/// <summary>
/// Returns whether or not the given map area intersects the current one. If you intend to
/// determine/use the exact intersection based on this return value, it is best to instead
/// call the <see cref="Area.GetIntersection(IReadOnlyArea, IReadOnlyArea)"/>, and
/// check the number of positions in the result (0 if no intersection).
/// </summary>
/// <param name="area">The area to check.</param>
/// <returns>True if the given map area intersects the current one, false otherwise.</returns>
public bool Intersects(IReadOnlyArea area)
{
if (!area.Bounds.Intersects(Bounds))
{
return(false);
}
if (Count <= area.Count)
{
foreach (Point pos in Positions)
{
if (area.Contains(pos))
{
return(true);
}
}
return(false);
}
foreach (Point pos in area.Positions)
{
if (Contains(pos))
{
return(true);
}
}
return(false);
}
/// <summary>
/// Gets an area containing all positions in <paramref name="area1"/>, minus those that are in
/// <paramref name="area2"/>.
/// </summary>
/// <param name="area1"/>
/// <param name="area2"/>
/// <returns>A area with exactly those positions in <paramref name="area1"/> that are NOT in
/// <paramref name="area2"/>.</returns>
public static Area GetDifference(IReadOnlyArea area1, IReadOnlyArea area2)
{
Area retVal = new Area();
foreach (Point pos in area1.Positions)
{
if (area2.Contains(pos))
{
continue;
}
retVal.Add(pos);
}
return(retVal);
}
/// <summary>
/// Gets an area containing exactly those positions contained in both of the given areas.
/// </summary>
/// <param name="area1"/>
/// <param name="area2"/>
/// <returns>An area containing exactly those positions contained in both of the given areas.</returns>
public static Area GetIntersection(IReadOnlyArea area1, IReadOnlyArea area2)
{
Area retVal = new Area();
if (!area1.Bounds.Intersects(area2.Bounds))
{
return(retVal);
}
if (area1.Count > area2.Count)
{
Swap(ref area1, ref area2);
}
foreach (Point pos in area1.Positions)
{
if (area2.Contains(pos))
{
retVal.Add(pos);
}
}
return(retVal);
}