Ensure that we take the DPI scaling into account so that surfaces will
be placed at their correct positions upon an AeroSnap operation on HiDPI
displays.
Also, use the X coordinate of the surface as-is during snap up so that
we do not inadvertently move the surface to the very left. Also fix the
AeroSnap indicator drawing for snap up so that it is drawn at the
correct places.
Since we are updating these functions, make the old GdkWindow-era
variable names to match better the names we use nowadays.
Use the debug envvar 'GDK_DEBUG=gl-egl' to determine whether we want to try to
initialize EGL first before trying WGL, as a means for people to more easily
enable EGL support on Windows to test EGL there (such as to debug the shaders,
for instance)
This will clean up the EGL code in GDK-Win32, as well as fixing crashes caused
by using an invalid EGL context in gdk_gl_context_make_current() as we did not
store up the EGL context in the correct place (lost during the transition to
the common EGL initialization code).
On the Windows/libANGLE side, the initialization of EGL has now fully moved to
the common code in GDK, but we will still default on WGL for now. Help is
really appreciated for fixing the shaders on libANGLE!
We need to ensure that gdk_display_get_egl_display() is available even if EGL
is not enabled in the build, so that things will continue to link and work.
For builds without EGL, just return NULL.
This will port the EGL code in GDK-Win32 to use the common GDK code to
initialize EGL. However, at the current state, although EGL is
correctly initialized, this code is disabled for now since
gdk_gl_context_make_current() fails as the shaders do not work for EGL
via libANGLE on Windows.
We can now clean things up in gdkglcontext-win32-egl.c as a result.
Ping/pong serials are not meant to be interpreted as user input serials
(e.g. those given back later to the compositor on grabs). As a matter
of fact, Mutter uses a different count (i.e. timestamps) in these, so
using these serials may confuse the compositor into denying certain
operations like DnD.
Instead of using GL_BACK, use GL_BACK_LEFT, because the spec demands
this (many drivers don't).
Also move the call from the GDK backends into the GLContext code, as
this is a generic EGL issue (nvidia being the main driver in need of
this call, see 9c4c4eaaa1 for a longer
discussion).
Fixes#4402
gdk_display_create_gl_context only returns NULL when there is
an error set or asserts/aborts. So nullalbe annotation isn't needed.
Similar to 53312cf696
This is an alternative to gdk_surface_create_gl_context() when the
context is meant to only draw to textures.
This is useful in the testsuite or in GStreamer or with GLArea,
basically whenever we want to do GL stuff but don't need to actually
draw anything on screen.
A bunch of code will need to be updated to deal with context->surface
being NULL.
