kernel 1.1.0

Abstract Reactive Streams
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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166

extern crate kernel;
extern crate rand;

use kernel::session_types::*;
use rand::{Rand, Rng};
use std::thread::spawn;

#[derive(Debug, Copy, Clone)]
struct Point(f64, f64, f64);

impl Rand for Point {
    fn rand<R: Rng>(rng: &mut R) -> Self {
        Point(rng.next_f64(), rng.next_f64(), rng.next_f64())
    }
}

#[derive(Debug, Copy, Clone)]
struct Plane(f64, f64, f64, f64);

impl Rand for Plane {
    fn rand<R: Rng>(rng: &mut R) -> Self {
        Plane(rng.next_f64(),
              rng.next_f64(),
              rng.next_f64(),
              rng.next_f64())
    }
}

fn above(Point(x, y, z): Point, Plane(a, b, c, d): Plane) -> bool {
    (a * x + b * y + c * z + d) / (a * a + b * b + c * c).sqrt() > 0.0
}

fn intersect(p1: Point, p2: Point, plane: Plane) -> Option<Point> {
    let Point(x1, y1, z1) = p1;
    let Point(x2, y2, z2) = p2;
    let Plane(a, b, c, d) = plane;

    if above(p1, plane) == above(p2, plane) {
        None
    } else {
        let t = (a * x1 + b * y1 + c * z1 + d) / (a * (x1 - x2) + b * (y1 - y2) + c * (z1 - z2));
        let x = x1 + (x2 - x1) * t;
        let y = y1 + (y2 - y1) * t;
        let z = z1 + (z2 - z1) * t;
        Some(Point(x, y, z))
    }
}

type SendList<A> = Rec<Choose<Eps, Send<A, Var<Z>>>>;
type RecvList<A> = Rec<Offer<Eps, Recv<A, Var<Z>>>>;

fn sendlist<A: std::marker::Send + Copy + 'static>(c: Chan<(), SendList<A>>, xs: Vec<A>) {
    let mut c = c.enter();
    for x in xs.iter() {
        let c1 = c.sel2().send(*x);
        c = c1.zero();
    }
    c.sel1().close();
}

fn recvlist<A: std::marker::Send + 'static>(c: Chan<(), RecvList<A>>) -> Vec<A> {
    let mut v = Vec::new();
    let mut c = c.enter();
    loop {
        c = match c.offer() {
            Branch::Left(c) => {
                c.close();
                break;
            }
            Branch::Right(c) => {
                let (c, x) = c.recv();
                v.push(x);
                c.zero()
            }
        }
    }

    v
}

fn clipper(plane: Plane, ic: Chan<(), RecvList<Point>>, oc: Chan<(), SendList<Point>>) {
    let mut oc = oc.enter();
    let mut ic = ic.enter();
    let (pt0, mut pt);

    match ic.offer() {
        Branch::Left(c) => {
            c.close();
            oc.sel1().close();
            return;
        }
        Branch::Right(c) => {
            let (c, ptz) = c.recv();
            ic = c.zero();
            pt0 = ptz;
            pt = ptz;
        }
    }

    loop {
        if above(pt, plane) {
            oc = oc.sel2().send(pt).zero();
        }
        ic = match ic.offer() {
            Branch::Left(c) => {
                if let Some(pt) = intersect(pt, pt0, plane) {
                    oc = oc.sel2().send(pt).zero();
                }
                c.close();
                oc.sel1().close();
                break;
            }
            Branch::Right(ic) => {
                let (ic, pt2) = ic.recv();
                if let Some(pt) = intersect(pt, pt2, plane) {
                    oc = oc.sel2().send(pt).zero();
                }
                pt = pt2;
                ic.zero()
            }
        }
    }
}

fn clipmany(planes: Vec<Plane>, points: Vec<Point>) -> Vec<Point> {
    let (tx, rx) = session_channel();
    spawn(move || sendlist(tx, points));
    let mut rx = rx;

    for plane in planes.into_iter() {
        let (tx2, rx2) = session_channel();
        spawn(move || clipper(plane, rx, tx2));
        rx = rx2;
    }
    recvlist(rx)
}

fn normalize_point(Point(a, b, c): Point) -> Point {
    Point(10.0 * (a - 0.5), 10.0 * (b - 0.5), 10.0 * (c - 0.5))
}

fn normalize_plane(Plane(a, b, c, d): Plane) -> Plane {
    Plane(10.0 * (a - 0.5),
          10.0 * (b - 0.5),
          10.0 * (c - 0.5),
          10.0 * (d - 0.5))
}

fn bench(n: usize, m: usize) {
    let mut g = rand::thread_rng();
    let points = (0..n)
        .map(|_| rand::Rand::rand(&mut g))
        .map(normalize_point)
        .collect();
    let planes = (0..m)
        .map(|_| rand::Rand::rand(&mut g))
        .map(normalize_plane)
        .collect();

    let points = clipmany(planes, points);
    println!("{}", points.len());
}

fn main() {
    bench(100, 5);
}