Update the README, so that if anyone stumbles on this repo before it's actually ready for any sort of public release, they should be fairly warned. It might be good to actually just make the repo private before release, but I am not that self-conscious about it

README.md

@@ -1,2 +1,9 @@
 # qtrocket
 Model Rocket Simulator written in C++ and Qt Toolkit
+
+QtRocket is still in the very early stages of development, and not suitable for any real use. It currently calculates the trajectory of a cannonball with the effects of air resistance. Some of the basic architecture is coming together, but the current implementation is only mature enough to create a cannonball and launch it.
+
+This is also an experiment and learning platform for me to learn Qt GUI programming, so if it is non-standard or very strange to experienced Qt programmers, that's why.
+
+Another feature is the use of ANSI standard C++17 for the bulk of the application. Qt specific features are limited to the GUI.
+

sim/Propagator.cpp

@@ -59,7 +59,7 @@ void Propagator::runUntilTerminate()
       }
       */
 
-      std::swap(currentState, nextState);
+      std::swap(currentState, tempRes);
       if(saveStates)
       {
          states.push_back(currentState);