Use [T; 2] as a vertex + some optimizations (#11)

* perf

* no_std

* more

* improve

* improments

* benchmarks on readme

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "earcut"
-version = "0.3.6"
+version = "0.4.0"
 edition = "2021"
 description = "A Rust port of the Earcut polygon triangulation library"
 authors = ["Taku Fukada <naninunenor@gmail.com>", "MIERUNE Inc. <info@mierune.co.jp>"]
@@ -9,7 +9,7 @@ repository = "https://github.com/MIERUNE/earcut-rs"
 categories = ["graphics", "science", "no-std"]
 
 [dependencies]
-num-traits = "0.2"
+num-traits = { version = "0.2", no-default-features = true }
 
 [dev-dependencies]
 serde_json = { version = "1.0", features = ["float_roundtrip"] }

README.md

@@ -7,10 +7,32 @@
 A Rust port of the [mapbox/earcut](https://github.com/mapbox/earcut) polygon triangulation library, implemented from scratch with some reference to [donbright/earcutr](https://github.com/donbright/earcutr).
 
 - Based on the latest earcut 2.2.4 release.
-- Designed to avoid unnecessary memory allocations. You can reuse the internal buffer and the output index vector.
-- (Experimental) An additional module, `utils3d`, can rotate polygons from 3D to 2D space before triangulation.
+- Designed to avoid unnecessary memory allocations. You can reuse the internal buffer and the output index vector for multiple triangulations.
+- (Experimental) An additional module, `utils3d`, can rotate 3D coplanar polygons into the 2D plane before triangulation.
 - License: ISC
 
 <p align="center">
 <img src="./docs/image.png" width="300">
 </p>
+
+
+## Benchmarks
+
+on Macbook Pro (M1 Pro)
+
+| Polygon        | earcut.hpp | earcut-rs (0.4.0) | earcutr (0.4.3) |
+|----------------|-------------:|--------------:|-------------:|
+| bad_hole       |  3.574 µs/i  |   4.630 µs/i  |  4.415 µs/i  |          
+| building       |    397 ns/i  |     197 ns/i  |    604 ns/i  |
+| degenerate     |    142 ns/i  |      46 ns/i  |    206 ns/i  |
+| dude           |  5.061 µs/i  |   6.516 µs/i  |  8.096 µs/i  |
+| empty_square   |    195 ns/i  |      88 ns/i  |    331 ns/i  |
+| water          |  459.6 µs/i  |   623.5 µs/i  |  801.3 µs/i  |
+| water2         |  334.1 µs/i  |   409.5 µs/i  |  450.3 µs/i  |
+| water3         |  13.12 µs/i  |   19.12 µs/i  |  23.46 µs/i  |
+| water3b        |  1.340 µs/i  |   1.368 µs/i  |  2.165 µs/i  |
+| water4         |  81.48 µs/i  |   122.0 µs/i  |  154.1 µs/i  |
+| water_huge     |  6.906 ms/i  |   11.01 ms/i  |  10.90 ms/i  |
+| water_huge2    |  15.38 ms/i  |   23.40 ms/i  |  22.35 ms/i  |
+
+(Earcutr is not besed on the latest earcut.)

benches/benchmark.rs

@@ -4,20 +4,15 @@ use criterion::{criterion_group, criterion_main, Criterion};
 
 use earcut::Earcut;
 
-fn load_fixture(name: &str) -> (Vec<f64>, Vec<usize>) {
+fn load_fixture(name: &str) -> (Vec<[f64; 2]>, Vec<usize>) {
     // load JSON
     type Coords = Vec<Vec<[f64; 2]>>;
     let s = fs::read_to_string("./tests/fixtures/".to_string() + name + ".json").unwrap();
     let expected = serde_json::from_str::<Coords>(&s).unwrap();
 
     // prepare input
     let num_holes = expected.len();
-    let data = expected
-        .clone()
-        .into_iter()
-        .flatten()
-        .flatten()
-        .collect::<Vec<_>>();
+    let data = expected.clone().into_iter().flatten().collect::<Vec<_>>();
     let hole_indices: Vec<_> = expected
         .iter()
         .map(|x| x.len())
@@ -109,7 +104,6 @@ fn bench(c: &mut Criterion) {
         let (data, hole_indices) = load_fixture("water-huge");
         b.iter(|| {
             earcut.earcut(data.iter().copied(), &hole_indices, &mut triangles);
-            assert_eq!(triangles.len(), 5177 * 3)
         })
     });
 

examples/example.rs

@@ -10,12 +10,7 @@ fn load_fixture(name: &str, num_triangles: usize, expected_deviation: f64) {
 
     // prepare input
     let num_holes = expected.len();
-    let vertices = expected
-        .clone()
-        .into_iter()
-        .flatten()
-        .flatten()
-        .collect::<Vec<_>>();
+    let vertices = expected.clone().into_iter().flatten().collect::<Vec<_>>();
     let hole_indices: Vec<_> = expected
         .into_iter()
         .map(|x| x.len() as u32)