This adds gs_enum_adapters and gs_get_adapter_count to the opengl
backend and promotes these to multiplatform graphics functions.
However we need to make an internal device change, device_enum_adapters
must pass in the current device on opengl to ensure that adapter #0 is
the display adapter. We do this to avoid changes to plugins already
checking against obs_video_info.adapter which is always 0 and expected
to be the device OBS was initialized on.
The actual implementation reports the dri render node (or /Software).
This allows plugins to query non-video features of the adapters like
VA-API/NVENC/etc or other cross device functionality. `/Software` is
chosen to avoid opening random files in the current directory if its
passed along as a file path like the regular dri render nodes.
When sharing DMA-BUFs it is required the announce the underlying
hardware capabilities via supported modifiers.
Add new device_query_dmabuf_capabilities vfunc to gs_exports and connect it
to the egl implementation stubs in the supported render platforms. Add a new
public method gs_query_dmabuf_capabilities() that calls the vfunc above.
Add new device_query_dmabuf_modifiers vfunc to gs_exports and connect it
to the egl implementation in the supported render platforms. Add a new
public method gs_query_dmabuf_modifiers() that calls the vfunc above.
This adds the drmbuf format as a parameter separate from the obs texture
format that will be used. drmbuf's may have a variety of formats that we
need to pass correctly to get a usable texture which may correspond to
multi-platform texture formats.
DMA-BUF is a widespread Linux buffer sharing mechanism. It is what's
commonly used zero-copy screen sharing by Wayland compositors.
Add a new 'device_texture_create_from_dmabuf' vfunc to gs_exports,
and stub implementations to libobs-opengl. Add a new public method
gs_texture_create_from_dmabuf() that calls this vfunc.
Move the OBS_USE_EGL environment variable check to obs-app.cpp,
and set the OBS platform to be either OBS_NIX_PLATFORM_X11_GLX
or OBS_NIX_PLATFORM_X11_EGL.
Move the GLX-related code to gl-x11-glx, and introduce gl-nix as
a winsys-agnostic abstraction layer. gl-nix serves as the runtime
selector of which winsys going to be used. Only the X11/GLX winsys
is available now, but later commits will introduce the X11/EGL
winsys as well.
The gl-nix code was originally written by Jason Francis <cycl0ps@tuta.io>
