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use crate::mesh::*;
use std::collections::HashSet;
impl Mesh {
pub fn connected_component(&self, start_face_id: FaceID) -> HashSet<FaceID> {
self.connected_component_with_limit(start_face_id, &|_| false)
}
pub fn connected_components(&self) -> Vec<HashSet<FaceID>> {
self.connected_components_with_limit(&|_| false)
}
pub fn connected_component_with_limit(
&self,
start_face_id: FaceID,
limit: &dyn Fn(HalfEdgeID) -> bool,
) -> HashSet<FaceID> {
let mut component = HashSet::new();
component.insert(start_face_id);
let mut to_be_tested = vec![start_face_id];
while let Some(test_face) = to_be_tested.pop() {
for halfedge_id in self.face_halfedge_iter(test_face) {
if !limit(halfedge_id) {
if let Some(face_id) =
self.walker_from_halfedge(halfedge_id).as_twin().face_id()
{
if !component.contains(&face_id) {
component.insert(face_id);
to_be_tested.push(face_id);
}
}
}
}
}
component
}
pub fn connected_components_with_limit(
&self,
limit: &dyn Fn(HalfEdgeID) -> bool,
) -> Vec<HashSet<FaceID>> {
let mut components: Vec<HashSet<FaceID>> = Vec::new();
for face_id in self.face_iter() {
if components
.iter()
.find(|com| com.contains(&face_id))
.is_none()
{
components.push(self.connected_component_with_limit(face_id, limit));
}
}
components
}
}
#[cfg(test)]
mod tests {
use super::*;
use three_d_asset::{Indices, Positions, TriMesh};
#[test]
fn test_one_connected_component() {
let mesh = create_connected_test_object();
let cc = mesh.connected_component(mesh.face_iter().next().unwrap());
assert_eq!(cc.len(), mesh.no_faces());
}
#[test]
fn test_connected_components() {
let mesh = create_unconnected_test_object();
let cc = mesh.connected_components();
assert_eq!(cc.len(), 3);
assert_eq!(cc[0].len() + cc[1].len() + cc[2].len(), 15);
assert!(cc.iter().find(|vec| vec.len() == 12).is_some());
assert!(cc.iter().find(|vec| vec.len() == 2).is_some());
assert!(cc.iter().find(|vec| vec.len() == 1).is_some());
}
fn create_connected_test_object() -> Mesh {
TriMesh {
positions: Positions::F64(vec![
vec3(1.0, -1.0, -1.0),
vec3(1.0, -1.0, 1.0),
vec3(-1.0, -1.0, 1.0),
vec3(-1.0, -1.0, -1.0),
vec3(1.0, 1.0, -1.0),
vec3(1.0, 1.0, 1.0),
vec3(-1.0, 1.0, 1.0),
vec3(-1.0, 1.0, -1.0),
]),
indices: Indices::U8(vec![
0, 1, 2, 0, 2, 3, 4, 7, 6, 4, 6, 5, 0, 4, 5, 0, 5, 1, 1, 5, 6, 1, 6, 2, 2, 6, 7, 2,
7, 3, 4, 0, 3, 4, 3, 7,
]),
..Default::default()
}
.into()
}
fn create_unconnected_test_object() -> Mesh {
TriMesh {
positions: Positions::F64(vec![
vec3(1.0, -1.0, -1.0),
vec3(1.0, -1.0, 1.0),
vec3(-1.0, -1.0, 1.0),
vec3(-1.0, -1.0, -1.0),
vec3(1.0, 1.0, -1.0),
vec3(1.0, 1.0, 1.0),
vec3(-1.0, 1.0, 1.0),
vec3(-1.0, 1.0, -1.0),
vec3(-1.0, 2.0, -1.0),
vec3(-1.0, 3.0, -1.0),
vec3(-2.0, 4.0, -1.0),
vec3(-2.0, 1.0, -1.0),
vec3(-1.0, 3.0, -2.0),
vec3(-2.0, 4.0, -3.0),
vec3(-2.0, 1.0, -4.0),
]),
indices: Indices::U8(vec![
0, 1, 2, 0, 2, 3, 4, 7, 6, 4, 6, 5, 0, 4, 5, 0, 5, 1, 1, 5, 6, 1, 6, 2, 2, 6, 7, 2,
7, 3, 4, 0, 3, 4, 3, 7, 8, 9, 10, 8, 10, 11, 12, 13, 14,
]),
..Default::default()
}
.into()
}
}