Path: chuka.playstation.co.uk!news
From: "grim" <frothy@fourny.demon.co.uk>
Newsgroups: scee.yaroze.programming.2d_graphics
Subject: Re: GsIMAGE pmode 8 - another red herring
Date: 2 Apr 1997 19:56:32 GMT
Organization: froth kid
Lines: 93
Message-ID: <01bc28b3$29e10100$c793989e@fourny.demon.co.uk>
References: <01bc289b$f6314fc0$c793989e@fourny.demon.co.uk> <33422052.4C18@interactive.sony.com>
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OK you asked for it :) 

Sorry if it's a bit C++. I'm not ashamed. Picture if you will an
object-oriented fishing game.

main()
{
	SetVideoMode(MODE_PAL);
	GsInitGraph(320, 256, 4, 0, 0);
	GsDefDispBuff(0, 0, 0, 256);
	CSea sea(0, 0, 0, 0);

calls contructor for CSea

CSea::CSea(int player1, int player2, int player3, int player4)
{
	mOT[0].length=OT_LENGTH;		//ordering tables, copied
	mOT[1].length=OT_LENGTH;		//from the balls demo	
	mOT[0].org=mTags[0];			//but irrelevant I think
	mOT[1].org=mTags[1];			//given I only get where I do
	CFish *firstfish=new CFish(30, 30);

calls constructor for CFish

CFish::CFish(unsigned int x, unsigned int y)
{
	mSprite = new CSprite(1);
	mX=x;
	mY=y;
}

calls constructor for CSprite

CSprite::CSprite(int frames)
{
	mFrames=frames;
	mTPages=new unsigned short[mFrames];
}

finishes, drops back to CSea constructor again

	firstfish->LoadSprite();

calls LoadSprite in CFish 

void CFish::LoadSprite()
{
	mSprite->Load(0, "small.tim", 576);
}

calls load in CSprite

void CSprite::Load(int frame, char *filename, int filesize)
{
	GsIMAGE image;
	RECT pixRect;
	RECT colRect;
	unsigned short tPage;

	MWRedirectIO(__MWIO_CDROM);
	void *location=malloc(filesize);
	long bytes=MWbload(filename, location);	
	GsGetTimInfo((u_long *)(((char *)location)+4), &image);
	pixRect.x=image.px;
	pixRect.y=image.py;
	pixRect.w=image.pw;
	pixRect.h=image.ph;
	LoadImage(&pixRect, image.pixel);
	DrawSync(0);
	tPage=GetTPage(0, 0, pixRect.x, pixRect.y);
	
Single step the debugger through that lot and it always crashes on
LoadImage. Likewise put a breakpoint on GetTPage it will always crash
before the breakpoint.

image.pixel points 40 bytes after location, on the heap (initialised by
codewarrior
between the end of the program and the start of the stack, both in default
positions). I believe there is a CLUT just before the pixel data.

576 bytes are actually read by MWbload, and this is also the DOS size of
the TIM.

I downloaded the textutil file as was suggested, but it looked just like I
expected it to, pretty much just like the code above. I wouldnt normally
pester people with my stupid bugs but this has been annoying me for 3 days
and I'm just not getting anywhere with it. Please let there be a simple
oversight on my part.

yours in hope

Grim