Segmented Voronoi for Rust

Boost 1.75.0 polygon::voronoi ported to 100% rust. This implementation of Fortune's algorithm works on line segments as well as points, making it useful for calculating centerlines.

Code still in development, not ready for any purpose.

Quick example: fish set -x LIBRARY_PATH /opt/local/lib/ #or wherever you store your SDL cargo run --example piston_gui

API example: ```rust type I1 = i32; // this is the integer input type type F1 = f64; // this is the float output type (circle event coordinates) type I2 = i64; // All integer calculations are made in this type (or num::BigInt when needed) type F2 = f64; // All float calculations are made in this type // it is ok to set I1=I2=i64 and F1=F2=f64

// Points should be unique, let p = vec![Point{x:9, y:10}]; // Lines should never intersect with other lines. // The only points that can intersect are the endpoints. let s = vec![Line::new(Point{x:10, y:11}, Point{x:12, y:13})]; let mut vb = VoronoiBuilder::::new();

// you will have to keep track of the input geometry. it will be referenced as // input geometry indices in the output. vb.withvertices(p.iter())?; vb.withsegments(s.iter())?;

// this will generate a the list of cells, edges and circle events (aka vertices) let result = vb.construct()?;

``` Edges may become curves when line segments are used as input, see the example code for discretization and interpolation.

Todo

• [ ] Error handling
• [ ] Evaluate the generic API. Is really needed?
• [ ] Replace the builtin ulp implementation
• [ ] Replace num::BigInt with something lighter
• [ ] Add many more test cases for voronoirobustftp.rs, specially for ulp
• [x] Remove use of vec_map::VecMap where not absolutely needed.
• [ ] Benchmark and optimize
• [ ] Example GUI with more features. fltk?

All credit goes to the original author (Andrii Sydorchuk), except the porting mistakes. They are all mine.