Mesh split, bogeys follow rails.

Wow. This commit is too big. It:

* splits obj loaded meshes into individual named objects.
* moves obj to mesh(es) code into new file obj.impl.cpp, removing the
  clutter from mesh
* removes Physical for providing the wrong level of abstraction
* bit of a hack to adjust loaded models to offset rail vehicle bogeys to
  0 centre, and then applies their calculated position to the mesh

All in all, quite a lot of mess... But the result is the rail vehicle
bogeys now follow the rails quite authentically.

1 files changed, 14 insertions, 4 deletions

diff --git a/test/test-obj.cpp b/test/test-obj.cpp
index 64dc030..68221b8 100644
--- a/test/test-obj.cpp
+++ b/test/test-obj.cpp
@@ -13,8 +13,18 @@ BOOST_AUTO_TEST_CASE(objparse)
 	BOOST_CHECK_EQUAL(48, op.vertices.size());
 	BOOST_CHECK_EQUAL(104, op.texCoords.size());
 	BOOST_CHECK_EQUAL(25, op.normals.size());
-	BOOST_CHECK_EQUAL(28, op.faces.size());
-	BOOST_CHECK_EQUAL(6, op.faces[0].size());
-	BOOST_CHECK_EQUAL(6, op.faces[1].size());
-	BOOST_CHECK_EQUAL(4, op.faces[12].size());
+	BOOST_CHECK_EQUAL(3, op.objects.size());
+	const auto & object {op.objects.front()};
+	BOOST_CHECK_EQUAL("Body", object.first);
+	BOOST_CHECK_EQUAL(18, object.second.size());
+	BOOST_CHECK_EQUAL(6, object.second[0].size());
+	BOOST_CHECK_EQUAL(6, object.second[1].size());
+	BOOST_CHECK_EQUAL(4, object.second[12].size());
+}
+
+BOOST_AUTO_TEST_CASE(create_meshes)
+{
+	ObjParser op {"/home/randomdan/dev/game/res/brush47.obj"};
+	const auto ms = op.createMeshes();
+	BOOST_REQUIRE_EQUAL(3, ms.size());
 }