Avoid blurry display on Windows High-DPI resolutions

Blurriness comes from scaling, this handles scaling correctly for pixel
count of our slides though it may lead to tiny windows. This is not an
issue when setting the window fullscreen however, so can be ignored (for
now?).

Closes #302.

pympress/__main__.py

@@ -53,6 +53,10 @@ def uncaught_handler(*exc_info):
         lang, enc = locale.getdefaultlocale()
         os.environ['LANG'] = lang
 
+    # Before any initialisation or imports
+    util.make_windows_dpi_aware()
+
+
 try:
     loaded_locale = locale.setlocale(locale.LC_ALL, '')
 except locale.Error as err:

pympress/util.py

@@ -33,6 +33,7 @@
 import gettext
 import os
 import sys
+import ctypes
 import pathlib
 
 if sys.version_info >= (3, 9):
@@ -524,6 +525,17 @@ def lookup_monitors(display, *windows):
 
         return (*pos, prim_area.most_intersection(all_geom), prim_area.least_intersection(all_geom))
 
+
+def make_windows_dpi_aware():
+    """ Set to avoid blurriness issues on High-DPI resolutions with scaling. """
+    if not IS_WINDOWS:
+        return
+
+    if hasattr(ctypes.windll.shcore, 'SetProcessDpiAwareness'):
+        ctypes.windll.shcore.SetProcessDpiAwareness(2)
+    else:
+        ctypes.windll.user32.SetProcessDPIAware()
+
 ##
 # Local Variables:
 # mode: python