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    <p>No. (Not up and including version 3 at least)</p> <p>XNA has bounding volumes such as <em>frustums</em> or <em>boxes</em> but it has no notion of polygons.</p> <p>A simple, fast and effective way of performing point in polygon with XNA can be found <a href="http://local.wasp.uwa.edu.au/~pbourke/geometry/insidepoly/" rel="nofollow noreferrer"><del>here</del></a>. I've recently implemented this and it was excellent.</p> <p>You know the point of your object, all you need to do is create a polygon surrounding this object - using vectors would be the best and easiest method. Then perform the point in polygon check. </p> <p>Here is the example code of my implementation. The default point class in XNA is used. Polygon is a simple class which contains a collection of vectors making up the polygon.</p> <pre><code>/// &lt;summary&gt; /// Point in polygon check. /// &lt;/summary&gt; /// &lt;param name="point"&gt;The point.&lt;/param&gt; /// &lt;param name="polygon"&gt;The polygon.&lt;/param&gt; /// &lt;returns&gt;True if point is inside, false otherwise.&lt;/returns&gt; /// &lt;see cref="http://local.wasp.uwa.edu.au/~pbourke/geometry/insidepoly/"/&gt; public bool PointInPolygon(Point point, Polygon polygon) { bool inside = false; foreach (var side in polygon.Lines) { if (point.Y &gt; Math.Min(side.Start.Y, side.End.Y)) if (point.Y &lt;= Math.Max(side.Start.Y, side.End.Y)) if (point.X &lt;= Math.Max(side.Start.X, side.End.X)) { float xIntersection = side.Start.X + ((point.Y - side.Start.Y) / (side.End.Y - side.Start.Y)) * (side.End.X - side.Start.X); if (point.X &lt;= xIntersection) inside = !inside; } return inside; } </code></pre> <p>The Polgyon class is very basic, in semi pseudo form:</p> <pre><code>class Polygon { public List&lt;Line&gt; Lines { get; set; } } public class Line { public Vector2 Start; public Vector2 End; } </code></pre> <p>The polygon class could very easily just store a collection of vectors, but I introduced a line class as lines were required elsewhere.</p>
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    1. PODoes XNA have a Polygon, like Rectangle?
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    1. COThis code is based on that article, except it uses C#. Plus it has been modified heavily. I should add, to understand this code. Google *"Point in Polygon"* with ray casting. This will explain the theory more. Wikipedia has a nice article on this too.
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    2. COCan I see the code for your polygon class? It seems hard to believe that XNA lacks this.
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    3. COI've spent a long time the past few weeks writing my own point in polygon functions. Testing the best methods and so forth. The ray casting method seems not only the best, but the nicest to implement. As for XNA lacking this functionality, yes, it may seem a little hard to believe, but most frameworks lack any sort of point in polygon detection.
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