Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!clyde!cbosgd!cwruecmp!neoucom!wtm From: wtm@neoucom.UUCP (Bill Mayhew) Newsgroups: comp.sys.amiga Subject: Re: Swapping graphics pages at 60Hz Message-ID: <617@neoucom.UUCP> Date: Sun, 5-Jul-87 23:53:16 EDT Article-I.D.: neoucom.617 Posted: Sun Jul 5 23:53:16 1987 Date-Received: Tue, 7-Jul-87 01:37:34 EDT References: <187@mv05.ecf.toronto.edu> Organization: Northeastern Ohio Universities College of Medicine Lines: 35 Keywords: stereographics, video signals, graphics buffers Summary: 3d graphics isn't terribly difficult I can't give the the absolute complete nitty gritty details, but I did help one of our faculty member's son get going on a science fair project on his Amiga. He programmed the project in AmigaBasic (the Mircosoft, not Metacomco interpreter). He used the ScreeToFront() and ScreenToBack() functions after opening two screens in Basic. He used the digital output lines of the printer port to darken and clear two LCD sheets installed in the frames from a cheap pair of sun glasses. WaitTOF() can be used to wait for the retrace interval so that the glasses can be switched at an unobtrusive time. The Addison-Wessley Rom Kernel Manual provides the necessay info on the routines. Note we used the printer port to control the glasses, as we had difficulty setting the second mouse prot for digital output. Something kept switching it back to input mode. Carolyn Schepner of CATS posted several nice examples of manipulating screens in Basic a while back. One thing that is helpful is to find somebody that has the "FD" files from the C compiler to feed into "ConvertFD" on the AmigaBasic disk to produce the necessary ".BMAP" files that enalbe Basic's LIBRARY statement to find the routines mentioned above. The Amigabasic disk also contians several example programs, LoadILBM, or some such name that are useful examples. Rather than swapping screens, you could also play with the color table to avoid the complexity of dealing with screens. That sould be OK for your application, since you are only interested in wire frame objects. Hope this helps, Bill (wtm@noeucom.UUCP)