Merge pull request #100 from devedse/copilot/fix-99

Optimize quad culling algorithm from O(N²) to O(N) using spatial partitioning

Author: devedse

DeveMazeGeneratorCore.Coaster3MF.Tests/DeveMazeGeneratorCore.Coaster3MF.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net9.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <IsPackable>false</IsPackable>

DeveMazeGeneratorCore.Coaster3MF/MazeCoaster3MF.cs

@@ -68,9 +68,21 @@ public void Generate3MFCoaster(int mazeSize, int? seed = null)
             var meshData = _geometryGenerator.GenerateMazeGeometry(maze.InnerMap, path);
 
             var nonManifoldEdgeDetector = new NonManifoldEdgeDetector();
-            var meshAnalyzeResult = nonManifoldEdgeDetector.AnalyzeMesh(meshData);
+            if (mazeSize < 50)
+            {
+                var meshAnalyzeResult = nonManifoldEdgeDetector.AnalyzeMesh(meshData);
+                Console.WriteLine($"Non-manifold edges detected:{Environment.NewLine}{meshAnalyzeResult.ToString("\t")}");
+            }
+            else if (mazeSize < 100)
+            {
+                var meshAnalyzeResult = nonManifoldEdgeDetector.AnalyzeMeshOnlyBorderEdges(meshData);
+                Console.WriteLine($"Border edges: {meshAnalyzeResult.Count}");
+            }
+            else
+            {
+                Console.WriteLine("Skipping non-manifold edge detection for large maze size.");
+            }
 
-            Console.WriteLine($"Non-manifold edges detected:{Environment.NewLine}{meshAnalyzeResult.ToString("\t")}");
 
             // Generate filename with triangle and vertex counts
             var usedSeed = seed ?? 1337;

DeveMazeGeneratorCore.Coaster3MF/MazeGeometryGenerator.cs

@@ -46,7 +46,7 @@ public MeshData GenerateMazeGeometry(InnerMap maze, List<MazePointPos> path, boo
         /// <summary>
         /// Generates quads representing the maze geometry (ground, walls, path).
         /// </summary>
-        public List<Quad> GenerateMazeQuads(InnerMap maze, List<MazePointPos> path, bool singleCuboidPerPixel = true)
+        public List<Quad> GenerateMazeQuads(InnerMap maze, List<MazePointPos> path, bool singleCuboidPerPixel = true, bool enableFaceCulling = true)
         {
             var quads = new List<Quad>();
 
@@ -63,7 +63,10 @@ public List<Quad> GenerateMazeQuads(InnerMap maze, List<MazePointPos> path, bool
             AddMazePath(maze, quads, pathData);
 
             // Cull hidden faces (interior faces between adjacent cubes)
-            MeshOptimizer.CullHiddenFaces(quads);
+            if (enableFaceCulling)
+            {
+                MeshOptimizer.CullHiddenFaces(quads);
+            }
 
             // Additional quad optimizations (merging adjacent quads) applied after adding paths
             // Even though this algorithm is quite cool, it doesn't work as it causes non-manifold edges