[organian]

The arrow operator is a field access through a pointer. That is, if you have a pointer to a struct, it's the same as dereferencing the pointer and accessing the field: "(*foo).bar" corresponds to "foo->bar".

I think the main driving logic is on line 228. It could definitely do with some more descriptive variable names, though - "a" for angle, and "s" for sense inputs seems a bit too short.