Similar change to the windowed apps, also resetting it when core context
creation fails or when the workaround is applied. This change is not
done for CGL, iOS and Windows EGL apps, as these are either GLES-only
or, in case of macOS, such flag is not available.
It's enabled by default, but it's possible to explicitly remove the flag
to allow for using features that are not enabled otherwise (such as wide
lines). To make the flag handling easier, there's now also new
addFlags() and clearFlags() methods.
There's much more to work around / fix, but this is a start. First we
need to create the context with a pbuffer, otherwise eglMakeCurrent()
crashes deep inside. Second, it doesn't treat EGL_CONTEXT_FLAGS_KHR as a
bitfield, so it blows up when encountering a combination of zero flags.
In that case we're simply not sending the flags there. This would also
blow up when there's more than one flag passed, but there's just one
flag for debug context at the moment, so shouldn't be a problem.
Same as windowSize(), it's there now just to make the ported examples
compile at the moment. Will need to be replaced with proper
implementation later.
What's new:
* The style is consistent with the dark m.css theme that's used on the
website and so provides a bit better "brand identity".
* The canvas is responsive, looking properly on mobile and scaling down
with aspect ratio preservation if the screen is too narrow.
* It's now possible to override canvas size and aspect ratio or make it
"fullscreen", i.e. occupying the whole browser window.
* If the app crashes, a helpful message is printed instead of
everything just being stuck.
With HiDPI support it's no longer just about window size changing -- if
the framebuffer size is different than window size, on resize both are
changed to new (different) values. Other than that, for example, when
moving a window from one display to another with a different DPI,
all three of window size, framebuffer size and DPI scaling can change as
well. This should be all reflected in the event.
This change is done in all Application classes, but the full
implementation is only in the SDL2 implementation at the moment, as the
others don't have full HiDPI support implemented yet. The old
viewportEvent(const Vector2i&) is deprecated and for backwards
compatibility called with either framebufferSize() or windowSize()
(depending on level of HiDPI support) from the new event. Overriding the
old one will still work as expected (in case you build with
MAGNUM_BUILD_DEPRECATED enabled and use the `override` keyword -- which
you should); overriding the new one will cause the compat implementation
to not be called anymore.
In order to make it possible to preserve backwards compatibility, the
viewportEvent() is no longer pure virtual in Screen. That's also
consistent with all Application implementations.
For consistency with the new Sdl2Application implementation. The
dpiScaling() function is not exposed, as I don't want to go through all
the pain of getting this through raw Xlib -- and the *XApplication
classes are meant to be used in very restricted embedded environments
that probably don't have any HiDPI issues anyway.
I'm not really sure if the extra work and link dependencies are worth
the warning, but since I *need* to do something similar for Windows, why
not have it here as well.