This code simulates the output of an Airbus A320 navigation display.
I originally wrote this code while on vacation in Hawaii. Besides enjoying the sun and the beach I also wanted spend some time working on something related to my hobby, which is flight simulation. In any case, I had some images of an Airbus 320 navigation display. I though it would be cool to hookup X-Plane 9 to an external iPad or Mac controlled display and see a closeup of some of the instrumentation.
The code in the ObjectiveC directory is a direct result of those efforts. Originally, the compass-rose displayed text at 30 degree increments around the circumference but Apple has since deprecated the API's I used to make that happen. Here is what the app looks like if you run it in macOS 10.14:
As it is currently written the compass-rose and the networking code that reads in and interprets UDP packets from X-plane are both broken. I have no plans to go back and fix these features. Actually in the case of the networking code, I'm not sure I finished getting that working as my whole team was laid-off in December '08, immediately after I returned from my vacation.
The drawing code was crafted using the mark-one eyeball. I would literally look at the images put some numbers into the drawing formula for each element of the display, then run it in order to see if I could match the output of the original instrumentation images. Not the best way to craft a drawing algorithm but when you don't have any specification or models except for a 2D image, you make do.
Some years, later, I ported the Objective-C implementation to Swift version 3. Actually, I'm not totally sure of that as Swift changes so quickly. Now that Swift 5 has been released and version 5.1 is on the way, I think it is time to finish this project and put it on iOS. I can use an old iPad as a display for my cockpit. I don't need to wire up a clunky monitor.
As you probably inferred from the timeline leading up to this point, this is a side project. I'm so busy trying to make a living and run a business that I don't have a lot of time or leftover energy to spend on it. As I make progress, I'll update the README.
I now have a Swift implementation that I plan to augment over time. The current version runs on iOS 12 on both the iPad and the iPhone. It displays only in profile mode and has only a few controls to run a built-in display test (bit), change the range in nautical miles (meaningless until I add code to display nav-aids), switch between different ADF and VOR types for channels 1 and 2, and to switch between master navigation modes including ILS, VOR, and OFF (none).
Having ported this code over from Objective-C without refactoring for Swift features, the code is pretty routine. I hope to get some time to analyze the implementation and perhaps implement a more protocol-oriented approach that will make testing and adding more features easier. Currently the app is very visual and doesn't have much logic for anything but drawing and taking input from a few buttons. As features are added, the need and opportunity for writing meaningful unit-tests will multiply.
In the original Objective-C implementation I make use of bindings in order to implement the test-panel.
I briefly considered using KVO with modern Swift syntax as a replacement but I don't think I like the dependencies on the Objective-C runtime that come with this facility. I'm currently considering alternatives. Ultimately, I need to have the view driven by changes to the model. I also need to model to be updated by controls in the UI as well as asynchronous inputs from the network (flight simulation).
- Add remaining controls for all existing graphics display features.
- Autopilot heading bug on/off
- Autopilot heading selection
- Nav course selection
- Nav course deviation
- Glide slope display on/off
- Glide slope deviation
- Implement landscaped views (use size classes) for both the iPhone and iPad.
- Networking support for X-Plane
- Networking support for DCS (maybe, need to research how this is done on DCS).
I never got around to working on this project and never will. I don't even use X-Plane anymore and haven't for a few years. I also lost interest in general aviation simulations as they are too slow and unexciting. Considering the fact that I've been interested in flight simulation since I bought my first simulation-game for the Commodore-64 decades ago, I guess it is not surprising that my tastes have changed. Now days, I spend all of my simulation time in Digital Combat Simulator (DCS). They have the most realistic environments and models (flight and 3D) for my money. They also have helicopters and high-speed military aircraft, all of which behave, fly, and feel different from one another. This makes DCS way more fun to fly than the stuff I used to fly in X-Plane or MSFS. Throw in a very expensive force-feedback and VR setup and my hobby has changed to the point that external instrumentation, outside of the VR interface, just doesn't matter all that much anymore. I still have a home-cockpit setup, but I don't use it very much. I much prefer being inside the VR cockpit. This combined with my advanced control setup makes the simulation much more immersive. On the upside, this allows me to stay focused on writing code that actually generates money. I am archiving this repo just in case anyone is interested but I consider the project dead.