Article View: comp.sys.amiga.tech
Article #14127Re: Clipping? Questions and recommendations.
From: Henry J. Cobb
Date: Fri, 09 Mar 1990 01:35
Date: Fri, 09 Mar 1990 01:35
26 lines
1694 bytes
1694 bytes
In article <10056@cbmvax.commodore.com>, peter@cbmvax (Peter Cherna) writes: > <The graphics library call InstallClipRegion() operates on a per-layer <basis. Since your two tasks share a layer, they would share a clip <region. So to have them use different clipping regions, there would <have to be some kind of locking protocol between them, say a semaphore, <which each of your tasks would have to obtain before installing its <clipping region and hold through its rendering operations, then remove <the clipping region and release the semaphore. < My copy of RKM: Includes & Autodocs shows this to be a function in layers.library. The Autodoc says to call InstallClipRegion(l,NULL) to "tidy up" when through. Is there anyway to tell if the Clip region is set to its default (NULL) value? Does this NULL value indicate that there is some sort of array somewhere where we can store our "commonly used" clipping regions and rapidly select from them? Lastly, how much "effort" does this call require? Would it hurt alot to call it before drawing each line? Henry J. Cobb hcobb@ccwf.cc.utexas.edu
Technical Details
Message-ID:
<25745@ut-emx.UUCP>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!ut-emx!hcobbReferences:
<27831.AA27831@slaka.sirius.se> <10056@cbmvax.commodore.com>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!ut-emx!hcobb From: hcobb@walt.cc.utexas.edu (Henry J. Cobb) Newsgroups: comp.sys.amiga.tech Subject: Re: Clipping? Questions and recommendations. Keywords: graphics Message-ID: <25745@ut-emx.UUCP> Date: 9 Mar 90 01:35:11 GMT References: <27831.AA27831@slaka.sirius.se> <10056@cbmvax.commodore.com> Sender: news@ut-emx.UUCP Reply-To: hcobb@walt.cc.utexas.edu (Henry J. Cobb) Organization: The University of Texas at Austin Lines: 26 In-reply-to: peter@cbmvax.commodore.com (Peter Cherna)