Replace `DllImport` usage with `LibraryImport` (#4084)

* Replace usage of `DllImport` with `LibraryImport`

* Mark methods as `partial`

* Marshalling

* More `partial` & marshalling

* More `partial` and marshalling

* More partial and marshalling

* Update GdiPlusHelper to LibraryImport

* Unicorn

* More Partial

* Marshal

* Specify EntryPoint

* Specify EntryPoint

* Change GlobalMemoryStatusEx to LibraryImport

* Change RegisterClassEx to LibraryImport

* Define EntryPoints

* Update Ryujinx.Ava/Ui/Controls/Win32NativeInterop.cs

Co-authored-by: TSRBerry <20988865+TSRBerry@users.noreply.github.com>

* Update Ryujinx.Graphics.Nvdec.FFmpeg/Native/FFmpegApi.cs

Co-authored-by: TSRBerry <20988865+TSRBerry@users.noreply.github.com>

* Move return mashal

* Remove calling convention specification

* Remove calling conventions

* Update Ryujinx.Common/SystemInfo/WindowsSystemInfo.cs

Co-authored-by: TSRBerry <20988865+TSRBerry@users.noreply.github.com>

* Update Ryujinx/Modules/Updater/Updater.cs

Co-authored-by: Mary-nyan <thog@protonmail.com>

* Update Ryujinx.Ava/Modules/Updater/Updater.cs

Co-authored-by: Mary-nyan <thog@protonmail.com>

Co-authored-by: TSRBerry <20988865+TSRBerry@users.noreply.github.com>
Co-authored-by: Mary-nyan <thog@protonmail.com>

1 files changed, 96 insertions, 0 deletions

diff --git a/Ryujinx.Common/SystemInterop/ForceDpiAware.cs b/Ryujinx.Common/SystemInterop/ForceDpiAware.cs
new file mode 100644
index 00000000..f17612a6
--- /dev/null
+++ b/Ryujinx.Common/SystemInterop/ForceDpiAware.cs
@@ -0,0 +1,96 @@
+using Ryujinx.Common.Logging;
+using System;
+using System.Globalization;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Common.SystemInterop
+{
+    public static partial class ForceDpiAware
+    {
+        [LibraryImport("user32.dll")]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static partial bool SetProcessDPIAware();
+
+        private const string X11LibraryName = "libX11.so.6";
+
+        [LibraryImport(X11LibraryName)]
+        private static partial IntPtr XOpenDisplay([MarshalAs(UnmanagedType.LPStr)] string display);
+
+        [LibraryImport(X11LibraryName)]
+        private static partial IntPtr XGetDefault(IntPtr display, [MarshalAs(UnmanagedType.LPStr)] string program, [MarshalAs(UnmanagedType.LPStr)] string option);
+
+        [LibraryImport(X11LibraryName)]
+        private static partial int XDisplayWidth(IntPtr display, int screenNumber);
+
+        [LibraryImport(X11LibraryName)]
+        private static partial int XDisplayWidthMM(IntPtr display, int screenNumber);
+
+        [LibraryImport(X11LibraryName)]
+        private static partial int XCloseDisplay(IntPtr display);
+
+        private static readonly double _standardDpiScale = 96.0;
+        private static readonly double _maxScaleFactor   = 1.25;
+
+        /// <summary>
+        /// Marks the application as DPI-Aware when running on the Windows operating system.
+        /// </summary>
+        public static void Windows()
+        {
+            // Make process DPI aware for proper window sizing on high-res screens.
+            if (OperatingSystem.IsWindowsVersionAtLeast(6))
+            {
+                SetProcessDPIAware();
+            }
+        }
+
+        public static double GetActualScaleFactor()
+        {
+            double userDpiScale = 96.0;
+
+            try
+            {
+                if (OperatingSystem.IsWindows())
+                {
+                    userDpiScale = GdiPlusHelper.GetDpiX(IntPtr.Zero);
+                }
+                else if (OperatingSystem.IsLinux())
+                {
+                    string xdgSessionType = Environment.GetEnvironmentVariable("XDG_SESSION_TYPE")?.ToLower();
+
+                    if (xdgSessionType == null || xdgSessionType == "x11")
+                    {
+                        IntPtr display = XOpenDisplay(null);
+                        string dpiString = Marshal.PtrToStringAnsi(XGetDefault(display, "Xft", "dpi"));
+                        if (dpiString == null || !double.TryParse(dpiString, NumberStyles.Any, CultureInfo.InvariantCulture, out userDpiScale))
+                        {
+                            userDpiScale = (double)XDisplayWidth(display, 0) * 25.4 / (double)XDisplayWidthMM(display, 0);
+                        }
+                        XCloseDisplay(display);
+                    }
+                    else if (xdgSessionType == "wayland")
+                    {
+                        // TODO
+                        Logger.Warning?.Print(LogClass.Application, $"Couldn't determine monitor DPI: Wayland not yet supported");
+                    }
+                    else
+                    {
+                        Logger.Warning?.Print(LogClass.Application, $"Couldn't determine monitor DPI: Unrecognised XDG_SESSION_TYPE: {xdgSessionType}");
+                    }
+                }
+            }
+            catch (Exception e)
+            {
+                Logger.Warning?.Print(LogClass.Application, $"Couldn't determine monitor DPI: {e.Message}");
+            }
+
+            return userDpiScale;
+        }
+
+        public static double GetWindowScaleFactor()
+        {
+            double userDpiScale = GetActualScaleFactor();
+
+            return Math.Min(userDpiScale / _standardDpiScale, _maxScaleFactor);
+        }
+    }
+}