Add support for OpenGL (3D graphics)

Packages describing “opengl” as local USE flag

Package “opengl” Flag Description
x11-misc/picom Enable features that require opengl (opengl backend, and opengl vsync methods)
dev-games/mygui Use the opengl render subsystem. (cannot combine with ogre)
dev-python/PyQt5 Build bindings for the QtOpenGL module
media-plugins/gst-plugins-gtk Enable gtkglsink OpenGL sink based on desktop OpenGL API
dev-python/QtPy Pull in bindings for the QtOpenGL module
media-video/mpv Enable support for various OpenGL-based video backends
media-libs/gst-plugins-base Enable OpenGL library and plugin via desktop OpenGL API
x11-libs/cairo Build the OpenGL backend
x11-misc/compton Enable VSync with SGI_swap_control OpenGL extension

All packages providing a “opengl” USE flag (112)