fix bug with lru cache

Author: FlurinBruehwiler

Flamui/Drawing/FontLoader.cs

@@ -110,11 +110,13 @@ public class FontAtlas
 
     public GpuTexture GpuTexture;
 
-    public required LRUCache<char, AtlasGlyphInfo> Table;
+    public required LRUCache<int, AtlasGlyphInfo> Table;
 
     public unsafe AtlasGlyphInfo FindGlyphEntry(char c, float resolutionMultiplier)
     {
-        if (Table.TryGet(c, out var entry))
+        var hash = HashCode.Combine(c, resolutionMultiplier);
+
+        if (Table.TryGet(hash, out var entry))
         {
             return entry;
         }
@@ -160,7 +162,7 @@ public unsafe AtlasGlyphInfo FindGlyphEntry(char c, float resolutionMultiplier)
             Scale = Font.Scale
         };
 
-        Table.Add(c, info);
+        Table.Add(hash, info);
 
         return info;
     }
@@ -230,13 +232,13 @@ public static unsafe Font LoadFont(string name)
 
     public static FontAtlas CreateFontAtlas(ScaledFont scaledFont)
     {
-        var table = new LRUCache<char, AtlasGlyphInfo>(10*10);
+        var table = new LRUCache<int, AtlasGlyphInfo>(10*10);
 
         for (int i = 1; i < 11; i++)
         {
             for (int j = 1; j < 11; j++)
             {
-                table.Add((char)(int.MaxValue - i - 100 * j), default(AtlasGlyphInfo) with
+                table.Add((int.MaxValue - i - 100 * j).GetHashCode(), default(AtlasGlyphInfo) with
                 {
                     AtlasX = i * 100,
                     AtlasY = j * 100,

Flamui/Drawing/GlCanvas.cs

@@ -1,6 +1,5 @@
 using System.Diagnostics;
 using System.Numerics;
-using System.Text.Json;
 using Silk.NET.Maths;
 using Silk.NET.OpenGL;
 
@@ -36,6 +35,8 @@ public void DrawText(ReadOnlySpan<char> text, float x, float y)
     {
         var resolutionMultiplier = new Vector2(1, 1).Multiply(MeshBuilder.Matrix.GetScale()).Y;
 
+        Console.WriteLine(resolutionMultiplier);
+
         var fontAtlas = _renderer.GetFontAtlas(Paint.Font);
 
         var xCoord = x;

Flamui/LRUCache.cs

@@ -30,6 +30,7 @@ public TValue GetLeastUsed()
     }
 
     public bool TryGet(TKey key, out TValue value) {
+
         if(dictionary.TryGetValue(key, out var node))
         {
             Remove(node);
@@ -91,23 +92,35 @@ private void Remove(LRUCacheEntry entry)
     {
         if (entry == head)
         {
-            entry.Next.Prev = entry.Prev;
+            head = entry.Next;
+            head.Prev = entry.Prev;
+
+            entry.Prev = null;
+            entry.Next = null;
+
             return;
         }
 
+
         entry.Prev.Next = entry.Next;
         if (entry.Next != null)
         {
             entry.Next.Prev = entry.Prev;
         }
         else
         {
+            entry.Prev.Next = null;
             head.Prev = entry.Prev;
         }
+
+        entry.Prev = null;
+        entry.Next = null;
+
     }
 
     private LRUCacheEntry AddFirst(TKey key, TValue value)
     {
+
         var entry = new LRUCacheEntry
         {
             Key = key,
@@ -118,4 +131,29 @@ private LRUCacheEntry AddFirst(TKey key, TValue value)
 
         return entry;
     }
+
+    private void ValidateTable()
+    {
+        if (head == null)
+            return;
+
+        var current = head;
+        int counter = 1;
+
+        while (true)
+        {
+            current = current.Next;
+
+            if (current == null)
+            {
+                // Debug.Assert(counter == capacity);
+                break;
+            }
+
+            if(counter > capacity)
+                Debug.Assert(false);
+
+            counter++;
+        }
+    }
 }