Set Windows DPI awareness to best possible setting.

Author: QuLogic

lib/matplotlib/backends/_backend_tk.py

@@ -866,7 +866,7 @@ def new_figure_manager_given_figure(cls, num, figure):
         with _restore_foreground_window_at_end():
             if cbook._get_running_interactive_framework() is None:
                 cbook._setup_new_guiapp()
-                _c_internal_utils.Win32_SetDpiAwareness()
+                _c_internal_utils.Win32_SetProcessDpiAwareness_max()
             window = tk.Tk(className="matplotlib")
             window.withdraw()
 

src/_c_internal_utils.c

@@ -125,10 +125,42 @@ mpl_SetForegroundWindow(PyObject* module, PyObject *arg)
 }
 
 static PyObject*
-mpl_SetDpiAwareness(PyObject* module)
+mpl_SetProcessDpiAwareness_max(PyObject* module)
 {
 #ifdef _WIN32
+#ifdef _DPI_AWARENESS_CONTEXTS_
+    // These functions and options were added in later Windows 10 updates, so
+    // must be loaded dynamically.
+    typedef BOOL (WINAPI *IsValidDpiAwarenessContext_t)(DPI_AWARENESS_CONTEXT);
+    typedef BOOL (WINAPI *SetProcessDpiAwarenessContext_t)(DPI_AWARENESS_CONTEXT);
+
+    HMODULE user32 = LoadLibrary("user32.dll");
+    IsValidDpiAwarenessContext_t IsValidDpiAwarenessContextPtr =
+        (IsValidDpiAwarenessContext_t)GetProcAddress(
+            user32, "IsValidDpiAwarenessContext");
+    SetProcessDpiAwarenessContext_t SetProcessDpiAwarenessContextPtr =
+        (SetProcessDpiAwarenessContext_t)GetProcAddress(
+            user32, "SetProcessDpiAwarenessContext");
+    if (IsValidDpiAwarenessContextPtr != NULL && SetProcessDpiAwarenessContextPtr != NULL) {
+        if (IsValidDpiAwarenessContextPtr(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2)) {
+            // Added in Creators Update of Windows 10.
+            SetProcessDpiAwarenessContextPtr(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
+        } else if (IsValidDpiAwarenessContextPtr(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE)) {
+            // Added in Windows 10.
+            SetProcessDpiAwarenessContextPtr(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE);
+        } else if (IsValidDpiAwarenessContextPtr(DPI_AWARENESS_CONTEXT_SYSTEM_AWARE)) {
+            // Added in Windows 10.
+            SetProcessDpiAwarenessContextPtr(DPI_AWARENESS_CONTEXT_SYSTEM_AWARE);
+        }
+    } else {
+        // Added in Windows Vista.
+        SetProcessDPIAware();
+    }
+    FreeLibrary(user32);
+#else
+    // Added in Windows Vista.
     SetProcessDPIAware();
+#endif
 #endif
     Py_RETURN_NONE;
 }
@@ -160,11 +192,11 @@ static PyMethodDef functions[] = {
      "Win32_SetForegroundWindow(hwnd, /)\n--\n\n"
      "Wrapper for Windows' SetForegroundWindow.  On non-Windows platforms, \n"
      "a no-op."},
-    {"Win32_SetDpiAwareness",
-     (PyCFunction)mpl_SetDpiAwareness, METH_NOARGS,
-     "Win32_SetDpiAwareness()\n--\n\n"
-     "Set Windows' process DPI awareness to be enabled. On non-Windows\n"
-     "platforms, does nothing."},
+    {"Win32_SetProcessDpiAwareness_max",
+     (PyCFunction)mpl_SetProcessDpiAwareness_max, METH_NOARGS,
+     "Win32_SetProcessDpiAwareness_max()\n--\n\n"
+     "Set Windows' process DPI awareness to best option available.\n"
+     "On non-Windows platforms, does nothing."},
     {NULL, NULL}};  // sentinel.
 static PyModuleDef util_module = {
     PyModuleDef_HEAD_INIT, "_c_internal_utils", "", 0, functions, NULL, NULL, NULL, NULL};