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|
use crate::geometry::{Contact, ContactManifold, CuboidFeatureFace, Triangle};
use crate::math::{Isometry, Point, Vector};
use crate::utils::WBasis;
use na::Point2;
use ncollide::shape::Segment;
#[derive(Debug)]
pub struct PolyhedronFace {
pub vertices: [Point<f32>; 4],
pub vids: [u8; 4], // Feature ID of the vertices.
pub eids: [u8; 4], // Feature ID of the edges.
pub fid: u8, // Feature ID of the face.
pub num_vertices: usize,
}
impl From<CuboidFeatureFace> for PolyhedronFace {
fn from(face: CuboidFeatureFace) -> Self {
Self {
vertices: face.vertices,
vids: face.vids,
eids: face.eids,
fid: face.fid,
num_vertices: 4,
}
}
}
impl From<Triangle> for PolyhedronFace {
fn from(tri: Triangle) -> Self {
Self {
vertices: [tri.a, tri.b, tri.c, tri.c],
vids: [0, 2, 4, 4],
eids: [1, 3, 5, 5],
fid: 0,
num_vertices: 3,
}
}
}
impl From<Segment<f32>> for PolyhedronFace {
fn from(seg: Segment<f32>) -> Self {
Self {
vertices: [seg.a, seg.b, seg.b, seg.b],
vids: [0, 2, 2, 2],
eids: [1, 1, 1, 1],
fid: 0,
num_vertices: 2,
}
}
}
impl PolyhedronFace {
pub fn transform_by(&mut self, iso: &Isometry<f32>) {
for v in &mut self.vertices[0..self.num_vertices] {
*v = iso * *v;
}
}
pub fn contacts(
prediction_distance: f32,
face1: &PolyhedronFace,
sep_axis1: &Vector<f32>,
face2: &PolyhedronFace,
pos21: &Isometry<f32>,
manifold: &mut ContactManifold,
) {
// Project the faces to a 2D plane for contact clipping.
// The plane they are projected onto has normal sep_axis1
// and contains the origin (this is numerically OK because
// we are not working in world-space here).
let basis = sep_axis1.orthonormal_basis();
let projected_face1 = [
Point2::new(
face1.vertices[0].coords.dot(&basis[0]),
face1.vertices[0].coords.dot(&basis[1]),
),
Point2::new(
face1.vertices[1].coords.dot(&basis[0]),
face1.vertices[1].coords.dot(&basis[1]),
),
Point2::new(
face1.vertices[2].coords.dot(&basis[0]),
face1.vertices[2].coords.dot(&basis[1]),
),
Point2::new(
face1.vertices[3].coords.dot(&basis[0]),
face1.vertices[3].coords.dot(&basis[1]),
),
];
let projected_face2 = [
Point2::new(
face2.vertices[0].coords.dot(&basis[0]),
face2.vertices[0].coords.dot(&basis[1]),
),
Point2::new(
face2.vertices[1].coords.dot(&basis[0]),
face2.vertices[1].coords.dot(&basis[1]),
),
Point2::new(
face2.vertices[2].coords.dot(&basis[0]),
face2.vertices[2].coords.dot(&basis[1]),
),
Point2::new(
face2.vertices[3].coords.dot(&basis[0]),
face2.vertices[3].coords.dot(&basis[1]),
),
];
// Also find all the vertices located inside of the other projected face.
if face2.num_vertices > 2 {
let normal2 = (face2.vertices[2] - face2.vertices[1])
.cross(&(face2.vertices[0] - face2.vertices[1]));
let denom = normal2.dot(&sep_axis1);
if !relative_eq!(denom, 0.0) {
let last_index2 = face2.num_vertices as usize - 1;
'point_loop1: for i in 0..face1.num_vertices as usize {
let p1 = projected_face1[i];
let sign = (projected_face2[0] - projected_face2[last_index2])
.perp(&(p1 - projected_face2[last_index2]));
for j in 0..last_index2 {
let new_sign = (projected_face2[j + 1] - projected_face2[j])
.perp(&(p1 - projected_face2[j]));
if new_sign * sign < 0.0 {
// The point lies outside.
continue 'point_loop1;
}
}
// All the perp had the same sign: the point is inside of the other shapes projection.
// Output the contact.
let dist = (face2.vertices[0] - face1.vertices[i]).dot(&normal2) / denom;
let local_p1 = face1.vertices[i];
let local_p2 = face1.vertices[i] + dist * sep_axis1;
if dist <= prediction_distance {
manifold.points.push(Contact {
local_p1,
local_p2: pos21 * local_p2,
impulse: 0.0,
tangent_impulse: Contact::zero_tangent_impulse(),
fid1: face1.vids[i],
fid2: face2.fid,
dist,
});
}
}
}
}
if face1.num_vertices > 2 {
let normal1 = (face1.vertices[2] - face1.vertices[1])
.cross(&(face1.vertices[0] - face1.vertices[1]));
let denom = -normal1.dot(&sep_axis1);
if !relative_eq!(denom, 0.0) {
let last_index1 = face1.num_vertices as usize - 1;
'point_loop2: for i in 0..face2.num_vertices as usize {
let p2 = projected_face2[i];
let sign = (projected_face1[0] - projected_face1[last_index1])
.perp(&(p2 - projected_face1[last_index1]));
for j in 0..last_index1 {
let new_sign = (projected_face1[j + 1] - projected_face1[j])
.perp(&(p2 - projected_face1[j]));
if new_sign * sign < 0.0 {
// The point lies outside.
continue 'point_loop2;
}
}
// All the perp had the same sign: the point is inside of the other shapes projection.
// Output the contact.
let dist = (face1.vertices[0] - face2.vertices[i]).dot(&normal1) / denom;
let local_p2 = face2.vertices[i];
let local_p1 = face2.vertices[i] - dist * sep_axis1;
if true {
// dist <= prediction_distance {
manifold.points.push(Contact {
local_p1,
local_p2: pos21 * local_p2,
impulse: 0.0,
tangent_impulse: Contact::zero_tangent_impulse(),
fid1: face1.fid,
fid2: face2.vids[i],
dist,
});
}
}
}
}
// Now we have to compute the intersection between all pairs of
// edges from the face 1 and from the face2.
for j in 0..face2.num_vertices {
let projected_edge2 = [
projected_face2[j],
|
