Merge pull request #977 from cjakeman/cache-sd-files

adds cache for SD files

Author: cjakeman

Source/Orts.Formats.Msts/ShapeDescriptorFile.cs

@@ -16,6 +16,7 @@
 // along with Open Rails.  If not, see <http://www.gnu.org/licenses/>.
 
 using System;
+using System.Collections.Generic;
 using Orts.Parsers.Msts;
 
 namespace Orts.Formats.Msts
@@ -29,16 +30,33 @@ public class ShapeDescriptorFile
             shape = new SDShape();
         }
 
+        public static Dictionary<string, SDShape> Cache = new Dictionary<string, SDShape>();
+
         public ShapeDescriptorFile(string filename)
         {
-            using (STFReader stf = new STFReader(filename, false))
+            var shapeDescriptorPath = filename.ToLowerInvariant();
+
+            if (Cache.ContainsKey(shapeDescriptorPath))
             {
-                stf.ParseFile(new STFReader.TokenProcessor[] {
-                    new STFReader.TokenProcessor("shape", ()=>{ shape = new SDShape(stf); }),
-                });
-                //TODO This should be changed to STFException.TraceError() with defaults values created
-                if (shape == null)
-                    throw new STFException(stf, "Missing shape statement");
+                shape = Cache[shapeDescriptorPath];
+            }
+            else
+            {
+                if (!System.IO.File.Exists(filename)) // If not found, skip
+                {
+                    shape = null;
+                    return;
+                }
+
+                using (STFReader stf = new STFReader(filename, false))
+                {
+                    stf.ParseFile(new STFReader.TokenProcessor[] {
+                        new STFReader.TokenProcessor("shape", ()=>{ shape = new SDShape(stf); }),
+                    });
+                    //TODO This should be changed to STFException.TraceError() with defaults values created
+                    if (shape == null) throw new STFException(stf, "Missing shape statement");
+                }
+                Cache.Add(shapeDescriptorPath, shape);
             }
         }
 

Source/RunActivity/Viewer3D/Scenery.cs

@@ -341,10 +341,11 @@ public WorldFile(Viewer viewer, int tileX, int tileZ, bool visible)
                     }
                 }
 
-                if (shapeFilePath != null && File.Exists(shapeFilePath + "d"))
+                var shapeDescriptorPath = shapeFilePath + "d";
+                if (shapeFilePath != null)
                 {
-                    var shape = new ShapeDescriptorFile(shapeFilePath + "d");
-                    if (shape.shape.ESD_Bounding_Box != null)
+                    var shape = new ShapeDescriptorFile(shapeDescriptorPath);
+                    if (shape.shape?.ESD_Bounding_Box != null)
                     {
                         var min = shape.shape.ESD_Bounding_Box.Min;
                         var max = shape.shape.ESD_Bounding_Box.Max;