Add ability to exclude tiles by implementing a C# class.

CHANGES.md

@@ -7,8 +7,9 @@
 - Added `CesiumPointCloudShading`, which allows point cloud tilesets to be rendered with attenuation based on geometric error. Attenuation is currently only supported in URP.
 - Added support for Unity's built-in render pipeline.
 - `GameObject` instances created for the tiles in a `Cesium3DTileset` now inherit the `layer` of the parent tileset.
-- Added setting in CesiumRuntimeSettings to configure the maximum number of items to keep in the Sqlite cache.
-- Added setting in CesiumRuntimeSettings to configure the number of requests to the cache database before pruning.
+- Added the `CesiumTileExcluder` abstract class. By creating a class derived from `CesiumTileExcluder`, then adding it to a `Cesium3DTileset`'s game object, you can implement custom rules for excluding tiles in the `Cesium3DTileset` from loading and rendering.
+- Added setting in `CesiumRuntimeSettings` to configure the maximum number of items to keep in the Sqlite cache.
+- Added setting in `CesiumRuntimeSettings` to configure the number of requests to the cache database before pruning.
 
 ##### Fixes :wrench:
 

Editor/ConfigureReinterop.cs

@@ -165,6 +165,7 @@ public void ExposeToCPP()
 
             CesiumRasterOverlay[] rasterOverlays = tileset.gameObject.GetComponents<CesiumRasterOverlay>();
             CesiumRasterOverlay overlay = rasterOverlays[0];
+            UnityEngine.Object.DestroyImmediate(overlay, true);
             UnityEngine.Object.DestroyImmediate(overlay);
 
             CesiumIonRasterOverlay[] ionRasterOverlays =

Reinterop~/CSharpTypeUtility.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis;
 using System.Collections.Immutable;
+using System.Text.RegularExpressions;
 
 namespace Reinterop
 {
@@ -63,5 +64,43 @@ public static IEnumerable<ISymbol> FindMembers(ITypeSymbol type, string name)
                 current = current.BaseType;
             }
         }
+
+        public static IPropertySymbol? GetAutoPropertyForField(IFieldSymbol field)
+        {
+            string fieldName = field.Name;
+
+            IPropertySymbol? autoProperty = field.AssociatedSymbol as IPropertySymbol;
+
+            // Unfortunately, the above will only work if the C# compiler is looking at the source code for the property.
+            // So for backing fields in referenced assemblies, we need to do this more manually.
+            if (autoProperty == null && fieldName.EndsWith("__BackingField"))
+            {
+                Match match = new Regex("<(.+)>k__BackingField").Match(fieldName);
+                if (match.Success && match.Groups.Count > 1)
+                {
+                    autoProperty = CSharpTypeUtility.FindMember(field.ContainingType, match.Groups[1].Value) as IPropertySymbol;
+                }
+            }
+
+            return autoProperty;
+        }
+
+        public static string GetFieldName(IFieldSymbol field)
+        {
+            IPropertySymbol? autoProperty = GetAutoPropertyForField(field);
+            if (autoProperty != null)
+                return autoProperty.Name;
+            else
+                return field.Name;
+        }
+
+        public static bool GetFieldIsPrivate(IFieldSymbol field)
+        {
+            IPropertySymbol? autoProperty = GetAutoPropertyForField(field);
+            if (autoProperty != null)
+                return autoProperty.DeclaredAccessibility != Accessibility.Public;
+            else
+                return field.DeclaredAccessibility != Accessibility.Public;
+        }
     }
 }

Reinterop~/Constructors.cs

@@ -1,4 +1,5 @@
 using Microsoft.CodeAnalysis;
+using System.Collections.Immutable;
 using System.Xml.Linq;
 
 namespace Reinterop
@@ -7,17 +8,6 @@ internal class Constructors
     {
         public static void Generate(CppGenerationContext context, TypeToGenerate item, GeneratedResult result)
         {
-            // TODO: We're not currently generating constructors for blittable value types. They'll need to be slightly different (no handle).
-            // We only need handle management for non-static classes.
-
-            GeneratedCppDeclaration declaration = result.CppDeclaration;
-            if (declaration.Type.Kind != InteropTypeKind.ClassWrapper &&
-                declaration.Type.Kind != InteropTypeKind.NonBlittableStructWrapper &&
-                declaration.Type.Kind != InteropTypeKind.Delegate)
-            {
-                return;
-            }
-
             if (item.Type.IsStatic)
                 GenerateStatic(context, item, result);
             else
@@ -50,8 +40,12 @@ private static void GenerateSingleNonStatic(CppGenerationContext context, TypeTo
             GeneratedInit init = result.Init;
 
             var parameters = constructor.Parameters.Select(parameter => (Name: parameter.Name, Type: CppType.FromCSharp(context, parameter.Type).AsParameterType()));
-            var interopReturnType = declaration.Type.AsInteropType();
+            var returnType = declaration.Type;
+            var interopReturnType = returnType.AsInteropType();
             var interopParameters = parameters.Select(parameter => (ParameterName: parameter.Name, CallSiteName: parameter.Name, Type: parameter.Type, InteropType: parameter.Type.AsInteropType()));
+
+            bool hasStructRewrite = Interop.RewriteStructReturn(ref interopParameters, ref returnType, ref interopReturnType);
+
             var interopParameterStrings = interopParameters.Select(parameter => $"{parameter.InteropType.GetFullyQualifiedName()} {parameter.ParameterName}");
 
             string interopFunctionName = $"Construct_{Interop.HashParameters(constructor.Parameters)}";
@@ -83,30 +77,65 @@ private static void GenerateSingleNonStatic(CppGenerationContext context, TypeTo
                 CSharpContent: csContent
             ));
 
-            // Constructor declaration
-            var parameterStrings = parameters.Select(parameter => $"{parameter.Type.GetFullyQualifiedName()} {parameter.Name}");
-            declaration.Elements.Add(new(
-                Content: $"{declaration.Type.Name}({string.Join(", ", parameterStrings)});",
-                TypeDeclarationsReferenced: parameters.Select(parameter => parameter.Type)
-            ));
-
-            // Constructor definition
-            var parameterPassStrings = interopParameters.Select(parameter => parameter.Type.GetConversionToInteropType(context, parameter.CallSiteName));
-            definition.Elements.Add(new(
-                Content:
-                    $$"""
-                    {{definition.Type.Name}}{{templateSpecialization}}::{{definition.Type.Name}}({{string.Join(", ", parameterStrings)}})
-                        : _handle({{interopFunctionName}}({{string.Join(", ", parameterPassStrings)}}))
+            // For blittable structs, add static "Construct" functions rather than C++ constructors.
+            // This way we can use default construction and member initialization and avoid a call into C# to
+            // construct simple blittable types, but can still call explicit C# constructors when necessary.
+            if (declaration.Type.Kind == InteropTypeKind.BlittableStruct)
+            {
+                // Constructor declaration
+                var parameterStrings = parameters.Select(parameter => $"{parameter.Type.GetFullyQualifiedName()} {parameter.Name}");
+                declaration.Elements.Add(new(
+                    Content: $"static {declaration.Type.Name} Construct({string.Join(", ", parameterStrings)});",
+                    TypeDeclarationsReferenced: parameters.Select(parameter => parameter.Type)
+                ));
+
+                // Constructor definition
+                var parameterPassStrings = interopParameters.Select(parameter => parameter.Type.GetConversionToInteropType(context, parameter.CallSiteName));
+                definition.Elements.Add(new(
+                    Content:
+                        $$"""
+                        {{definition.Type.Name}} {{definition.Type.Name}}{{templateSpecialization}}::Construct({{string.Join(", ", parameterStrings)}})
+                        {
+                            {{definition.Type.Name}} result;
+                            {{interopFunctionName}}({{string.Join(", ", parameterPassStrings)}});
+                            return result;
+                        }
+                        """,
+                    TypeDefinitionsReferenced: new[]
                     {
-                    }
-                    """,
-                TypeDefinitionsReferenced: new[]
-                {
-                    definition.Type,
-                    interopReturnType,
-                    CppObjectHandle.GetCppType(context)
-                }.Concat(parameters.Select(parameter => parameter.Type))
-            ));
+                        definition.Type,
+                        interopReturnType,
+                        CppObjectHandle.GetCppType(context)
+                    }.Concat(parameters.Select(parameter => parameter.Type))
+                ));
+            }
+            else
+            {
+                // Constructor declaration
+                var parameterStrings = parameters.Select(parameter => $"{parameter.Type.GetFullyQualifiedName()} {parameter.Name}");
+                declaration.Elements.Add(new(
+                    Content: $"{declaration.Type.Name}({string.Join(", ", parameterStrings)});",
+                    TypeDeclarationsReferenced: parameters.Select(parameter => parameter.Type)
+                ));
+
+                // Constructor definition
+                var parameterPassStrings = interopParameters.Select(parameter => parameter.Type.GetConversionToInteropType(context, parameter.CallSiteName));
+                definition.Elements.Add(new(
+                    Content:
+                        $$"""
+                        {{definition.Type.Name}}{{templateSpecialization}}::{{definition.Type.Name}}({{string.Join(", ", parameterStrings)}})
+                            : _handle({{interopFunctionName}}({{string.Join(", ", parameterPassStrings)}}))
+                        {
+                        }
+                        """,
+                    TypeDefinitionsReferenced: new[]
+                    {
+                        definition.Type,
+                        interopReturnType,
+                        CppObjectHandle.GetCppType(context)
+                    }.Concat(parameters.Select(parameter => parameter.Type))
+                ));
+            }
         }
     }
 }

Reinterop~/Fields.cs

@@ -43,28 +43,8 @@ private static void GenerateField(CppGenerationContext context, TypeToGenerate i
             if (field.IsStatic)
                 return;
 
-            string fieldName = field.Name;
-            bool isPrivate = field.DeclaredAccessibility != Accessibility.Public;
-
-            // If this is a backing field for an automatic property, use the property name instead.
-            IPropertySymbol? autoProperty = field.AssociatedSymbol as IPropertySymbol;
-
-            // Unfortunately, the above will only work if the C# compiler is looking at the source code for the property.
-            // So for backing fields in referenced assemblies, we need to do this more manually.
-            if (autoProperty == null && fieldName.EndsWith("__BackingField"))
-            {
-                Match match = new Regex("<(.+)>k__BackingField").Match(fieldName);
-                if (match.Success && match.Groups.Count > 1)
-                {
-                    autoProperty = CSharpTypeUtility.FindMember(field.ContainingType, match.Groups[1].Value) as IPropertySymbol;
-                }
-            }
-
-            if (autoProperty != null)
-            {
-                fieldName = autoProperty.Name;
-                isPrivate = autoProperty.DeclaredAccessibility != Accessibility.Public;
-            }
+            string fieldName = CSharpTypeUtility.GetFieldName(field);
+            bool isPrivate = CSharpTypeUtility.GetFieldIsPrivate(field);
 
             CppType fieldType = CppType.FromCSharp(context, field.Type);
 

Runtime/Cesium3DTile.cs

@@ -0,0 +1,37 @@
+
+using Reinterop;
+using System;
+using Unity.Mathematics;
+using UnityEngine;
+
+namespace CesiumForUnity
+{
+    /// <summary>
+    /// Represents a tile in a <see cref="Cesium3DTileset"/> and allows information
+    /// about the tile to be queried from the underlying C++ tile representation.
+    /// </summary>
+    [ReinteropNativeImplementation("CesiumForUnityNative::Cesium3DTileImpl", "Cesium3DTileImpl.h", staticOnly: true)]
+    public partial class Cesium3DTile
+    {
+        internal double4x4 _transform;
+        internal IntPtr _pTile;
+
+        internal Cesium3DTile()
+        {
+        }
+
+        /// <summary>
+        /// Gets the axis-aligned bounding box of this tile. If this tile came from a <see cref="CesiumTileExcluder"/>,
+        /// the bounding box is expressed in the local coordinates of the excluder's game object.
+        /// </summary>
+        public Bounds bounds
+        {
+            get
+            {
+                return Cesium3DTile.getBounds(this._pTile, this._transform);
+            }
+        }
+
+        private static partial Bounds getBounds(IntPtr pTile, double4x4 ecefToLocalMatrix);
+    }
+}

Runtime/CesiumTileExcluder.cs

@@ -0,0 +1,47 @@
+using Reinterop;
+using UnityEngine;
+
+namespace CesiumForUnity
+{
+    /// <summary>
+    /// The abstract base class for <see cref="Cesium3DTileset"/> tile excluders. By creating a class derived
+    /// from `CesiumTileExcluder`, then adding it to a game object containing a `Cesium3DTileset` (or one of
+    /// its parents), you can implement custom rules for excluding tiles in the `Cesium3DTileset` from loading
+    /// and rendering.
+    /// </summary>
+    [ExecuteInEditMode]
+    [ReinteropNativeImplementation("CesiumForUnityNative::CesiumTileExcluderImpl", "CesiumTileExcluderImpl.h", staticOnly: true)]
+    public abstract partial class CesiumTileExcluder : MonoBehaviour
+    {
+        /// <summary>
+        /// Determines whether the given tile should be excluded from loading and rendering. If a tile is
+        /// excluded, all of its children and other descendants in the bounding volume hierarchy will be
+        /// excluded as well.
+        /// </summary>
+        /// <param name="tile">The tile to check. This instance is only valid for the duration of this call. Saving
+        /// it and using it later will result in undefined behavior, including crashes.</param>
+        /// <returns>True if the tile should be excluded, false if the tile should be loaded and rendered.</returns>
+        public abstract bool ShouldExclude(Cesium3DTile tile);
+
+        protected virtual void OnEnable()
+        {
+            Cesium3DTileset[] tilesets = this.GetComponentsInChildren<Cesium3DTileset>();
+            foreach (Cesium3DTileset tileset in tilesets)
+            {
+                this.AddToTileset(tileset);
+            }
+        }
+
+        protected virtual void OnDisable()
+        {
+            Cesium3DTileset[] tilesets = this.GetComponentsInChildren<Cesium3DTileset>();
+            foreach (Cesium3DTileset tileset in tilesets)
+            {
+                this.RemoveFromTileset(tileset);
+            }
+        }
+
+        internal partial void AddToTileset(Cesium3DTileset tileset);
+        internal partial void RemoveFromTileset(Cesium3DTileset tileset);
+    }
+}

Runtime/ConfigureReinterop.cs

@@ -160,6 +160,7 @@ public void ExposeToCPP()
             meshRenderer.sharedMaterial = meshRenderer.sharedMaterial;
             meshRenderer.material.shader = meshRenderer.material.shader;
             UnityEngine.Object.Destroy(meshGameObject);
+            UnityEngine.Object.DestroyImmediate(meshGameObject, true);
             UnityEngine.Object.DestroyImmediate(meshGameObject);
 
             MeshFilter meshFilter = new MeshFilter();
@@ -341,6 +342,7 @@ public void ExposeToCPP()
             georeference.ecefY = georeference.ecefY;
             georeference.ecefZ = georeference.ecefZ;
             georeference.originAuthority = georeference.originAuthority;
+            double4x4 ecefToLocal = georeference.ecefToLocalMatrix;
 
             CesiumGeoreference inParent = go.GetComponentInParent<CesiumGeoreference>();
             inParent.MoveOrigin();
@@ -458,6 +460,15 @@ Cesium3DTilesetLoadFailureDetails tilesetDetails
             globeAnchor._lastLocalToWorld = new Matrix4x4();
             globeAnchor.UpdateGeoreferenceIfNecessary();
 
+            CesiumTileExcluder[] excluders = go.GetComponentsInParent<CesiumTileExcluder>();
+            CesiumTileExcluder excluder = excluders[0];
+            excluder.AddToTileset(null);
+            excluder.RemoveFromTileset(null);
+            excluder.ShouldExclude(new Cesium3DTile());
+            Cesium3DTile tile = new Cesium3DTile();
+            tile._transform = new double4x4();
+            tile._pTile = IntPtr.Zero;
+
             Cesium3DTileInfo info;
             info.usesAdditiveRefinement = true;
             info.geometricError = 1.0f;