http://www.ogre3d.org/wiki/index.php/Building_From_Source#Linux
emerge USE="cegui devil cg doc" ACCEPT_KEYWORDS="~x86" ogre
emerge -pv sys-devel/automake sys-devel/autoconf sys-devel/libtool dev-util/cppunit\
media-libs/libsdl media-libs/devil media-libs/freetype dev-cpp/gtkmm dev-java/xerces\
media-libs/libpng media-libs/tiff media-libs/lcms media-libs/jpeg dev-cpp/libglademm \
x11-libs/Xaw3d media-libs/openexr media-gfx/nvidia-cg-toolkit