@@ -35,54 +37,75 @@ The GL/glfbdev.h header file defines the glFBDev interface.
The progs/fbdev/glfbdevtest.c demonstrates how to use the glFBDev interface.
+
+You will need at minimum, a framebuffer device, check /dev/fb0
+
2. Compilation
To compile Mesa with support for the glFBDev interface:
- XXX todo
+ make realclean
+ make linux-fbdev
When compilation is finished look in progs/glfbdev/ for the glfbdevtest demo.
-
-
-xxx todo
-
-
-
-
3. Compiling and linking glFBDev programs
+
3. Permissions
-xxx todo
-
-
-
+Typically /dev/fb/0 is grouped to the video group. It may be useful to add
+your user to the video group so the demos will not have to be run as root.
+To use fbdevglut with the prefered tty input, you should add the user to the
+tty group as well
+
-
4. Running glFBDev programs
+
4. Using fbdevglut
+Almost all of the programs in the progs directory use glut, and they compile with fbdevglut.
-First, you need to have a working fbdev environment.
-See the
-
-Framebuffer Howto for information.
+To compile the redbook sample programs:
+
+ cd progs/redbook
+ make
+
-
+
glut features not supported:
+
Overlays
+
Subwindows
+
Input devices other than Keyboard/Mouse
+
No support for GLUT_MULTISAMPLE, GLUT_STEREO, or GLUT_LUMINANCE
+
Cursor and Menu Support will flicker in GLUT_SINGLE mode
+
+
Keyboard input is read by opening /dev/tty and reading keycodes in medium raw mode.
+
Mouse input is read from env var MOUSE, or /dev/gpmdata and should be in ms3 format.
+To forward data in this format to /dev/gpmdata, run gpm with the -Rms3 option.
+
glutInit allows glut programs to pass parameters to the glut library, currently the
+following options are supported for fbdevglut:
+
-geometry widthxheight -- This will force the resolution to be widthxheight instead of autodetecting.
+The modes are read from /etc/fb.modes
+
-bpp -- This will force the bitdepth to the one specified
+
-vt -- This allows you to specify the virtual terminal to attach keyboard input to. It is useful to specify when running inside screen.
+
-mousespeed -- A floating point multiplication factor to increase mouse speed
+
-nomouse -- Disable mouse support
+
-nokeyboard -- Disable keyboard support (this will probably break mouse support as well)
+
-stdin -- Use stdin for input instead of attaching to kbd in medium-raw mode.
+This will make it impossible to detect keypresses like Shift+Tab, you will also need to specify -gpmmouse for mouse support. This option can be used with a debugger, and it is possible to single step a program with gdb and set the FRAMEBUFFER environment variable to a different framebuffer for display. The program will not be able to handle vt switching on it's own, so it will always display.
+
-gpmmouse -- This will attempt to connect to the /dev/gpmctl socket using liblow
+for mouse data. Gpm does not provide this data when in graphics mode, so vt switching
+will briefly display text. This mode typically has no initial mouse delay.
+
-- Ignore any additional arguments
+
Notes:
-Programs must be run with root permission.
+1. The mouse pointer flickers in single buffering mode, as it must be rendered in software. Hopefully in the future there will be a way to access hardware cursors in fbdev devices.