From 648f64535a4d1621310296be6a361866bd8f6845 Mon Sep 17 00:00:00 2001
From: Andrii Kurdiumov <kant2002@gmail.com>
Date: Tue, 24 Jan 2023 20:11:37 +0600
Subject: [PATCH] Introduce AOT friendly version of ToLogFont and FromLogFont
 These methods used by WinForms Closes #70358

---
 .../ref/System.Drawing.Common.netcoreapp.cs   |  7 ++
 .../src/System/Drawing/Font.cs                | 75 +++++++++++++++++++
 2 files changed, 82 insertions(+)

diff --git a/src/libraries/System.Drawing.Common/ref/System.Drawing.Common.netcoreapp.cs b/src/libraries/System.Drawing.Common/ref/System.Drawing.Common.netcoreapp.cs
index 389223c06e17dc..1ed2302cdc519f 100644
--- a/src/libraries/System.Drawing.Common/ref/System.Drawing.Common.netcoreapp.cs
+++ b/src/libraries/System.Drawing.Common/ref/System.Drawing.Common.netcoreapp.cs
@@ -26,6 +26,13 @@ public void FillPie(System.Drawing.Brush brush, System.Drawing.RectangleF rect,
         [System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Never)]
         public void GetContextInfo(out PointF offset, out Region? clip) { throw null; }
     }
+    public sealed partial class Font
+    {
+        public void ToLogFont<T>(ref T logFont, Graphics graphics) where T: unmanaged  { throw null; }
+        public static Font FromLogFont<T>(in T logFont) where T: unmanaged { throw null; }
+        public static Font FromLogFont<T>(in T logFont, IntPtr hdc) where T: unmanaged { throw null; }
+        public void ToLogFont<T>(ref T logFont) where T: unmanaged { throw null; }
+    }
 }
 namespace System.Drawing.Drawing2D
 {
diff --git a/src/libraries/System.Drawing.Common/src/System/Drawing/Font.cs b/src/libraries/System.Drawing.Common/src/System/Drawing/Font.cs
index a008f77a3c5c1a..ddd6a697ae5e8a 100644
--- a/src/libraries/System.Drawing.Common/src/System/Drawing/Font.cs
+++ b/src/libraries/System.Drawing.Common/src/System/Drawing/Font.cs
@@ -291,6 +291,29 @@ public unsafe void ToLogFont(object logFont, Graphics graphics)
             }
         }
 
+        /// <summary>
+        /// Update the given LOGFONT with data from given graphics.
+        /// </summary>
+        /// <param name="logFont">A structure to populate with LOGFONT data.</param>
+        /// <param name="graphics">Graphics object which provide information about font.</param>
+        public unsafe void ToLogFont<T>(ref T logFont, Graphics graphics)
+            where T: unmanaged
+        {
+            ArgumentNullException.ThrowIfNull(logFont);
+
+            if (sizeof(T) != sizeof(Interop.User32.LOGFONT))
+            {
+                // If we don't actually have an object that is LOGFONT in size, trying to pass
+                // it to GDI+ is likely to cause an AV.
+                throw new ArgumentException(null, nameof(logFont));
+            }
+
+            fixed (T* pLogFont = &logFont)
+            {
+                *(Interop.User32.LOGFONT*)pLogFont = ToLogFontInternal(graphics);
+            }
+        }
+
         private unsafe Interop.User32.LOGFONT ToLogFontInternal(Graphics graphics)
         {
             ArgumentNullException.ThrowIfNull(graphics);
@@ -551,6 +574,20 @@ public static Font FromLogFont(object lf)
             }
         }
 
+        /// <summary>
+        /// Creates a <see cref="Font"/> from the given LOGFONT using the screen device context.
+        /// </summary>
+        /// <param name="logFont">A structure holding LOGFONT data.</param>
+        /// <returns>The newly created <see cref="Font"/>.</returns>
+        public static Font FromLogFont<T>(in T logFont)
+            where T: unmanaged
+        {
+            using (ScreenDC dc = ScreenDC.Create())
+            {
+                return FromLogFont<T>(in logFont, dc);
+            }
+        }
+
         internal static Font FromLogFont(ref Interop.User32.LOGFONT logFont)
         {
             using (ScreenDC dc = ScreenDC.Create())
@@ -616,6 +653,30 @@ public static unsafe Font FromLogFont(object lf, IntPtr hdc)
             return FromLogFontInternal(ref logFont, hdc);
         }
 
+        /// <summary>
+        /// Creates a <see cref="Font"/> from the given LOGFONT using the given device context.
+        /// </summary>
+        /// <param name="logFont">A structure holding LOGFONT data.</param>
+        /// <param name="hdc">Handle to a device context (HDC).</param>
+        /// <returns>The newly created <see cref="Font"/>.</returns>
+        public static unsafe Font FromLogFont<T>(in T logFont, IntPtr hdc)
+            where T: unmanaged
+        {
+            ArgumentNullException.ThrowIfNull(logFont);
+
+            if (sizeof(T) != sizeof(Interop.User32.LOGFONT))
+            {
+                // If we don't actually have an object that is LOGFONT in size, trying to pass
+                // it to GDI+ is likely to cause an AV.
+                throw new ArgumentException(null, nameof(logFont));
+            }
+
+            fixed (T* pLogFont = &logFont)
+            {
+                return FromLogFontInternal(ref *(Interop.User32.LOGFONT*)pLogFont, hdc);
+            }
+        }
+
         /// <summary>
         /// Creates a <see cref="Font"/> from the specified handle to a device context (HDC).
         /// </summary>
@@ -681,6 +742,20 @@ public void ToLogFont(object logFont)
             }
         }
 
+        /// <summary>
+        /// Update the given LOGFONT with data from the screen device context.
+        /// </summary>
+        /// <param name="logFont">A structure to populate with LOGFONT data.</param>
+        public void ToLogFont<T>(ref T logFont)
+            where T: unmanaged
+        {
+            using (ScreenDC dc = ScreenDC.Create())
+            using (Graphics graphics = Graphics.FromHdcInternal(dc))
+            {
+                ToLogFont<T>(ref logFont, graphics);
+            }
+        }
+
         /// <summary>
         /// Returns a handle to this <see cref='Font'/>.
         /// </summary>