Ray-casting algorithm: Difference between revisions
Add C# implementation
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return 0;
}</syntaxhighlight>
=={{header|C#}}==
{{trans|Java}}
<syntaxhighlight lang="C#">
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 };
}
</syntaxhighlight>
{{out}}
<pre>
True True False True False True False
False True False False False True False
True False False False False True False
True True False False False True False
</pre>
=={{header|C++}}==
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