parry2d 0.1.2

2 dimensional collision detection library in Rust.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147

use crate::bounding_volume::AABB;
use crate::math::{Point, Real, Vector, DIM};
use crate::num::{Bounded, Zero};
use crate::query::{PointProjection, PointQuery};
use crate::shape::FeatureId;
use na;

impl AABB {
    fn do_project_local_point(
        &self,
        pt: &Point<Real>,
        solid: bool,
    ) -> (bool, Point<Real>, Vector<Real>) {
        let mins_pt = self.mins - pt;
        let pt_maxs = pt - self.maxs;
        let shift = mins_pt.sup(&na::zero()) - pt_maxs.sup(&na::zero());

        let inside = shift.is_zero();

        if !inside {
            (false, pt + shift, shift)
        } else if solid {
            (true, *pt, shift)
        } else {
            let _max: Real = Bounded::max_value();
            let mut best = -_max;
            let mut is_mins = false;
            let mut best_id = 0;

            for i in 0..DIM {
                let mins_pt_i = mins_pt[i];
                let pt_maxs_i = pt_maxs[i];

                if mins_pt_i < pt_maxs_i {
                    if pt_maxs[i] > best {
                        best_id = i;
                        is_mins = false;
                        best = pt_maxs_i
                    }
                } else if mins_pt_i > best {
                    best_id = i;
                    is_mins = true;
                    best = mins_pt_i
                }
            }

            let mut shift: Vector<Real> = na::zero();

            if is_mins {
                shift[best_id] = best;
            } else {
                shift[best_id] = -best;
            }

            (inside, pt + shift, shift)
        }
    }
}

impl PointQuery for AABB {
    #[inline]
    fn project_local_point(&self, pt: &Point<Real>, solid: bool) -> PointProjection {
        let (inside, ls_pt, _) = self.do_project_local_point(pt, solid);
        PointProjection::new(inside, ls_pt)
    }

    #[allow(unused_assignments)] // For last_zero_shift which is used only in 3D.
    #[allow(unused_variables)] // For last_zero_shift which is used only in 3D.
    #[inline]
    fn project_local_point_and_get_feature(
        &self,
        pt: &Point<Real>,
    ) -> (PointProjection, FeatureId) {
        let (inside, ls_pt, shift) = self.do_project_local_point(pt, false);
        let proj = PointProjection::new(inside, ls_pt);
        let mut nzero_shifts = 0;
        let mut last_zero_shift = 0;
        let mut last_not_zero_shift = 0;

        for i in 0..DIM {
            if shift[i].is_zero() {
                nzero_shifts += 1;
                last_zero_shift = i;
            } else {
                last_not_zero_shift = i;
            }
        }

        if nzero_shifts == DIM {
            for i in 0..DIM {
                if ls_pt[i] > self.maxs[i] - crate::math::DEFAULT_EPSILON {
                    return (proj, FeatureId::Face(i as u32));
                }
                if ls_pt[i] <= self.mins[i] + crate::math::DEFAULT_EPSILON {
                    return (proj, FeatureId::Face((i + DIM) as u32));
                }
            }

            (proj, FeatureId::Unknown)
        } else if nzero_shifts == DIM - 1 {
            // On a 3D face.
            if ls_pt[last_not_zero_shift] < self.center()[last_not_zero_shift] {
                (proj, FeatureId::Face((last_not_zero_shift + DIM) as u32))
            } else {
                (proj, FeatureId::Face(last_not_zero_shift as u32))
            }
        } else {
            // On a vertex or edge.
            let mut id = 0;
            let center = self.center();

            for i in 0..DIM {
                if ls_pt[i] < center[i] {
                    id |= 1 << i;
                }
            }

            #[cfg(feature = "dim3")]
            {
                if nzero_shifts == 0 {
                    (proj, FeatureId::Vertex(id))
                } else {
                    (proj, FeatureId::Edge((id << 2) | (last_zero_shift as u32)))
                }
            }

            #[cfg(feature = "dim2")]
            {
                (proj, FeatureId::Vertex(id))
            }
        }
    }

    #[inline]
    fn distance_to_local_point(&self, pt: &Point<Real>, solid: bool) -> Real {
        let mins_pt = self.mins - pt;
        let pt_maxs = pt - self.maxs;
        let shift = mins_pt.sup(&pt_maxs).sup(&na::zero());

        if solid || !shift.is_zero() {
            shift.norm()
        } else {
            // FIXME: optimize that.
            -na::distance(pt, &self.project_local_point(pt, solid).point)
        }
    }
}