/// <summary>
/// Grow the octree to fit in all objects.
/// </summary>
/// <param name="direction">Direction to grow.</param>
void Grow(XYZ direction)
{
int xDirection = direction.X >= 0 ? 1 : -1;
int yDirection = direction.Y >= 0 ? 1 : -1;
int zDirection = direction.Z >= 0 ? 1 : -1;
BoundsOctreeNode <T> oldRoot = rootNode;
float half = rootNode.BaseLength / 2;
float newLength = rootNode.BaseLength * 2;
var newCenter = rootNode.Center + new XYZ(xDirection * half, yDirection * half, zDirection * half);
// Create a new, bigger octree root node
rootNode = new BoundsOctreeNode <T>(newLength, minSize, looseness, newCenter);
// Create 7 new octree children to go with the old root as children of the new root
int rootPos = GetRootPosIndex(xDirection, yDirection, zDirection);
BoundsOctreeNode <T>[] children = new BoundsOctreeNode <T> [8];
for (int i = 0; i < 8; i++)
{
if (i == rootPos)
{
children[i] = oldRoot;
}
else
{
xDirection = i % 2 == 0 ? -1 : 1;
yDirection = i > 3 ? -1 : 1;
zDirection = (i < 2 || (i > 3 && i < 6)) ? -1 : 1;
children[i] = new BoundsOctreeNode <T>(rootNode.BaseLength, minSize, looseness, newCenter + new XYZ(xDirection * half, yDirection * half, zDirection * half));
}
}
// Attach the new children to the new root node
rootNode.SetChildren(children);
}
