This is needed to support CHERI, and thus Arm's experimental Morello
prototype, where pointers are implemented using unforgeable capabilities
that include bounds and permissions metadata to provide fine-grained
spatial and referential memory safety, as well as revocation by sweeping
memory to provide heap temporal memory safety.
On most systems (anything with a flat memory hierarchy rather than using
segment-based addressing), size_t and uintptr_t are the same type.
However, on CHERI, size_t is just an integer offset, whereas uintptr_t
is still a capability as described above. Casting a pointer to size_t
will strip the metadata and validity tag, and casting from size_t to a
pointer will result in a null-derived capability whose validity tag is
not set, and thus cannot be dereferenced without faulting.
The audio and cursor casts were harmless as they intend to stuff an
integer into a pointer, but using uintptr_t is the idiomatic way to do
that and silences our compiler warnings (which our build tool makes
fatal by default as they often indicate real problems). The iconv and
egl casts were true positives as SDL_iconv_t and iconv_t are pointer
types, as is NativeDisplayType on most OSes, so this would have trapped
at run time when using the round-tripped pointers. The gles2 casts were
also harmless; the OpenGL API defines this argument to be a pointer type
(and uses the argument name "pointer"), but it in fact represents an
integer offset, so like audio and cursor the additional idiomatic cast
is needed to silence the warning.
- especially because we can be promoted to true color 888
make sure we don't select a potentially software implementation
- hopefully fix bug #1482 (EGL ChooseConfig selects software renderer on Android)
It's already set with ANativeWindow_setGeometry, and eventually set/changed also by eglCreateWindowSurface.
- avoid issues with older device where SurfaceView cycle create/changed/destroy appears broken:
calling create/changed/changed, and leading to "deuqueBuffer failed at server side, error: -19", with black screen.
- re-read the format after egl window surface is created, to report the correct one (sometimes, changed from RGBA8888 to RGB24)
There is an error "E libEGL : validate_display:91 error 3008 (EGL_BAD_DISPLAY)"
that occurs when calling "eglQueryString(display, EGL_VERSION)", with EGL_NO_DISPLAY.
Khronos says "EGL_BAD_DISPLAY is generated if display is not an EGL display connection, unless display is EGL_NO_DISPLAY and name is EGL_EXTENSIONS."
but this was added in SDL with "EGL 1.5 allows querying for client version"
( 56363ebf61 )
In fact:
- it actually doesn't work on Android that has 1.5 egl client
- it works on desktop X11 (using SDL_VIDEO_X11_FORCE_EGL=1)
The commit moves the version call where it's used, eg inside the "if (platform) {"
and checks that "eglGetPlatformDisplay" has been correctly loaded.
If app requested <= 16 color depth and there is a 24-bit config available,
favor that. This fixes things that quietly expect to get truecolor output
but don't request it (...like SDL's render api...) and things that are
probably requesting 16-bit color as a fallback but expecting reasonable
systems to give them full depth.
Specifically, this fixes Life is Strange on Wayland, which uses the latter
approach, and anything using SDL_Render on Wayland, which uses the former.
Fixes#4056.
Fixes#4132.
- Move an immutable condition out of a for loop.
- Add a break statement to that loop when we find what we're looking for.
- Add an assert to make sure we don't overflow a buffer.
- Wrap a single-statement if block in braces.
- Adjust some whitespace.
This is handled in in the higher-level SDL_GL_LoadLibrary().
All uses of SDL_EGL_LoadLibrary (which calls the Only version) are just
target-specific wrappers for their own GL_LoadLibrary hook, with two
exceptions which now handle driver_loaded correctly (although it's
questionable if these init-if-no-one-did-it-correctly-already code blocks
should exist at all, fwiw).
Fixes Bugzilla #5190.
On Raspberry Pi 3 via the VC4 driver in firmware KMS mode, none of the
found configs match the desired format, causing the function to fall through
without any config being selected.
Fix by first iterating over the found configs, and if no match exists,
don't exclude the non-matching configs. This should fix RPI3 and possibly other
targets without breaking targets that have a matching native format (such as RPI4).
This allows you to bind surfaceless contexts on a background thread to, for
example, load assets in a separate context, for platforms that have different
requirements about sharing surfaces, etc.
Martin's notes on the matter:
"Here's a patch that enables passing NULL windows to SDL_GL_MakeCurrent, if
the involved APIs allow it. Currently, this is only the case for EGL, and
even then only if some specific extensions are present (which they usually
are).
If "surfaceless" contexts are not supported, SDL_GL_MakeCurrent continues to
generate an error (albeit with a more specific error message than it used to),
so this should not break anything that wasn't broken before."
(Please see https://bugzilla.libsdl.org/show_bug.cgi?id=3695 for more
discussion.)
Fixes Bugzilla #3695.
This results in a dlsym() call, which causes Emscripten to panic if the game
wasn't explicitly built dlopen support. eglGetProcAddress works just fine on
this platform, so just let that codepath handle it.
Use eglGetProcAddress for everything on EGL >= 1.5. Try SDL_LoadFunction first
for EGL <= 1.4 in case it's a core symbol, and as a fallback if
eglGetProcAddress fails. Finally, for EGL <= 1.4, fallback to
eglGetProcAddress to catch extensions not exported from the shared library.
(Maybe) Fixes Bugzilla #4794.
The Offscreen video driver is intended to be used for headless rendering
as well as allows for multiple GPUs to be used for headless rendering
Currently only supports EGL (OpenGL / ES) or Framebuffers
Adds a hint to specifiy which EGL device to use: SDL_HINT_EGL_DEVICE
Adds testoffscreen.c which can be used to test the backend out
Disabled by default for now
Rainer Sabelka
After I did an upgrade of my arch Linux installation (resulting in an update of Mesa to version 18.2.3), all my SDL2 applications which use the KMS/DRM driver stopped working.
Reason: Creating a Window with SDL_CreateWindow failed because the call to EGL
eglCreateWindowSurface() returns an error "EGL_BAD_MATCH".
After investigating with the debugger I figured, that the configuration, which has been selected from the output of eglChooseConfig(), has an "EGL_NATIVE_VISUAL_ID" which does not match the "format" of the underlying gbm surface.
The attached patch fixes the problem. It does so, by mimicking Weston's behavior.
All configurations returned from eglChooseConfig() which have an visual_id different from the gbm format are discarded, and only from the remaining ones the "best" match is selected.
If we change the current context behind the app's back, those tracking
the current context to minimize context changes are going to get
confused.
This brings the EGL backend in line with the GLX one.
Fixes Bugzilla #4199.
Sam Lantinga
Ryan C. Gordon
Martin Mauersics
Ivan Epifanov
Ethan Lee
Eric Engestrom
Jessica Clarke
Sylvain
Haelwenn (lanodan) Monnier
Cacodemon345
Manuel Alfayate Corchete
Conn O'Griofa
Brandon Schaefer
Tomeu Vizoso
sezero