System font API (space-wizards#5393)

* System font API

This is a new API that allows operating system fonts to be loaded by the engine and used by content.

Fonts are provided in a flat list exposing all the relevant metadata. They are loaded from disk with a Load call.

Initial implementation is only for Windows DirectWrite.

* Load system fonts as memory mapped files if possible.

This allows sharing the font file memory with other processes which is always good.

* Use ArrayPool to reduce char array allocations

* Disable verbose logging

* Implement system font support on Linux via Fontconfig

* Implement macOS support

* Add "FREEDESKTOP" define constant

This is basically LINUX || FREEBSD. Though FreeBSD currently gets detected as LINUX too. Oh well.

* Compile out Fontconfig and CoreText system font backends when not on those platforms

* Don't add Fontconfig package dep on Mac/Windows

* Allow disabling system font support via CVar

Cuz why not.

Author: PJB3005

Directory.Packages.props

@@ -62,6 +62,7 @@
     <PackageVersion Include="SpaceWizards.Sdl" Version="1.0.0" />
     <PackageVersion Include="SpaceWizards.SharpFont" Version="1.1.0" />
     <PackageVersion Include="SpaceWizards.Sodium" Version="0.2.1" />
+    <PackageVersion Include="SpaceWizards.Fontconfig.Interop" Version="1.0.0" />
     <PackageVersion Include="libsodium" Version="1.0.20.1" />
     <PackageVersion Include="System.Management" Version="9.0.8" />
     <PackageVersion Include="TerraFX.Interop.Windows" Version="10.0.26100.1" />

MSBuild/Robust.DefineConstants.targets

@@ -13,7 +13,7 @@
     </When>
     <Otherwise>
       <PropertyGroup>
-        <DefineConstants>$(DefineConstants);LINUX;UNIX</DefineConstants>
+        <DefineConstants>$(DefineConstants);LINUX;UNIX;FREEDESKTOP</DefineConstants>
       </PropertyGroup>
     </Otherwise>
   </Choose>

MSBuild/Robust.Platform.props

@@ -31,5 +31,6 @@
     <Python>python3</Python>
     <Python Condition="'$(ActualOS)' == 'Windows'">py -3</Python>
     <UseSystemSqlite Condition="'$(TargetOS)' == 'FreeBSD'">True</UseSystemSqlite>
+    <IsFreedesktop Condition="'$(TargetOS)' == 'FreeBSD' Or '$(TargetOS)' == 'Linux'">True</IsFreedesktop>
   </PropertyGroup>
 </Project>

RELEASE-NOTES.md

@@ -47,6 +47,9 @@ END TEMPLATE-->
 * Sandbox:
   * Exposed `System.Reflection.Metadata.MetadataUpdateHandlerAttribute`.
   * Exposed more overloads on `StringBuilder`.
+* The engine can now load system fonts.
+  * At the moment only available on Windows.
+  * See `ISystemFontManager` for API.
 
 ### Bugfixes
 

Robust.Client/ClientIoC.cs

@@ -8,6 +8,7 @@
 using Robust.Client.GameStates;
 using Robust.Client.Graphics;
 using Robust.Client.Graphics.Clyde;
+using Robust.Client.Graphics.FontManagement;
 using Robust.Client.HWId;
 using Robust.Client.Input;
 using Robust.Client.Localization;
@@ -121,6 +122,8 @@ public static void RegisterIoC(GameController.DisplayMode mode, IDependencyColle
                     deps.Register<IInputManager, InputManager>();
                     deps.Register<IFileDialogManager, DummyFileDialogManager>();
                     deps.Register<IUriOpener, UriOpenerDummy>();
+                    deps.Register<ISystemFontManager, SystemFontManagerFallback>();
+                    deps.Register<ISystemFontManagerInternal, SystemFontManagerFallback>();
                     break;
                 case GameController.DisplayMode.Clyde:
                     deps.Register<IClyde, Clyde>();
@@ -131,6 +134,8 @@ public static void RegisterIoC(GameController.DisplayMode mode, IDependencyColle
                     deps.Register<IInputManager, ClydeInputManager>();
                     deps.Register<IFileDialogManager, FileDialogManager>();
                     deps.Register<IUriOpener, UriOpener>();
+                    deps.Register<ISystemFontManager, SystemFontManager>();
+                    deps.Register<ISystemFontManagerInternal, SystemFontManager>();
                     break;
                 default:
                     throw new ArgumentOutOfRangeException();

Robust.Client/GameController/GameController.cs

@@ -96,6 +96,7 @@ internal sealed partial class GameController : IGameControllerInternal
         [Dependency] private readonly IReflectionManager _reflectionManager = default!;
         [Dependency] private readonly IReloadManager _reload = default!;
         [Dependency] private readonly ILocalizationManager _loc = default!;
+        [Dependency] private readonly ISystemFontManagerInternal _systemFontManager = default!;
 
         private IWebViewManagerHook? _webViewHook;
 
@@ -143,6 +144,7 @@ internal bool StartupContinue(DisplayMode displayMode)
             _taskManager.Initialize();
             _parallelMgr.Initialize();
             _fontManager.SetFontDpi((uint)_configurationManager.GetCVar(CVars.DisplayFontDpi));
+            _systemFontManager.Initialize();
 
             // Load optional Robust modules.
             LoadOptionalRobustModules(displayMode, _resourceManifest!);

Robust.Client/Graphics/Font.cs

@@ -104,6 +104,12 @@ public VectorFont(FontResource res, int size)
             Handle = IoCManager.Resolve<IFontManagerInternal>().MakeInstance(res.FontFaceHandle, size);
         }
 
+        internal VectorFont(IFontInstanceHandle handle, int size)
+        {
+            Size = size;
+            Handle = handle;
+        }
+
         public override int GetAscent(float scale) => Handle.GetAscent(scale);
         public override int GetHeight(float scale) => Handle.GetHeight(scale);
         public override int GetDescent(float scale) => Handle.GetDescent(scale);
@@ -222,4 +228,74 @@ public override float DrawChar(DrawingHandleBase handle, Rune rune, Vector2 base
             return null;
         }
     }
+
+    /// <summary>
+    /// Possible values for font weights. Larger values have thicker font strokes.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// These values are based on the <c>usWeightClass</c> property of the OpenType specification:
+    /// https://learn.microsoft.com/en-us/typography/opentype/spec/os2#usweightclass
+    /// </para>
+    /// </remarks>
+    /// <seealso cref="ISystemFontFace.Weight"/>
+    public enum FontWeight : ushort
+    {
+        Thin = 100,
+        ExtraLight = 200,
+        UltraLight = ExtraLight,
+        Light = 300,
+        SemiLight = 350,
+        Normal = 400,
+        Regular = Normal,
+        Medium = 500,
+        SemiBold = 600,
+        DemiBold = SemiBold,
+        Bold = 700,
+        ExtraBold = 800,
+        UltraBold = ExtraBold,
+        Black = 900,
+        Heavy = Black,
+        ExtraBlack = 950,
+        UltraBlack = ExtraBlack,
+    }
+
+    /// <summary>
+    /// Possible slant values for fonts.
+    /// </summary>
+    /// <seealso cref="ISystemFontFace.Slant"/>
+    public enum FontSlant : byte
+    {
+        // NOTE: Enum values correspond to DWRITE_FONT_STYLE.
+        Normal = 0,
+        Oblique = 1,
+
+        // FUN FACT: they're called "italics" because they look like the Leaning Tower of Pisa.
+        // Don't fact-check that.
+        Italic = 2
+    }
+
+    /// <summary>
+    /// Possible values for font widths. Larger values are proportionally wider.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// These values are based on the <c>usWidthClass</c> property of the OpenType specification:
+    /// https://learn.microsoft.com/en-us/typography/opentype/spec/os2#uswidthclass
+    /// </para>
+    /// </remarks>
+    /// <seealso cref="ISystemFontFace.Width"/>
+    public enum FontWidth : ushort
+    {
+        UltraCondensed = 1,
+        ExtraCondensed = 2,
+        Condensed = 3,
+        SemiCondensed = 4,
+        Normal = 5,
+        Medium =  Normal,
+        SemiExpanded = 6,
+        Expanded = 7,
+        ExtraExpanded = 8,
+        UltraExpanded = 9,
+    }
 }

Robust.Client/Graphics/FontManagement/SystemFontDebug.cs

@@ -0,0 +1,15 @@
+using Robust.Shared.Console;
+
+namespace Robust.Client.Graphics.FontManagement;
+
+internal sealed class SystemFontDebugCommand : IConsoleCommand
+{
+    public string Command => "system_font_debug";
+    public string Description => "";
+    public string Help => "";
+
+    public void Execute(IConsoleShell shell, string argStr, string[] args)
+    {
+        new SystemFontDebugWindow().OpenCentered();
+    }
+}

Robust.Client/Graphics/FontManagement/SystemFontDebugWindow.xaml

@@ -0,0 +1,14 @@
+<DefaultWindow xmlns="https://spacestation14.io"
+               Title="System font debug">
+    <SplitContainer Orientation="Horizontal" MinSize="800 600">
+        <ScrollContainer HScrollEnabled="False">
+            <BoxContainer Name="SelectorContainer" Orientation="Vertical" />
+        </ScrollContainer>
+        <ScrollContainer HScrollEnabled="False">
+            <BoxContainer Orientation="Vertical">
+                <Label Name="FamilyLabel" />
+                <BoxContainer Orientation="Vertical" Name="FaceContainer" />
+            </BoxContainer>
+        </ScrollContainer>
+    </SplitContainer>
+</DefaultWindow>

Robust.Client/Graphics/FontManagement/SystemFontDebugWindow.xaml.cs

@@ -0,0 +1,98 @@
+using System.Linq;
+using Robust.Client.AutoGenerated;
+using Robust.Client.UserInterface;
+using Robust.Client.UserInterface.Controls;
+using Robust.Client.UserInterface.CustomControls;
+using Robust.Client.UserInterface.XAML;
+using Robust.Shared.IoC;
+using Robust.Shared.Maths;
+using Robust.Shared.Utility;
+
+namespace Robust.Client.Graphics.FontManagement;
+
+[GenerateTypedNameReferences]
+internal sealed partial class SystemFontDebugWindow : DefaultWindow
+{
+    private static readonly int[] ExampleFontSizes = [8, 12, 16, 24, 36];
+    private const string ExampleString = "The quick brown fox jumps over the lazy dog";
+
+    [Dependency] private readonly ISystemFontManager _systemFontManager = default!;
+
+    public SystemFontDebugWindow()
+    {
+        IoCManager.InjectDependencies(this);
+        RobustXamlLoader.Load(this);
+
+        var buttonGroup = new ButtonGroup();
+
+        foreach (var group in _systemFontManager.SystemFontFaces.GroupBy(k => k.FamilyName).OrderBy(k => k.Key))
+        {
+            var fonts = group.ToArray();
+            SelectorContainer.AddChild(new Selector(this, buttonGroup, group.Key, fonts));
+        }
+    }
+
+    private void SelectFontFamily(ISystemFontFace[] fonts)
+    {
+        FamilyLabel.Text = fonts[0].FamilyName;
+
+        FaceContainer.RemoveAllChildren();
+
+        foreach (var font in fonts)
+        {
+            var exampleContainer = new BoxContainer
+            {
+                Orientation = BoxContainer.LayoutOrientation.Vertical,
+                Margin = new Thickness(8)
+            };
+
+            foreach (var size in ExampleFontSizes)
+            {
+                var fontInstance = font.Load(size);
+
+                var richTextLabel = new RichTextLabel
+                {
+                    Stylesheet = new Stylesheet([
+                        StylesheetHelpers.Element<RichTextLabel>().Prop("font", fontInstance)
+                    ]),
+                };
+                richTextLabel.SetMessage(FormattedMessage.FromUnformatted(ExampleString));
+                exampleContainer.AddChild(richTextLabel);
+            }
+
+            FaceContainer.AddChild(new BoxContainer
+            {
+                Orientation = BoxContainer.LayoutOrientation.Vertical,
+                Children =
+                {
+                    new RichTextLabel
+                    {
+                        Text = $"""
+                        {font.FullName}
+                        Family: "{font.FamilyName}", face: "{font.FaceName}", PostScript = "{font.PostscriptName}"
+                        Weight: {font.Weight} ({(int) font.Weight}), slant: {font.Slant} ({(int) font.Slant}), width: {font.Width} ({(int) font.Width})
+                        """,
+                    },
+                    exampleContainer
+                },
+                Margin = new Thickness(0, 0, 0, 8)
+            });
+        }
+    }
+
+    private sealed class Selector : Control
+    {
+        public Selector(SystemFontDebugWindow window, ButtonGroup group, string family, ISystemFontFace[] fonts)
+        {
+            var button = new Button
+            {
+                Text = family,
+                Group = group,
+                ToggleMode = true
+            };
+            AddChild(button);
+
+            button.OnPressed += _ => window.SelectFontFamily(fonts);
+        }
+    }
+}