4,0,0);

  /* Tell system where the double-buffer screen is in the global fbuf */
  GsDefDispBuff(0,0,0,256);

  /* Set up the ordering tables */
  for (t=0; t<2; t++) {
    OT[t].length = 1;
    OT[t].org = Tag[t];
  }

  loadthetexture();
  setupsprite();

/* ORDER OF DOING THINGS: */
/*    Compute frame X */
/*    Check drawing of frame X-1 is finished */
/*    Wait for vertical blanking */
/*    Shift X-1 into screen, bring X-2 to buffer for overwrite */
/*    Start drawing frame X */
/*    Increment X, go to top */

  while (padval != PADselect) {
    
    frame = GsGetActiveBuff();
    GsSetWorkBase((PACKET *)Packets[frame]);
    GsClearOt(0,0,&OT[frame]);

    padval = PadRead(1);
    if (padval & PADLright) oursprite.rotate += 4096;
    if (padval & PADLleft) oursprite.rotate -= 4096;  

    GsSortSprite(&oursprite, &OT[frame], 0);

    DrawSync(0);
    VSync(0);
    GsSwapDispBuff();
    GsSortClear(0,0,0,&OT[frame]); 
    GsDrawOt(&OT[frame]);
  }

}


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