Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!microsoft!kensy From: kensy@microsoft.UUCP (Ken SYKES) Newsgroups: comp.windows.ms.programmer Subject: Re: Fast linedrawing in Windows Message-ID: <72440@microsoft.UUCP> Date: 20 May 91 02:30:30 GMT References: Reply-To: kensy@microsoft.UUCP (Ken SYKES) Distribution: comp.windows.ms.programmer Organization: Microsoft Corp., Redmond WA Lines: 25 In article rujo@ulrik.uio.no (Rune J|rgensen) writes: >With advanced graphics adapters, you may download an entire >displayfile with vectors. Then you send commands to the adapter, >asking it to perform a local zoom or redraw. This may be a 100 >or a 1000 times faster than sending vectors one by one. > >Is there any way you may utilize smart graphics adapters with >MS Windows? Or is MoveTTo/LineTo the only way? They PlayMetaFile() The general answer to this is "Write a display driver." Windows will still pass the commands one at a time but instead of setting all the individual pixels it will send the smart command. This alone buys reasonable speedup. It is also possible to make the display driver deal with a Coprocesser by queuing up the commands as they come in and executing them in chunks. This requires a fair amount of Windows display driver knowledge to get working correctly since Windows deals with things in a serial manner, but it can be done. Applications should not depend on the display driver they use if at all possible. Ken Sykes Disclaimer: The above opinions are solely my own.