// set a neighbor to this node
public void SetNeighbor(en_NeighborDirection direction, CQuadtree pToNode, en_NeighborDirection directionFromThere)
{
if (pToNode.m_HasChildren)
{
// the other node has children, which means this node was in coarse resolution,
// so find correct child to link to...
// need to find which two of the 4 children
// of the other node that links to the parent of this node or to this node itself
// then, decide which of the two children is closer to this node
// and update the correct (nearest) child to link to this node
CQuadtree pCorrectNode = null;
float dist = 0;
byte neighDirection = 0;
// for each child of that node...
for (byte i=0; i<4; i++)
{
CQuadtree pChild = pToNode.m_Children[i];
// for each direction of that child of that node...
for (byte j=0; j<4; j++)
{
// check if that child links from that direction to our parent
if (pChild.m_Neighbors[j].node.Equals(m_Parent))
{
if (pCorrectNode == null)
{
// as there is no best correct child yet,
// temporarily selects that child as the correct
pCorrectNode = pChild;
neighDirection = j;
dist = CMath.QuickDistance(pChild.m_Center, m_Center);
break;
}
else
{
// check if this child is closer than
// the currently selected as the closer child
if (CMath.QuickDistance(pChild.m_Center, m_Center) < dist)
{
pCorrectNode = pChild;
neighDirection = j;
// as we can have only two childs
// pointing to our own parent, and the other child has been scanned already,
// we can safely bail out of the outer loop and stop searching
i = 4;
break;
}
}
}
else if (pChild.m_Neighbors[j].node == this)
{
// that child relinked to this node first
// which means both nodes are at same level
// so just get it and bail out
pCorrectNode = pChild;
neighDirection = j;
// link back to that node
m_Neighbors[(int)direction].node = pCorrectNode;
m_Neighbors[(int)direction].directionThere = (en_NeighborDirection)neighDirection;
// update edges of this node
m_NeedsReedge = true;
// bail out
return;
}
}
}
if (pCorrectNode != null)
{
// link to that node
m_Neighbors[(int)direction].node = pCorrectNode;
m_Neighbors[(int)direction].directionThere = (en_NeighborDirection)neighDirection;
// link that node back to this node
pCorrectNode.m_Neighbors[neighDirection].node = this;
pCorrectNode.m_Neighbors[neighDirection].directionThere = direction;
// update edges and gaps
m_NeedsReedge = true;
pCorrectNode.m_NeedsReedge = true;
// the other node was discarding resolution
// because this node was at coarse level
// now that both are at same level,
// lets force the other node to use full mesh at the edge that links to this node
pCorrectNode.m_GapFixMask |= (byte)(1 << neighDirection);
pCorrectNode.m_Neighbors[neighDirection].isFixed = false;
}
}
else
{
// the other node has no children...
// so, the other node is at a coarse level
// OR at same level (a brother node);
// link directly to that node
m_Neighbors[(int)direction].node = pToNode;
m_Neighbors[(int)direction].directionThere = directionFromThere;
m_Neighbors[(int)direction].node.m_NeedsReedge = true;
// only this node needs to update edges and fix gaps
m_NeedsReedge = true;
m_GapFixMask |= (byte)(1 << (int)direction);
m_Neighbors[(int)direction].isFixed = false;
// the other node stays linked to the node it is already linked to.
}
}
// get a neighbor to this node
public TNeighbor GetNeighbor(en_NeighborDirection direction)
{
return m_Neighbors[(int)direction];
}