Path: utzoo!attcan!uunet!aplcen!samsung!zaphod.mps.ohio-state.edu!wuarchive!cs.utexas.edu!rutgers!cbmvax!cbmehq!cbmfra!swinjm!forgeas
From: forgeas@swinjm.UUCP (Jean-Michel Forgeas)
Newsgroups: comp.sys.amiga.tech
Subject: Re: ClipRect's, Intuition & User code..
Message-ID: <18129527.ARN02064@swinjm.UUCP>
Date: 19 Oct 90 10:23:35 GMT
References: <4863@baird.cs.strath.ac.uk>
Reply-To: forgeas@swinjm.UUCP (Jean-Michel Forgeas)
Followup-To: comp.sys.amiga.tech
Distribution: comp.sys.amiga.tech
Organization: The Software Winery
Lines: 45

In article <4863@baird.cs.strath.ac.uk>, Brian J Syme IE88 writes:

> [...] Is it possible
> to 'and' in an additional clipping rectangle without disturbing Intuition's
> use of them (for gadgets, etc.) in a manner similar to Begin/EndUpdate()
> (or whatever it's called.)
>
> I assume the answer to my question is "no, you can't" [...]

Do not assume that. I just found (six month ago!) that Intuition have
a function to do that (since AmigaOS 1.2 :-).
(You have to open layers.library too)
Here an example:

MyClipList( rp, list )
{
  struct Rectangle rect;
  struct Region *oldregion, *listregion;

    if (! (listregion = (struct Region *) NewRegion())) return;
    rect.MinX = list->MinX; rect.MinY = list->MinY;
    rect.MaxX = list->MaxX; rect.MaxY = list->MaxY;
    if (! OrRectRegion( listregion, &rect ))
        {
        DisposeRegion( listregion );
        return;
        }
    oldregion = InstallClipRegion( rp->Layer, listregion );
    MyDrawList( rp, list );    /* <== it's there !!! */
    InstallClipRegion( rp->Layer, oldregion );
    DisposeRegion( listregion );
}

Note that if you need, you can add more rectangles to your listregion.

Best regards,
Jean-Michel
--
                                     \___/
Jean-Michel Forgeas                   \-/
cbmvax!cbmehq!cbmfra!swinjm!forgeas    |    The Software Winery
                                      -^-
                           And, where is the universe ?