From: ranla AT post DOT tau DOT ac DOT il (Tal Lavi) Newsgroups: comp.os.msdos.djgpp Subject: Inevitebly slow writes in VESA? Date: Sat, 10 Oct 1998 01:56:09 LOCAL Organization: Tel-Aviv University Computation Center Lines: 24 Message-ID: NNTP-Posting-Host: slip-107.tau.ac.il X-Newsreader: Trumpet for Windows [Version 1.0 Rev B final beta #4] To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com My ray-caster needs only to draw vertical lines in a 16bpp mode. This, ofcourse, makes it hard to write a dword in a time. I have succeeded in rewriting the engine so that he'll calculate two vertical scan-lines at once, so they could be drawn on the screen at once(I have not calculated each one dependendly, stored them, at then drawed them, but actually calculated both simultaniusly). I am calculating every two CONSECUTIVE veritical scan-lines at once(0&1, 2&3, etc..), which means that every dword that is written in dword-alligned to the beginning of the LFB. To my disapointment, I haven't gained ALLOT more speed, rather than just some. Does anyone has a clue about what could have gone wrong? according to my calculations, I should have gained X8 speed. My guess(which is very improbable), is that the beginning of the LFB is not DWord alligned. Can this be true? Please, don't tell me to post my code, it's much too complicated, and it won't do any good. Virge ranla AT post DOT tau DOT ac DOT il