Added GearJoint:getJoints (resolves issue #922.)

src/modules/physics/box2d/wrap_GearJoint.cpp

@@ -51,10 +51,61 @@ int w_GearJoint_getRatio(lua_State *L)
 	return 1;
 }
 
+int w_GearJoint_getJoints(lua_State *L)
+{
+	GearJoint *t = luax_checkgearjoint(L, 1);
+	Joint *j1 = nullptr;
+	Joint *j2 = nullptr;
+
+	luax_catchexcept(L, [&]() {
+		j1 = t->getJointA();
+		j2 = t->getJointB();
+	});
+
+	auto pushjoint = [](lua_State *L, Joint *j) -> void
+	{
+		if (j == nullptr)
+			return lua_pushnil(L);
+
+		switch (j->getType())
+		{
+		case Joint::JOINT_DISTANCE:
+			return luax_pushtype(L, "DistanceJoint", PHYSICS_DISTANCE_JOINT_T, j);
+		case Joint::JOINT_REVOLUTE:
+			return luax_pushtype(L, "RevoluteJoint", PHYSICS_REVOLUTE_JOINT_T, j);
+		case Joint::JOINT_PRISMATIC:
+			return luax_pushtype(L, "PrismaticJoint", PHYSICS_PRISMATIC_JOINT_T, j);
+		case Joint::JOINT_MOUSE:
+			return luax_pushtype(L, "MouseJoint", PHYSICS_MOUSE_JOINT_T, j);
+		case Joint::JOINT_PULLEY:
+			return luax_pushtype(L, "PulleyJoint", PHYSICS_PULLEY_JOINT_T, j);
+		case Joint::JOINT_GEAR:
+			return luax_pushtype(L, "GearJoint", PHYSICS_GEAR_JOINT_T, j);
+		case Joint::JOINT_FRICTION:
+			return luax_pushtype(L, "FrictionJoint", PHYSICS_FRICTION_JOINT_T, j);
+		case Joint::JOINT_WELD:
+			return luax_pushtype(L, "WeldJoint", PHYSICS_WELD_JOINT_T, j);
+		case Joint::JOINT_WHEEL:
+			return luax_pushtype(L, "WheelJoint", PHYSICS_WHEEL_JOINT_T, j);
+		case Joint::JOINT_ROPE:
+			return luax_pushtype(L, "RopeJoint", PHYSICS_ROPE_JOINT_T, j);
+		case Joint::JOINT_MOTOR:
+			return luax_pushtype(L, "MotorJoint", PHYSICS_MOTOR_JOINT_T, j);
+		default:
+			return lua_pushnil(L);
+		}
+	};
+
+	pushjoint(L, j1);
+	pushjoint(L, j2);
+	return 2;
+}
+
 static const luaL_Reg functions[] =
 {
 	{ "setRatio", w_GearJoint_setRatio },
 	{ "getRatio", w_GearJoint_getRatio },
+	{ "getJoints", w_GearJoint_getJoints },
 	// From Joint.
 	{ "getType", w_Joint_getType },
 	{ "getBodies", w_Joint_getBodies },