Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!rutgers!cbmvax!spence From: spence@cbmvax.commodore.com (Spencer Shanson) Newsgroups: comp.sys.amiga.programmer Subject: Re: ScrollVPort() and Interlaced Views/ViewPorts Keywords: Interlace ViewPorts ScrollVPort Message-ID: <20557@cbmvax.commodore.com> Date: 11 Apr 91 16:04:45 GMT References: Reply-To: spence@cbmvax.commodore.com (Spencer Shanson) Distribution: comp Organization: Commodore, West Chester, PA Lines: 46 In article brianm@sco.COM (Brian Moffet) writes: > >HELP! I was trying to write a program which used >Views and ViewPorts to allow fast scrolling of an interlaced image. >I got the initial setup done which allowed me to show an image, >but when I called ScrollVPort(), it seemed to flip the odd and even lines. > >I was able to get this to work with a non-interlaced display. > >Does anyone have any ideas? It looks like ScrollVPort is not resetting >one of the copper lists (2 for interlaced ViewPorts) correctly, or is >doing something to corrupt it. > >Suggestions? > >I need to finish this program soon, so a quick answer/solution >would be appreciated! I just tried this with a quick test, and everything was OK for me. So, a number of questions: 1) What Kickstart are you using? 2) Were you creating your own view and viewport, and if so, were all the mode bits set properly? 3) Are you sure that you have not somehow enabled the LightPen? That would cause the two frames to flip. > >thanks > >brian moffet >-- >O Fortuna - velut luna - statu variabilis - semper crescis - aut decrescis > vita detestabilis - nunc obdurat - et tunc curat - ludo mentis aciem > egestatem - potestatem - dissolvit ut glaciem >brianm@sco.com Speaking for Myself -- --------------------------------------------------------------------------- Spencer Shanson - Amiga Software Engineer | email: spence@commodore.COM | or uunet!cbmvax!spence All opinions expressed are my own, and do not | "You know my methods. Apply (necessarily) represent those of Commodore. | them" -- Sir Arthur Conan | Doyle - 'The Sign of Four'