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

#![allow(clippy::new_without_default)]

#[macro_use]
extern crate anyhow;

use serde::{Deserialize, Deserializer, Serialize, Serializer};

pub use crate::angle::Angle;
pub use crate::bounds::{Bounds, GPSBounds};
pub use crate::circle::Circle;
pub use crate::distance::Distance;
pub use crate::duration::Duration;
pub use crate::find_closest::FindClosest;
pub use crate::gps::LonLat;
pub use crate::line::{InfiniteLine, Line};
pub use crate::percent::Percent;
pub use crate::polygon::{Polygon, Triangle};
pub use crate::polyline::{ArrowCap, PolyLine};
pub use crate::pt::{HashablePt2D, Pt2D};
pub use crate::ring::Ring;
pub use crate::speed::Speed;
pub use crate::stats::{HgramValue, Histogram, Statistic};
pub use crate::time::Time;

mod angle;
mod bounds;
mod circle;
mod distance;
mod duration;
mod find_closest;
mod gps;
mod line;
mod percent;
mod polygon;
mod polyline;
mod pt;
mod ring;
mod speed;
mod stats;
mod time;

// About 0.4 inches... which is quite tiny on the scale of things. :)
pub const EPSILON_DIST: Distance = Distance::const_meters(0.01);

/// Reduce the precision of an f64. This helps ensure serialization is idempotent (everything is
/// exacly the same before and after saving/loading). Ideally we'd use some kind of proper
/// fixed-precision type instead of f64.
pub fn trim_f64(x: f64) -> f64 {
    (x * 10_000.0).round() / 10_000.0
}

/// Serializes a trimmed `f64` as an `i32` to save space.
fn serialize_f64<S: Serializer>(x: &f64, s: S) -> Result<S::Ok, S::Error> {
    // So a trimmed f64's range becomes 2**31 / 10,000 =~ 214,000, which is plenty
    // We don't need to round() here; trim_f64 already handles that.
    let int = (x * 10_000.0) as i32;
    int.serialize(s)
}

/// Deserializes a trimmed `f64` from an `i32`.
fn deserialize_f64<'de, D: Deserializer<'de>>(d: D) -> Result<f64, D::Error> {
    let x = <i32>::deserialize(d)?;
    Ok(x as f64 / 10_000.0)
}

/// Specifies how to stringify different geom objects.
#[derive(Clone, Serialize, Deserialize, Copy)]
pub struct UnitFmt {
    /// Round `Duration`s to a whole number of seconds.
    pub round_durations: bool,
    /// Display in metric; US imperial otherwise.
    pub metric: bool,
}

#[derive(Clone, Copy, Debug)]
pub struct CornerRadii {
    pub top_left: f64,
    pub top_right: f64,
    pub bottom_right: f64,
    pub bottom_left: f64,
}

impl CornerRadii {
    pub fn uniform(radius: f64) -> Self {
        Self {
            top_left: radius,
            top_right: radius,
            bottom_right: radius,
            bottom_left: radius,
        }
    }

    pub fn zero() -> Self {
        Self::uniform(0.0)
    }
}

impl std::convert::From<f64> for CornerRadii {
    fn from(uniform: f64) -> Self {
        Self::uniform(uniform)
    }
}

impl std::default::Default for CornerRadii {
    fn default() -> Self {
        Self::zero()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use rand::{Rng, SeedableRng};

    #[test]
    fn f64_trimming() {
        // Roundtrip a bunch of random f64's
        let mut rng = rand_xorshift::XorShiftRng::seed_from_u64(42);
        for _ in 0..1_000 {
            let input = rng.gen_range(-214_000.00..214_000.0);
            let trimmed = trim_f64(input);
            let json_roundtrip: f64 =
                abstutil::from_json(abstutil::to_json(&trimmed).as_bytes()).unwrap();
            let bincode_roundtrip: f64 =
                abstutil::from_binary(&abstutil::to_binary(&trimmed)).unwrap();
            assert_eq!(json_roundtrip, trimmed);
            assert_eq!(bincode_roundtrip, trimmed);
        }

        // Hardcode a particular case, where we can hand-verify that it trims to 4 decimal places
        let input = 1.2345678;
        let trimmed = trim_f64(input);
        let json_roundtrip: f64 =
            abstutil::from_json(abstutil::to_json(&trimmed).as_bytes()).unwrap();
        let bincode_roundtrip: f64 = abstutil::from_binary(&abstutil::to_binary(&trimmed)).unwrap();
        assert_eq!(json_roundtrip, 1.2346);
        assert_eq!(bincode_roundtrip, 1.2346);
    }
}