The SGI extension does not define calling SwapInterval with a parameter
of zero as valid. It was just lucky that drivers interpreted this as
vsync off. The EXT_swap_control extension defines zero as a valid value.
Mesa does not appear to support the EXT variant, so we fall back to
MESA_swap_control here, which also supports zero.
This makes the EGL interface select OpenGL|ES contexts over "desktop"
OpenGL ones.
Possibly not useful for anyone outside my own debugging, but you never
know
The spec says it should have an EXT not OES suffix, as it's enabled as
an interaction with GL_EXT_multi_draw_arrays.
On some drivers GetProcAddress() returns NULL, which causes the
GLExtensions init to fail
This 'happened' to work if GetProcAddress() doesn't return NULL on missing
functions (as allowed in EGL) - as the function appears to never be called so
this would not have been noticed.
Mesa also (incorrectly?) exports the EXT version, so this would all
happen to work there, but appears to be contrary to the spec.
This invalid prefix even ended up in the upstream khronos registry, the
issue was reported here:
https://github.com/KhronosGroup/OpenGL-Registry/issues/81
Regression introduced in e99cd57 / 4935: VideoBackends: Set the maximum
range when the depth range is oversized[1]. The NV_depth_buffer_float
extension is not part of OpenGL 3.0, and requiring it causes a hard
crash when it's not supported (e.g. macOS).
[1]: https://github.com/dolphin-emu/dolphin/pull/4935
allthough this is a mesa bug, this is a simple enough workaround for context
creation fails with EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR set.
Otherwise dolphin will fail to create 3.3+ core context with current mesa
version
Seems like NVidia just ignores the forward compatible flag.
Additionally, they neither enable any extension which was designed later...
So either compatible profile, or a huge list of core profiles....
