Don't crash when using Alt-Tab on Windows or Linux while fullscreen

[bsittler]

Don't crash when using Alt-Tab on Windows or Linux while fullscreen. This fix was already present on macOS.

[bsittler]

Specifically this crash on Alt-Tab while fullscreened was seen in Windows 10 using the DirectX driver. Pressing the Windows key also crashed it the same way. Both are resolved by this change

[bsittler]

The new OpenGL driver on Windows exhibits the same symptoms, unfortunately. Also I got similar crashes in Linux. If I use Alt-Enter to switch to true fullscreen mode, then press the Windows key to access the Start menu (or its Linux equivalent), Meka crashes instantly.

[ocornut]

Where exactly do you get a crash?

Note that enabling this essentially breaks fullscreen mode for me, as I end up with desktop resolution and the MEKA contents in e.g. a quarter of the corner.

[bsittler]

Where exactly do you get a crash?

Note that enabling this essentially breaks fullscreen mode for me, as I end up with desktop resolution and the MEKA contents in e.g. a quarter of the corner.

I see. I use the config file to make MEKA and desktop resolution identical. When I use unmodified current MEKA on Windows and make it fullscreen using Alt-Enter and then tap the Win key, it crashes like this:

In the console where I started it I see:

Assertion failed: g_screenbuffer_locked_region != NULL && g_screenbuffer_locked_buffer != NULL, file D:\cygwin64\home\bsitt\src\meka\meka\srcs\video.cpp, line 367