Path: utzoo!censor!geac!torsqnt!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!rutgers!psuvax1!xavier!jackiw
From: jackiw@cs.swarthmore.edu (Nick Jackiw)
Newsgroups: comp.sys.mac.programmer
Subject: Re: How do you set the mouse position?
Message-ID: <ZJKFJ8N@xavier.swarthmore.edu>
Date: 26 Feb 90 14:42:15 GMT
References: <4081@hub.UUCP>
Sender: news@xavier.swarthmore.edu (USENET News System)
Reply-To: jackiw@cs.swarthmore.edu (Nick Jackiw)
Organization: Visual Geometry Project, Swarthmore College, PA
Lines: 53

6500stom@hub.UUCP (Josh Pritikin) writes:
> I need to be able to set the position of the mouse for a game that
> I'm writting. Actually, limiting the mouse movement to a rectangle
> on the screen would work as well but I remember seeing a lot of
> letters in MacTutor argueing the point. Does anyone have the code
> to put the mouse somewhere the "correct way" or limit the mouse to
> a rect?
> 

No. You bad, bad rabbit.

The incorrect way, in that it violates all sorts of interface rules
(like: the user decides where the mouse goes) and compatibility
guidelines (like: don't access undocumented low-memory globals) was
discussed here quite some time ago.  Try:

procedure SetMouse(where:point);

{Thanks to Chris Muir, pacbell!well!cbm, for posting the original
version of this.}

var LowGlob:integer; LowMem:ptr; PointPtr:^point; finalTicks:longint;

const
   MBState=$172; MTemp=$828; RawMouse=$82C; Mouse=$830; 
   CrsrNew=$8ce; 

begin
 LocalToGlobal(where);
 LowMem:=pointer(RawMouse);
 PointPtr:=@LowMem^;
 PointPtr^:=where;
 LowMem:=pointer(MTemp);
 PointPtr:=@LowMem^;
 PointPtr^:=where;
 LowMem:=pointer(CrsrNew);
 LowMem^:=$ffff;
 Delay(5,finalTicks) 
end;

If you're after user friendliness, you might want to check that your app is
running on an architecture (hardware+System Version) with which you've
tested this works, and if not, warn them of a possible incompatibility before
letting them start the game.

-Nick
jackiw@cs.swarthmore.edu

--
"'I have seen too often your filthy teeth snap with rage and your august
countenance, covered with the fungus of time, blush like a flaming coal
because of some microscopic futility that man had commited, to be able
to pause longer before the signpost of that silly hypothesis.'" -Maldoror