Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!newstop!sun!imagen!atari!apratt
From: apratt@atari.UUCP (Allan Pratt)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: Can't get Setpallete() to work.
Message-ID: <2919@atari.UUCP>
Date: 29 Apr 91 17:27:48 GMT
References: <LoiX11w164w@sys6626.bison.mb.ca>
Organization: Atari Corp., Sunnyvale CA
Lines: 44

marco@sys6626.bison.mb.ca (Marco) writes:

>Here's the code I've been trying to use to blank (black) my screen:
>----------------------------------------------------------------------
>#include <stdio.h>
>#include <osbind.h>

>main()
>{
>int i, pal;
>for (i=0;i<16;i++)
>        pal = i;
>Setpallete(pal);
>}

This won't work because Setpallete (sic) takes a LONG argument which is a
POINTER to an ARRAY of 16 INT's.  Check those types in the documentation!
If you look at your code again I think you'll realize that it doesn't make
any sense at all.

main()
{
	int i, pal[16];
	for (i=0; i<16; i++)
		pal[i] = 0;
	Setpallete(pal);
}

Setpallete is a misspelling of Setpallete, and is that way because Atari's
original docs and include files spelled it wrong in the first place.
As has been pointed out, this is now retained by most compilers.

A caveat for Setpallete users: the above program is unreliable because
Setpallete copies its argument to a variable, and the palette registers are
loaded from the 16 int's found there AT THE NEXT VBLANK.  Since the above
program has terminated by the time the next VBLANK rolls around, that means
this memory is not owned by anybody, violating the commandment "Thou shalt
not mess with memory thou ownest not."  I know the "program" is just an
example of this poor slob's problem, but it bears repeating that Setpallete
is a delayed-action call.

============================================
Opinions expressed above do not necessarily	-- Allan Pratt, Atari Corp.
reflect those of Atari Corp. or anyone else.	  ...ames!atari!apratt