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use crate::geometry::{Triangle, WQuadtree};
use crate::math::{Isometry, Point};
use na::Point3;
use ncollide::bounding_volume::{HasBoundingVolume, AABB};
#[cfg(feature = "dim3")]
use {
crate::geometry::{Ray, RayIntersection},
ncollide::query::RayCast,
};
#[derive(Clone)]
#[cfg_attr(feature = "serde-serialize", derive(Serialize, Deserialize))]
/// A triangle mesh.
pub struct Trimesh {
wquadtree: WQuadtree<usize>,
aabb: AABB<f32>,
vertices: Vec<Point<f32>>,
indices: Vec<Point3<u32>>,
}
impl Trimesh {
/// Creates a new triangle mesh from a vertex buffer and an index buffer.
pub fn new(vertices: Vec<Point<f32>>, indices: Vec<Point3<u32>>) -> Self {
assert!(
vertices.len() > 1,
"A triangle mesh must contain at least one point."
);
assert!(
indices.len() > 1,
"A triangle mesh must contain at least one triangle."
);
let aabb = AABB::from_points(&vertices);
let data = indices.iter().enumerate().map(|(i, idx)| {
let aabb = Triangle::new(
vertices[idx[0] as usize],
vertices[idx[1] as usize],
vertices[idx[2] as usize],
)
.local_bounding_volume();
(i, aabb)
});
let mut wquadtree = WQuadtree::new();
// NOTE: we apply no dilation factor because we won't
// update this tree dynamically.
wquadtree.clear_and_rebuild(data, 0.0);
Self {
wquadtree,
aabb,
vertices,
indices,
}
}
/// Compute the axis-aligned bounding box of this triangle mesh.
pub fn aabb(&self, pos: &Isometry<f32>) -> AABB<f32> {
self.aabb.transform_by(pos)
}
pub(crate) fn waabbs(&self) -> &WQuadtree<usize> {
&self.wquadtree
}
/// The number of triangles forming this mesh.
pub fn num_triangles(&self) -> usize {
self.indices.len()
}
/// An iterator through all the triangles of this mesh.
pub fn triangles(&self) -> impl Iterator<Item = Triangle> + '_ {
self.indices.iter().map(move |ids| {
Triangle::new(
self.vertices[ids.x as usize],
self.vertices[ids.y as usize],
self.vertices[ids.z as usize],
)
})
}
/// Get the `i`-th triangle of this mesh.
pub fn triangle(&self, i: usize) -> Triangle {
let idx = self.indices[i];
Triangle::new(
self.vertices[idx.x as usize],
self.vertices[idx.y as usize],
self.vertices[idx.z as usize],
)
}
/// The vertex buffer of this mesh.
pub fn vertices(&self) -> &[Point<f32>] {
&self.vertices[..]
}
/// The index buffer of this mesh.
pub fn indices(&self) -> &[Point3<u32>] {
&self.indices
}
/// A flat view of the index buffer of this mesh.
pub fn flat_indices(&self) -> &[u32] {
unsafe {
let len = self.indices.len() * 3;
let data = self.indices.as_ptr() as *const u32;
std::slice::from_raw_parts(data, len)
}
}
}
#[cfg(feature = "dim3")]
impl RayCast<f32> for Trimesh {
fn toi_and_normal_with_ray(
&self,
m: &Isometry<f32>,
ray: &Ray,
max_toi: f32,
solid: bool,
) -> Option<RayIntersection> {
// FIXME: do a best-first search.
let mut intersections = Vec::new();
let ls_ray = ray.inverse_transform_by(m);
self.wquadtree
.cast_ray(&ls_ray, max_toi, &mut intersections);
let mut best: Option<RayIntersection> = None;
for inter in intersections {
let tri = self.triangle(inter);
if let Some(inter) = tri.toi_and_normal_with_ray(m, ray, max_toi, solid) {
if let Some(curr) = &mut best {
if curr.toi > inter.toi {
*curr = inter;
}
} else {
best = Some(inter);
}
}
}
best
}
fn intersects_ray(&self, m: &Isometry<f32>, ray: &Ray, max_toi: f32) -> bool {
// FIXME: do a best-first search.
let mut intersections = Vec::new();
let ls_ray = ray.inverse_transform_by(m);
self.wquadtree
.cast_ray(&ls_ray, max_toi, &mut intersections);
for inter in intersections {
let tri = self.triangle(inter);
if tri.intersects_ray(m, ray, max_toi) {
return true;
}
}
false
}
}
|
