Path: utzoo!dptcdc!jarvis.csri.toronto.edu!mailrus!purdue!decwrl!labrea!Portia!Jessica!rick
From: rick@Jessica.stanford.edu (Rick Wong)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Method to Define my own "strechable shapes"
Message-ID: <1648@Portia.Stanford.EDU>
Date: 18 Apr 89 17:21:16 GMT
References: <820@garcon.cso.uiuc.edu>
Sender: USENET News System <news@Portia.stanford.edu>
Reply-To: rick@Jessica.stanford.edu (Rick Wong)
Organization: Stanford University
Lines: 43

In article <820@garcon.cso.uiuc.edu> emb90619@uxa.cso.uiuc.edu (Eric M Berdahl) writes:
>I have a general shape stored in a RgnHandle.
>
>I want to be able to take this arbitrary shape and drag it out to
>an arbitrary size (ala MacDraw).  I have looked at MapRgn() and
>InsetRgn() and neither routine gives me just what I'm looking for.
>(Of course, I may just be doing them wrong.)  If ANYONE can come
>up with suggestions for how to implement this, I'd be eternally
>grateful.

QuickDraw pictures automatically perform scaling for you, so you could
do the following to include your region in a picture:

	/* Save clipping */
	aClipSave = NewRgn();
	GetClip(aClipSave);

	aRect = (**myRgn).rgnBBox;
	ClipRect(&aRect);	/* Make sure the picture's clipping is okay */
	/***
	    The picture saves the port's pen attributes.  Since I presume
	    you are doing this for some sort of mouse-tracking, use xor mode.
	***/
	PenNormal();
	PenMode(patXor);
	aPicHandle = OpenPicture(&aRect);
	FrameRgn(myRgn);	/* Or PaintRgn() */
	ClosePicture();

	/* Restore clipping */
	SetClip(aClipSave);
	DisposeRgn(aClipSave);

Once you've got xor'ed region in a PicHandle, you can perform your mouse-
tracking feedback by repeatedly calling DrawPicture.

You could also make your feedback more user-friendly by drawing the region
with its actual pen mode, then using offscreen drawing in your mouse-
tracking loop (although, of course, this would be more work).

Rick Wong
Courseware Authoring Tools Project, Stanford University
rick@jessica.stanford.edu