As written, these contain undefined stack contents, which in practice
causes crashes/hangs and/or triggers the validation layers (they
complain about `pNext` and `flags` not being NULL).
this variable was added in commit 2067a7db8e and
ultimately tracks if this is a surface's first present. checking if the current
bo is NULL provides the same functionality and cuts down on a redundant piece
of state potentially getting out of sync in the future
SetDisplayMode needs to recreate the EGL surfaces, which then need to be
bound along with the correct context in each rendering thread
commit 3a1d7d9c9a removed this behavior which
has broken using SetDisplayMode when rendering with multiple contexts
the commit message was rather vague, but if the surfaces do need to be
created immediately, this process probably needs to be split such that
surface is created immediately, but the binding is deferred
and remove duplicate SDL_WINDOWEVENT_RESIZED event
commit 2067a7db8e made SDL_SetWindowSize and
SDL_SetWindowFullscreen modify the display mode previously set by a call to
SDL_SetWindowDisplayMode
as far as I understand the SDL API, calling SDL_SetWindowDisplayMode followed
by calling SDL_SetWindowFullscreen(..., SDL_WINDOW_FULLSCREEN) is the correct
way to mode set / switch to fullscreen
this change restores that functionaliy when switching to SDL_WINDOW_FULLSCREEN,
but other cases are still modifying the display mode set by the user. rather
than modifying the display mode set by the user, it seems this logic inside of
KMSDRM_ReconfigureWindow should be pushed further down into KMSDRM_CreateSurfaces
(as it was originally) to only modify the final mode that's set (based on the
fullscreen flags), but not override the mode requested by the user
commit 2067a7db8e introduced new surface_w and surface_h
variables which were passed to gbm_surface_create rather than the dimensions from the
drmModeModeInfo structure. commit 5105ecf8b1 further
refactored this code and no longer synchronized these variables inside
KMSDRM_SetDisplayMode, breaking it
this change removes the variables since they're seemingly redundant to begin with
In some cases, it can be useful to have the KMSDRM backend even if it cannot
be used for rendering. An app may want to use SDL for input processing while
using another rendering API (such as an MMAL overlay on Raspberry Pi) or
using its own code to render to DRM overlays that SDL doesn't support.
This also moves the check for DRM master to an earlier point where we can fail
initialization of the backend, rather than allowing the backend to initialize
then failing the creation of a window later.
