Xref: utzoo unix-pc.general:3882 comp.sys.att:7787 Path: utzoo!attcan!hjespers From: hjespers@attcan.UUCP (Hans Jespersen) Newsgroups: unix-pc.general,comp.sys.att Subject: Re: general purpose bit blitter Message-ID: <10419@attcan.UUCP> Date: 16 Oct 89 21:01:12 GMT References: Distribution: na Organization: AT&T Canada Inc., Toronto Lines: 38 From article , by wjc@hoswjc.ATT.COM (Bill Carpenter): > ... > So, who has some nice, post-able, fairly general bitblt routine? > Given that, I'd be able to post a UNIXpc version of the infamous > "crabs" program. I'm currently working on a dmd library to enable me to compile and run programs written for the 5620/630/730 DMD environment. The bitblt(3R) routine is just one of many necessary graphics routines (ie. box(3R), circle(3L), ellipse(3L), etc.) as well as all the font, and mouse manipulation routines. I started hoping that I could simply map all the bitblt() parameters over to the coresponding wrastop() parameters but the structure of Bitmap is all backwards. Even provided the 630 bitplanes are 16 bit Words the bits are a mirror image of the bitplanes on the 3b1. Therefore my bitblt() has to check the source and destination bitplanes and if they are in display memory the Words have to be flipped, otherwise you will get unrecognizable results. Even with the bits flipped, the results can be disappointing since the 630 has a nice 1:1 aspect ratio and the 3b1 has a horribly scewed 7:3 (approx) ratio. Getting bitblt() ported is a nice first step and will allow a lot of 630 demo stuff to run ( should be enough for "crabs" ) but in order to use some of the REALLY neat stuff that the labs are putting out for DMD terminals it would be advantageous to have the complete DMD environment. Then the next step would be to get 'layers' up, perhaps through the use of the existing window drivers. -- Hans Jespersen UUCP: uunet!attcan!hjespers AT&T Canada Inc. Toronto, Ontario PS. The ultimate would be to get "gebaca" running on the 3b1. This has got to be one of the all time best arcade style games I've ever played but alas, it only runs on DMD terminals.