GameplayKit A*?
Let’s try to use the builtin [A](https://en.wikipedia.org/wiki/A_search_algorithm) in GameplayKit, and see if it works for our current demands.
This reminded me that nothing in the game API:s uses CGPoint, so everything has been changed to use vector_int2 instead.
Next related
Path Finding
First attempt at using the GamePlayKit path finding GKGridGraph. Unfortunately, the playground currently crashes (because of some internal XCode bug maybe?), so it can’t be tested.
Previous related
Directional Navigation
Prereq work for implementing path finding: eight direction navigation. A tile can find its neighbours within its layer exit(direction:). Currently only within a single map region, because we haven’t implemented interregion links yet.
Caching?
Spent at huge part of the hour today troubleshooting why my API change to an init method was not being seen by the playground. Weird caching bugs? No; it turns out that XCode was building for target instead of simulator, so the playground didn’t get a rebuilt version of the framework when I hit build. Still don’t know why that changed since last time, but oh well.
Swift First Lesson
The first lesson turns out to be about access control: nothing is public by default, even classes or their init methods. With public access to our classes the playground plays.