Implemented High-DPI support for Windows.

Applications should use ``scaleToDpi()`` to convert pixel numbers from 96 DPI to system DPI.

2 files changed, 17 insertions, 3 deletions

diff --git a/src/nigui/private/windows/platform_impl.nim b/src/nigui/private/windows/platform_impl.nim
index a84ffbd..6a04c46 100755
--- a/src/nigui/private/windows/platform_impl.nim
+++ b/src/nigui/private/windows/platform_impl.nim
@@ -17,7 +17,6 @@ import tables
 const pTopLevelWindowClass = "1"
 const pContainerWindowClass = "2"
 const pCustomControlWindowClass = "3"
-
 var pDefaultParentWindow: pointer
 var pKeyState: KeyState
 var pKeyDownKey: Key
@@ -37,7 +36,7 @@ proc pCheckGdiplusStatus(status: int32, showAlert = true) =
       pRaiseLastOSError(showAlert)
     else:
       raiseError("A GDI+ error occured. (Status: " & $status & ")", showAlert)
-
+  
 proc pColorToRGB32(color: Color): RGB32 =
   result.red = color.red
   result.green = color.green
@@ -379,6 +378,10 @@ proc init(app: App) =
   app.defaultBackgroundColor = GetSysColor(COLOR_BTNFACE).pRgb32ToColor()
   app.defaultFontFamily = "Arial"
   fScrollbarSize = GetSystemMetrics(SM_CXVSCROLL)
+  # High DPI support:
+  discard SetProcessDpiAwareness(PROCESS_SYSTEM_DPI_AWARE)
+  fSystemDpi = GetDpiForWindow(pDefaultParentWindow)
+  fDefaultFontSize = defaultFontSizeForDefaultDpi.scaleToDpi
 
 proc runMainLoop() =
   var msg: Msg
diff --git a/src/nigui/private/windows/windows.nim b/src/nigui/private/windows/windows.nim
index f35e603..e43bc56 100755
--- a/src/nigui/private/windows/windows.nim
+++ b/src/nigui/private/windows/windows.nim
@@ -24,6 +24,7 @@
 {.pragma: libShell32, stdcall, dynlib: "Shell32.dll".}
 {.pragma: libGdiplus, stdcall, dynlib: "Gdiplus.dll".}
 {.pragma: libComdlg32, stdcall, dynlib: "Comdlg32.dll".}
+{.pragma: libShcore, stdcall, dynlib: "Shcore.dll".}
 
 
 # ----------------------------------------------------------------------------------------
@@ -190,7 +191,9 @@ const
   PixelFormat32bppARGB* = 2498570
   ImageLockModeWrite* = 2
   MAPVK_VSC_TO_VK_EX* = 3
-
+  PROCESS_DPI_UNAWARE* = 0
+  PROCESS_SYSTEM_DPI_AWARE* = 1
+  PROCESS_PER_MONITOR_DPI_AWARE* = 2
 
 
 # ----------------------------------------------------------------------------------------
@@ -428,6 +431,7 @@ proc GetClipboardData*(uFormat: int32): pointer {.importc: "GetClipboardData", l
 proc SetClipboardData*(uFormat: int32, hMem: pointer): pointer {.importc: "SetClipboardData", libUser32.}
 proc EmptyClipboard*(): bool {.importc: "EmptyClipboard", libUser32.}
 proc MapVirtualKeyW*(uCode, uMapType: int32): int32 {.importc: "MapVirtualKeyW", libUser32.}
+proc GetDpiForWindow*(hWnd: pointer): int32 {.importc: "GetDpiForWindow", libUser32.}
 
 when defined(cpu64):
   # Only available on 64-bit Windows:
@@ -523,3 +527,10 @@ proc CommDlgExtendedError*(): int32 {.importc: "CommDlgExtendedError", libComdlg
 proc GetOpenFileNameW*(lpofn: var OpenFileName): bool {.importc: "GetOpenFileNameW", libComdlg32.}
 proc GetSaveFileNameW*(lpofn: var OpenFileName): bool {.importc: "GetSaveFileNameW", libComdlg32.}
 
+
+# ----------------------------------------------------------------------------------------
+#                                       Comdlg32 Procs
+# ----------------------------------------------------------------------------------------
+
+proc SetProcessDpiAwareness*(value: int32): int32 {.importc: "SetProcessDpiAwareness", libShcore.}
+