Data update

Task/Ray-casting-algorithm/C-sharp/ray-casting-algorithm.cs

@@ -0,0 +1,67 @@
+using System;
+
+class RayCasting {
+
+    static bool Intersects(int[] A, int[] B, double[] P) {
+        if (A[1] > B[1])
+            return Intersects(B, A, P);
+
+        if (P[1] == A[1] || P[1] == B[1])
+            P[1] += 0.0001;
+
+        if (P[1] > B[1] || P[1] < A[1] || P[0] >= Math.Max(A[0], B[0]))
+            return false;
+
+        if (P[0] < Math.Min(A[0], B[0]))
+            return true;
+
+        double red = (P[1] - A[1]) / (P[0] - A[0]);
+        double blue = (B[1] - A[1]) / (B[0] - A[0]);
+        return red >= blue;
+    }
+
+    static bool Contains(int[][] shape, double[] pnt) {
+        bool inside = false;
+        int len = shape.Length;
+        for (int i = 0; i < len; i++) {
+            if (Intersects(shape[i], shape[(i + 1) % len], pnt))
+                inside = !inside;
+        }
+        return inside;
+    }
+
+    public static void Main(string[] args) {
+        double[][] testPoints = new double[][] {
+            new double[] { 10, 10 }, new double[] { 10, 16 }, new double[] { -20, 10 },
+            new double[] { 0, 10 }, new double[] { 20, 10 }, new double[] { 16, 10 },
+            new double[] { 20, 20 }
+        };
+
+        foreach (int[][] shape in shapes) {
+            foreach (double[] pnt in testPoints)
+                Console.Write($"{Contains(shape, pnt),7} ");
+            Console.WriteLine();
+        }
+    }
+
+    readonly static int[][] square = new int[][] {
+        new int[] { 0, 0 }, new int[] { 20, 0 }, new int[] { 20, 20 }, new int[] { 0, 20 }
+    };
+
+    readonly static int[][] squareHole = new int[][] {
+        new int[] { 0, 0 }, new int[] { 20, 0 }, new int[] { 20, 20 }, new int[] { 0, 20 },
+        new int[] { 5, 5 }, new int[] { 15, 5 }, new int[] { 15, 15 }, new int[] { 5, 15 }
+    };
+
+    readonly static int[][] strange = new int[][] {
+        new int[] { 0, 0 }, new int[] { 5, 5 }, new int[] { 0, 20 }, new int[] { 5, 15 },
+        new int[] { 15, 15 }, new int[] { 20, 20 }, new int[] { 20, 0 }
+    };
+
+    readonly static int[][] hexagon = new int[][] {
+        new int[] { 6, 0 }, new int[] { 14, 0 }, new int[] { 20, 10 }, new int[] { 14, 20 },
+        new int[] { 6, 20 }, new int[] { 0, 10 }
+    };
+
+    readonly static int[][][] shapes = new int[][][] { square, squareHole, strange, hexagon };
+}