From: Matan Ziv-Av (matan@svgalib.org)
Date: Fri 21 Dec 2001 - 22:56:17 IST
On Fri, 21 Dec 2001, Frank H. Baker wrote: > After a lapse, I am back to my interest of exploring the use of SVGAlib > in a multi-monitor system.Your email responding to my inquiry of some > months ago (many thanks) has encouraged me to pursue that path, but I > have questions about the implementation. > > -- It is not clear how the programmer designates the adapter being > written to.While I've not looked much into the 1.9.12 source (I'm not > currently a SVGAlib user), I have scanned src/ and looked for likely > calls in vga.h. Is there an example program in the distribution that > demonstrates the usage of two monitors, or could you send me an example? There is actually no true multi monitor support in svgalib. A single process that uses svgalib can only access one video card. Which card is used by svgalib is decided when vga_init() is called, by the value of some config parameters (chipset, pcistart). The way I use this is by having different config file for each card (libvga.config.nv3, libvga.config.g450, etc.), and setting the environment variable SVGALIB_CARD according to the card I want to use, before running the program. If this variable exists, svgalib uses the config file libvga.config.$SVGALIB_CARD, instead of libvga.config. If you wan't to write a single program to use two monitors, you'll need to fork the program into two processes before running vga_init(), call the correct setenv("SVGALIB_CARD",cardname,1) in each process and then call vga_init(). Of course, then the processes need to use some IPC method to cooperate. > -- Am I correct in assuming from your response to my inquiry that there > is no problem driving two displays with SVGAlib while X handles athird > display? Yes. I actually do exactly that quite often. -- Matan Ziv-Av. matan@svgalib.org ------------------------------------------------------------------ Unsubscribe: To: listbot@svgalib.org Body: unsubscribe linux-svgalib
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