Reinstate texture slot reuse

TRDataControl/Transport/TRDataImporter.cs

@@ -344,6 +344,7 @@ protected void ImportTextures(List<B> blobs)
 
         // Packing passed, so remap mesh textures to their new object references
         Dictionary<string, Dictionary<int, int>> globalRemap = new();
+        Queue<int> freeSlots = new(Level.GetFreeTextureSlots());
         foreach (TRTextileRegion region in importRegions)
         {
             globalRemap[region.ID] = new();
@@ -352,13 +353,23 @@ protected void ImportTextures(List<B> blobs)
                 if (globalRemap[region.ID].ContainsKey(segment.Index))
                     continue;
 
-                if (Level.ObjectTextures.Count >= Data.TextureObjectLimit)
+                int newIndex;
+                if (freeSlots.Count > 0)
+                {
+                    newIndex = freeSlots.Dequeue();
+                    Level.ObjectTextures[newIndex] = segment.Texture as TRObjectTexture;
+                }
+                else if (Level.ObjectTextures.Count < Data.TextureObjectLimit)
+                {
+                    newIndex = Level.ObjectTextures.Count;
+                    Level.ObjectTextures.Add(segment.Texture as TRObjectTexture);
+                }
+                else
                 {
                     throw new PackingException($"Limit of {Data.TextureObjectLimit} textures reached.");
                 }
 
-                globalRemap[region.ID][segment.Index] = Level.ObjectTextures.Count;
-                Level.ObjectTextures.Add(segment.Texture as TRObjectTexture);
+                globalRemap[region.ID][segment.Index] = newIndex;
             }
         }
 

TRDataControl/Transport/TRTextureRemapper.cs

@@ -1,4 +1,5 @@
 using System.Drawing;
+using TRImageControl;
 using TRImageControl.Packing;
 using TRLevelControl.Model;
 
@@ -89,7 +90,7 @@ static string Hash(TRObjectTexture t)
             {
                 int j = _level.ObjectTextures.IndexOf(copies[i]);
                 remap[j] = rootIndex;
-                _level.ObjectTextures[j].Atlas = ushort.MaxValue;
+                _level.ObjectTextures[j].Invalidate();
             }
         }
 
@@ -108,23 +109,8 @@ public void ResetUnusedTextures()
             .Distinct();
         foreach (int unused in allIndices.Except(usedIndices))
         {
-            _level.ObjectTextures[unused].Atlas = ushort.MaxValue;
+            _level.ObjectTextures[unused].Invalidate();
         }
-
-        // Remap all indices after deleting the nulls
-        Dictionary<int, int> remap = new();
-        List<TRObjectTexture> oldTextures = new(_level.ObjectTextures);
-        _level.ObjectTextures.RemoveAll(o => o.Atlas == ushort.MaxValue);
-        for (int i = 0; i < oldTextures.Count; i++)
-        {
-            if (oldTextures[i].Atlas != ushort.MaxValue)
-            {
-                remap[i] = _level.ObjectTextures.IndexOf(oldTextures[i]);
-            }
-        }
-
-        // Update all faces
-        RemapTextures(remap);
     }
 
     private void RemapTextures(Dictionary<int, int> remap)

TRDataControl/Utilities/TRModelExtensions.cs

@@ -1,5 +1,6 @@
 using System.Security.Cryptography;
 using System.Text;
+using TRImageControl;
 using TRLevelControl.Build;
 using TRLevelControl.Model;
 
@@ -29,6 +30,19 @@ public static void ResetUnusedTextures(this TRLevelBase level)
         }
     }
 
+    public static List<int> GetFreeTextureSlots(this TRLevelBase level)
+    {
+        List<int> slots = new();
+        for (int i = 0; i < level.ObjectTextures.Count; i++)
+        {
+            if (!level.ObjectTextures[i].IsValid())
+            {
+                slots.Add(i);
+            }
+        }
+        return slots;
+    }
+
     public static string ComputeSkeletonHash(this IEnumerable<TRMesh> meshes)
     {
         using MemoryStream ms = new();

TRDataControlTests/Remapping/RemappingTests.cs

@@ -8,10 +8,34 @@
 namespace TRDataControlTests.IO;
 
 [TestClass]
-[TestCategory("OriginalIO")]
 public class RemappingTests : TestBase
 {
     [TestMethod]
+    [TestCategory("DataTransport")]
+    [Description("Test that texture slots are freed correctly when requested.")]
+    public void TestFreeSlots()
+    {
+        TR1Level level = GetTR1TestLevel();
+
+        HashSet<int> slots = new();
+        Random random = new();
+        while (slots.Count < 10)
+        {
+            slots.Add(random.Next(0, level.ObjectTextures.Count));
+        }
+
+        foreach (int slot in slots)
+        {
+            level.ObjectTextures[slot].Invalidate();
+            Assert.IsFalse(level.ObjectTextures[slot].IsValid());
+        }
+
+        List<int> freeSlots = level.GetFreeTextureSlots();
+        CollectionAssert.AreEquivalent(slots.ToList(), freeSlots);
+    }
+
+    [TestMethod]
+    [TestCategory("OriginalIO")]
     [Description("Test that object textures are correct after removing data.")]
     public void TestTextureRemoval()
     {
@@ -46,6 +70,7 @@ string GetFaceID(TRFace face)
     }
 
     [TestMethod]
+    [TestCategory("OriginalIO")]
     [Description("As above, but with an added dependency on a different model.")]
     public void TestDependencies()
     {

TRImageControl/Extensions/ColourExtensions.cs

@@ -191,4 +191,17 @@ public static int FindClosest(this IEnumerable<Color> palette, Color colour, int
             .Where(item => item.Index >= startIndex)
             .MinBy(item => item.Delta).Index;
     }
+
+    public static bool IsValid(this TRTexture texture)
+    {
+        return texture.Atlas != 0 || texture.Bounds != _nullBounds;
+    }
+
+    public static void Invalidate(this TRTexture texture)
+    {
+        texture.Atlas = 0;
+        texture.Bounds = _nullBounds;
+    }
+
+    private static readonly Rectangle _nullBounds = new(0, 0, 1, 1);
 }

TRImageControl/Packing/TRTextileSegment.cs

@@ -28,12 +28,12 @@ public void Commit(int tileIndex)
 
     public void Invalidate()
     {
-        Atlas = ushort.MaxValue;
+        Texture.Invalidate();
     }
 
     public bool IsValid()
     {
-        return Atlas != ushort.MaxValue;
+        return Texture.IsValid();
     }
 
     public override string ToString()

TRImageControl/Packing/Types/TR1TexturePacker.cs

@@ -44,6 +44,9 @@ protected override List<TRTextileSegment> LoadObjectSegments()
         List<TRTextileSegment> segments = new();
         for (int i = 0; i < _level.ObjectTextures.Count; i++)
         {
+            if (!_level.ObjectTextures[i].IsValid())
+                continue;
+
             segments.Add(new()
             {
                 Index = i,

TRImageControl/Packing/Types/TR2TexturePacker.cs

@@ -40,6 +40,9 @@ protected override List<TRTextileSegment> LoadObjectSegments()
         List<TRTextileSegment> segments = new();
         for (int i = 0; i < _level.ObjectTextures.Count; i++)
         {
+            if (!_level.ObjectTextures[i].IsValid())
+                continue;
+
             segments.Add(new()
             {
                 Index = i,

TRImageControl/Packing/Types/TR3TexturePacker.cs

@@ -40,6 +40,9 @@ protected override List<TRTextileSegment> LoadObjectSegments()
         List<TRTextileSegment> segments = new();
         for (int i = 0; i < _level.ObjectTextures.Count; i++)
         {
+            if (!_level.ObjectTextures[i].IsValid())
+                continue;
+
             segments.Add(new()
             {
                 Index = i,

TRImageControl/Packing/Types/TR4TexturePacker.cs

@@ -122,7 +122,7 @@ protected override List<TRTextileSegment> LoadObjectSegments()
         for (int i = 0; i < _level.ObjectTextures.Count; i++)
         {
             TRObjectTexture texture = _level.ObjectTextures[i];
-            if (group != null && !group.Contains(texture))
+            if (group != null && !group.Contains(texture) || !texture.IsValid())
                 continue;
 
             segments.Add(new()

TRImageControl/Packing/Types/TR5TexturePacker.cs

@@ -113,7 +113,7 @@ protected override List<TRTextileSegment> LoadObjectSegments()
         for (int i = 0; i < _level.ObjectTextures.Count; i++)
         {
             TRObjectTexture texture = _level.ObjectTextures[i];
-            if (group != null && !group.Contains(texture))
+            if (group != null && !group.Contains(texture) || !texture.IsValid())
                 continue;
 
             segments.Add(new()

TRRandomizerCore/Processors/TR2/TR2TextureDeduplicator.cs

@@ -102,7 +102,6 @@ protected override void ProcessImpl()
 
                     TR2TextureRemapper remapper = new(level.Data);
                     remapper.ResetUnusedTextures();
-                    remapper.Remap();
 
                     _outer.SaveLevel(level);
                 }

TRRandomizerCore/Resources/TR2/Textures/Deduplication/HOUSE.TR2-TextureRemap.json

@@ -0,0 +1 @@
+{}

TRRandomizerCore/Resources/TR2/Textures/Mapping/BOAT.TR2-Textures.json

@@ -5,7 +5,7 @@
         {
           "RoomNumber": 0,
           "RectangleIndices": [ 57 ],
-          "BackgroundIndex": 1464
+          "BackgroundIndex": 1520
         }
       ]
     }

TRRandomizerCore/Resources/TR2/Textures/Mapping/CATACOMB.TR2-Textures.json

@@ -105,7 +105,7 @@
         {
           "RoomNumber": 73,
           "RectangleIndices": [ 9 ],
-          "BackgroundIndex": 1297
+          "BackgroundIndex": 1314
         }
       ]
     },
@@ -114,7 +114,7 @@
         {
           "RoomNumber": 121,
           "RectangleIndices": [ 7 ],
-          "BackgroundIndex": 1330
+          "BackgroundIndex": 1344
         }
       ]
     }

TRRandomizerCore/Resources/TR2/Textures/Mapping/FLOATING.TR2-Textures.json

@@ -5,7 +5,7 @@
         {
           "RoomNumber": 40,
           "RectangleIndices": [ 29, 58 ],
-          "BackgroundIndex": 1611
+          "BackgroundIndex": 1667
         }
       ]
     }

TRRandomizerCore/Resources/TR2/Textures/Mapping/FLOATING.TR2-UKBox-Textures.json

@@ -5,7 +5,7 @@
         {
           "RoomNumber": 40,
           "RectangleIndices": [ 29, 58 ],
-          "BackgroundIndex": 1627
+          "BackgroundIndex": 1683
         }
       ]
     }

TRRandomizerCore/Resources/TR2/Textures/Mapping/ICECAVE.TR2-Textures.json

@@ -5,7 +5,7 @@
         {
           "RoomNumber": 5,
           "RectangleIndices": [ 72 ],
-          "BackgroundIndex": 1360
+          "BackgroundIndex": 1378
         }
       ]
     }

TRRandomizerCore/Resources/TR2/Textures/Mapping/SKIDOO.TR2-Textures.json

@@ -5,7 +5,7 @@
         {
           "RoomNumber": 131,
           "RectangleIndices": [ 15 ],
-          "BackgroundIndex": 1462
+          "BackgroundIndex": 1480
         }
       ]
     },
@@ -14,7 +14,7 @@
         {
           "RoomNumber": 124,
           "RectangleIndices": [ 4 ],
-          "BackgroundIndex": 1332
+          "BackgroundIndex": 1350
         }
       ]
     }

TRRandomizerCore/Resources/TR2/Textures/Mapping/WALL.TR2-Textures.json

@@ -59,7 +59,7 @@
         {
           "RoomNumber": 65,
           "RectangleIndices": [ 134 ],
-          "BackgroundIndex": 1130
+          "BackgroundIndex": 1186
         }
       ]
     }