Clean-up and bug fixes to Lua bindings:

- Fixed a regression introduced in v3.0 that could cause a Lua stack leak, causing eventual crash in some Lua-based games.
- Fixed a number of problematic and potentially unsafe Lua usage scenarios, where passing a subclass object to a function that expects a base class could cause a crash. This fix was accomplished by adding support for automatic and safe conversion between base classes and subclasses (and vice-versa) when passing objects from Lua to C++.
- Removed the global 'convert' Lua function since it was unsafe. Instead, when manual object casting is required in Lua, such as when needing to convert a base class to a known subclass to access subclass-specific interfaces, the Lua bindings now support a safe 'to(type)' function on all polymorphic classes.
- When using the new built-in 'to(type)' conversion function, nil will be returned if no suitable conversion exists. Similarly, when attempting to pass an incompatible object type to a Lua C++ function, the function will gracefully fail and log a script error.

Author: sgrenier

gameplay/src/Base.h

@@ -22,6 +22,7 @@
 #include <set>
 #include <stack>
 #include <map>
+#include <unordered_map>
 #include <queue>
 #include <algorithm>
 #include <limits>
@@ -116,7 +117,7 @@ extern int strcmpnocase(const char* s1, const char* s2);
     #pragma warning( disable : 4244 )
     #pragma warning( disable : 4267 )
     #pragma warning( disable : 4311 )
-	#pragma warning( disable : 4316 )
+    #pragma warning( disable : 4316 )
     #pragma warning( disable : 4390 )
     #pragma warning( disable : 4800 )
     #pragma warning( disable : 4996 )

gameplay/src/Joint.cpp

@@ -35,6 +35,11 @@ Node::Type Joint::getType() const
     return Node::JOINT;
 }
 
+const char* Joint::getTypeName() const
+{
+    return "Joint";
+}
+
 Scene* Joint::getScene() const
 {
     // Overrides Node::getScene() to search the node our skins.

gameplay/src/Joint.h

@@ -34,6 +34,14 @@ class Joint : public Node
      */
     Scene* getScene() const;
 
+    /**
+     * Extends ScriptTarget::getTypeName() to return the type name of this class.
+     *
+     * @return The type name of this class: "Joint"
+     * @see ScriptTarget::getTypeName()
+     */
+    const char* getTypeName() const;
+
     /**
      * Returns the inverse bind pose matrix for this joint.
      * 

gameplay/src/Logger.cpp

@@ -65,7 +65,7 @@ void Logger::log(Level level, const char* message, ...)
     else if (state.logFunctionLua)
     {
         // Pass call to registered Lua log function
-        Game::getInstance()->getScriptController()->executeFunction<void>(state.logFunctionLua, "[Logger::Level]s", level, str);
+        Game::getInstance()->getScriptController()->executeFunction<void>(state.logFunctionLua, "[Logger::Level]s", NULL, level, str);
     }
     else
     {

gameplay/src/PhysicsCollisionObject.cpp

@@ -325,6 +325,7 @@ void PhysicsCollisionObject::ScriptListener::collisionEvent(PhysicsCollisionObje
 {
     Game::getInstance()->getScriptController()->executeFunction<void>(function.c_str(), 
         "[PhysicsCollisionObject::CollisionListener::EventType]<PhysicsCollisionObject::CollisionPair><Vector3><Vector3>",
+        NULL,
         type, &collisionPair, &contactPointA, &contactPointB);
 }
 

gameplay/src/Scene.cpp

@@ -200,7 +200,8 @@ void Scene::visitNode(Node* node, const char* visitMethod)
     ScriptController* sc = Game::getInstance()->getScriptController();
 
     // Invoke the visit method for this node.
-    if (!sc->executeFunction<bool>(visitMethod, "<Node>", dynamic_cast<void*>(node)))
+    bool result;
+    if (!sc->executeFunction<bool>(visitMethod, "<Node>", &result, (void*)node) || !result)
         return;
 
     // If this node has a model with a mesh skin, visit the joint hierarchy within it