/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="items"></param>
/// <param name="getPosition"></param>
/// <param name="grid"></param>
/// <param name="indexMap"></param>
/// <param name="tolerance"></param>
/// <returns></returns>
public static List <T> RemoveCoincident <T>(IReadOnlyList <T> items, Func <T, Vec3d> getPosition, HashGrid3d <int> grid, out int[] indexMap, double tolerance = SlurMath.ZeroTolerance)
{
var result = new List <T>();
var map = new int[items.Count];
grid.Scale = tolerance * RadiusToHashScale;
// add points to result if no duplicates are found
for (int i = 0; i < items.Count; i++)
{
var p0 = getPosition(items[i]);
// search for concident in result
foreach (int j in grid.Search(new Interval3d(p0, tolerance)))
{
if (p0.ApproxEquals(getPosition(result[j]), tolerance))
{
map[i] = j;
goto EndFor;
}
}
// no coincident item found, add i to result
grid.Insert(p0, result.Count);
map[i] = result.Count;
result.Add(items[i]);
EndFor :;
}
indexMap = map;
return(result);
}
/// <summary>
/// For each item in A, returns the index of the first coincident item in B. If no coincident point is found, -1 is returned.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <typeparam name="U"></typeparam>
/// <param name="itemsA"></param>
/// <param name="getPositionA"></param>
/// <param name="itemsB"></param>
/// <param name="getPositionB"></param>
/// <param name="grid"></param>
/// <param name="tolerance"></param>
/// <returns></returns>
public static IEnumerable <int> GetFirstCoincident <T, U>(IReadOnlyList <T> itemsA, Func <T, Vec3d> getPositionA, IReadOnlyList <U> itemsB, Func <U, Vec3d> getPositionB, HashGrid3d <int> grid, double tolerance = SlurMath.ZeroTolerance)
{
grid.Scale = tolerance * RadiusToHashScale;
// insert B
for (int i = 0; i < itemsB.Count; i++)
{
grid.Insert(getPositionB(itemsB[i]), i);
}
// search from A
for (int i = 0; i < itemsA.Count; i++)
{
var p0 = getPositionA(itemsA[i]);
foreach (var j in grid.Search(new Interval3d(p0, tolerance)))
{
if (p0.ApproxEquals(getPositionB(itemsB[j]), tolerance))
{
yield return(j);
goto EndFor;
}
}
yield return(-1);
EndFor :;
}
}
/// <summary>
/// For each item, returns the index of the first coincident item within the same list. If no coincident point is found, -1 is returned.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="items"></param>
/// <param name="grid"></param>
/// <param name="getPosition"></param>
/// <param name="tolerance"></param>
/// <returns></returns>
public static IEnumerable <int> GetFirstCoincident <T>(IReadOnlyList <T> items, Func <T, Vec3d> getPosition, HashGrid3d <int> grid, double tolerance = 1.0e-8)
{
grid.BinScale = tolerance * RadiusToBinScale;
// insert
for (int i = 0; i < items.Count; i++)
{
grid.Insert(getPosition(items[i]), i);
}
// search
for (int i = 0; i < items.Count; i++)
{
var p0 = getPosition(items[i]);
foreach (var j in grid.Search(new Interval3d(p0, tolerance)))
{
if (i != j && p0.ApproxEquals(getPosition(items[j]), tolerance))
{
yield return(j);
goto EndFor;
}
}
yield return(-1);
EndFor :;
}
}
/// <summary>
/// For each item in A, returns the index of each coincident items in B.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <typeparam name="U"></typeparam>
/// <param name="itemsA"></param>
/// <param name="getPositionA"></param>
/// <param name="itemsB"></param>
/// <param name="getPositionB"></param>
/// <param name="grid"></param>
/// <param name="tolerance"></param>
/// <returns></returns>
public static IEnumerable <IEnumerable <int> > GetAllCoincident <T, U>(IReadOnlyList <T> itemsA, Func <T, Vec3d> getPositionA, IReadOnlyList <U> itemsB, Func <U, Vec3d> getPositionB, HashGrid3d <int> grid, double tolerance = SlurMath.ZeroTolerance)
{
grid.Scale = tolerance * RadiusToHashScale;
// insert B
for (int i = 0; i < itemsB.Count; i++)
{
grid.Insert(getPositionB(itemsB[i]), i);
}
// search from A
for (int i = 0; i < itemsA.Count; i++)
{
var p0 = getPositionA(itemsA[i]);
yield return(grid.Search(new Interval3d(p0, tolerance))
.Where(j => p0.ApproxEquals(getPositionB(itemsB[j]), tolerance)));
}
}
/// <summary>
/// Consolidates points within a given search radius.
/// Returns true if the solution converged within the given maximum number of steps.
/// </summary>
/// <param name="points"></param>
/// <param name="radius"></param>
/// <param name="tolerance"></param>
/// <param name="maxSteps"></param>
/// <returns></returns>
public static bool ConsolidatePoints(IList <Vec3d> points, double radius, double tolerance = SlurMath.ZeroTolerance, int maxSteps = 4)
{
var grid = new HashGrid3d <Vec3d>(radius * RadiusToHashScale, points.Count);
var radSqr = radius * radius;
var tolSqr = tolerance * tolerance;
var converged = false;
while (!converged && maxSteps-- > 0)
{
converged = true;
// insert into grid
for (int i = 0; i < points.Count; i++)
{
var p = points[i];
grid.Insert(p, p);
}
// search grid
for (int i = 0; i < points.Count; i++)
{
var p0 = points[i];
var p1 = grid.Search(new Interval3d(p0, radius))
.Where(p => p0.SquareDistanceTo(p) < radSqr)
.Mean();
points[i] = p1;
if (p0.SquareDistanceTo(p1) > tolSqr)
{
converged = false;
}
}
grid.Clear();
}
return(maxSteps > 0);
}