WIP: load fonts with FreeType.

Voile/Source/Resources/Font.cs

@@ -1,5 +1,18 @@
+using System.Numerics;
+
 namespace Voile;
 
+public struct Glyph
+{
+    public int TextureId { get; set; } = -1;
+    public float Width { get; set; }
+    public float Height { get; set; }
+    public Vector2 Bearing { get; set; }
+    public int Advance { get; set; }
+
+    public Glyph() { }
+}
+
 /// <summary>
 /// Represents font data.
 /// </summary>
@@ -18,4 +31,24 @@ public class Font : Resource
     {
         Buffer = buffer;
     }
+
+    public void Measure(string text)
+    {
+        foreach (char c in text)
+        {
+
+        }
+    }
+
+    internal void AddGlyph(char c, Glyph glyph)
+    {
+        _glyphs.Add(c, glyph);
+    }
+
+    internal void GetGlyphBoundingBox(Glyph glyph)
+    {
+
+    }
+
+    private Dictionary<char, Glyph> _glyphs = new();
 }

Voile/Source/Resources/Loaders/FontLoader.cs

@@ -1,6 +1,13 @@
 
+using System.Numerics;
+using System.Runtime.InteropServices;
+using FreeTypeSharp;
 using Voile.VFS;
 
+using static FreeTypeSharp.FT;
+using static FreeTypeSharp.FT_LOAD;
+using static FreeTypeSharp.FT_Render_Mode_;
+
 namespace Voile.Resources;
 
 public class FontLoader : ResourceLoader<Font>
@@ -10,7 +17,6 @@ public class FontLoader : ResourceLoader<Font>
         ".ttf"
     };
 
-
     protected override Font LoadResource(string path)
     {
         using Stream stream = VirtualFileSystem.Read(path);
@@ -21,6 +27,57 @@ public class FontLoader : ResourceLoader<Font>
 
         result.BufferSize = bytesRead;
 
+        LoadFaceData(result);
+
         return result;
     }
+
+    private unsafe void LoadFaceData(Font font)
+    {
+        LoadFreeType();
+
+        fixed (FT_LibraryRec_** lib = &_lib)
+        {
+            fixed (FT_FaceRec_* face = &_face)
+            {
+                FT_Error error;
+
+                var buffer = new Memory<byte>(font.Buffer);
+                var handle = buffer.Pin();
+
+                error = FT_New_Memory_Face(*lib, (byte*)handle.Pointer, (nint)font.BufferSize, 0, &face);
+                error = FT_Set_Pixel_Sizes(face, 0, (uint)font.Size);
+
+                error = FT_Load_Char(face, 'F', FT_LOAD_NO_BITMAP);
+
+                var metrics = face->glyph->metrics;
+
+                font.AddGlyph('F', new Glyph()
+                {
+                    Width = metrics.width >> 6,
+                    Height = metrics.height >> 6,
+                    Bearing = new Vector2(metrics.horiBearingX >> 6, metrics.horiBearingY >> 6),
+                    Advance = (int)metrics.horiAdvance >> 6,
+                });
+
+                FT_Done_Face(face);
+                FT_Done_FreeType(*lib);
+            }
+        }
+    }
+
+    private unsafe void LoadFreeType()
+    {
+        fixed (FT_LibraryRec_** lib = &_lib)
+        {
+            FT_Error error;
+            if (_lib == null)
+            {
+                error = FT_Init_FreeType(lib);
+            }
+        }
+    }
+
+    private unsafe FT_LibraryRec_* _lib;
+    private unsafe FT_FaceRec_ _face;
 }