Blurry window on Windows and HiDPI displays

[emersion]

See:

• https://blogs.msdn.microsoft.com/patricka/2010/04/15/why-does-a-high-dpi-setting-make-my-application-look-fuzzy-and-have-clipped-text/
• https://msdn.microsoft.com/en-us/library/dn469266(v=vs.85).aspx#using_an_application_manifest

[andlabs]

High DPI is a TODO that I will get to soon.

[ebraminio]

There are also some other corner cases like multi monitor dpi, https://bugs.chromium.org/p/chromium/issues/detail?id=426656 but I feel supporting that would be just unnecessary.

[ssylvan]

FWIW I still see blurry text on latest. See screenshots here. Left is default, middle is using compatibility mode to override it so that the application is in charge of scaling, right is using "System (Enhanced)" scaling.

This is with 125% DPI scaling. Note that the left is blurry, the right is sharp but too small, and the right looks sharp and the right size. So it seems like it would somehow need to tell windows to do the "enhanced" scaling, whatever that means.

Applying the changes in andrew-pa's fork seems to work for me.

[andlabs]

The problem is simply calling SetProcessDPIAware() isn't enough to be properly DPI aware; I would need to go through and handle DPI changes correctly (including propagating them to children, or at leat I think I have to, I'm not sure), and make sure I"m not accidentally doing pixel-specific stuff (like in that color button snippet).

[SatoMew]

Here is the latest official documentation for Windows. Notably, libui needs to support per-monitor v1 and v2 properly so at least Windows 8.1 and 10 Creators Update, respectively, plus the latter's GDI scaling and the mixed mode introduced by 10 Anniversary Update. This is because users with high PPI screens are equally likely to use these recent Windows versions.

Windows Vista, 7, and 8 are limited to system DPI awareness and the optional exclusivity of using the old Windows XP scaling or also the new one. This article is very informative, too.

[chris-morgan]

Here is an example of an excellently-done DPI awareness implementation: https://github.com/tomaka/winit/blob/master/src/platform/windows/dpi.rs. (See rust-windowing/winit#332 and rust-windowing/winit#548 for further background.)