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From: peter@cbmvax.commodore.com (Peter Cherna)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: Sharing layers.library with intuition
Message-ID: <17689@cbmvax.commodore.com>
Date: 16 Jan 91 22:15:40 GMT
References: <1991Jan11.001055.2055@mintaka.lcs.mit.edu> <17398@cbmvax.commodore.com> <1991Jan16.162030.7783@murdoch.acc.Virginia.EDU>
Reply-To: peter@cbmvax.commodore.com (Peter Cherna)
Organization: Commodore, West Chester, PA
Lines: 42

In article <1991Jan16.162030.7783@murdoch.acc.Virginia.EDU> tmb@davinci.acc.Virginia.EDU (Thomas M. Breeden) writes:
>Is it in the same tricky territory to attempt to add a clipping
>rectangle within an Intuition window?

No.  It's actually fairly easy.  See layers.library/InstallClipRegion().
Here's a cheap simple example, with no guarantees :-)

    
    if ( myregion = NewRegion() )
	{
	/* myrect describes the rectangle you want to contain rendering
	 * inside of.  Use region operations to build this.
	 */
	OrRectRegion(myregion, &myrect);

	/* Install the region.  All YOUR rendering will be constrained,
	 * such as graphics calls, PrintIText(), DrawImage() etc.
	 * Don't try to constrain Intuition's own rendering of borders,
	 * gadgets, etc.  They happen everywhere.
	 */
	ocr = InstallClipRegion(win->RPort->Layer, myregion);

	DrawImage(win->RPort, myimage, left, top);

	/* Remove your region */
	InstallClipRegion(win->RPort->Layer, ocr);
	DisposeRegion(myregion);
	}
    }


>            - Tom Breeden
>              tmb@virginia.EDU      -> Internet
>              tmb@virginia          -> BITNET


     Peter
--
     Peter Cherna, Software Engineer, Commodore-Amiga, Inc.
     {uunet|rutgers}!cbmvax!peter    peter@cbmvax.commodore.com
My opinions do not necessarily represent the opinions of my employer.
"Oh, PIN-compatible!  I thought you wanted me to make it IN-compatible!"