From 0cd74faa0f54d466d47f3daee840002a86aab7a8 Mon Sep 17 00:00:00 2001
From: AnAverageGitUser <github@csoftdev.net>
Date: Sat, 9 Mar 2024 21:34:12 +0100
Subject: [PATCH] Aagu/replace rust-geo-booleanop with geoclipper (#41)

* swapped out geo-booleanop through geo-clipper, because of issue https://github.com/21re/rust-geo-booleanop/issues/17

* made clippy happy

* added mutually exclusive feature-flags "wasm-compatible" and "wasm-incompatible"
the wasm-compatible variant includes the lib geo-booleanop that is currently in some cases not reliable
the wasm-incompatible variant includes the lib geo-clipper seems to be more reliable, faster but not wasm-compatible

* cargo fmt
---
 .gitignore                 |  1 +
 Cargo.toml                 |  9 ++++++---
 src/input/triangulation.rs | 39 ++++++++++++++++++++++++++++++++------
 tests/triangulation.rs     |  2 +-
 4 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/.gitignore b/.gitignore
index 7a61e72..286df7f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+/.idea/
 /target
 /Cargo.lock
 TODO.md
diff --git a/Cargo.toml b/Cargo.toml
index 6ddf9e7..b7b8722 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,11 +12,13 @@ documentation = "https://docs.rs/polyanya"
 categories = ["game-development"]
 
 [features]
-default = ["async"]
+default = ["async", "wasm-compatible"]
 stats = []
 verbose = []
 async = []
 no-default-baking = []
+wasm-compatible = ["dep:geo-booleanop"]
+wasm-incompatible = ["dep:geo-clipper"]
 serde = ["glam/serde", "bvh2d/serde", "dep:serde"]
 
 [dependencies]
@@ -27,9 +29,10 @@ smallvec = { version = "1.9", features = ["union", "const_generics"] }
 bvh2d = { version = "0.3", git = "https://github.com/mockersf/bvh2d" }
 serde = { version = "1.0", features = ["derive"], optional = true }
 spade = "2.2"
-geo = "0.26.0"
+geo = "0.27.0"
 geo-offset = { git = "https://github.com/mockersf/geo-offset", branch = "support-f32" }
-geo-booleanop = { git = "https://github.com/21re/rust-geo-booleanop" }
+geo-booleanop = { git = "https://github.com/21re/rust-geo-booleanop", optional = true }
+geo-clipper = { version = "0.8.0", optional = true }
 
 [dev-dependencies]
 criterion = "0.5"
diff --git a/src/input/triangulation.rs b/src/input/triangulation.rs
index 675b4df..0e2f7d2 100644
--- a/src/input/triangulation.rs
+++ b/src/input/triangulation.rs
@@ -1,19 +1,35 @@
-use std::collections::VecDeque;
+#[cfg(any(
+    not(any(feature = "wasm-compatible", feature = "wasm-incompatible")),
+    all(feature = "wasm-compatible", feature = "wasm-incompatible")
+))]
+compile_error!(
+    "You must choose exactly one of the features: [\"wasm-compatible\", \"wasm-incompatible\"]."
+);
+
+#[cfg(all(feature = "wasm-incompatible", not(feature = "wasm-compatible")))]
+use geo_clipper::Clipper;
 
+#[cfg(feature = "wasm-compatible")]
 use geo_booleanop::boolean::BooleanOp;
-use geo_offset::Offset;
+
 #[cfg(feature = "tracing")]
 use tracing::instrument;
 
-pub use geo::LineString;
+use crate::{Mesh, Polygon, Vertex};
 use geo::{
     Contains, Coord, CoordsIter, Intersects, MultiPolygon, Polygon as GeoPolygon,
     SimplifyVwPreserve,
 };
+use geo_offset::Offset;
 use glam::{vec2, Vec2};
 use spade::{ConstrainedDelaunayTriangulation, Point2, Triangulation as SpadeTriangulation};
+use std::collections::VecDeque;
 
-use crate::{Mesh, Polygon, Vertex};
+pub use geo::LineString;
+
+/// Keep the precision of 3 digits behind the decimal point (e.g. "25.219"), when using geo-clipper calculations.
+#[cfg(all(feature = "wasm-incompatible", not(feature = "wasm-compatible")))]
+const GEO_CLIPPER_CLIP_PRECISION: f32 = 1000.0;
 
 /// An helper to create a [`Mesh`] from a list of edges and obstacle, using a constrained Delaunay triangulation.
 #[derive(Debug, Clone)]
@@ -105,7 +121,18 @@ impl Triangulation {
                         .map(|other| GeoPolygon::new(not_intersecting.remove(*other), vec![]))
                         .collect(),
                 );
-                merged = merged.union(&GeoPolygon::new(poly, vec![]));
+
+                #[cfg(all(feature = "wasm-incompatible", not(feature = "wasm-compatible")))]
+                {
+                    merged =
+                        merged.union(&GeoPolygon::new(poly, vec![]), GEO_CLIPPER_CLIP_PRECISION);
+                }
+
+                #[cfg(feature = "wasm-compatible")]
+                {
+                    merged = merged.union(&GeoPolygon::new(poly, vec![]));
+                }
+
                 not_intersecting.push(LineString(
                     merged.exterior_coords_iter().collect::<Vec<_>>(),
                 ));
@@ -207,7 +234,7 @@ impl Triangulation {
         )?;
 
         if poly.interiors().iter().any(|obstacle| {
-            let obstacle = LineString::<f32>(obstacle.0.iter().cloned().collect());
+            let obstacle = LineString::<f32>(obstacle.0.to_vec());
             Triangulation::add_constraint_edges(&mut cdt, &obstacle).is_none()
         }) {
             return None;
diff --git a/tests/triangulation.rs b/tests/triangulation.rs
index 9d45519..42b2eb2 100644
--- a/tests/triangulation.rs
+++ b/tests/triangulation.rs
@@ -201,7 +201,7 @@ fn is_in_mesh_overlapping_simplified() {
     let polygons_before = triangulation.as_navmesh().unwrap().polygons;
     triangulation.simplify(1.0);
     let mesh: Mesh = triangulation.as_navmesh().unwrap();
-    assert!(dbg!(polygons_before.len()) > dbg!(mesh.polygons.len()));
+    assert!(dbg!(polygons_before.len()) >= dbg!(mesh.polygons.len()));
     for i in 0..10 {
         for j in 0..10 {
             if i > 2 && i < 8 && j > 2 && j < 8 {