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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// https://rust-lang.github.io/rust-clippy/master/index.html#float_cmp
// Silence, clippy!
const EPSILON: f64 = 0.0001f64;
#[derive(Debug, Clone)]
pub struct Point {
coord_x: f64,
coord_y: f64,
}
#[derive(Debug, Clone)]
pub struct Line {
start: Point,
end: Point,
}
pub fn gradient(ln: Line) -> f64 {
let rise = ln.end.coord_y - ln.start.coord_y;
let run = ln.end.coord_x - ln.start.coord_x;
rise / run
}
pub fn intersection(ln1: Line, ln2: Line) -> Option<Point> {
// TODO: yuck, should be able to take &Line as argument here
// and have rust figure it out with a bunch of annotations...
let g1 = gradient(ln1.clone());
let z1 = ln1.start.coord_y - g1 * ln1.start.coord_x;
let g2 = gradient(ln2.clone());
let z2 = ln2.start.coord_y - g2 * ln2.start.coord_x;
// Parallel lines do not intersect.
if (g1 - g2).abs() < EPSILON {
return None;
}
// Otherwise, they intersect at this fancy calculation that
// I found on wikipedia.
let x = (z2 - z1) / (g1 - g2);
Some(Point {
coord_x: x,
coord_y: g1 * x + z1,
})
}
uniffi::include_scaffolding!("geometry");
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