ncollide2d 0.33.0

2 and 3-dimensional collision detection library in Rust. Will be superseded by the parry2d crate.
Documentation
use crate::bounding_volume::AABB;
use crate::math::{Isometry, Point, Vector};
use crate::partitioning::{BestFirstVisitStatus, BestFirstVisitor};
use crate::query::{self, PointQuery, Proximity};
use crate::shape::{CompositeShape, Shape};
use na::{self, RealField};

/// Proximity between a composite shape (`Mesh`, `Compound`) and any other shape.
pub fn proximity_composite_shape_shape<N: RealField + Copy, G1: ?Sized>(
    m1: &Isometry<N>,
    g1: &G1,
    m2: &Isometry<N>,
    g2: &dyn Shape<N>,
    margin: N,
) -> Proximity
where
    G1: CompositeShape<N>,
{
    assert!(
        margin >= na::zero(),
        "The proximity margin must be positive or null."
    );

    let mut visitor = CompositeShapeAgainstAnyInterfVisitor::new(m1, g1, m2, g2, margin);

    match g1.bvh().best_first_search(&mut visitor) {
        None => Proximity::Disjoint,
        Some(prox) => prox.1,
    }
}

/// Proximity between a shape and a composite (`Mesh`, `Compound`) shape.
pub fn proximity_shape_composite_shape<N: RealField + Copy, G2: ?Sized>(
    m1: &Isometry<N>,
    g1: &dyn Shape<N>,
    m2: &Isometry<N>,
    g2: &G2,
    margin: N,
) -> Proximity
where
    G2: CompositeShape<N>,
{
    proximity_composite_shape_shape(m2, g2, m1, g1, margin)
}

struct CompositeShapeAgainstAnyInterfVisitor<'a, N: 'a + RealField + Copy, G1: ?Sized + 'a> {
    msum_shift: Vector<N>,
    msum_margin: Vector<N>,

    m1: &'a Isometry<N>,
    g1: &'a G1,
    m2: &'a Isometry<N>,
    g2: &'a dyn Shape<N>,
    margin: N,
}

impl<'a, N: RealField + Copy, G1: ?Sized> CompositeShapeAgainstAnyInterfVisitor<'a, N, G1>
where
    G1: CompositeShape<N>,
{
    pub fn new(
        m1: &'a Isometry<N>,
        g1: &'a G1,
        m2: &'a Isometry<N>,
        g2: &'a dyn Shape<N>,
        margin: N,
    ) -> CompositeShapeAgainstAnyInterfVisitor<'a, N, G1> {
        let ls_m2 = m1.inverse() * m2.clone();
        let ls_aabb2 = g2.aabb(&ls_m2);

        CompositeShapeAgainstAnyInterfVisitor {
            msum_shift: -ls_aabb2.center().coords,
            msum_margin: ls_aabb2.half_extents(),
            m1,
            g1,
            m2,
            g2,
            margin,
        }
    }
}

impl<'a, N: RealField + Copy, G1: ?Sized> BestFirstVisitor<N, usize, AABB<N>>
    for CompositeShapeAgainstAnyInterfVisitor<'a, N, G1>
where
    G1: CompositeShape<N>,
{
    type Result = Proximity;

    fn visit(
        &mut self,
        best: N,
        bv: &AABB<N>,
        data: Option<&usize>,
    ) -> BestFirstVisitStatus<N, Self::Result> {
        // Compute the minkowski sum of the two AABBs.
        let msum = AABB::new(
            bv.mins + self.msum_shift + (-self.msum_margin),
            bv.maxs + self.msum_shift + self.msum_margin,
        );

        // Compute the distance to the origin.
        let dist = msum.distance_to_point(&Isometry::identity(), &Point::origin(), true);
        let mut res = BestFirstVisitStatus::Continue {
            cost: dist,
            result: None,
        };

        if let Some(b) = data {
            if dist < best {
                self.g1
                    .map_part_at(*b, self.m1, &mut |m1, g1| match query::proximity(
                        m1,
                        g1,
                        self.m2,
                        self.g2,
                        self.margin,
                    ) {
                        Proximity::WithinMargin => {
                            res = BestFirstVisitStatus::Continue {
                                cost: self.margin,
                                result: Some(Proximity::WithinMargin),
                            }
                        }
                        Proximity::Intersecting => {
                            res = BestFirstVisitStatus::ExitEarly(Some(Proximity::Intersecting))
                        }
                        Proximity::Disjoint => {}
                    });
            }
        }

        res
    }
}