Added better font search stuff.

Quik.Media.Defaults/EnvironmentVariables.cs

@@ -0,0 +1,13 @@
+namespace Quik.Media.Defaults
+{
+    internal static class EnvironmentVariables
+    {
+        public const string SerifFont = "QUIK_SERIF_FONT";
+        public const string SansFont = "QUIK_SANS_FONT";
+        public const string MonospaceFont = "QUIK_MONOSPACE_FONT";
+        public const string CursiveFont = "QUIK_CURSIVE_FONT";
+        public const string FantasyFont = "QUIK_FANTASY_FONT";
+
+        public const string FallbackFontDatabase = "QUIK_FALLBACK_FONT_DB";
+    }
+}

Quik.Media.Defaults/Fallback/FallbackFontDatabase.cs

@@ -0,0 +1,275 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.Json.Serialization;
+using System.Text.Json;
+using Quik.FreeType;
+using Quik.Media.Font;
+using Quik.PAL;
+using Quik.Media.Defaults.Linux;
+
+namespace Quik.Media.Defaults.Fallback
+{
+    public class FallbackFontDatabase : IFontDataBase
+    {
+        private readonly string DbPath =
+            Environment.GetEnvironmentVariable(EnvironmentVariables.FallbackFontDatabase) ??
+            Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "QUIK/fontdb.json");
+
+        private Dictionary<FontFace, FileInfo> FilesMap { get; } = new Dictionary<FontFace, FileInfo>();
+        private Dictionary<string, List<FontFace>> ByFamily { get; } = new Dictionary<string, List<FontFace>>();
+        private Dictionary<SystemFontFamily, FontFace> SystemFonts { get; } = new Dictionary<SystemFontFamily, FontFace>();
+        private List<FontFace> All { get; } = new List<FontFace>();
+
+        IEnumerable<FontFace> IFontDataBase.All => this.All;
+
+        public FallbackFontDatabase(bool rebuild = false)
+        {
+            // Load existing database if desired.
+            List<DbEntry> database;
+
+            if(!rebuild)
+            {
+                database = LoadDatabase();
+            }
+            else
+            {
+                database = new List<DbEntry>();
+            }
+
+            VerifyDatabase(database);
+            FlushDatabase(database);
+
+            (FontFace, FileInfo) serif      = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.SerifFont, LinuxFonts.DefaultSerifFamilies, this);
+            SystemFonts[SystemFontFamily.Serif] = serif.Item1;
+            (FontFace, FileInfo) sans       = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.SansFont, LinuxFonts.DefaultSansFamilies, this);
+            SystemFonts[SystemFontFamily.Sans] = sans.Item1;
+            (FontFace, FileInfo) mono       = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.MonospaceFont, LinuxFonts.DefaultMonospaceFamilies, this);
+            SystemFonts[SystemFontFamily.Monospace] = mono.Item1;
+            (FontFace, FileInfo) cursive    = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.CursiveFont, LinuxFonts.DefaultCursiveFamilies, this);
+            SystemFonts[SystemFontFamily.Cursive] = cursive.Item1;
+            (FontFace, FileInfo) fantasy    = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.FantasyFont, LinuxFonts.DefaultFantasyFamilies, this);
+            SystemFonts[SystemFontFamily.Fantasy] = fantasy.Item1;
+
+            AddFont(serif.Item1, serif.Item2);
+            AddFont(sans.Item1, sans.Item2);
+            AddFont(mono.Item1, mono.Item2);
+            AddFont(cursive.Item1, cursive.Item2);
+            AddFont(fantasy.Item1, fantasy.Item2);
+
+            database.ForEach(x => AddFont(x.Face, new FileInfo(x.FilePath)));
+        }
+
+        public FileInfo FontFileInfo(FontFace face)
+        {
+            if (FilesMap.TryGetValue(face, out FileInfo info))
+                return info;
+            else
+                return null;
+        }
+
+        public Stream Open(FontFace face)
+        {
+            return FontFileInfo(face)?.OpenRead() ?? throw new FileNotFoundException();
+        }
+
+        public IEnumerable<FontFace> Search(FontFace prototype, FontMatchCriteria criteria = FontMatchCriteria.All)
+        {
+            // A bit scuffed and LINQ heavy but it should work.
+            IEnumerable<FontFace> candidates;
+            
+            if (criteria.HasFlag(FontMatchCriteria.Family))
+            {
+                List<FontFace> siblings;
+                
+                if (!ByFamily.TryGetValue(prototype.Family, out siblings))
+                {
+                    return Enumerable.Empty<FontFace>();
+                }
+
+                candidates = siblings;
+            }
+            else
+            {
+                candidates = All;
+            }
+
+            return 
+                candidates
+                    .Where(x =>
+                        implies(criteria.HasFlag(FontMatchCriteria.Slant), prototype.Slant == x.Slant) ||
+                        implies(criteria.HasFlag(FontMatchCriteria.Weight), prototype.Weight == x.Weight) ||
+                        implies(criteria.HasFlag(FontMatchCriteria.Stretch), prototype.Stretch == x.Stretch)
+                    )
+                    .OrderByDescending(x =>
+
+                        (prototype.Slant == x.Slant ? 1 : 0) +
+                        (prototype.Weight == x.Weight ? 1 : 0) +
+                        (prototype.Stretch == x.Stretch ? 1 : 0) +
+                        confidence(prototype.Family, x.Family) * 3
+                    );
+
+            // a => b = a'+b
+            static bool implies(bool a, bool b)
+            {
+                return !a || b;
+            }
+
+            static int confidence(string target, string testee)
+            {
+                int i;
+                for (i = 0; i < target.Length && i < testee.Length && target[i] == testee[i]; i++);
+                return i;
+            }
+        }
+
+        public FontFace GetSystemFontFace(SystemFontFamily family)
+        {
+            return SystemFonts[family];
+        }
+
+        private void AddFont(FontFace face, FileInfo file)
+        {
+            if (!All.Contains(face))
+                All.Add(face);
+
+            FilesMap.TryAdd(face, file);
+
+            if (!ByFamily.TryGetValue(face.Family, out List<FontFace> siblings))
+            {
+                siblings = new List<FontFace>();
+                ByFamily.Add(face.Family, siblings);
+            }
+
+            if (!siblings.Contains(face))
+                siblings.Add(face);
+        }
+
+        private List<DbEntry> LoadDatabase()
+        {
+            FileInfo info = new FileInfo(DbPath);
+
+            if (!info.Exists)
+                return new List<DbEntry>();
+
+            using Stream str = info.OpenRead();
+            try 
+            {
+                return JsonSerializer.Deserialize<List<DbEntry>>(str);
+            }
+            catch
+            {
+                return new List<DbEntry>();
+            }
+        }
+
+        private void VerifyDatabase(List<DbEntry> db)
+        {
+            // Very slow way to do this but how many fonts could a system have on average?
+            Dictionary<string, DbEntry> entires = new Dictionary<string, DbEntry>();
+
+            foreach (DbEntry entry in db)
+            {
+                FileInfo info = new FileInfo(entry.FilePath);
+
+                // Reprocess fonts that appear like this.
+                if (!info.Exists) continue;
+                else if (info.LastWriteTime > entry.AccessTime) continue;
+            }
+
+            string fontpath = null;
+            try
+            {
+                fontpath = Environment.GetFolderPath(Environment.SpecialFolder.Fonts);
+                if (string.IsNullOrEmpty(fontpath))
+                    throw new Exception();
+            }
+            catch
+            {
+                foreach (string path in FontPaths)
+                {
+                    if (Directory.Exists(path))
+                    {
+                        fontpath = path;
+                        break;
+                    }
+                }
+
+                // rip
+                if (string.IsNullOrEmpty(fontpath))
+                    return;
+            }
+
+            SearchPathForFonts(entires, fontpath);
+
+            db.Clear();
+            db.AddRange(entires.Values);
+        }
+
+        private static void SearchPathForFonts(Dictionary<string, DbEntry> entries, string path)
+        {
+            DirectoryInfo dir = new DirectoryInfo(path);
+
+            foreach (FileInfo file in dir.EnumerateFiles())
+            {
+                SearchFileForFonts(entries, file);
+            }
+
+            foreach (DirectoryInfo directory in dir.EnumerateDirectories())
+            {
+                SearchPathForFonts(entries, directory.FullName);
+            }
+        }
+
+        private static void SearchFileForFonts(Dictionary<string, DbEntry> entries, FileInfo file)
+        {
+            if (entries.ContainsKey(file.FullName))
+                return;
+
+            if (FT.NewFace(FTProvider.Ft, file.FullName, 0, out FTFace face) != FTError.None)
+                return;
+
+            FontFace facename = FontFace.Parse(face.FamilyName, face.StyleName);
+
+            DbEntry entry = new DbEntry(facename, file.FullName);
+            entries.Add(file.FullName, entry);
+            FT.DoneFace(face);
+        }
+
+        private void FlushDatabase(List<DbEntry> db)
+        {
+            FileInfo info = new FileInfo(DbPath);
+            Directory.CreateDirectory(Path.GetDirectoryName(DbPath));
+            using Stream str = info.OpenWrite();
+            JsonSerializer.Serialize(str, db);
+        }
+
+        private static readonly string[] FontPaths = new string[] {
+            "/usr/share/fonts",
+        };
+
+        [JsonSerializable(typeof(DbEntry))]
+        private class DbEntry
+        {
+            [JsonIgnore] public FontFace Face => new FontFace(Family, Slant, Weight, Stretch);
+            public string Family { get; set; }
+            public FontSlant Slant { get; set; }
+            public FontWeight Weight { get; set; }
+            public FontStretch Stretch { get; set; }
+            public string FilePath { get; set; }
+            public DateTime AccessTime { get; set; }
+
+            public DbEntry() {}
+            public DbEntry(FontFace face, string path)
+            {
+                Family = face.Family;
+                Slant = face.Slant;
+                Weight = face.Weight;
+                Stretch = face.Stretch;
+                FilePath = path;
+                AccessTime = DateTime.Now;
+            }
+        }
+    }
+}

Quik.Media.Defaults/FontDatabaseProvider.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using Quik.FreeType;
+using Quik.Media.Defaults.Fallback;
+using Quik.Media.Defaults.Linux;
+using Quik.Media.Font;
+using Quik.PAL;
+
+namespace Quik.Media.Defaults
+{
+    public static class FontDataBaseProvider
+    {
+        public static IFontDataBase Instance { get; }
+
+        static FontDataBaseProvider()
+        {
+            try
+            {
+                // TODO: add as other operating systems are supported.
+                if (OperatingSystem.IsLinux())
+                {
+                    Instance = new FontConfigFontDatabase();
+                }
+                else
+                {
+                    Instance = new FallbackFontDatabase();
+                }
+            }
+            catch (Exception ex)
+            {
+                throw new NotSupportedException("Could not load a suitable font database implementation.", ex);
+            }
+        }
+
+        public static (FontFace, FileInfo) ResolveSystemFont(string envVar, string defaults, IFontDataBase db)
+        {
+            StringBuilder builder = new StringBuilder();
+
+            string user = Environment.GetEnvironmentVariable(envVar);
+            if (user != null)
+            {
+                builder.Append(user);
+                builder.Append(':');
+            }
+
+            builder.Append(defaults);
+
+            string[] list = builder.ToString().Split(':');
+
+            foreach (string item in list)
+            {
+                if (File.Exists(item))
+                {
+                    // Process file.
+                    if (FT.NewFace(FTProvider.Ft, item, 0, out FTFace ftface) != FTError.None)
+                    {
+                        continue;
+                    }
+
+                    FontFace face = FontFace.Parse(ftface.FamilyName, ftface.StyleName);
+                    FT.DoneFace(ftface);
+
+                    return (face, new FileInfo(item));
+                }
+                else
+                {
+                    IEnumerable<FontFace> faces = db.Search(
+                        new FontFace(item, FontSlant.Normal, FontWeight.Normal, FontStretch.Normal),
+                        FontMatchCriteria.Family);
+
+                    if (faces.Any())
+                    {
+                        FontFace face = faces.First();
+                        return (face, db.FontFileInfo(face));
+                    }
+                }
+            }
+
+            try
+            {
+                FontFace face = db.GetSystemFontFace(SystemFontFamily.Sans);
+                return (face, db.FontFileInfo(face));
+            }
+            catch (Exception ex)
+            {
+                throw new NotImplementedException("No fallback font yet.", ex);
+            }
+        }
+    }
+}

Quik.Media.Defaults/Linux/FontConfigFontDatabase.cs

@@ -2,7 +2,10 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using System.Text;
+using Quik.FreeType;
 using Quik.Media.Font;
 using Quik.PAL;
 
@@ -13,10 +16,12 @@ namespace Quik.Media.Defaults.Linux
     /// </summary>
     public class FontConfigFontDatabase : IFontDataBase
     {
-        private IReadOnlyDictionary<FontFace, FileInfo> FilesMap { get; }
-        private IReadOnlyDictionary<string, IReadOnlyList<FontFace>> ByFamily { get; }
+        private Dictionary<FontFace, FileInfo> FilesMap { get; } = new Dictionary<FontFace, FileInfo>();
+        private Dictionary<string, List<FontFace>> ByFamily { get; } = new Dictionary<string, List<FontFace>>();
+        private Dictionary<SystemFontFamily, FontFace> SystemFonts { get; } = new Dictionary<SystemFontFamily, FontFace>();
+        private List<FontFace> All { get; } = new List<FontFace>();
 
-        public IEnumerable<FontFace> All { get; }
+        IEnumerable<FontFace> IFontDataBase.All => this.All;
 
         public FontConfigFontDatabase()
         {
@@ -25,10 +30,6 @@ namespace Quik.Media.Defaults.Linux
                 throw new NotSupportedException("This host doesn't have fontconfig installed.");
             }
 
-            List<FontFace> faces = new List<FontFace>();
-            Dictionary<FontFace, FileInfo> files = new Dictionary<FontFace, FileInfo>();
-            Dictionary<string, List<FontFace>> byFamily = new Dictionary<string, List<FontFace>>();
-            
             FcConfig config = FontConfig.ConfigGetCurrent();
             FcPattern pattern = FontConfig.PatternCreate();
             FcObjectSet os = FontConfig.ObjectSetBuild(FontConfig.FAMILY, FontConfig.STYLE, FontConfig.FILE);
@@ -49,32 +50,51 @@ namespace Quik.Media.Defaults.Linux
                 string style = Marshal.PtrToStringUTF8(pStyle);
 
                 FontFace face = FontFace.Parse(family, style);
-                faces.Add(face);
-
-                if (!byFamily.TryGetValue(face.Family, out List<FontFace> siblings))
-                {
-                    siblings = new List<FontFace>();
-                    byFamily.Add(face.Family, siblings);
-                }
-                siblings.Add(face);
 
                 FontConfig.PatternGetString(current, FontConfig.FILE, 0, out IntPtr pFile);
                 string file = Marshal.PtrToStringAnsi(pFile);
 
-                files.TryAdd(face, new FileInfo(file));
+                AddFont(face, new FileInfo(file));
             }
 
             FontConfig.FontSetDestroy(fs);
             FontConfig.ObjectSetDestroy(os);
             FontConfig.PatternDestroy(pattern);
 
-            All = faces.ToArray();
-            FilesMap = files;
-            ByFamily = new Dictionary<string, IReadOnlyList<FontFace>>(
-                byFamily.Select(x =>
-                    new KeyValuePair<string, IReadOnlyList<FontFace>>(x.Key, x.Value)
-                )
-            );
+            (FontFace, FileInfo) serif      = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.SerifFont, LinuxFonts.DefaultSerifFamilies, this);
+            SystemFonts[SystemFontFamily.Serif] = serif.Item1;
+            (FontFace, FileInfo) sans       = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.SansFont, LinuxFonts.DefaultSansFamilies, this);
+            SystemFonts[SystemFontFamily.Sans] = sans.Item1;
+            (FontFace, FileInfo) mono       = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.MonospaceFont, LinuxFonts.DefaultMonospaceFamilies, this);
+            SystemFonts[SystemFontFamily.Monospace] = mono.Item1;
+            (FontFace, FileInfo) cursive    = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.CursiveFont, LinuxFonts.DefaultCursiveFamilies, this);
+            SystemFonts[SystemFontFamily.Cursive] = cursive.Item1;
+            (FontFace, FileInfo) fantasy    = FontDataBaseProvider.ResolveSystemFont(EnvironmentVariables.FantasyFont, LinuxFonts.DefaultFantasyFamilies, this);
+            SystemFonts[SystemFontFamily.Fantasy] = fantasy.Item1;
+
+            AddFont(serif.Item1, serif.Item2);
+            AddFont(sans.Item1, sans.Item2);
+            AddFont(mono.Item1, mono.Item2);
+            AddFont(cursive.Item1, cursive.Item2);
+            AddFont(fantasy.Item1, fantasy.Item2);
+
+        }
+
+        private void AddFont(FontFace face, FileInfo file)
+        {
+            if (!All.Contains(face))
+                All.Add(face);
+
+            FilesMap.TryAdd(face, file);
+
+            if (!ByFamily.TryGetValue(face.Family, out List<FontFace> siblings))
+            {
+                siblings = new List<FontFace>();
+                ByFamily.Add(face.Family, siblings);
+            }
+
+            if (!siblings.Contains(face))
+                siblings.Add(face);
         }
 
         public IEnumerable<FontFace> Search(FontFace prototype, FontMatchCriteria criteria = FontMatchCriteria.All)
@@ -84,7 +104,7 @@ namespace Quik.Media.Defaults.Linux
             
             if (criteria.HasFlag(FontMatchCriteria.Family))
             {
-                IReadOnlyList<FontFace> siblings;
+                List<FontFace> siblings;
                 
                 if (!ByFamily.TryGetValue(prototype.Family, out siblings))
                 {
@@ -139,5 +159,10 @@ namespace Quik.Media.Defaults.Linux
         {
             return FontFileInfo(face)?.OpenRead() ?? throw new FileNotFoundException();
         }
+
+        public FontFace GetSystemFontFace(SystemFontFamily family)
+        {
+            return SystemFonts[family];
+        }
     }
 }

Quik.Media.Defaults/Linux/LinuxFonts.cs

@@ -0,0 +1,11 @@
+namespace Quik.Media.Defaults.Linux
+{
+    internal static class LinuxFonts
+    {
+        public const string DefaultSerifFamilies = "Noto Serif:Nimbus Roman:Liberation Serif:FreeSerif:Times:Times New Roman";
+        public const string DefaultSansFamilies = "Noto Sans:Nimbus Sans:Droid Sans:Liberation Sans:FreeSans:Helvetica Neue:Helvetica:Arial";
+        public const string DefaultMonospaceFamilies = "Noto Mono:Nimbus Mono PS:Liberation Mono:DejaVu Mono:FreeMono:Lucida Console:Consolas:Courier:Courier New";
+        public const string DefaultCursiveFamilies = "";
+        public const string DefaultFantasyFamilies = "";
+    }
+}

Quik.Media.Defaults/Quik.Media.Defaults.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
@@ -7,10 +7,13 @@
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Quik.FreeType" Version="1.1.0" />
+    <PackageReference Include="Quik.StbImage" Version="1.1.0" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\Quik\Quik.csproj" />
-    <ProjectReference Include="..\Quik.StbImage\Quik.StbImage.csproj" />
-    <ProjectReference Include="..\Quik.FreeType\Quik.FreeType.csproj" />
   </ItemGroup>
 
 </Project>

Quik/Media/Font/FontFace.cs

@@ -1,7 +1,5 @@
 using System;
-using System.Net.WebSockets;
 using System.Text;
-using Quik.Media.Font;
 
 namespace Quik.Media.Font
 {

Quik/Media/Font/SystemFontFamily.cs

@@ -0,0 +1,26 @@
+namespace Quik.Media.Font
+{
+    public enum SystemFontFamily
+    {
+        /// <summary>
+        /// A font with serifs, like Times New Roman.
+        /// </summary>
+        Serif,
+        /// <summary>
+        /// A font without serifs, like Helvetica or Arial.
+        /// </summary>
+        Sans,
+        /// <summary>
+        /// A monospace font like Courier New.
+        /// </summary>
+        Monospace,
+        /// <summary>
+        /// A cursive font like Lucida Handwriting.
+        /// </summary>
+        Cursive,
+        /// <summary>
+        /// An immature font like Comic Sans or Papyrus, nghehehehe.
+        /// </summary>
+        Fantasy
+    }
+}

Quik/PAL/IFontDatabase.cs

@@ -29,6 +29,12 @@ namespace Quik.PAL
         /// </summary>
         IEnumerable<FontFace> All { get; }
 
+        public FontFace Serif => GetSystemFontFace(SystemFontFamily.Serif);
+        public FontFace Sans => GetSystemFontFace(SystemFontFamily.Sans);
+        public FontFace Monospace => GetSystemFontFace(SystemFontFamily.Monospace);
+        public FontFace Cursive => GetSystemFontFace(SystemFontFamily.Cursive);
+        public FontFace Fantasy => GetSystemFontFace(SystemFontFamily.Fantasy);
+
         /// <summary>
         /// Search for the given font face.
         /// </summary>
@@ -50,5 +56,12 @@ namespace Quik.PAL
         /// <param name="face">The font face to open.</param>
         /// <returns>The stream to the font face.</returns>
         Stream Open(FontFace face);
+
+        /// <summary>
+        /// Get a system font family.
+        /// </summary>
+        /// <param name="family">The family type to look up.</param>
+        /// <returns>The name of a font in this family.</returns>
+        FontFace GetSystemFontFace(SystemFontFamily family);
     }
 }

Quik/Quik.csproj

@@ -3,7 +3,7 @@
     <PropertyGroup>
         <TargetFramework>net6.0</TargetFramework>
         <Nullable>disable</Nullable>
-        <LangVersion>7.3</LangVersion>
+        <LangVersion>8</LangVersion>
         <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     </PropertyGroup>