Path: chuka.playstation.co.uk!news
From: ScoTT Campbell <escotia@escotia.freeserve.co.uk>
Newsgroups: scee.yaroze.programming.2d_graphics
Subject: Re: pmode in GsIMAGE
Date: Sun, 28 Feb 1999 01:48:52 +0000
Organization: PlayStation Net Yaroze (SCEE)
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References: <7ba63i$9po27@chuka.playstation.co.uk>
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I've pasted the function I use to initialise sprites below. There's even a
couple of comments in it!

It sets up a sprite regardless of position in the frame buffer too.
ie Sprite doesn't need to be on a TP edge.(Can't cross TPs though)

You could do some of the testing a bit quicker though.

ScoTT

void InitSprite(GsSPRITE* spritePtr, unsigned long int spriteAddress, int
xPosition, int yPosition)
{
 RECT rect;
 GsIMAGE timData;


 // Get info at spriteAddress and put into timData
 GsGetTimInfo((unsigned long*)(spriteAddress+4), &timData);


 // Load sprite into frame buffer
 rect.x = timData.px;
 rect.y = timData.py;
 rect.w = timData.pw;
 rect.h = timData.ph;
 LoadImage(&rect, timData.pixel);


 // Assign values to the sprite handler
 spritePtr->attribute = (unsigned long int) (timData.pmode << 24); // Set sprite
to correct display mode
 spritePtr->attribute &= 0x03000000;         // Set all other attribute bits to
zero


 /* Set the width according to the colour mode */
 /* And load CLUT if neccessary      */
 if(spritePtr->attribute & 0x01000000)
 {
  spritePtr->w = (timData.pw * 2); // 8-bit clut
  // Load sprites CLUT into frame buffer
  rect.x = timData.cx;
  rect.y = timData.cy;
  rect.w = timData.cw;
  rect.h = timData.ch;
  LoadImage(&rect, timData.clut);

  spritePtr->cx = timData.cx;
  spritePtr->cy = timData.cy;

  spritePtr->tpage = GetTPage(1, 0, (64 * (timData.px / 64)), (256 * (timData.py
/ 256)));

  spritePtr->u = (timData.px % 64) * 2;
  spritePtr->v = timData.py % 256;
 }

 else
 if(spritePtr->attribute & 0x02000000)
 {
  spritePtr->w = (timData.pw); // 15-bit direct

  spritePtr->tpage = GetTPage(2, 0, (64 * (timData.px / 64)), (256 * (timData.py
/ 256)));

  spritePtr->u = timData.px % 64;
  spritePtr->v = timData.py % 256;
 }
 else
 {
  spritePtr->w = (timData.pw * 4); // 4-bit clut
  // Load sprites CLUT into frame buffer
  rect.x = timData.cx;
  rect.y = timData.cy;
  rect.w = timData.cw;
  rect.h = timData.ch;
  LoadImage(&rect, timData.clut);

  spritePtr->cx = timData.cx;
  spritePtr->cy = timData.cy;

  spritePtr->tpage = GetTPage(0, 0, (64 * (timData.px / 64)), (256 * (timData.py
/ 256)));

  spritePtr->u = (timData.px % 64) * 4;
  spritePtr->v = timData.py % 256;
 }

 spritePtr->h = (timData.ph);
 spritePtr->mx = spritePtr->w/2;
 spritePtr->my = spritePtr->h/2;
 spritePtr->x = xPosition;
 spritePtr->y = yPosition;

 spritePtr->r = 128;
 spritePtr->g = 128;
 spritePtr->b = 128;
 spritePtr->scalex = ONE;
 spritePtr->scaley = ONE;
 spritePtr->rotate = 0;

 DrawSync(0);


}/* InitSprite */

Rikki Prince wrote:

> I'm currently trying to write a function which will set up a sprite, just by
> passing as few  as possible parameters i.e. only the absolutely needed ones
> are passed: TIM address, pointer to sprite etc. However, one thing that I
> cannot currently get to work is getting the function to work out within
> itself whether the TIM is 4bit CLUT, 8bit CLUT or otherwise. From the look
> of the GsIMAGE structure in the library reference manual, I should be able
> to read the pmode member and work out whether it is 4bit, 8 bit or
> otherwise. However, when I put this in a switch statement, it doesn't work.
> I've also tried it in an if/else if/else setup, and it still doesn't work.
> I've just realised I should have put this earlier in the message, but the
> problem I'm having is (constructing sentences and messages!! lol) trying to
> set the width of the sprite in the GsSPRITE structure, as when the TIM is
> 4bit, you need to *4, and when it's 8bit you need to *2 (something I picked
> up from the Ira Rainey tutorial). As this is going to be a function I'll
> need to use for different TIMs, and therefore not specific, I need it to
> work out for itself whether the TIM is 4/8/16 bit etc. I've got it partly
> working, by putting in  if((tim.pmode>>3)&0x01) sprite->w=tim.pw*2;  the
> 'if' part of which I took from the texture load in Peter Passmore's 3d
> tutorial, but I believe (well, guess) this bit manipulation tests whether
> it's one of 8 or 4 bit, not either individually, which is what I want!
>
> Basically in conclusion, I need some help on how I can test to see if the
> sprite is 4bit/8bit/otherwise, so I can set the width accordingly, something
> which seems not to work normally, and only with bits shifts and clever
> tricky stuff which the 286 in me 'ead don't seem to be able to cope with.
>
> Thanks in advance to anyone who can decipher what I've said in the preceding
> message, and decides to help this poor little beginner :-)
>
> Rikki
>
> PS here's my switch statement which doesn't work, if anyone is interested.
>
> switch (tim.pmode)
>   {
>   case 0 :sprite->w=tim.pw*4; /* If sprite is 4 bit, make width 4 times
> bigger */
>     break;
>   case 1 :sprite->w=tim.pw*2; /* If sprite is 8 bit, make width 2 times
> bigger */
>     break;
>   default :sprite->w=tim.pw*2; /* Else set it to width got from tim info */
>     break;
>   }