private Rect CreateCandidateRect(Point2D <int> start, int deltaX, int deltaY, Size requiredSize)
{
Double42 x = deltaX > 0 ? _verticalPartitions[start.X] : (Double42)(_verticalPartitions[start.X + 1] - requiredSize.Width);
Double42 y = deltaY > 0 ? _horizontalPartitions[start.Y] : (Double42)(_horizontalPartitions[start.Y + 1] - requiredSize.Height);
return(new Rect(new Point(x, y), requiredSize));
}
// Returns true if the candidate is available, and expansion
// will be set to a non-null value if the candidate causes
// the subspace bounds to expand. Returns false if the candidate
// overlaps other rectangles.
public bool EvaluateCandidate(Rect candidateRect, out Double42 expansion)
{
expansion = 0.0;
Int32Rect subspaceBounds = GetSubspaceRect(candidateRect);
for (int iY = 0; iY < subspaceBounds.Height; iY++)
{
int y = iY + subspaceBounds.Y;
for (int iX = 0; iX < subspaceBounds.Width; iX++)
{
int x = iX + subspaceBounds.X;
if (_subspaces[x, y])
{
// There is already a rect in this subspace location.
// We can fail immediately.
return(false);
}
}
}
Rect oldBounds = Bounds;
if (!oldBounds.Contains(candidateRect))
{
Rect newBounds = oldBounds;
newBounds.Union(candidateRect);
expansion = (newBounds.Width * newBounds.Height) - (oldBounds.Width * oldBounds.Height);
}
return(true);
}
private void InsertVerticalPartition(Double42 partition)
{
if (_verticalPartitions.Add(partition))
{
int index;
_verticalPartitions.TryFind(partition, out index);
_subspaces.InsertColumn(index - 1);
}
}
private void InsertHorizontalPartition(Double42 partition)
{
if (_horizontalPartitions.Add(partition))
{
int index;
_horizontalPartitions.TryFind(partition, out index);
_subspaces.InsertRow(index - 1);
}
}
// Find the last subspace index that spans space that contains the value.
// A key assumption is that this is only used for mapping candidate rects
// onto the subspace grid, and candidate rects always intersect the
// subspace grid. Thus, if the value is greater than the partitions, we
// assume that we should still end with the last index.
private static int FindLastSubspaceIndex(NumberSet <Double42> partitions, Double42 value, int iSubspaceStart)
{
int last = partitions.Count - 1;
for (int iPartition = iSubspaceStart + 1; iPartition < partitions.Count; iPartition++)
{
if (partitions[iPartition] >= value)
{
last = iPartition - 1;
break;
}
}
return(last);
}
// Find the first subspace index that spans space that contains the value.
// A key assumption is that this is only used for mapping candidate rects
// onto the subspace grid, and candidate rects always intersect the
// subspace grid. Thus, if the value is less than the partitions, we
// assume that we should still start with index 0.
private static int FindFirstSubspaceIndex(NumberSet <Double42> partitions, Double42 value)
{
int first = 0;
for (int iPartition = 1; iPartition < partitions.Count; iPartition++)
{
if (partitions[iPartition] > value)
{
first = iPartition - 1;
break;
}
}
return(first);
}
