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c#geometrysystem.drawing

How to find which rectangle is closest to a point

If I have two System.Drawing.Rectangle objects on a canvas and a Point, what is the best way to calculate which Rectangle (any part of the Rectangle, not just its Location Point) is closest to that Point?

An example from a unit test:

Rectangle one = new Rectangle (0, 0, 10, 10);

Rectangle two = new Rectangle (20, 20, 10, 10);

Point point = new Point(14, 14);

Rectangle actual = ClosestToPoint(point, one, two);

// should be closer to one since one's bottom right is at (10, 10)
Assert.That(actual, Is.SameAs(one));

// method to write
public Rectangle ClosestToPoint(Point p, params Rectangle[] rectangles) { }
Solution

  • distance to rectangle = min (distance to each of the 4 line segments that are the edges of the rectangle)

    For distance to line segment, see this question