Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!spool.mu.edu!think.com!mintaka!bloom-beacon!eru!hagbard!sunic!kth.se!cyklop.nada.kth.se!news
From: d88-jwa@dront.nada.kth.se (Jon W{tte)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Emergeny help on picture drawing wanted!!!
Message-ID: <1991Jan30.183547.3571@nada.kth.se>
Date: 30 Jan 91 18:35:47 GMT
References: <1991Jan29.194323.7665@cs.umu.se> <91029.212938CXT105@psuvm.psu.edu>
Organization: Royal Institute of Technology, Stockholm, Sweden
Lines: 27

In article <91029.212938CXT105@psuvm.psu.edu> CXT105@psuvm.psu.edu (Christopher Tate) writes:

>I don't know why DrawPicture() behaves this way, but unless you set
>the clipping region to be small, the picture won't produce output.
>This is documented in Inside Macintosh Volume I, in the QuickDraw
>chapter, in the section on OpenPicture() and DrawPicture().

Think about it:

	Rect clipRect = { -32768 , -32768 , 32767 , 32767 } ;

if you now offset the picture, you offset the clip rect as well.

	OffsetRect ( & clipRect , 100 , 100 ) ;

now clipRect == { -32668 , -32668 , -32667 , -32667 } That's
an empty rect (top, left > bottom, right)

Presumably scaling the pict works in an analogous way.

This is my guess. Anyone care to comment ? Am I right ?

							h+
::::::::       Jon W{tte, Stockholm, Sweden, h+@nada.kth.se       ::::::::
"The IM-IV file manager chapter documents zillions of calls, all of which
seem to do almost the same thing and none of which seem to do what I want
them to do."  --  Juri Munkki (jmunkki@hut.fi) in comp.sys.mac.programmer