From: "Tony O'Bryan" Newsgroups: comp.os.msdos.djgpp Subject: Re: allegro scrolling limitation? Date: Tue, 11 Nov 1997 18:10:21 -0600 Organization: Southwest Missouri State University Lines: 19 Message-ID: <3468F3ED.6D3A@nic.smsu.edu> References: <01bcee43$9495dc40$0c2331ce AT pentium> Reply-To: aho450s AT nic DOT smsu DOT edu NNTP-Posting-Host: marie.a14.smsu.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk Alistair Bain wrote: > > In article <01bcee43$9495dc40$0c2331ce AT pentium>, RL > writes > >Does anyone know any tricks to get allegro/djgpp to create smooth > >screen scroll (ie. not skipping by 4 pixels) in high resolution? > >In other words, not using modex. My game Mythos smoothly scrolls a 640x480x256 screen using compiled sprite tiles. Using compiled sprites was the fastest way I could think of to scroll such a large screen. The only speed drain is that although the compiled sprites are drawn quickly to an invisible screen, the invisible screen has to be blit()ed to the video screen. All the drawing and scrolling is done through software, but the frame rate is still very good on a fast computer (my system is 120Mhz Pentium). The blit of a 640x480x256 regular Allegro bitmap is the only slow part of the entire algorithm. E-Mail me if you want to try the executable on your system for a speed trial.