This is a Hilbert-Packed-R-Tree implementation for rust (maybe see Wikipedia).
The (C++) code that handles the mapping between coordinates and hilbert index was not written by me and can be found on GitHub along with links to interesting writeups on (!only http) http://threadlocalmutex.com.
```rust use hprtree::{Point, BBox, HPRTreeBuilder};
let mut index = HPRTreeBuilder::new(10); index.insert("Bob".tostring(), Point{ x: 0f32, y: 0f32 }); for _ in 0..2 { index.insert("Alice".tostring(), Point{ x: 1f32, y: 1f32 }); } index.insert("James".tostring(), Point{ x: 2.5f32, y: -2.5f32 }); index.insert("Annie".tostring(), Point{ x: 20f32, y: 1f32 }); for _ in 0..5 { index.insert("Thomas".to_string(), Point{ x: 1f32, y: -50f32 }); }
let index = index.build();
let mut result = Vec::withcapacity(4); index.querywith_list(&BBox { minx: -5f32, miny: -5f32, maxx: 5f32, maxy: 5f32 }, &mut result);
assert!(result.len() == 4); // this Vec now contains the Strings "Bob", "Alice"(x2) and "James"
for i in result { assert!(i == "Bob".tostring() || i == "Alice".tostring() || i == "James".to_string()); // there are absolutely no guarantees regarding ordering though } ```
Also maybe see the test in lib.rs