Path: chuka.playstation.co.uk!news
From: "Kezza <swiseltd@" <"remove no spam>aol.com">
Newsgroups: scee.yaroze.programming.2d_graphics,scee.yaroze.beginners
Subject: Re: Trying to display a sprite
Date: Sat, 27 Mar 1999 01:06:14 +0000
Organization: StreetWise Consulting Limited.
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Xref: chuka.playstation.co.uk scee.yaroze.programming.2d_graphics:920 scee.yaroze.beginners:756

Hmmm,

Just a guess from a total novice, but maybe +1 and +4 are worked out by the
compiler to fit into the same 4-byte boundary, and therefor the same physical
memory address?

-Kezza
http://www.netyaroze-europe.com/~kmillar

Charles Nicholson wrote:

> heh... funny.  I've been looking through all my code (just to double check
> at the chance of sounding like a fool), and it all has the sprite address +
> 1 inside the cast.  Go figure- seems to work fine for me... :)
>
> ah well.
> -charles
>
> Peter Dollochan wrote in message <7avh7s$9po2@chuka.playstation.co.uk>...
> >Hi all
> >
> >I think the addition is carried out before the cast so keep the +4 or it'll
> >break :) apart from that Scott is right after the first draw your blank out
> >the sprite and clut..
> >
> >
> >Pete.
> >
> >
> >Charles Nicholson wrote in message <7av7s5$8jb8@scea>...
> >>Umm... most of it looks pretty good- You might want to change the line in
> >>InitSprite() that calls GsGetTimInfo though...
> >>
> >>Your first parameter, "(u_long *)(spriteAdd + 4)" should probably be
> >changed
> >>to
> >>"(u_long *)(spriteAdd + 1)".
> >>
> >>The information that GetTimInfo needs is actually 4 bytes in from the
> >>header.  Since you're casting spriteAdd to a u_long, it will multiply any
> >>addition you do (in this case +4) by the size of a u_long.  The final
> >offset
> >>calculated (in bytes, not dwords) by "(u_long *)(spriteAdd + 4)" is 16
> >bytes
> >>into spriteAdd.  (u_long *)(spriteAdd + 1) will give you the proper 4 byte
> >>advancement.
> >>
> >>This was a real pain for me too... :)
> >>
> >>hope i helped.
> >>-charles
> >>
> >>
> >>
> >>>I've just typed out the code at the end of Ira Rainey's tutorial (typed,
> >>not
> >>>copied and pasted, to try and gain some experience, and extra knowledge
> >>from
> >>>doing so. However, I've compiled, and attempted to run, it flashes
> >>something
> >>>very quickly on the screen, and then the screen goes blank, with the
> thick
> >>>black strips at the top and bottom. Anyway, I've attached the code, so if
> >>>anyone has the chance to look at it, and tell me what's been copied
> >>>incorrectly, or what's in the wrong order, etc. I would be very thankful.
> >>>
> >>>Rikki
> >>
> >>
> >>
> >
> >