/// <summary>
/// Computes the <see cref="BoundingRectangle" /> that contains the two specified
/// <see cref="BoundingRectangle" /> structures.
/// </summary>
/// <param name="first">The first bounding rectangle.</param>
/// <param name="second">The second bounding rectangle.</param>
/// <param name="result">The resulting bounding rectangle that contains both the <paramref name="first" /> and the
/// <paramref name="second" />.</param>
public static void Union(ref BoundingRectangle first, ref BoundingRectangle second, out BoundingRectangle result)
{
// Real-Time Collision Detection, Christer Ericson, 2005. Chapter 6.5; Bounding Volume Hierarchies - Merging Bounding Volumes. pg 267
var firstMinimum = first.Center - first.HalfExtents;
var firstMaximum = first.Center + first.HalfExtents;
var secondMinimum = second.Center - second.HalfExtents;
var secondMaximum = second.Center + second.HalfExtents;
var minimum = Point2.Minimum(firstMinimum, secondMinimum);
var maximum = Point2.Maximum(firstMaximum, secondMaximum);
result = CreateFrom(minimum, maximum);
}
/// <summary>
/// Computes the <see cref="BoundingRectangle" /> that is in common between the two specified
/// <see cref="BoundingRectangle" /> structures.
/// </summary>
/// <param name="first">The first bounding rectangle.</param>
/// <param name="second">The second bounding rectangle.</param>
/// <param name="result">The resulting bounding rectangle that is in common between both the <paramref name="first" /> and
/// the <paramref name="second" />, if they intersect; otherwise, <see cref="Empty"/>.</param>
public static void Intersection(ref BoundingRectangle first,
ref BoundingRectangle second, out BoundingRectangle result)
{
var firstMinimum = first.Center - first.HalfExtents;
var firstMaximum = first.Center + first.HalfExtents;
var secondMinimum = second.Center - second.HalfExtents;
var secondMaximum = second.Center + second.HalfExtents;
var minimum = Point2.Maximum(firstMinimum, secondMinimum);
var maximum = Point2.Minimum(firstMaximum, secondMaximum);
if ((maximum.X < minimum.X) || (maximum.Y < minimum.Y))
{
result = new BoundingRectangle();
}
else
{
result = CreateFrom(minimum, maximum);
}
}
/// <summary>
/// Computes the <see cref="RectangleF" /> that is in common between the two specified
/// <see cref="RectangleF" /> structures.
/// </summary>
/// <param name="first">The first rectangle.</param>
/// <param name="second">The second rectangle.</param>
/// <param name="result">The resulting rectangle that is in common between both the <paramref name="first" /> and
/// the <paramref name="second" />, if they intersect; otherwise, <see cref="Empty"/>.</param>
public static void Intersection(ref RectangleF first,
ref RectangleF second, out RectangleF result)
{
var firstMinimum = first.TopLeft;
var firstMaximum = first.BottomRight;
var secondMinimum = second.TopLeft;
var secondMaximum = second.BottomRight;
var minimum = Point2.Maximum(firstMinimum, secondMinimum);
var maximum = Point2.Minimum(firstMaximum, secondMaximum);
if ((maximum.X < minimum.X) || (maximum.Y < minimum.Y))
{
result = new RectangleF();
}
else
{
result = CreateFrom(minimum, maximum);
}
}
internal static void CreateRectangleFromPoints(IReadOnlyList <Point2> points, out Point2 minimum, out Point2 maximum)
{
// Real-Time Collision Detection, Christer Ericson, 2005. Chapter 4.2; Bounding Volumes - Axis-aligned Bounding Boxes (AABBs). pg 82-84
if (points == null || points.Count == 0)
{
minimum = Point2.Zero;
maximum = Point2.Zero;
return;
}
minimum = maximum = points[0];
// ReSharper disable once ForCanBeConvertedToForeach
for (var index = points.Count - 1; index > 0; --index)
{
var point = points[index];
minimum = Point2.Minimum(minimum, point);
maximum = Point2.Maximum(maximum, point);
}
}
