/// <summary>
/// Returns the position of the nearest vertex.
/// </summary>
/// <returns>
/// Grid position of the nearest vertex.
/// </returns>
///
/// <param name="grid">
/// The rectangular grid instance.
/// </param>
/// <param name="point">
/// Point in world space.
/// </param>
/// <param name="system">
/// Coordinate system to use.
/// </param>
///
/// <remarks>
/// Returns the position of the nearest vertex from a given point in
/// either grid- or world space.
/// </remarks>
public static Vector3 NearestVertex(this RectGrid grid, Vector3 point, CSystem system)
{
var gridPoint = grid.WorldToGrid(point);
var roundedPoint = RoundVector3(gridPoint);
return(system == CSystem.Grid ? roundedPoint : grid.GridToWorld(roundedPoint));
}
/// <summary>
/// Returns the grid position of the nearest box.
/// </summary>
/// <returns>
/// Grid position of the nearest box.
/// </returns>
/// <param name="grid">
/// The rectangular grid instance.
/// </param>
/// <param name="point">
/// Point in world space.
/// </param>
/// <param name="system">
/// Coordinate system to use.
/// </param>
/// <remarks>
/// <para>
/// returns the coordinates of a cell in the grid. Since cell lies
/// between vertices all three values will always have +0.5
/// compared to vertex coordinates.
/// </para>
/// </remarks>
/// <example>
/// <code>
/// GFRectGrid myGrid;
/// Vector3 worldPoint;
/// // something like (2.5, -1.5, 3.5)
/// Vector3 box = myGrid.NearestBoxG(worldPoint);
/// </code>
/// </example>
public static Vector3 NearestCell(this RectGrid grid, Vector3 point, CSystem system)
{
var shift = .5f * Vector3.one;
var gridPoint = grid.WorldToGrid(point);
var shifted = gridPoint - shift;
var rounded = RoundVector3(shifted);
var gridCell = rounded + shift;
return(system == CSystem.Grid ? gridCell : grid.GridToWorld(gridCell));
}