We have a global GdkGLBackendType now, just set it.
This way, using the variable forces the backend type, and we don't need
special code handling the env vars in the backends.
It also means setting the env var will now "work" on GDK backends that
don't even support that GL backend and simualte another GDK backend
having registered that GL backend already. So you can run
GDK_DEBUG=gl-wgl gtk4-demo
on test what Wayland will do when WGL is in use.
Include the appropriate headers as some function prototypes were moved lately.
Also, re-order the include order of the gdk/*private.h headers alphabetically
in the files that were updated.
Creative people managed to create an X11 display and a Wayland display
at once, thereby getting EGL and GLX involved in a fight to the death
over the ownership of the glFoo() symbolspace.
A way to force such a fight with available tools here is (on Wayland)
running something like:
GTK_INSPECTOR_DISPLAY=:1 GTK_DEBUG=interactive gtk4-demo
Related: xdg-desktop-portal-gnome#5
On Windows, GLES is not that widely available unless one installs wrapper
libraries such as libANGLE, so GLES/EGL support on Windows is used more like
a fallback mode if Desktop OpenGL (WGL) support is inadequate on the system.
Hence, unless one forces WGL or EGL, we will first try to initialize WGL, and
then try to initialize GLES if enabled and if WGL initialization failed, and
then just return whatever the last result we can obtain from these
initialization attempts, since unlike X11 EGL contexts, we do not have
separate modes for WGL except for legacy and non-legacy contexts.
We were setting the WGL pixel format in GdkWin32Display too early, so the code
does not bail out correctly when we retry establishing the WGL context.
Fix this by pushing back setting the WGL pixel format only after it passes the
shader availability check.
Should fix issue #4257.
When we initialize OpenGL, check whether we have OpenGL 2.0 or later; if not,
check whether we have the 'GL_ARB_shader_objects' extension, since we must be
able to support shaders if using OpenGL for GTK.
If we don't support shaders, as some Windows graphics drivers do not support
OpenGL adequately, notably older Intel drivers, reject and destroy the GL
context that we created, and so fallback to the Cairo GSK renderer, so that
things continue to run, albeit with an expected warning message that the GL
context cannot be realized.
Also, when we could not make the created dummy WGL context current during
initialization, make sure that we destroy the dummy WGL context as well.
Fixes issue #4165.
It is basically not used by default and is pretty much broken at this point, so
it's about time to drop it.
Let's focus on fixing the OLE2 DnD protocol.
The dummy Win32 window that we use to capture display change events and
to create dummy WGL contexts was created with CS_OWNDC, so we really do
not need to (and should not) call ReleaseDC() on the HDC that we
obtained from it, so drop these calls.
Since the shaders need to be updated for using with GLES (libANGLE at
least), default to WGL for now. Unfortunately it is not that common for
Windows to have GLES support, in which the easiest way to obtain such
support is via Google's libANGLE.
It turns out that the problem of the WGL window not drawing was due to
the fact that I messed up where I placed SwapBuffers() during the
conversion... doh:|
At the same time, stop storing the HDC in the GdkWin32GLContextWGL, but
instead always create it along the surface we created, so that it is ready
for use for operating with WGL when we are not dealing with "surfaceless"
contexts. If we are dealing with "surfaceless" contexts, just use the
HDC of the dummy window that we created when we created the
Gdk(Win32)Display.
WGL contexts should now be in working order at this point.
This commit attempts to split GdkWin32GLContext into two parts, one for
WGL and the other for EGL (ANGLE), and attempts to simplify things a
bit, by:
* We are already creating a Win32 window to capture display changes,
so we can just use that to act as our dummy window that we use to
find out the pixel format that the system supports for WGL. We also
use it to obtain the dummy legacy WGL context that we will always
require to create our more advanced Core WGL contexts.
* Like what is done in X11, store up the WGL pixel format or the
EGLConfig in our GdkWin32Display.
* Ensure we do not create the dummy WGL context unnecessarily.
In this way, we can successfully create the WGL/EGL contexts, however
there are some issues at this point:
* For WGL, the code successfully initializes and realizes the WGL
Contexts, but for some reason things became invisible. When running
gtk4-demo, this can be verified by seeing the mouse cursor changing
when moved to spots where one can resize the window, although they
were invisible.
* For EGL, the code initializes EGL but could not realize the EGL
context as shaders failed to compile. It seems like the shader issue
is definitely outside the scope of this MR.
Now that we have the display's context to hook into, we can use it to
construct other GL contexts and don't need a GdkSurface vfunc anymore.
This has the added benefit that backends can have different GdkGLContext
classes on the display and get new GLContexts generated from them, so
we get multiple GL backend support per GDK backend for free.
I originally wanted to make this a vfunc on GdkGLContextClass, but
it turns out all the abckends would just call g_object_new() anyway.
Instead of
Display::make_gl_context_current()
we now have
GLContext::clear_current()
GLContext::make_current()
This fits better with the backends (we can actually implement
clearCurrent on macOS now) and makes it easier to implement different GL
backends for backends (like EGL/GLX on X11).
We also pass a surfaceless boolean to make_current() so the calling code
can decide if a surface needs to be bound or not, because the backends
were all doing whatever, which was very counterproductive.
... or more exactly: Only use paint contexts with
gdk_cairo_draw_from_gl().
Instead of paint contexts being the only contexts who call swapBuffer(),
any context can be used for this, when it's used with
begin_frame()/end_frame().
This removes 2 features:
1. We no longer need a big sharing hierarchy. All contexts are now
shared with gdk_display_get_gl_context().
2. There is no longer a difference between attached and non-attached
contexts. All contexts work the same way.
The vfunc is called to initialize GL and it returns a "base" context
that GDK then uses as the context all others are shared with. So the GL
context share tree now looks like:
+ context from init_gl
- context1
- context2
...
So this is a flat tree now, the complexity is gone.
The only caveat is that backends now need to create a GL context when
initializing GL so some refactoring was needed.
Two new functions have been added:
* gdk_display_prepare_gl()
This is public API and can be used to ensure that GL has been
initialized or if not, retrieve an error to display (or debug-print).
* gdk_display_get_gl_context()
This is a private function to retrieve the base context from
init_gl(). It replaces gdk_surface_get_shared_data_context().
Make _gdk_win32_display_get_monitor_scale_factor() less complex, by:
* Drop the preceding underscore.
* Dropping an unused parameter.
* Using a GdkSurface instead of a HWND, as the HWND that we pass into
this function might have been taken from a GdkSurface, which are now
always created with CS_OWNDC. This means if a GdkSurface was passed
in, we ensure that we only acquire the DC from the HWND once, and do
not attempt to call ReleaseDC() on it.
* Store the HDC that we acquire from the GdkSurface's HWND into the
surface, and use that as the HDC we need for our GdkGLContext.
* Drop the gl_hwnd from GdkWin32Display, as that is really should be
stored in the GdkSurface.
* For functions that were updated, name GdkWin32Display variables as
display_win32 and GdkSurface variables as surface, to unify things.
* Stop calling ReleaseDC() on the HDC that we use for OpenGL, since
they were acquired from HWND's created with CS_OWNDC.
It apparently worked by chance in the past, but now causes e.g.
alphanumeric characters to be interpreted as half-width katakana
when using the Japanese IME.
Determine the root_x and root_y coordinates of the drag surface by
relying on the coordinates of the surface where the drag is being
carried out, plus the coordinates that we receive from the drag event,
which is in-line with what the X11 backend does.
This will prevent the drag surface from being initially drawn at the
correct position, but jumping towards the top-left corner of the screen
shortly afterwards.
The DnD support will still need some more updates to function correctly
on Windows, but at least this is a small improvement.
Fixes issue #3798.
If we are undergoing a surface move, just apply the next_layout anyways,
even if we are not moving a toplevel surface.
Update the way how we obtain the x and y coordinates of a surface, if it
is a toplevel, apply the x and y coordinates from the results from we
obtained the underlying Win32 HWND, as we did before. But if it is a
popup, use gdk_win32_surface_get_geometry() to obtain the correct x and
y coordinates to place our popup surface.
Also correct how we compute the shadow dimensions, and the final popup
rectangle as we attempt to layout the popup surface, since GDK-Win32
keeps track of the shadow dimensions in system (unscaled) units, not GDK
units.
Fixes issue #3793.
Add support to share the WGL context in GDK with the WGL context in GStreamer,
so that we can also use OpenGL in the gstreamer media backend to playback
videos. For now OpenGL/ES is not supported for this under Windows.
The process of setting this up in Windows is a little bit more involved, as:
* The OpenGL support in GstGL requires a GL 4.1 Core context, but we may just
get the GL version from wglCreateContextAttribsARB() that we pass into the
attributes, which is 3.2 by default. So, try to ask for a 4.1 Core context
first if we are asking for anything less.
* There is only one GstDisplay available for Windows, so we just use
gst_gl_display_new().
* We must explicitly tell libepoxy that we are using wglMakeCurrent() outside
of libepoxy that is being used in GdkGL, otherwise we would end up crashing
as the GL/WGL function pointers would become invalid.
* We must also deactivate temporarily the underlying WGL context that was made
current by gdk_gl_context_make_current() so that when
gst_gl_display_create_context() calls wglShareLists(), we won't get bitten
by error 0xaa (resource busy), as some drivers don't handle this well when
the GL context is current in another thread.
For the last two points we make use of macros defined by the platforms that the
build is done for to help us carry out the necessary tasks as needed.
Thanks to Matthew Waters for the info on integrating GstGL and windowing
toolkits on Windows.
