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can reuse an existing mesh for triangulation
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@mockersf
mockersf committed Aug 1, 2024
1 parent 70a2dac commit 8574c4f
Showing 1 changed file with 240 additions and 1 deletion.
241 changes: 240 additions & 1 deletion src/input/triangulation.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@ pub struct Triangulation {
GeoPolygon<f32>,
ConstrainedDelaunayTriangulation<Point2<f32>>,
)>,
base_layer: Option<Layer>,
}

impl std::fmt::Debug for Triangulation {
Expand All @@ -38,6 +39,25 @@ impl Triangulation {
vec![],
),
prebuilt: None,
base_layer: None,
}
}

/// Create a new triangulation from an existing `Mesh`, cloning the specified [`Layer`].
pub fn from_mesh(mesh: &Mesh, layer: u8) -> Triangulation {
Self {
inner: GeoPolygon::new(LineString::new(Vec::new()), vec![]),
prebuilt: None,
base_layer: Some(mesh.layers[layer as usize].clone()),
}
}

/// Create a new triangulation from an existing `Layer` of a [`Mesh`].
pub fn from_mesh_layer(layer: Layer) -> Triangulation {
Self {
inner: GeoPolygon::new(LineString::new(Vec::new()), vec![]),
prebuilt: None,
base_layer: Some(layer),
}
}

Expand Down Expand Up @@ -88,6 +108,9 @@ impl Triangulation {
cdt: &mut ConstrainedDelaunayTriangulation<Point2<f32>>,
edges: &LineString<f32>,
) {
if edges.0.is_empty() {
return;
}
let mut edge_iter = edges.coords().peekable();
let mut next_point = None;
loop {
Expand Down Expand Up @@ -119,6 +142,9 @@ impl Triangulation {
///
/// This can be used to cache part of the navmesh generation when some of the obstacles won't change.
pub fn prebuild(&mut self) {
if self.base_layer.is_some() {
return;
}
let mut cdt = ConstrainedDelaunayTriangulation::<Point2<f32>>::new();
Triangulation::add_constraint_edges(&mut cdt, self.inner.exterior());

Expand Down Expand Up @@ -166,6 +192,26 @@ impl Triangulation {
};
let used = self.prebuilt.as_ref().map(|(used, _)| used);

if let Some(base_layer) = &self.base_layer {
for polygon in &base_layer.polygons {
polygon.edges_index().for_each(|[p0, p1]| {
let p0 = cdt
.insert(Point2 {
x: base_layer.vertices[p0 as usize].coords.x,
y: base_layer.vertices[p0 as usize].coords.y,
})
.unwrap();
let p1 = cdt
.insert(Point2 {
x: base_layer.vertices[p1 as usize].coords.x,
y: base_layer.vertices[p1 as usize].coords.y,
})
.unwrap();
cdt.add_constraint_and_split(p0, p1, |v| v);
});
}
}

self.inner
.interiors()
.iter()
Expand All @@ -184,8 +230,22 @@ impl Triangulation {

let center = face.center();
let center = Coord::from((center.x, center.y));
(used.map(|used| used.contains(&center)).unwrap_or(true)

((used.map(|used| used.contains(&center)).unwrap_or(true)
&& self.inner.contains(&center))
|| (self.base_layer.is_some()
&& self
.base_layer
.as_ref()
.map(|base_layer| {
base_layer
.get_point_location(vec2(center.x, center.y), 0.0)
.is_some()
})
.unwrap_or(true)
&& !self.inner.interiors().iter().any(|obstacle| {
GeoPolygon::new(obstacle.clone(), vec![]).contains(&center)
})))
.then(|| {
#[cfg(feature = "tracing")]
let _preparing_span = tracing::info_span!("preparing polygon").entered();
Expand Down Expand Up @@ -249,3 +309,182 @@ impl Triangulation {
}
}
}

#[cfg(test)]
mod tests {
use super::*;

#[test]
fn triangulation() {
let mut triangulation = Triangulation::from_outer_edges(&[
vec2(0.0, 0.0),
vec2(1.0, 0.0),
vec2(1.0, 1.0),
vec2(0.0, 1.0),
]);
triangulation.add_obstacle(vec![
vec2(0.0, 0.25),
vec2(0.25, 0.25),
vec2(0.25, 0.0),
vec2(0.0, 0.0),
]);
triangulation.add_obstacle(vec![
vec2(1.0, 0.75),
vec2(0.75, 0.75),
vec2(0.75, 1.0),
vec2(1.0, 1.0),
]);
let mesh = triangulation.as_navmesh();
assert_eq!(
mesh.layers[0]
.vertices
.iter()
.map(|v| v.coords)
.collect::<Vec<_>>(),
vec![
vec2(0.0, 0.0),
vec2(1.0, 0.0),
vec2(1.0, 1.0),
vec2(0.0, 1.0),
vec2(0.0, 0.25),
vec2(0.25, 0.25),
vec2(0.25, 0.0),
vec2(1.0, 0.75),
vec2(0.75, 0.75),
vec2(0.75, 1.0)
]
);
assert_eq!(
mesh.layers[0]
.polygons
.iter()
.map(|v| v.vertices.clone())
.collect::<Vec<_>>(),
vec![
[5, 1, 8],
[4, 5, 3],
[5, 6, 1],
[8, 3, 5],
[7, 8, 1],
[8, 9, 3]
]
);
}

#[test]
fn triangulation_prebuilt() {
let mut triangulation = Triangulation::from_outer_edges(&[
vec2(0.0, 0.0),
vec2(1.0, 0.0),
vec2(1.0, 1.0),
vec2(0.0, 1.0),
]);
triangulation.add_obstacle(vec![
vec2(0.0, 0.25),
vec2(0.25, 0.25),
vec2(0.25, 0.0),
vec2(0.0, 0.0),
]);
triangulation.prebuild();
triangulation.add_obstacle(vec![
vec2(1.0, 0.75),
vec2(0.75, 0.75),
vec2(0.75, 1.0),
vec2(1.0, 1.0),
]);
let mesh = triangulation.as_navmesh();
assert_eq!(
mesh.layers[0]
.vertices
.iter()
.map(|v| v.coords)
.collect::<Vec<_>>(),
vec![
vec2(0.0, 0.0),
vec2(1.0, 0.0),
vec2(1.0, 1.0),
vec2(0.0, 1.0),
vec2(0.0, 0.25),
vec2(0.25, 0.25),
vec2(0.25, 0.0),
vec2(1.0, 0.75),
vec2(0.75, 0.75),
vec2(0.75, 1.0)
]
);
assert_eq!(
mesh.layers[0]
.polygons
.iter()
.map(|v| v.vertices.clone())
.collect::<Vec<_>>(),
vec![
[5, 1, 8],
[4, 5, 3],
[5, 6, 1],
[8, 3, 5],
[7, 8, 1],
[8, 9, 3]
]
);
}

#[test]
fn triangulation_existing_mesh() {
let mut base_triangulation = Triangulation::from_outer_edges(&[
vec2(0.0, 0.0),
vec2(1.0, 0.0),
vec2(1.0, 1.0),
vec2(0.0, 1.0),
]);
base_triangulation.add_obstacle(vec![
vec2(0.0, 0.25),
vec2(0.25, 0.25),
vec2(0.25, 0.0),
vec2(0.0, 0.0),
]);
let mesh = base_triangulation.as_navmesh();

let mut triangulation = Triangulation::from_mesh(&mesh, 0);
triangulation.add_obstacle(vec![
vec2(1.0, 0.75),
vec2(0.75, 0.75),
vec2(0.75, 1.0),
vec2(1.0, 1.0),
]);
let mesh = triangulation.as_navmesh();
assert_eq!(
mesh.layers[0]
.vertices
.iter()
.map(|v| v.coords)
.collect::<Vec<_>>(),
vec![
vec2(1.0, 1.0),
vec2(0.0, 1.0),
vec2(0.25, 0.25),
vec2(1.0, 0.0),
vec2(0.0, 0.25),
vec2(0.25, 0.0),
vec2(1.0, 0.75),
vec2(0.75, 0.75),
vec2(0.75, 1.0)
]
);
assert_eq!(
mesh.layers[0]
.polygons
.iter()
.map(|v| v.vertices.clone())
.collect::<Vec<_>>(),
vec![
[2, 3, 7],
[4, 2, 1],
[3, 2, 5],
[1, 2, 7],
[6, 7, 3],
[7, 8, 1]
]
);
}
}

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