...when GDK_DEBUG=opengl is enabled. There was an extraneous "legacy: %s" in
the GDK_NOTE (OPENGL, g_message("...")) line that should not have been there,
due to a copy-and-paste mishap. Get rid of it.
...if GLES (libANGLE) support was enabled in the build. This way, we can
check whether the GL driver is capable enough to support the OpenGL
features that we use in GTK. If the driver is not capable enough, and
GLES support is enabled, we can try to create the GdkGLContext again as a
GLES context.
Group the WGL-specific code and GLES-specific code together, so that we
can reduce the number of #ifdef ... in the code, to make the code more
readable and easily maintained. This will pave the way to add a
fallback mode to use libANGLE (OpenGL/ES) in case the Desktop OpenGL
support is inadequte, if OpenGL/ES support is enabled in the build.
This is somewhat based on the updates that were done in GTK master, so
we are using one subclass for WGL-based GdkGLContexts, and another for
GLES-based GdkGLContexts.
Also remove the underscores in many of the functions in
gdkglcontext-win32.*.
Clean up the code a bit as a result.
Like the recent updates in GTK4, the HWND that we use to obtain the HDC
that we need for OpenGL/GLES operations should really be tied to
GdkWindow, not GdkDisplay, as that is where the Win32 HWND where we
originate from is located, so stop storing the GL HWND in
GdkWin32Display, but just grab them from the GdkWindow that is bound to
the GdkGLContext.
We are more conservative about freeing up GL resources in GTK3, so we
will continue to call ReleaseDC() as we did before.
Some GL drivers such as Mesa-D3D12 do not allow one to call SetPixelFormat() on
a given HDC if one pixel format has been already set for it, so first check the
HDC with GetPixelFormat() to see whether a pixel format has already been set
with the HDC, and only attempt to acquire the pixel format if one has not been
set.
This will fix running with GL on Windows using the Mesa drivers.
We can just group the code for the desktop GL codepath and the EGL
codepath a bit so that we can just have a single location where we
return TRUE upon a successful setup of our WGL/EGL context, and avoid
the C4715 warning that is considered an error when building with
GLib-2.68.x or later using Visual Studio, when we are building without
EGL support.
Intel OpenGL drivers have an issue where the results of a series of
glBlitFramebuffer() can delay updating the display, when we use GDK_GL=always,
which is manifested when attempting to enter text in text boxes.
This attempts to work around this issue by requiring a glFlush() call and a
retry to the same glBlitFramebuffer() calls to avoid delays in keystrokes when
using GDK_GL=always and when not using libANGLE OpenGL/ES emulation, when an
Intel OpenGL driver is being used.
Special thanks to Lukas K. for the analysis and coming up with a workaround,
which this patch builds upon.
Fixes issue 3487
If GLES support is enabled on Windows, force GLES mode if we are running
on a ARM64 version of Windows (i.e. Windows 10 for ARM).
This is required as ARM64 versions of Windows only provide a software
implementation of OpenGL 1.1/1.2, which is not enough for our purposes.
Thus, we could make instead use the GLES support provided via Google's
libANGLE (which emulates OpenGL/ES 3 with Direct3D 9/11), so that we
can run GtkGLArea programs under OpenGL/ES in ARM64 versions of Windows.
Note that eventually we could update the libepoxy build files for Windows
to not check nor enable WGL when building for ARM64 Windows, as the WGL
items do not work, although they do build.
We need to force redraws of the whole window when we are using EGL/ANGLE
during maximize, restore and Aerosnap ops so that we do not get glitches
in the resulting window.
This is for adding a EGL-based renderer which is done via the ANGLE
project, which translate EGL calls to Direct3D 9/11. This is done as a
possible solution to issue #105, especially for cases where the needed
full GL extensions to map OpenGL to Direc3D is unavailable or
unreliable, or when the OpenGL implementation from the graphics drivers
are problematic.
To enable this, do the following:
-Build ANGLE and ensure the ANGLE libEGL.dll and libGLESv2.dll are
available. A sufficiently-recent ANGLE is needed for things to
work correctly--note that the copy of ANGLE that is included in
qtbase-5.10.1 is sufficient. ANGLE is licensed under a BSD 3-clause
license. Note also that Visual Studio 2013 or later is required to
build ANGLE from QT-5.10.1, but the 2013-built ANGLE DLLs can work
without without problems for GTK+ that is built with Visual Studio
2008 or later.
-Build libepoxy on Windows with EGL support enabled.
-Define GDK_WIN32_ENABLE_EGL when building gdk-win32.lib when building
with Visual Studio, or pass in --enable-win32-gles during configure
when building with MinGW/mingw-w64.
-Prior to running GTK+ programs, the GDK_GL envvar needs to contain
gles.
Known issues:
-Only OpenGL ES 3 is supported, ANGLE's ES 2 does not support the needed
extensions, notably GL_OES_vertex_array_object, but its ES 3 support is
sufficient.
-There is no autodetection or fallback mechanism to enable using
EGL/Angle automatically yet. There is no plans to do this in this
commit.
Thanks to LRN for pointing out that we should #include
"win32/gdkwin32.h" instead of #include "gdkwin32.h" for gdkgl.c. LRN
also did the autotools portion of this patch.
Further notes about the autotools --enable-win32-gles option, fom LRN:
This adds --enable-win32-gles option, which enables the
code for GLES renderer. This commit also adds tests for WGL and
EGL in epoxy. The absence of WGL is highly unlikely (it's enabled
by default), but checking for EGL when GLES is enabled is necessary,
as EGL is disabled in Windows builds of epoxy by default.
Since on Windows we need to use a good amount of temporary GL contexts,
we need to switch back to the original GL contexts we were using when
we are done with the temporary GL contexts, otherwise multi-GL windows
will cause confusions causing display artifacts and crashes.
Also, use the GdkWin32GLContext::gl_hdc consistently throughout
the code and remove the GdkWin32Display::gl_hdc as Lukas K pointed out
that GdkWin32Display::gl_hdc becomes out-of-date and so the HDC that the
GL context is bound to becomes incorrect in sceanarios using multiple
windows with GtkGLArea/GdkGLArea items (which would cause the artifacts in
programs that use multiple windows with GtkGLArea/GdkGLArea items, and it
turns out that GdkWin32Display::gl_hdc is actually not necessary to help
keep track of the HDCs we use for our GL contexts.
Partly based on patch from Lukas K <lu@0x83.eu>
https://bugzilla.gnome.org/show_bug.cgi?id=789213
Update the GDKGL implementation:
-Allow legacy contexts to be created.
-Use finer-grained attributes to ask for a pixel format when possible,
which also adds support for anti-aliasing
In fact the changes here are required for GTKGL to work properly on
Windows for 4.x.
Note that creation of gles contexts are not done here, as the system does
not support such contexts directly on Windows, but only through means such
as ANGLE, which is a totally different issue here.
https://bugzilla.gnome.org/show_bug.cgi?id=773528
Other portions of the GDK-Win32 backend make use of this function as
layered windows need to be disabled for GL windows and possibly other
parts, so make this function a private function that is available within
the backend.
https://bugzilla.gnome.org/show_bug.cgi?id=763285
Layered windows and GL do not work well together, so disable layered
windows when initiating a GdkGLContext, so that GtkGLArea programs can run
properly.
Also based on patch by LRN to address the issue.
https://bugzilla.gnome.org/show_bug.cgi?id=763080
We now have proper checks for gdk_screen_is_composited() and a proper
implementation for gdk_screen_get_rgba_visual() for Windows, so we
can remove the comments in this file stating that they aren't
available for Windows.
The existence of OpenGL implementations that do not provide the full
core profile compatibility because of reasons beyond the technical, like
llvmpipe not implementing floating point buffers, makes the existence of
GdkGLProfile and documenting the fact that we use core profiles a bit
harder.
Since we do not have any existing profile except the default, we can
remove the GdkGLProfile and its related API from GDK and GTK+, and sweep
the whole thing under the carpet, while we wait for an extension that
lets us ask for the most compatible profile possible.
https://bugzilla.gnome.org/show_bug.cgi?id=744407
Now that we have a two-stages GL context creation sequence, we can move
the profile to a pre-realize option, like the debug and forward
compatibility bits, or the GL version to use.
Emit an error if the profile is different.
This is a follow-up commit to commits cc45e82 (x11/gl: Ensure we use the
3.2 core profile) and 2d9081d (wayland/gl: Ensure we use the 3.2 core
profile), so that we do the same on GDK-Win32. Update variable names and
comments so that the code is clearer to people, as we still need a
temporary legacy WGL context first before we can use
wglCreateContextAttribsARB() to create a WGL core (3.2+) context.
https://bugzilla.gnome.org/show_bug.cgi?id=741946
Like what is being done in the X11 and Wayland backends, create the
GdkWin32GLContext in 2 steps, where we only create the actual WGL context
in _gdk_win32_gl_context_realize().
https://bugzilla.gnome.org/show_bug.cgi?id=741946
The default ->upload_texture() works also for Windows since commit 27cf0fa,
as some of the problems described in 742953 also applied for GL core
contexts on Windows as well before 27cf0fa. Clean up the GDK-Win32 code a
little bit as a result.
This adds support for OpenGL to the GDK Windows backend using the WGL API
calls, which enables programs that uses the GTK+ GLArea widgets to work on
Windows as well.
This also adds a simple utility function to query for the version of OpenGL
that is supported by the Windows system, like the one provided by the X11
backend.
Many thanks to Alex (and Emmanuele, who started the OpenGL integration in
GTK+) who offered advice and help along the way, as well as the X11 and
Wayland backend for this work to refer to and to model upon.
https://bugzilla.gnome.org/show_bug.cgi?id=740795
