Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uwm.edu!linac!att!pacbell.com!tandem!zorch!amiga0!mykes From: mykes@amiga0.SF-Bay.ORG (Mike Schwartz) Newsgroups: comp.sys.amiga.hardware Subject: Re: Using the copper (was Re: 3d Graphics) Message-ID: Date: 30 Mar 91 17:45:59 GMT References: <12305@monu1.cc.monash.oz> <7183@harrier.ukc.ac.uk> Organization: Amiga makes it possible Lines: 45 In article <7183@harrier.ukc.ac.uk> mr3@ukc.ac.uk (M.Rizzo) writes: >In article <12305@monu1.cc.monash.oz> int131d@monu3.cc.monash.edu.au (mr s.d. twyford) writes: > >> Then improve it by ... >> ...generating your own copper lists for the screen display. > >Why do you do this and what exactly do you put in your copper lists ? >Can you or anyone else give me a few examples of what can be gained >by generating one's own copper lists please ? > >Other than having two copper lists for double buffering, as >shown in the RKM Libraries & Devices (Yep I'm still using the >old ones :-), and changing the colour palette in the middle of scan >lines for nice demos :-), I can't see much point in messing around with >copper lists. I can't understand what people do with copper >lists in programs such as Stuart's. Help please ! > > >> Stuart Twyford > >Michael Rizzo > >Mike The Maltese Amigan >Yes we've got Amigas in Malta too ! First of all, you don't need TWO copper lists to do double buffering. All you need to do is change the plane pointers in a single copper list. Second, the copper is a coprocessor with the ability to wait until a specific scanline position (x and y) and it can store values into the Amiga hardware registers. The Operating System uses this trick to allow you to drag/pull down screens. What is really going on here is the copper list (program) is changing the hardware plane pointers and color palettes at the first scan line of the screen that was dragged down. The game shadow of the beast uses the copper heavily to achieve its stunning visual effects. -- ******************************************************** * Appendix A of the Amiga Hardware Manual tells you * * everything you need to know to take full advantage * * of the power of the Amiga. And it is only 10 pages! * ********************************************************