Initial Commit

2026-05-18 01:12:52 -05:00
commit fc0b04a4bc
13 changed files with 2225 additions and 0 deletions
@@ -0,0 +1,162 @@
+using Hexa.NET.ImGui;
+
+namespace SDL3_TestingSuite.SDL3;
+
+public struct FontMetrics
+{
+    public ushort UnitsPerEm;
+
+    public short TypoAscender;
+    public short TypoDescender;
+    public short TypoLineGap;
+
+    public short WinAscent;
+    public short WinDescent;
+
+    public int TypoLineHeight;
+    public int WinLineHeight;
+}
+
+public static class FontFind
+{
+    extension(ImGuiIOPtr io)
+    {
+        public unsafe ImFontPtr AddFont(string fontPath)
+        {
+            try
+            {
+                if (fontPath == null || io.Handle == null) return null;
+                FileInfo info = new FileInfo(fontPath);
+                if (!info.Exists || info.Length <= 0) return null;
+
+                FontMetrics metrics = FontFind.ReadFontMetrics(fontPath);
+                float size = FontFind.GetRecommendedPixelSize(metrics);
+
+                ImFontConfigPtr config = ImGui.ImFontConfig();
+                config.FontLoaderFlags |= (uint)ImGuiFreeTypeLoaderFlags.LoadColor;
+                ImFontPtr font = io.Fonts.AddFontFromFileTTF(fontPath, size, config);
+                Program.Logger.Log("Added font: " + Path.GetFileName(fontPath));
+                return font;
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine(e);
+            }
+            return null;
+        }
+        public unsafe bool RemoveFont(string? fontName)
+        {
+            if (fontName == null || io.Handle == null) return false;
+
+            bool flag = false;
+            ImVector<ImFontPtr> fonts = io.Fonts.Fonts;
+            List<ImFontPtr> toRemove = new List<ImFontPtr>();
+            
+            for (int i = 0; i < fonts.Size; i++)
+            {
+                ImFontPtr font = fonts[i];
+                if (font.GetDebugNameS() == fontName)
+                {
+                    toRemove.Add(font);
+                    flag = true;
+                }
+            }
+            
+            foreach (ImFontPtr font in toRemove)
+            {
+                io.Fonts.RemoveFont(font);
+                Program.Logger.Log("Removed font: " + fontName);
+            }
+            
+            return flag;
+        }
+    }
+
+    public static FontMetrics ReadFontMetrics(string fontPath)
+    {
+        byte[] data = File.ReadAllBytes(fontPath);
+
+        ushort numTables = ReadU16Be(4);
+        const int tableDir = 12;
+
+        int headOffset = 0;
+        int os2Offset = 0;
+
+        for (int i = 0; i < numTables; i++)
+        {
+            int entry = tableDir + i * 16;
+            string tag = ReadTag(entry);
+
+            uint offset = ReadU32Be(entry + 8);
+
+            if (tag == "head")
+                headOffset = (int)offset;
+
+            if (tag == "OS/2")
+                os2Offset = (int)offset;
+        }
+
+        FontMetrics metrics = new FontMetrics();
+
+        metrics.UnitsPerEm = ReadU16Be(headOffset + 18);
+
+        if (os2Offset != 0)
+        {
+            metrics.TypoAscender = ReadS16Be(os2Offset + 68);
+            metrics.TypoDescender = ReadS16Be(os2Offset + 70);
+            metrics.TypoLineGap = ReadS16Be(os2Offset + 72);
+
+            metrics.WinAscent = ReadS16Be(os2Offset + 74);
+            metrics.WinDescent = ReadS16Be(os2Offset + 76);
+        }
+
+        metrics.TypoLineHeight =
+            metrics.TypoAscender - metrics.TypoDescender + metrics.TypoLineGap;
+
+        metrics.WinLineHeight =
+            metrics.WinAscent + metrics.WinDescent;
+
+        return metrics;
+
+        ushort ReadU16Be(int o)
+        {
+            return (ushort)((data[o] << 8) | data[o + 1]);
+        }
+
+        short ReadS16Be(int o)
+        {
+            return (short)ReadU16Be(o);
+        }
+
+        uint ReadU32Be(int o)
+        {
+            return (uint)((data[o] << 24) | (data[o + 1] << 16) | (data[o + 2] << 8) | data[o + 3]);
+        }
+
+        string ReadTag(int o)
+        {
+            char c1 = (char)data[o];
+            char c2 = (char)data[o + 1];
+            char c3 = (char)data[o + 2];
+            char c4 = (char)data[o + 3];
+            return new string(new char[] { c1, c2, c3, c4 });
+        }
+    }
+    
+    public static int GetRecommendedPixelSize(FontMetrics metrics)
+    {
+        if (metrics.UnitsPerEm == 0 || metrics.TypoLineHeight == 0)
+            return 16;
+
+        const float targetLineHeightPx = 18.0f;
+
+        float scale = targetLineHeightPx * metrics.UnitsPerEm / metrics.TypoLineHeight;
+
+        int size = (int)MathF.Round(scale);
+
+        if (size < 10) size = 10;
+        if (size > 72) size = 72;
+
+        return size;
+    }
+}