Initial data commit

Task/Ray-casting-algorithm/Rust/ray-casting-algorithm.rust

@@ -0,0 +1,131 @@
+use std::f64;
+
+const _EPS: f64 = 0.00001;
+const _MIN: f64 = f64::MIN_POSITIVE;
+const _MAX: f64 = f64::MAX;
+
+#[derive(Clone)]
+struct Point {
+    x: f64,
+    y: f64,
+}
+
+#[derive(Clone)]
+struct Edge {
+    pt1: Point,
+    pt2: Point,
+}
+
+impl Edge {
+    fn new(pt1: (f64, f64), pt2: (f64, f64)) -> Edge {
+        Edge {
+            pt1: Point { x: pt1.0, y: pt1.1 },
+            pt2: Point { x: pt2.0, y: pt2.1 },
+        }
+    }
+}
+
+struct Polygon {
+    edges: Vec<Edge>, // Polygon has to be created with counter-clockwise coordinates
+}
+
+fn pt_in_polygon(pt: &Point, poly: &Polygon) -> bool {
+    let count = poly.edges
+        .iter()
+        .filter(|edge| ray_intersect_seg(pt, edge))
+        .count();
+
+    count % 2 == 1
+}
+
+fn ray_intersect_seg(p: &Point, edge: &Edge) -> bool {
+    let mut pt = p.clone();
+    let (mut a, mut b): (&Point, &Point) = (&edge.pt1, &edge.pt2);
+    if a.y > b.y {
+        std::mem::swap(&mut a, &mut b);
+    }
+    if pt.y == a.y || pt.y == b.y {
+        pt.y += _EPS;
+    }
+
+    if (pt.y > b.y || pt.y < a.y) || pt.x > a.x.max(b.x) {
+        false
+    } else if pt.x < a.x.min(b.x) {
+        true
+    } else {
+        let m_red = if (a.x - b.x).abs() > _MIN {
+            (b.y - a.y) / (b.x - a.x)
+        } else {
+            _MAX
+        };
+        let m_blue = if (a.x - pt.x).abs() > _MIN {
+            (pt.y - a.y) / (pt.x - a.x)
+        } else {
+            _MAX
+        };
+        m_blue >= m_red
+    }
+}
+
+fn main() {
+    let p = |x, y| Point { x, y };
+    let testpoints = [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)];
+    let poly_square = Polygon {
+        edges: vec![
+            Edge::new((0.0, 0.0), (10.0, 0.0)),
+            Edge::new((10.0, 0.0), (10.0, 10.0)),
+            Edge::new((10.0, 10.0), (0.0, 10.0)),
+            Edge::new((0.0, 10.0), (0.0, 0.0)),
+        ],
+    };
+    let poly_square_hole = Polygon {
+        edges: vec![
+            Edge::new((0.0, 0.0), (10.0, 0.0)),
+            Edge::new((10.0, 0.0), (10.0, 10.0)),
+            Edge::new((10.0, 10.0), (0.0, 10.0)),
+            Edge::new((0.0, 10.0), (0.0, 0.0)),
+            Edge::new((2.5, 2.5), (7.5, 2.5)),
+            Edge::new((7.5, 2.5), (7.5, 7.5)),
+            Edge::new((7.5, 7.5), (2.5, 7.5)),
+            Edge::new((2.5, 7.5), (2.5, 2.5)),
+        ],
+    };
+    let poly_strange = Polygon {
+        edges: vec![
+            Edge::new((0.0, 0.0), (2.5, 2.5)),
+            Edge::new((2.5, 2.5), (0.0, 10.0)),
+            Edge::new((0.0, 10.0), (2.5, 7.5)),
+            Edge::new((2.5, 7.5), (7.5, 7.5)),
+            Edge::new((7.5, 7.5), (10.0, 10.0)),
+            Edge::new((10.0, 10.0), (10.0, 0.0)),
+            Edge::new((10.0, 0.0), (2.5, 2.5)),
+        ],
+    };
+    let poly_hexagon = Polygon {
+        edges: vec![
+            Edge::new((3.0, 0.0), (7.0, 0.0)),
+            Edge::new((7.0, 0.0), (10.0, 5.0)),
+            Edge::new((10.0, 5.0), (7.0, 10.0)),
+            Edge::new((7.0, 10.0), (3.0, 10.0)),
+            Edge::new((3.0, 10.0), (0.0, 5.0)),
+            Edge::new((0.0, 5.0), (3.0, 0.0)),
+        ],
+    };
+    print!("\nSquare :");
+    for pt in &testpoints {
+        print!(" {:?}", pt_in_polygon(pt, &poly_square));
+    }
+    print!("\nSquare with hole:");
+    for pt in &testpoints {
+        print!(" {:?}", pt_in_polygon(pt, &poly_square_hole));
+    }
+    print!("\nStrange polygon :");
+    for pt in &testpoints {
+        print!(" {:?}", pt_in_polygon(pt, &poly_strange));
+    }
+    print!("\nHexagon :");
+    for pt in &testpoints {
+        print!(" {:?}", pt_in_polygon(pt, &poly_hexagon));
+    }
+    println!();
+}