Check HVA files validity at load time

OpenRA.Game/FileFormats/HvaReader.cs

@@ -9,7 +9,10 @@
 
 #endregion
 
+using System;
 using System.IO;
+using System.Linq;
+using OpenRA.Graphics;
 
 namespace OpenRA.FileFormats
 {
@@ -19,7 +22,7 @@ namespace OpenRA.FileFormats
 		public readonly uint LimbCount;
 		public readonly float[] Transforms;
 
-		public HvaReader(Stream s)
+		public HvaReader(Stream s, string fileName)
 		{
 			// Index swaps for transposing a matrix
 			var ids = new byte[] { 0, 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14 };
@@ -31,6 +34,8 @@ namespace OpenRA.FileFormats
 			// Skip limb names
 			s.Seek(16 * LimbCount, SeekOrigin.Current);
 			Transforms = new float[16 * FrameCount * LimbCount];
+
+			var testMatrix = new float[16];
 			for (var j = 0; j < FrameCount; j++)
 				for (var i = 0; i < LimbCount; i++)
 				{
@@ -43,13 +48,19 @@ namespace OpenRA.FileFormats
 
 					for (var k = 0; k < 12; k++)
 						Transforms[c + ids[k]] = s.ReadFloat();
+
+					Array.Copy(Transforms, 16 * (LimbCount * j + i), testMatrix, 0, 16);
+					if (Util.MatrixInverse(testMatrix) == null)
+						throw new InvalidDataException(
+							"The transformation matrix for HVA file `{0}` section {1} frame {2} is invalid because it is not invertible!"
+							.F(fileName, i, j));
 				}
 		}
 
 		public static HvaReader Load(string filename)
 		{
 			using (var s = File.OpenRead(filename))
-				return new HvaReader(s);
+				return new HvaReader(s, Path.GetFileName(filename));
 		}
 	}
 }

OpenRA.Game/Graphics/VoxelLoader.cs

@@ -220,7 +220,7 @@ namespace OpenRA.Graphics
 			using (var s = GlobalFileSystem.Open(files.First + ".vxl"))
 				vxl = new VxlReader(s);
 			using (var s = GlobalFileSystem.Open(files.Second + ".hva"))
-				hva = new HvaReader(s);
+				hva = new HvaReader(s, files.Second + ".hva");
 			return new Voxel(this, vxl, hva);
 		}