119 lines
3.5 KiB
Text
119 lines
3.5 KiB
Text
use std::f64;
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use std::clone::Clone;
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const _EPS: f64 = 0.00001;
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const _MIN: f64 = f64::MIN_POSITIVE;
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const _MAX: f64 = f64::MAX;
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#[derive(Debug, Clone)]
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struct Point {
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x: f64,
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y: f64
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}
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#[derive(Debug, Clone)]
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struct Edge {
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pt1: Point,
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pt2: Point
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}
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impl Edge {
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fn new(pt1: (f64, f64), pt2: (f64, f64)) -> Edge {
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Edge { pt1: Point {x: pt1.0, y: pt1.1}, pt2: Point {x: pt2.0, y: pt2.1} }
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}
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}
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#[derive(Debug)]
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struct Polygon{
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edges: Vec<Edge> // Polygon has to be created with counter-clockwise coordinates
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}
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fn pt_in_polygon(pt: &Point, poly: &Polygon) -> bool {
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poly.edges.iter()
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.map(|edge| ray_intersect_seg(pt, edge))
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.fold(0u8, |sum, val| sum + (val as u8)) % 2 == 1
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}
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fn ray_intersect_seg(p: &Point, edge: &Edge) -> bool {
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let mut pt = p.clone();
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let (mut a, mut b): (&Point, &Point) = (&edge.pt1, &edge.pt2);
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if a.y > b.y {
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let t = a; a = b; b = t;
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}
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if pt.y == a.y || pt.y == b.y {
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pt = Point {x: pt.x, y: pt.y + _EPS};
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}
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if (pt.y > b.y || pt.y < a.y) || pt.x > a.x.max(b.x) {
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return false;
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}
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if pt.x < a.x.min(b.x) {
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return true;
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} else {
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let m_red = if (a.x - b.x).abs() > _MIN { (b.y - a.y) / (b.x - a.x) } else { _MAX };
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let m_blue = if (a.x - pt.x).abs() > _MIN { (pt.y - a.y) / (pt.x - a.x) } else { _MAX };
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return m_blue >= m_red;
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}
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}
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fn main(){
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let p = |x,y| Point {x: x, y: y};
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let testpoints = vec![p(5.0, 5.0), p(5.0, 8.0), p(-10.0, 5.0), p(0.0, 5.0), p(10.0, 5.0), p(8.0, 5.0), p(10.0, 10.0)];
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let poly_square = Polygon {
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edges: vec![
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Edge::new((0.0, 0.0), (10.0, 0.0)),
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Edge::new((10.0, 0.0), (10.0, 10.0)),
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Edge::new((10.0, 10.0), (0.0, 10.0)),
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Edge::new((0.0, 10.0), (0.0, 0.0))
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]
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};
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let poly_square_hole = Polygon {
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edges: vec![
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Edge::new((0.0, 0.0), (10.0, 0.0)),
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Edge::new((10.0, 0.0), (10.0, 10.0)),
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Edge::new((10.0, 10.0), (0.0, 10.0)),
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Edge::new((0.0, 10.0), (0.0, 0.0)),
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Edge::new((2.5, 2.5), (7.5, 2.5)),
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Edge::new((7.5, 2.5), (7.5, 7.5)),
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Edge::new((7.5, 7.5), (2.5, 7.5)),
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Edge::new((2.5, 7.5), (2.5, 2.5))
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]
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};
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let poly_strange = Polygon {
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edges: vec![
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Edge::new((0.0, 0.0), (2.5, 2.5)),
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Edge::new((2.5, 2.5), (0.0, 10.0)),
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Edge::new((0.0, 10.0), (2.5, 7.5)),
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Edge::new((2.5, 7.5), (7.5, 7.5)),
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Edge::new((7.5, 7.5), (10.0, 10.0)),
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Edge::new((10.0, 10.0), (10.0, 0.0)),
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Edge::new((10.0, 0.0), (2.5, 2.5))
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]
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};
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let poly_hexagon = Polygon {
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edges: vec![
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Edge::new((3.0, 0.0), (7.0, 0.0)),
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Edge::new((7.0, 0.0), (10.0, 5.0)),
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Edge::new((10.0, 5.0), (7.0, 10.0)),
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Edge::new((7.0, 10.0), (3.0, 10.0)),
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Edge::new((3.0, 10.0), (0.0, 5.0)),
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Edge::new((0.0, 5.0), (3.0, 0.0))
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]
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};
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print!("\nSquare :");
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for pt in testpoints.iter() {
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print!(" {:?}", pt_in_polygon(pt, &poly_square));
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}
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print!("\nSquare with hole:");
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for pt in testpoints.iter() {
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print!(" {:?}", pt_in_polygon(pt, &poly_square_hole));
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}
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print!("\nStrange polygon :");
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for pt in testpoints.iter() {
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print!(" {:?}", pt_in_polygon(pt, &poly_strange));
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}
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print!("\nHexagon :");
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for pt in testpoints.iter() {
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print!(" {:?}", pt_in_polygon(pt, &poly_hexagon));
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}
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print!("\n");
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}
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