# For OpenGL we have three separate concepts, with a list of possibilities in each:
# * opengl APIs - opengl and/or gles2; USE=opengl and USE=gles2 enable these accordingly; if neither is enabled, OpenGL helper library and elements are not built at all and all the other options aren't relevant
# * opengl platforms - glx and/or egl; also cgl, wgl, eagl for non-linux; USE="X opengl" enables glx platform; USE="egl" enables egl platform. Rest is up for relevant prefix teams.
# * opengl windowing system - x11, wayland, win32, cocoa, android, viv_fb, gbm and/or dispmanx; USE=X enables x11 (but for WSI it's automagic - FIXME), USE=wayland enables wayland, USE=gbm enables gbm (automagic upstream - FIXME); rest is up for relevant prefix/arch teams/contributors to test and provide patches
# With the following limitations:
# * If opengl and/or gles2 is enabled, a platform has to be enabled - x11 or egl in our case, but x11 (glx) is acceptable only with opengl
# * If opengl and/or gles2 is enabled, a windowing system has to be enabled - x11, wayland or gbm in our case
# * glx platform requires opengl API
# * wayland, gbm and most other non-glx WSIs require egl platform
# Additionally there is optional dmabuf support with egl for additional dmabuf based upload/download/eglimage options;
# and optional graphene usage for gltransformation and glvideoflip elements and more GLSL Uniforms support in glshader;
# and libpng/jpeg are required for gloverlay element;
# Keep default IUSE options for relevant ones mirrored with gst-plugins-gtk and gst-plugins-bad
# Dependencies needed by opengl library and plugin (enabled via USE gles2 and/or opengl)
# dmabuf automagic from libdrm headers (drm_fourcc.h) and EGL, so ensure it with USE=egl (platform independent header used only, thus no MULTILIB_USEDEP); provides dmabuf based upload/download/eglimage options