From: jsturm AT sigma6 DOT com (Jeff Sturm) Subject: Re: server X 22 Sep 1998 18:26:47 -0700 Message-ID: <3607A48D.311B41C6.cygnus.gnu-win32@sigma6.com> References: <01BDDD75 DOT 00B69600 AT sos> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: David Fox Cc: gnu-win32 AT cygnus DOT com David Fox wrote: > Sergey Okhapkin writes: > > Porting _Xfree86_ to win32 is a bad idea, because Xfree86 requires direct > > video hardware access. > > Could you expand on this further? Why is direct video hardware access > more of a problem under windows than it is under Unix? (A small clarification to Sergey's post: XFree86 is designed for video framebuffer access. It need not access video registers directly. Recent work in Linux for example has moved video drivers out of X and into the kernel; X opens the display via the /dev/fb device.) The big difference is that under Unix, the X server controls the entire display. Under Win32 however, X has to cooperate with the native window subsystem. I think that precludes an X server from accessing video memory from Win32 (does anyone know otherwise?). It may be able to write to backing store... I'm not sure if this is better (easier or more efficient, that is) than just translating X drawing requests into GDI requests. If it turns out that the "virtual framebuffer" technique is feasible, I'd contend that the XFree86 source is a better starting point than TOG's X11R6.4, since they have cleaned up and fixed a lot of the cfb code. -- Jeff Sturm jsturm AT sigma6 DOT com - For help on using this list (especially unsubscribing), send a message to "gnu-win32-request AT cygnus DOT com" with one line of text: "help".