3 releases
0.1.2 | Mar 20, 2023 |
---|---|
0.1.1 | Mar 18, 2023 |
0.1.0 | Mar 17, 2023 |
#127 in Geospatial
33 downloads per month
440KB
3K
SLoC
poly2tri-rs
An idiomatic and fast(not just because the language) rust porting for poly2tri
cpp project. It calculates CDT (Constrained Delaunay Triangulation) on a polygon.
Install
Add following to cargo.toml
[dependencies]
poly2tri-rs = "0.1"
Or
cargo add poly2tri-rs
Features
- Multiple hole and steiner points
- Fast
- Test coverage, there are both stable and random tests(prop test). Actually discovered and fixed several bugs from cpp lib.
Performance
Introduced a bunch of perf optimizations to meet the cpp version, without breaking the type system.
Timing at the time of writing on my m1 mbp:
example | poly2tri-rs | poly2tri (cpp) | point count |
---|---|---|---|
bird | 0.08ms | 0.17ms | 275 |
debug | 0.06ms | 0.14ms | 200 |
nazca_heron | 0.4ms | 0.55ms | 1036 |
nazca_monkey | 0.52ms | 0.76ms | 1204 |
Limitations
- Only one polyline supported. For multiple polyline, need to preprocess them.
- Duplicate point not supported. (yet)
Examples
A square with a hole
cargo run --example square && open square_with_hole.svg
Sample code
fn example() {
// randomly generate steinier points (point with no edge)
let mut points = Vec::<Point>::new();
for _ in 0..100 {
let x: f64 = rand::thread_rng().gen_range(0.0..800.);
let y: f64 = rand::thread_rng().gen_range(0.0..800.);
points.push(Point::new(x, y));
}
// outer square
let builder = SweeperBuilder::new(vec![
Point::new(-10., -10.),
Point::new(810., -10.),
Point::new(810., 810.),
Point::new(-10., 810.),
])
.add_steiner_points(points)
// square hole
.add_hole(vec![
Point::new(400., 400.),
Point::new(600., 400.),
Point::new(600., 600.),
Point::new(400., 600.),
]);
// consume builder and grab a sweeper
let sweeper = builder.build();
// triangulate with cdt
let triangles = sweeper.triangulate();
// draw
draw(triangles, "square_with_hole.svg".into());
}
Draw test data from poly2tri's testbed
# clone repos
git clone git@github.com:jhasse/poly2tri.git
git clone git@github.com:shuoli84/poly2tri-rs.git
cd poly2tri-rs
cargo run --example draw --release -- --path ../poly2tri/testbed/data/funny.dat --output funny.svg
# open the svg
open funny.svg
Dependencies
~0.8–1.2MB
~20K SLoC