Merge pull request #7 from chickensoft-games/feat/native-resolution

feat: determine correct scale factor and native pixel resolution on windows

Chickensoft.PlatformExt/src/extensions/Displays.cs

@@ -40,6 +40,32 @@ public float GetDisplayScaleFactor(Window window) {
     return DisplayServer.Singleton.ScreenGetScale(window.CurrentScreen);
   }
 
+  /// <summary>
+  /// Finds the native resolution of the screen that the given window is on using
+  /// platform-specific API's on macOS and Windows.
+  /// </summary>
+  /// <param name="window">Godot window.</param>
+  /// <returns>Native resolution on macOS or Windows.</returns>
+#if GDEXTENSION
+  [BindMethod]
+#endif
+  public Vector2I GetNativeResolution(Window window) {
+    var id = window.GetWindowId();
+
+    if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX)) {
+      return MacOS.Displays.GetScreenResolution(
+        MacOS.Displays.GetCGDirectDisplayID(id)
+      );
+    }
+    else if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows)) {
+      return Windows.Monitors.GetMonitorResolution(
+        Windows.Monitors.GetMonitorHandle(id)
+      );
+    }
+
+    return DisplayServer.Singleton.ScreenGetSize(window.CurrentScreen);
+  }
+
   private static float GetDisplayScaleFactorMacOS(Window window) {
     // This will always be 1, 2, or 3, due to limited information from macOS.
     // This scale factor represents the type of retina display, but not the
@@ -54,6 +80,9 @@ private static float GetDisplayScaleFactorMacOS(Window window) {
 
     var logicalResolutionRetina =
       DisplayServer.Singleton.ScreenGetSize(window.CurrentScreen);
+
+    // Note that we divide by Godot's reported retina scale factor, since
+    // the Godot DisplayServer has scaled the logical resolution by it.
     var logicalResolution = new Vector2I(
       Mathf.RoundToInt(logicalResolutionRetina.X / retinaScale),
       Mathf.RoundToInt(logicalResolutionRetina.Y / retinaScale)
@@ -66,6 +95,7 @@ private static float GetDisplayScaleFactorMacOS(Window window) {
 
   private static float GetDisplayScaleFactorWindows(Window window) {
     var hMonitor = Windows.Monitors.GetMonitorHandle(window.GetWindowId());
+
     return Windows.Monitors.GetMonitorScale(hMonitor);
   }
 }

Chickensoft.PlatformExt/src/macOS/Displays.cs

@@ -1,9 +1,9 @@
 namespace Chickensoft.Platform.MacOS;
 
+using System;
 using Godot;
-using ObjC = Lib.ObjectiveC;
 using CG = Lib.CoreGraphics;
-using System;
+using ObjC = Lib.ObjectiveC;
 
 internal static partial class Displays {
   /// <summary>

Chickensoft.PlatformExt/src/windows/Monitors.cs

@@ -1,6 +1,8 @@
 namespace Chickensoft.Platform.Windows;
 
 using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
 using Godot;
 
 internal sealed class Monitors {
@@ -9,15 +11,16 @@ internal sealed class Monitors {
   /// </summary>
   /// <param name="godotWindowId">Godot window id.</param>
   /// <returns>Win32 monitor handle.</returns>
-  public static uint GetMonitorHandle(int godotWindowId) {
+  public static long GetMonitorHandle(int godotWindowId) {
     var nativeHandle = DisplayServer
       .Singleton
-      .WindowGetNativeHandle(DisplayServer.HandleType.WindowHandle, godotWindowId);
+      .WindowGetNativeHandle(
+        DisplayServer.HandleType.WindowHandle, godotWindowId
+      );
 
     var hWnd = new IntPtr(nativeHandle);
-    return (uint)User32
-      .MonitorFromWindow(hWnd, User32.MONITOR_DEFAULTTONEAREST)
-      .ToInt32();
+    return User32
+      .MonitorFromWindow(hWnd, User32.MONITOR_DEFAULTTONEAREST).ToInt64();
   }
 
   /// <summary>
@@ -26,15 +29,76 @@ public static uint GetMonitorHandle(int godotWindowId) {
   /// </summary>
   /// <param name="hMonitor">Win32 monitor handle.</param>
   /// <returns>Monitor scale factor.</returns>
-  public static float GetMonitorScale(uint hMonitor) {
+  public static float GetMonitorScale(long hMonitor) {
+    // We need to get the DPI of the monitor itself, not the system DPI.
+    // Windows 10+ only.
+    var oldDpiAwareness = User32.SetThreadDpiAwarenessContext(
+      User32.DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
+    );
+
     Shcore.GetDpiForMonitor(
       new IntPtr(hMonitor),
       Shcore.MONITOR_DPI_TYPE.MDT_EFFECTIVE_DPI,
       out var dpiX,
       out var dpiY
     );
 
+    // Restore previous thread dpi awareness context, just to be safe.
+    User32.SetThreadDpiAwarenessContext(oldDpiAwareness);
+
     // https://stackoverflow.com/a/69573593
     return dpiY / 96f;
   }
+
+  public static Vector2I GetMonitorResolution(long hMonitor) {
+    var hMonitorPtr = new IntPtr(hMonitor);
+    var monSize = Marshal.SizeOf(typeof(User32.MonitorInfoEx));
+    var pMonitorInfo = Marshal.AllocHGlobal(monSize);
+
+    // We have to set the structure size first.
+    Marshal.WriteInt32(pMonitorInfo, monSize);
+
+    if (!User32.GetMonitorInfo(hMonitorPtr, pMonitorInfo)) {
+      Debug.WriteLine(
+        "Failed to get monitor info. Error Code: " +
+          Marshal.GetLastWin32Error()
+      );
+      return Vector2I.Zero;
+    }
+
+    var monitorInfo =
+      Marshal.PtrToStructure<User32.MonitorInfoEx>(pMonitorInfo);
+
+    // Create a string from the szDevice char array. Why Windows wants to use
+    // a string as a monitor identifier, I have no idea...
+
+    var deviceChars = monitorInfo!.szDevice;
+    var length = Array.IndexOf(deviceChars, '\0'); // stop at null terminator
+    if (length < 0) {
+      length = deviceChars.Length;
+    }
+
+    var deviceName = new string(deviceChars, 0, length);
+    Debug.WriteLine($"Monitor Device Name: {deviceName}");
+
+    // Create a device context for the monitor so we can use GDI api's.
+    var hdc = Gdi32.CreateDC(null!, deviceName, null!, IntPtr.Zero);
+    if (hdc == IntPtr.Zero) {
+      Debug.WriteLine(
+        "Failed to create device context. Error Code: " +
+          Marshal.GetLastWin32Error()
+      );
+      return Vector2I.Zero;
+    }
+
+    try {
+      // Actually get the monitor's native resolution :P
+      var w = Gdi32.GetDeviceCaps(hdc, Gdi32.DESKTOP_HORZ_RES);
+      var h = Gdi32.GetDeviceCaps(hdc, Gdi32.DESKTOP_VERT_RES);
+      return new Vector2I(w, h).Abs();
+    }
+    finally {
+      Gdi32.DeleteDC(hdc);
+    }
+  }
 }

Chickensoft.PlatformExt/src/windows/lib/Gdi32.cs

@@ -0,0 +1,30 @@
+namespace Chickensoft.Platform.Windows;
+
+using System;
+using System.Runtime.InteropServices;
+
+internal static partial class Gdi32 {
+  public const string GDI32 = "gdi32.dll";
+  public const int DESKTOP_VERT_RES = 117;
+  public const int DESKTOP_HORZ_RES = 118;
+
+  [LibraryImport(
+    GDI32,
+    SetLastError = true,
+    StringMarshalling = StringMarshalling.Utf16,
+    EntryPoint = "CreateDCW"
+  )]
+  internal static partial IntPtr CreateDC(
+    string pwszDriver,   // typically null for display
+    string pwszDevice,   // "\\.\DISPLAYx"
+    string pwszOutput,   // null
+    IntPtr lpInitData    // IntPtr.Zero
+  );
+
+  [LibraryImport(GDI32, SetLastError = true)]
+  [return: MarshalAs(UnmanagedType.Bool)]
+  internal static partial bool DeleteDC(IntPtr hdc);
+
+  [LibraryImport(GDI32, SetLastError = true)]
+  internal static partial int GetDeviceCaps(IntPtr hdc, int nIndex);
+}

Chickensoft.PlatformExt/src/windows/lib/Shcore.cs

@@ -5,6 +5,7 @@ namespace Chickensoft.Platform.Windows;
 
 
 internal static partial class Shcore {
+  public const string SHCORE = "shcore.dll";
   public enum DEVICE_SCALE_FACTOR {
     DEVICE_SCALE_FACTOR_INVALID = 0,
     SCALE_100_PERCENT = 100,
@@ -31,9 +32,13 @@ public enum MONITOR_DPI_TYPE {
     MDT_RAW_DPI = 2
   }
 
-  [LibraryImport("shcore.dll", SetLastError = true)]
-  internal static partial int GetScaleFactorForMonitor(IntPtr hMonitor, out DEVICE_SCALE_FACTOR pScale);
+  [LibraryImport(SHCORE, SetLastError = true)]
+  internal static partial int GetScaleFactorForMonitor(
+    IntPtr hMonitor, out DEVICE_SCALE_FACTOR pScale
+  );
 
-  [LibraryImport("shcore.dll", SetLastError = true)]
-  internal static partial int GetDpiForMonitor(IntPtr hMonitor, MONITOR_DPI_TYPE dpiType, out uint dpiX, out uint dpiY);
+  [LibraryImport(SHCORE, SetLastError = true)]
+  internal static partial int GetDpiForMonitor(
+    IntPtr hMonitor, MONITOR_DPI_TYPE dpiType, out uint dpiX, out uint dpiY
+  );
 }

Chickensoft.PlatformExt/src/windows/lib/User32.cs

@@ -4,10 +4,62 @@ namespace Chickensoft.Platform.Windows;
 using System.Runtime.InteropServices;
 
 internal static partial class User32 {
+  public const string USER32 = "user32.dll";
   public const int MONITOR_DEFAULTTONULL = 0x00000000;
   public const int MONITOR_DEFAULTTOPRIMARY = 0x00000001;
   public const int MONITOR_DEFAULTTONEAREST = 0x00000002;
 
-  [LibraryImport("user32.dll", SetLastError = true)]
+#pragma warning disable IDE1006 // Naming Styles
+  [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
+  public sealed class MonitorInfoEx {
+    public int cbSize;
+    public Rect rcMonitor;
+    public Rect rcWork;
+    public int dwFlags;
+    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
+    public char[] szDevice;
+
+    public MonitorInfoEx() {
+      cbSize = Marshal.SizeOf<MonitorInfoEx>();
+      szDevice = new char[32];
+    }
+  }
+#pragma warning restore IDE1006 // Naming Styles
+
+  [StructLayout(LayoutKind.Sequential)]
+  public struct Rect {
+    public int Left;
+    public int Top;
+    public int Right;
+    public int Bottom;
+
+    public readonly int Width => Right - Left;
+    public readonly int Height => Bottom - Top;
+  }
+
+  [LibraryImport(USER32, SetLastError = true)]
   public static partial IntPtr MonitorFromWindow(IntPtr hwnd, uint dwFlags);
+
+  [LibraryImport(
+    USER32,
+    StringMarshalling = StringMarshalling.Utf16,
+    SetLastError = true,
+    EntryPoint = "GetMonitorInfoW"
+  )]
+  [return: MarshalAs(UnmanagedType.I1)]
+  public static partial bool GetMonitorInfo(IntPtr hMonitor, IntPtr lpmi);
+
+  public static readonly IntPtr DPI_AWARENESS_CONTEXT_UNAWARE = new(-1);
+  public static readonly IntPtr DPI_AWARENESS_CONTEXT_SYSTEM_AWARE = new(-2);
+  public static readonly IntPtr DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE =
+    new(-3);
+  public static readonly IntPtr DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 =
+    new(-4);
+  public static readonly IntPtr DPI_AWARENESS_CONTEXT_UNAWARE_GDISCALED =
+    new(-5);
+
+  [LibraryImport(USER32, SetLastError = true)]
+  internal static partial IntPtr SetThreadDpiAwarenessContext(
+    IntPtr dpiContext
+  );
 }

cspell.json

@@ -45,12 +45,14 @@
     "fabrik",
     "framebuffer",
     "GDEXTENSION",
+    "GDISCALED",
     "gdscript",
     "globaltool",
     "gltf",
     "godotengine",
     "godotenv",
     "hmac",
+    "HORZ",
     "hwnd",
     "iossimulator",
     "issuecomment",
@@ -64,6 +66,7 @@
     "lightmapper",
     "lihop",
     "linecoverage",
+    "lpmi",
     "maccatalyst",
     "Mathf",
     "methodcoverage",
@@ -86,6 +89,7 @@
     "OPTOUT",
     "paramref",
     "pascalcase",
+    "pwsz",
     "randomizer",
     "raymarch",
     "reloadable",

sandbox/Chickensoft.Platform.Sandbox/project.godot

@@ -11,7 +11,7 @@ config_version=5
 [application]
 
 config/name="Chickensoft.Platform.Sandbox"
-run/main_scene="uid://cywpu6lxdjhuu"
+run/main_scene="res://src/game/Game.tscn"
 config/features=PackedStringArray("4.4")
 config/icon="res://icon.png"
 

sandbox/Chickensoft.Platform.Sandbox/src/game/game.gd

@@ -1,6 +1,10 @@
 extends Control
 
 func _ready() -> void:
+	print("ready")
 	var displays = Displays.new()
-	var scaleFactor = displays.GetDisplayScaleFactor(get_window())
+	var window := get_window()
+	var scaleFactor = displays.GetDisplayScaleFactor(window)
 	print("scale factor: ", scaleFactor)
+	var resolution = displays.GetNativeResolution(window)
+	print("native resolution: ", resolution)

sandbox/Chickensoft.Platform.SandboxRef/.vscode/launch.json

@@ -0,0 +1,15 @@
+{
+  "configurations": [
+    {
+      "name": "🕹 Debug Game",
+      "type": "coreclr",
+      "request": "launch",
+      "preLaunchTask": "build",
+      "program": "${env:GODOT}",
+      "args": [],
+      "cwd": "${workspaceFolder}",
+      "stopAtEntry": false,
+      "console": "integratedTerminal"
+    },
+  ]
+}