refactor: improve unsafe collection API usage per review

- Replace float[3] with Vector3 (System.Numerics)
- Use UnsafeList.GetUnsafePtr() instead of fixed blocks
- Use AllocationManager.CreateStackScope() for temporary collections
- Remove redundant properties in ClodConfig (public fields suffice)
- Use MeshOptApi directly instead of Api alias
- Fix method signatures to not require allocator for stack-scoped collections

src/Runtime/Ghost.Graphics/Meshlet/ClodBounds.cs

@@ -1,8 +1,10 @@
+using System.Numerics;
+
 namespace Ghost.Graphics.Meshlet;
 
-public unsafe struct ClodBounds
+public struct ClodBounds
 {
-    public fixed float center[3];
+    public Vector3 center;
     public float radius;
     public float error;
 }

src/Runtime/Ghost.Graphics/Meshlet/ClodBoundsHelper.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Numerics;
 using Ghost.MeshOptimizer;
 using Misaki.HighPerformance;
 
@@ -8,47 +9,36 @@ internal static class ClodBoundsHelper
 {
     public static ClodBounds ComputeBounds(ClodMesh mesh, UnsafeList<uint> indices, float error)
     {
-        fixed (uint* pIndices = new uint[(int)indices.Length])
+        var bounds = MeshOptApi.meshopt_computeClusterBounds(indices.Ptr, (nuint)indices.Length, mesh.vertexPositions, mesh.vertexCount, mesh.vertexPositionsStride);
-        {
-            for (int i = 0; i < (int)indices.Length; i++)
-            {
-                pIndices[i] = indices[i];
-            }
-
-            var bounds = Api.meshopt_computeClusterBounds(pIndices, (nuint)indices.Length, mesh.vertexPositions, mesh.vertexCount, mesh.vertexPositionsStride);
         
         var result = new ClodBounds();
-            result.center[0] = bounds.center[0];
+        result.center = new Vector3(bounds.center[0], bounds.center[1], bounds.center[2]);
-            result.center[1] = bounds.center[1];
-            result.center[2] = bounds.center[2];
         result.radius = bounds.radius;
         result.error = error;
         return result;
     }
-    }
 
     public static ClodBounds MergeBounds(UnsafeList<Cluster> clusters, UnsafeList<int> group)
     {
-        var boundsList = new ClodBounds[group.Length];
+        using var scope = AllocationManager.CreateStackScope();
+        var boundsList = new UnsafeList<ClodBounds>(group.Length, scope.AllocationHandle);
+        boundsList.Resize((nuint)group.Length);
+        
         for (int j = 0; j < (int)group.Length; j++)
         {
             boundsList[j] = clusters[group[j]].bounds;
         }
 
-        fixed (ClodBounds* pBounds = boundsList)
+        var merged = MeshOptApi.meshopt_computeSphereBounds(
-        {
+            (float*)boundsList.Ptr,
-            var merged = Api.meshopt_computeSphereBounds(
+            (nuint)group.Length,
-                &pBounds[0].center[0],
-                (nuint)boundsList.Length,
             (nuint)sizeof(ClodBounds),
-                &pBounds[0].radius,
+            (float*)boundsList.Ptr + 3, // offset to radius field
             (nuint)sizeof(ClodBounds)
         );
 
         var result = new ClodBounds();
-            result.center[0] = merged.center[0];
+        result.center = new Vector3(merged.center[0], merged.center[1], merged.center[2]);
-            result.center[1] = merged.center[1];
-            result.center[2] = merged.center[2];
         result.radius = merged.radius;
 
         result.error = 0.0f;
@@ -59,5 +49,4 @@ internal static class ClodBoundsHelper
 
         return result;
     }
-    }
 }

src/Runtime/Ghost.Graphics/Meshlet/ClodBuilder.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Numerics;
 using Ghost.MeshOptimizer;
 using Misaki.HighPerformance;
 
@@ -34,7 +35,7 @@ public unsafe static class ClodBuilder
         // Generate position-only remap
         var remap = new UnsafeList<uint>((int)mesh.vertexCount, allocator);
         remap.Resize(mesh.vertexCount);
-        Api.meshopt_generatePositionRemap(remap.Ptr, mesh.vertexPositions, mesh.vertexCount, mesh.vertexPositionsStride);
+        MeshOptApi.meshopt_generatePositionRemap(remap.Ptr, mesh.vertexPositions, mesh.vertexCount, mesh.vertexPositionsStride);
 
         // Set up protect bits on UV seams
         if (mesh.attributeProtectMask != 0)
@@ -49,7 +50,7 @@ public unsafe static class ClodBuilder
                     {
                         if (mesh.vertexAttributes[i * maxAttributes + j] != mesh.vertexAttributes[r * maxAttributes + j])
                         {
-                            locks[(int)i] |= (byte)Api.meshopt_SimplifyVertex_Protect;
+                            locks[(int)i] |= (byte)MeshOptApi.meshopt_SimplifyVertex_Protect;
                         }
                     }
                 }
@@ -74,16 +75,16 @@ public unsafe static class ClodBuilder
 
         while (pending.Length > 1)
         {
-            var groups = ClodInternal.Partition(config, mesh, clusters, pending, remap, allocator);
+            var groups = ClodPartition.Partition(config, mesh, clusters, pending, remap);
 
             pending.Clear();
 
             // Lock boundaries
-            ClodInternal.LockBoundary(locks, groups, clusters, remap, mesh.vertexLock);
+            ClodBoundary.LockBoundary(locks, groups, clusters, remap, mesh.vertexLock);
 
             for (int i = 0; i < (int)groups.Length; i++)
             {
-                var merged = new UnsafeList<uint>(groups[i].Length * (int)config.MaxTriangles * 3, allocator);
+                var merged = new UnsafeList<uint>(groups[i].Length * (int)config.maxTriangles * 3, allocator);
                 for (int j = 0; j < (int)groups[i].Length; j++)
                 {
                     var clusterIndices = clusters[groups[i][j]].indices;
@@ -91,14 +92,14 @@ public unsafe static class ClodBuilder
                         merged.Add(clusterIndices[k]);
                 }
 
-                nuint targetSize = ((nuint)merged.Length / 3) * (nuint)config.SimplifyRatio * 3;
+                nuint targetSize = ((nuint)merged.Length / 3) * (nuint)config.simplifyRatio * 3;
 
                 var bounds = ClodBoundsHelper.MergeBounds(clusters, groups[i]);
 
                 float error = 0.0f;
-                var simplified = ClodSimplify.Simplify(config, mesh, merged, locks, targetSize, &error, allocator);
+                var simplified = ClodSimplify.Simplify(config, mesh, merged, locks, targetSize, &error);
 
-                if (simplified.Length > (nuint)(merged.Length * config.SimplifyThreshold))
+                if (simplified.Length > (nuint)(merged.Length * config.simplifyThreshold))
                 {
                     bounds.error = float.MaxValue;
                     OutputGroup(config, mesh, clusters, groups[i], bounds, depth, outputContext, outputCallback, allocator);
@@ -107,7 +108,7 @@ public unsafe static class ClodBuilder
                     continue;
                 }
 
-                bounds.error = Math.Max(bounds.error * config.SimplifyErrorMergePrevious, error) + error * config.SimplifyErrorMergeAdditive;
+                bounds.error = Math.Max(bounds.error * config.simplifyErrorMergePrevious, error) + error * config.simplifyErrorMergeAdditive;
 
                 int refined = OutputGroup(config, mesh, clusters, groups[i], bounds, depth, outputContext, outputCallback, allocator);
 
@@ -171,7 +172,7 @@ public unsafe static class ClodBuilder
         Allocator allocator
     )
     {
-        var groupClusters = new UnsafeList<ClodCluster>((int)group.Length, allocator);
+        var groupClusters = new UnsafeList<ClodCluster>(group.Length, allocator);
         groupClusters.Resize((nuint)group.Length);
 
         for (int i = 0; i < (int)group.Length; i++)
@@ -180,7 +181,7 @@ public unsafe static class ClodBuilder
             ref var dstCluster = ref groupClusters[i];
 
             dstCluster.refined = srcCluster.refined;
-            dstCluster.bounds = (config.OptimizeBounds && srcCluster.refined != -1)
+            dstCluster.bounds = (config.optimizeBounds && srcCluster.refined != -1)
                 ? ClodBoundsHelper.ComputeBounds(mesh, srcCluster.indices, srcCluster.bounds.error)
                 : srcCluster.bounds;
             dstCluster.indices = srcCluster.indices.Ptr;

src/Runtime/Ghost.Graphics/Meshlet/ClodConfig.cs

@@ -34,26 +34,4 @@ public struct ClodConfig
     public bool optimizeBounds;
 
     public bool optimizeClusters;
-
-    public nuint MaxVertices { get => maxVertices; set => maxVertices = value; }
-    public nuint MinTriangles { get => minTriangles; set => minTriangles = value; }
-    public nuint MaxTriangles { get => maxTriangles; set => maxTriangles = value; }
-    public bool PartitionSpatial { get => partitionSpatial; set => partitionSpatial = value; }
-    public bool PartitionSort { get => partitionSort; set => partitionSort = value; }
-    public nuint PartitionSize { get => partitionSize; set => partitionSize = value; }
-    public bool ClusterSpatial { get => clusterSpatial; set => clusterSpatial = value; }
-    public float ClusterFillWeight { get => clusterFillWeight; set => clusterFillWeight = value; }
-    public float ClusterSplitFactor { get => clusterSplitFactor; set => clusterSplitFactor = value; }
-    public float SimplifyRatio { get => simplifyRatio; set => simplifyRatio = value; }
-    public float SimplifyThreshold { get => simplifyThreshold; set => simplifyThreshold = value; }
-    public float SimplifyErrorMergePrevious { get => simplifyErrorMergePrevious; set => simplifyErrorMergePrevious = value; }
-    public float SimplifyErrorMergeAdditive { get => simplifyErrorMergeAdditive; set => simplifyErrorMergeAdditive = value; }
-    public float SimplifyErrorFactorSloppy { get => simplifyErrorFactorSloppy; set => simplifyErrorFactorSloppy = value; }
-    public float SimplifyErrorEdgeLimit { get => simplifyErrorEdgeLimit; set => simplifyErrorEdgeLimit = value; }
-    public bool SimplifyPermissive { get => simplifyPermissive; set => simplifyPermissive = value; }
-    public bool SimplifyFallbackPermissive { get => simplifyFallbackPermissive; set => simplifyFallbackPermissive = value; }
-    public bool SimplifyFallbackSloppy { get => simplifyFallbackSloppy; set => simplifyFallbackSloppy = value; }
-    public bool SimplifyRegularize { get => simplifyRegularize; set => simplifyRegularize = value; }
-    public bool OptimizeBounds { get => optimizeBounds; set => optimizeBounds = value; }
-    public bool OptimizeClusters { get => optimizeClusters; set => optimizeClusters = value; }
 }

src/Runtime/Ghost.Graphics/Meshlet/ClodInternal.cs

@@ -8,7 +8,7 @@ internal static class ClodInternal
 {
     public static UnsafeList<Cluster> Clusterize(ClodConfig config, ClodMesh mesh, uint* indices, nuint indexCount, Allocator allocator)
     {
-        nuint maxMeshlets = Api.meshopt_buildMeshletsBound(indexCount, config.MaxVertices, config.MinTriangles);
+        nuint maxMeshlets = MeshOptApi.meshopt_buildMeshletsBound(indexCount, config.maxVertices, config.minTriangles);
 
         var meshlets = new UnsafeList<meshopt_Meshlet>(maxMeshlets, allocator);
         var meshletVertices = new UnsafeList<uint>(indexCount, allocator);
@@ -17,9 +17,9 @@ internal static class ClodInternal
         meshlets.Resize(maxMeshlets);
         
         nuint meshletCount;
-        if (config.ClusterSpatial)
+        if (config.clusterSpatial)
         {
-            meshletCount = Api.meshopt_buildMeshletsSpatial(
+            meshletCount = MeshOptApi.meshopt_buildMeshletsSpatial(
                 meshlets.Ptr, 
                 meshletVertices.Ptr, 
                 meshletTriangles.Ptr, 
@@ -28,15 +28,15 @@ internal static class ClodInternal
                 mesh.vertexPositions, 
                 mesh.vertexCount, 
                 mesh.vertexPositionsStride,
-                config.MaxVertices, 
+                config.maxVertices, 
-                config.MinTriangles, 
+                config.minTriangles, 
-                config.MaxTriangles, 
+                config.maxTriangles, 
-                config.ClusterFillWeight
+                config.clusterFillWeight
             );
         }
         else
         {
-            meshletCount = Api.meshopt_buildMeshletsFlex(
+            meshletCount = MeshOptApi.meshopt_buildMeshletsFlex(
                 meshlets.Ptr, 
                 meshletVertices.Ptr, 
                 meshletTriangles.Ptr, 
@@ -45,11 +45,11 @@ internal static class ClodInternal
                 mesh.vertexPositions, 
                 mesh.vertexCount, 
                 mesh.vertexPositionsStride,
-                config.MaxVertices, 
+                config.maxVertices, 
-                config.MinTriangles, 
+                config.minTriangles, 
-                config.MaxTriangles, 
+                config.maxTriangles, 
                 0.0f, 
-                config.ClusterSplitFactor
+                config.clusterSplitFactor
             );
         }
         meshlets.Resize(meshletCount);
@@ -60,9 +60,9 @@ internal static class ClodInternal
         {
             ref var meshlet = ref meshlets[i];
 
-            if (config.OptimizeClusters)
+            if (config.optimizeClusters)
             {
-                Api.meshopt_optimizeMeshlet(
+                MeshOptApi.meshopt_optimizeMeshlet(
                     meshletVertices.Ptr + meshlet.vertexOffset, 
                     meshletTriangles.Ptr + meshlet.triangleOffset, 
                     meshlet.triangleCount, 

src/Runtime/Ghost.Graphics/Meshlet/ClodInternal_Boundary.cs

@@ -1,3 +1,10 @@
+using Ghost.MeshOptimizer;
+using Misaki.HighPerformance;
+
+namespace Ghost.Graphics.Meshlet;
+
+internal static class ClodBoundary
+{
     public static void LockBoundary(UnsafeList<byte> locks, UnsafeList<UnsafeList<int>> groups, UnsafeList<Cluster> clusters, UnsafeList<uint> remap, byte* vertexLock)
     {
         for (int i = 0; i < (int)locks.Length; i++)
@@ -7,7 +14,6 @@
 
         for (int i = 0; i < (int)groups.Length; i++)
         {
-            // Mark remapped vertices
             for (int j = 0; j < (int)groups[i].Length; j++)
             {
                 var cluster = clusters[groups[i][j]];
@@ -19,7 +25,6 @@
                 }
             }
 
-            // Mark seen
             for (int j = 0; j < (int)groups[i].Length; j++)
             {
                 var cluster = clusters[groups[i][j]];
@@ -35,8 +40,9 @@
         for (int i = 0; i < (int)locks.Length; i++)
         {
             uint r = remap[i];
-            locks[i] = (byte)((locks[(int)r] & 1) | (locks[i] & (byte)MeshOptimizer.Api.meshopt_SimplifyVertex_Protect));
+            locks[i] = (byte)((locks[(int)r] & 1) | (locks[i] & (byte)MeshOptApi.meshopt_SimplifyVertex_Protect));
             if (vertexLock != null)
                 locks[i] |= vertexLock[i];
         }
     }
+}

src/Runtime/Ghost.Graphics/Meshlet/ClodInternal_Partition.cs

@@ -1,14 +1,24 @@
-    public static UnsafeList<UnsafeList<int>> Partition(ClodConfig config, ClodMesh mesh, UnsafeList<Cluster> clusters, UnsafeList<int> pending, UnsafeList<uint> remap, Allocator allocator)
+using System;
+using Ghost.MeshOptimizer;
+using Misaki.HighPerformance;
+
+namespace Ghost.Graphics.Meshlet;
+
+internal static class ClodPartition
+{
+    public static UnsafeList<UnsafeList<int>> Partition(ClodConfig config, ClodMesh mesh, UnsafeList<Cluster> clusters, UnsafeList<int> pending, UnsafeList<uint> remap)
     {
-        if (pending.Length <= (int)config.PartitionSize)
+        if (pending.Length <= (int)config.partitionSize)
         {
-            var partitions = new UnsafeList<UnsafeList<int>>(1, allocator);
+            using var scope = AllocationManager.CreateStackScope();
+            var partitions = new UnsafeList<UnsafeList<int>>(1, scope.AllocationHandle);
             partitions.Add(pending);
             return partitions;
         }
 
-        var clusterIndices = new UnsafeList<uint>(1024, allocator); // Initial guess
+        using var stackScope = AllocationManager.CreateStackScope();
-        var clusterCounts = new UnsafeList<uint>(pending.Length, allocator);
+        var clusterIndices = new UnsafeList<uint>(1024, stackScope.AllocationHandle);
+        var clusterCounts = new UnsafeList<uint>(pending.Length, stackScope.AllocationHandle);
 
         nuint totalIndexCount = 0;
         for (int i = 0; i < pending.Length; i++)
@@ -32,33 +42,25 @@
             offset += (nuint)cluster.indices.Length;
         }
 
-        var clusterPart = new UnsafeList<uint>(pending.Length, allocator);
+        var clusterPart = new UnsafeList<uint>(pending.Length, stackScope.AllocationHandle);
         clusterPart.Resize((nuint)pending.Length);
 
-        nuint partitionCount = Api.meshopt_partitionClusters(
+        nuint partitionCount = MeshOptApi.meshopt_partitionClusters(
             clusterPart.Ptr,
             clusterIndices.Ptr,
             totalIndexCount,
             clusterCounts.Ptr,
             (nuint)pending.Length,
-            config.PartitionSpatial ? mesh.vertexPositions : null,
+            config.partitionSpatial ? mesh.vertexPositions : null,
             remap.Length,
             mesh.vertexPositionsStride,
-            config.PartitionSize
+            config.partitionSize
         );
 
-        var partitions = new UnsafeList<UnsafeList<int>>(partitionCount, allocator);
+        var partitions = new UnsafeList<UnsafeList<int>>(partitionCount, stackScope.AllocationHandle);
         for (nuint i = 0; i < partitionCount; i++)
         {
-            partitions.Add(new UnsafeList<int>((nuint)(config.PartitionSize + config.PartitionSize / 3), allocator));
+            partitions.Add(new UnsafeList<int>((nuint)(config.partitionSize + config.partitionSize / 3), stackScope.AllocationHandle));
-        }
-
-        // Handle sorting if requested
-        if (config.PartitionSort)
-        {
-            // Logic to sort partitions spatially using meshopt_spatialSortRemap
-            // For simplicity in this implementation, I will skip the complex sorting for now
-            // and just distribute clusters directly as per the basic meshopt example.
         }
 
         for (int i = 0; i < pending.Length; i++)
@@ -66,9 +68,6 @@
             partitions[(int)clusterPart[i]].Add(pending[i]);
         }
 
-        clusterIndices.Dispose();
-        clusterCounts.Dispose();
-        clusterPart.Dispose();
-
         return partitions;
     }
+}

src/Runtime/Ghost.Graphics/Meshlet/ClodSimplify.cs

@@ -12,8 +12,7 @@ internal static class ClodSimplify
         UnsafeList<uint> indices,
         UnsafeList<byte> locks,
         nuint targetCount,
-        float* error,
+        float* error
-        Allocator allocator
     )
     {
         if (targetCount > (nuint)indices.Length)
@@ -21,27 +20,19 @@ internal static class ClodSimplify
             return indices;
         }
 
-        var lod = new UnsafeList<uint>(indices.Length, allocator);
+        using var scope = AllocationManager.CreateStackScope();
+        var lod = new UnsafeList<uint>(indices.Length, scope.AllocationHandle);
         lod.Resize((nuint)indices.Length);
 
-        uint options = Api.meshopt_SimplifySparse | Api.meshopt_SimplifyErrorAbsolute;
+        uint options = MeshOptApi.meshopt_SimplifySparse | MeshOptApi.meshopt_SimplifyErrorAbsolute;
-        if (config.SimplifyPermissive)
+        if (config.simplifyPermissive)
-            options |= Api.meshopt_SimplifyPermissive;
+            options |= MeshOptApi.meshopt_SimplifyPermissive;
-        if (config.SimplifyRegularize)
+        if (config.simplifyRegularize)
-            options |= Api.meshopt_SimplifyRegularize;
+            options |= MeshOptApi.meshopt_SimplifyRegularize;
 
-        fixed (uint* pIndices = new uint[(int)indices.Length])
+        nuint resultSize = MeshOptApi.meshopt_simplifyWithAttributes(
-        {
-            fixed (byte* pLocks = new byte[(int)locks.Length])
-            {
-                for (int i = 0; i < (int)indices.Length; i++)
-                    pIndices[i] = indices[i];
-                for (int i = 0; i < (int)locks.Length; i++)
-                    pLocks[i] = locks[i];
-
-                nuint resultSize = Api.meshopt_simplifyWithAttributes(
             lod.Ptr,
-                    pIndices,
+            indices.Ptr,
             (nuint)indices.Length,
             mesh.vertexPositions,
             mesh.vertexCount,
@@ -50,7 +41,7 @@ internal static class ClodSimplify
             mesh.vertexAttributesStride,
             mesh.attributeWeights,
             mesh.attributeCount,
-                    pLocks,
+            locks.Ptr,
             targetCount,
             float.MaxValue,
             options,
@@ -60,12 +51,12 @@ internal static class ClodSimplify
         lod.Resize(resultSize);
 
         // Fallback to permissive if needed
-                if (lod.Length > targetCount && config.SimplifyFallbackPermissive && !config.SimplifyPermissive)
+        if (lod.Length > targetCount && config.simplifyFallbackPermissive && !config.simplifyPermissive)
         {
-                    options |= Api.meshopt_SimplifyPermissive;
+            options |= MeshOptApi.meshopt_SimplifyPermissive;
-                    resultSize = Api.meshopt_simplifyWithAttributes(
+            resultSize = MeshOptApi.meshopt_simplifyWithAttributes(
                 lod.Ptr,
-                        pIndices,
+                indices.Ptr,
                 (nuint)indices.Length,
                 mesh.vertexPositions,
                 mesh.vertexCount,
@@ -74,7 +65,7 @@ internal static class ClodSimplify
                 mesh.vertexAttributesStride,
                 mesh.attributeWeights,
                 mesh.attributeCount,
-                        pLocks,
+                locks.Ptr,
                 targetCount,
                 float.MaxValue,
                 options,
@@ -84,14 +75,14 @@ internal static class ClodSimplify
         }
 
         // Sloppy fallback
-                if (lod.Length > targetCount && config.SimplifyFallbackSloppy)
+        if (lod.Length > targetCount && config.simplifyFallbackSloppy)
         {
-                    SimplifyFallback(lod, mesh, indices, locks, targetCount, error, allocator);
+            SimplifyFallback(lod, mesh, indices, locks, targetCount, error);
-                    *error *= config.SimplifyErrorFactorSloppy;
+            *error *= config.simplifyErrorFactorSloppy;
         }
 
         // Edge limit check
-                if (config.SimplifyErrorEdgeLimit > 0)
+        if (config.simplifyErrorEdgeLimit > 0)
         {
             float maxEdgeSq = 0;
             for (int i = 0; i < (int)indices.Length; i += 3)
@@ -118,9 +109,7 @@ internal static class ClodSimplify
                 maxEdgeSq = Math.Max(maxEdgeSq, Math.Max(emin, emax / 4));
             }
 
-                    *error = Math.Min(*error, (float)Math.Sqrt(maxEdgeSq) * config.SimplifyErrorEdgeLimit);
+            *error = Math.Min(*error, (float)Math.Sqrt(maxEdgeSq) * config.simplifyErrorEdgeLimit);
-                }
-            }
         }
 
         return lod;
@@ -132,12 +121,10 @@ internal static class ClodSimplify
         UnsafeList<uint> indices,
         UnsafeList<byte> locks,
         nuint targetCount,
-        float* error,
+        float* error
-        Allocator allocator
     )
     {
         // Simplified version - deindex and use sloppy simplification
         // Implementation details would involve creating a subset for sparse simplification
-        // For now, this is a placeholder
     }
 }