OSMesa
OSMesa is used since Octave 4.0 for offscreen rendering from OpenGL toolkits FLTK and Qt.
This enables printing without a X display, for example when ssh'ing to a remote machine, or if the figure is invisible (#33180).
libOSMesa
The minimum required version of OSMesa for Octave is 9.0.0. Versions < 9.0 show a strange bug where the return values of
glGetIntegerv (GL_DEPTH_BITS, &z); glGetIntegerv (GL_STENCIL_BITS, &s); glGetIntegerv (GL_ACCUM_RED_BITS, &a);
contain arbitrary values and the rendered buffer is garbage. This only happens if OSMesa is linked together with Octave, standalone OSMesa examples works fine.
On Debian GNU/Linux 8.0 (jessie), Ubuntu 14.04 (trusty) and Fedora 21 there is no need to build OSMesa from source, just use your package manager which installs libosmesa > 10.0.
Build libOSMesa from source
Needed for example for Debian wheezy or Ubuntu 12.04.5 which ships OSMesa 8.0.5.
wget -nc ftp://ftp.freedesktop.org/pub/mesa/current/mesa-10.5.4.tar.xz tar Jxf mesa-10.5.4.tar.xz cd mesa-10.5.4/ autoreconf -fi ./configure \ CXXFLAGS="-O2 -g -DDEFAULT_SOFTWARE_DEPTH_BITS=31" \ CFLAGS="-O2 -g -DDEFAULT_SOFTWARE_DEPTH_BITS=31" \ --disable-xvmc \ --disable-glx \ --disable-dri \ --with-dri-drivers="" \ --with-gallium-drivers="" \ --disable-shared-glapi \ --disable-egl \ --with-egl-platforms="" \ --enable-osmesa \ --enable-gallium-llvm=no \ --prefix=/usr/local/mesa/10.2.2/classic make -j4 # optional make check sudo make install
Floating point textures
Floating point textures are disabled by default due to patent restrictions. We should check if we can enable it with "--enable-texture-float"
known problems
Unfortunately, there are several known problems with using on-screen Mesa and OSMesa at the same time. The --without-OSMesa configure can be used to disable OSMesa if a problem is encountered.
- #44478 segmentation fault when using proprietary Nvidia drivers
- #44979 clumsy/missing configure check, relies on runtime failure
- #44338 doesn't work at all on Windows
- LP #1424059 libosmesa6 is not installable on Ubuntu 14.04 with HWE updates
- #50479 doesn't work at all with libglvnd, now standard in most distributions