use std::ops::{Add, AddAssign, Sub, SubAssign, Mul, MulAssign, Div, DivAssign, Neg};
+////////// POINT ///////////////////////////////////////////////////////////////
+
#[macro_export]
macro_rules! point {
( $x:expr, $y:expr ) => {
}
}
+////////// INTERSECTION ////////////////////////////////////////////////////////
+
+#[derive(Debug)]
+pub enum Intersection {
+ Point(Point<f64>),
+ //Line(Point<f64>, Point<f64>), // TODO: overlapping collinear
+ None,
+}
+
+impl Intersection {
+ pub fn lines(p1: Point<f64>, p2: Point<f64>, p3: Point<f64>, p4: Point<f64>) -> Intersection {
+ let s1 = p2 - p1;
+ let s2 = p4 - p3;
+
+ let denomimator = -s2.x * s1.y + s1.x * s2.y;
+ if denomimator != 0.0 {
+ let s = (-s1.y * (p1.x - p3.x) + s1.x * (p1.y - p3.y)) / denomimator;
+ let t = ( s2.x * (p1.y - p3.y) - s2.y * (p1.x - p3.x)) / denomimator;
+
+ if s >= 0.0 && s <= 1.0 && t >= 0.0 && t <= 1.0 {
+ return Intersection::Point(p1 + (s1 * t))
+ }
+ }
+
+ Intersection::None
+ }
+}
+
+////////// DIMENSION ///////////////////////////////////////////////////////////
+
#[macro_export]
macro_rules! dimen {
( $w:expr, $h:expr ) => {
};
}
-#[derive(Debug, Default)]
+#[derive(Debug, Default, Copy, Clone, PartialEq)]
pub struct Dimension<T> {
pub width: T,
pub height: T,
}
}
-#[macro_export]
-macro_rules! hashmap {
- ($($k:expr => $v:expr),*) => {
- {
- let mut map = std::collections::HashMap::new();
- $(map.insert($k, $v);)*
- map
+impl<T> From<Dimension<T>> for (T, T) {
+ fn from(item: Dimension<T>) -> Self {
+ (item.width, item.height)
+ }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+#[allow(dead_code)]
+pub fn supercover_line_int(p1: Point<isize>, p2: Point<isize>) -> Vec<Point<isize>> {
+ let d = p2 - p1;
+ let n = point!(d.x.abs(), d.y.abs());
+ let step = point!(
+ if d.x > 0 { 1 } else { -1 },
+ if d.y > 0 { 1 } else { -1 }
+ );
+
+ let mut p = p1.clone();
+ let mut points = vec!(point!(p.x as isize, p.y as isize));
+ let mut i = point!(0, 0);
+ while i.x < n.x || i.y < n.y {
+ let decision = (1 + 2 * i.x) * n.y - (1 + 2 * i.y) * n.x;
+ if decision == 0 { // next step is diagonal
+ p.x += step.x;
+ p.y += step.y;
+ i.x += 1;
+ i.y += 1;
+ } else if decision < 0 { // next step is horizontal
+ p.x += step.x;
+ i.x += 1;
+ } else { // next step is vertical
+ p.y += step.y;
+ i.y += 1;
+ }
+ points.push(point!(p.x as isize, p.y as isize));
+ }
+
+ points
+}
+
+/// Calculates all points a line crosses, unlike Bresenham's line algorithm.
+/// There might be room for a lot of improvement here.
+pub fn supercover_line(mut p1: Point<f64>, mut p2: Point<f64>) -> Vec<Point<isize>> {
+ let mut delta = p2 - p1;
+ if (delta.x.abs() > delta.y.abs() && delta.x.is_sign_negative()) || (delta.x.abs() <= delta.y.abs() && delta.y.is_sign_negative()) {
+ std::mem::swap(&mut p1, &mut p2);
+ delta = -delta;
+ }
+
+ let mut last = point!(p1.x as isize, p1.y as isize);
+ let mut coords: Vec<Point<isize>> = vec!();
+ coords.push(last);
+
+ if delta.x.abs() > delta.y.abs() {
+ let k = delta.y / delta.x;
+ let m = p1.y as f64 - p1.x as f64 * k;
+ for x in (p1.x as isize + 1)..=(p2.x as isize) {
+ let y = (k * x as f64 + m).floor();
+ let next = point!(x as isize - 1, y as isize);
+ if next != last {
+ coords.push(next);
+ }
+ let next = point!(x as isize, y as isize);
+ coords.push(next);
+ last = next;
+ }
+ } else {
+ let k = delta.x / delta.y;
+ let m = p1.x as f64 - p1.y as f64 * k;
+ for y in (p1.y as isize + 1)..=(p2.y as isize) {
+ let x = (k * y as f64 + m).floor();
+ let next = point!(x as isize, y as isize - 1);
+ if next != last {
+ coords.push(next);
+ }
+ let next = point!(x as isize, y as isize);
+ coords.push(next);
+ last = next;
}
}
+
+ let next = point!(p2.x as isize, p2.y as isize);
+ if next != last {
+ coords.push(next);
+ }
+
+ coords
}
+////////// TESTS ///////////////////////////////////////////////////////////////
+
#[cfg(test)]
mod tests {
use super::*;
assert_eq!(r.area(), 30 * 20);
// let a = Dimension::from(("a".to_string(), "b".to_string())).area(); // this doesn't work, because area() is not implemented for String
}
+
+ #[test]
+ fn intersection_of_lines() {
+ let p1 = point!(0.0, 0.0);
+ let p2 = point!(2.0, 2.0);
+ let p3 = point!(0.0, 2.0);
+ let p4 = point!(2.0, 0.0);
+ let r = Intersection::lines(p1, p2, p3, p4);
+ if let Intersection::Point(p) = r {
+ assert_eq!(p, point!(1.0, 1.0));
+ } else {
+ panic!();
+ }
+ }
+
+ #[test]
+ fn some_coordinates_on_line() {
+ // horizontally up
+ let coords = supercover_line(point!(0.0, 0.0), point!(3.3, 2.2));
+ assert_eq!(coords.as_slice(), &[point!(0, 0), point!(1, 0), point!(1, 1), point!(2, 1), point!(2, 2), point!(3, 2)]);
+
+ // horizontally down
+ let coords = supercover_line(point!(0.0, 5.0), point!(3.3, 2.2));
+ assert_eq!(coords.as_slice(), &[point!(0, 5), point!(0, 4), point!(1, 4), point!(1, 3), point!(2, 3), point!(2, 2), point!(3, 2)]);
+
+ // vertically right
+ let coords = supercover_line(point!(0.0, 0.0), point!(2.2, 3.3));
+ assert_eq!(coords.as_slice(), &[point!(0, 0), point!(0, 1), point!(1, 1), point!(1, 2), point!(2, 2), point!(2, 3)]);
+
+ // vertically left
+ let coords = supercover_line(point!(5.0, 0.0), point!(3.0, 3.0));
+ assert_eq!(coords.as_slice(), &[point!(5, 0), point!(4, 0), point!(4, 1), point!(3, 1), point!(3, 2), point!(3, 3)]);
+
+ // negative
+ let coords = supercover_line(point!(0.0, 0.0), point!(-3.0, -2.0));
+ assert_eq!(coords.as_slice(), &[point!(-3, -2), point!(-2, -2), point!(-2, -1), point!(-1, -1), point!(-1, 0), point!(0, 0)]);
+
+ //
+ let coords = supercover_line(point!(0.0, 0.0), point!(2.3, 1.1));
+ assert_eq!(coords.as_slice(), &[point!(0, 0), point!(1, 0), point!(2, 0), point!(2, 1)]);
+ }
}
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