// ---------------------------------------------------------------------
// Reset the patch.
//
public void reset()
{
// Assume patch is not visible.
m_isVisible = 0;
// Reset the important relationships
m_BaseLeft.setLeftChild(null);
m_BaseLeft.setRightChild(null);
m_BaseRight.setLeftChild(null);
m_BaseLeft.setLeftChild(null);
// Attach the two m_Base triangles together
m_BaseLeft.setBaseNeighbor(m_BaseRight);
m_BaseRight.setBaseNeighbor(m_BaseLeft);
// Clear the other relationships.
m_BaseLeft.setRightNeighbor(null);
m_BaseLeft.setLeftNeighbor(null);
m_BaseRight.setRightNeighbor(null);
m_BaseRight.setLeftNeighbor(null);
}
// ---------------------------------------------------------------------
// Split a single Triangle and link it into the mesh.
// Will correctly force-split diamonds.
//
public void split(TriTreeNode tri)
{
if (tri != null)
{
// We are already split, no need to do it again.
if (tri.getLeftChild() != null)
{
return;
}
// If this triangle is not in a proper diamond, force split our base neighbor
if (tri.getBaseNeighbor() != null && tri.getBaseNeighbor().getBaseNeighbor() != tri)
{
split(tri.getBaseNeighbor());
}
// Create children and link into mesh
tri.setLeftChild(landscape.allocateTri());
tri.setRightChild(landscape.allocateTri());
// If creation failed, just exit.
if (tri.getLeftChild() == null)
{
return;
}
if (tri.getRightChild() == null)
{
return;
}
// Fill in the information we can get from the parent (neighbor pointers)
tri.getLeftChild().setBaseNeighbor(tri.getLeftNeighbor());
tri.getLeftChild().setLeftNeighbor(tri.getRightChild());
tri.getRightChild().setBaseNeighbor(tri.getRightNeighbor());
tri.getRightChild().setRightNeighbor(tri.getLeftChild());
// Link our Left Neighbor to the new children
if (tri.getLeftNeighbor() != null)
{
if (tri.getLeftNeighbor().getBaseNeighbor() == tri)
{
tri.getLeftNeighbor().setBaseNeighbor(tri.getLeftChild());
}
else if (tri.getLeftNeighbor().getLeftNeighbor() == tri)
{
tri.getLeftNeighbor().setLeftNeighbor(tri.getLeftChild());
}
else if (tri.getLeftNeighbor().getRightNeighbor() == tri)
{
tri.getLeftNeighbor().setRightNeighbor(tri.getLeftChild());
}
else
{
;// Illegal Left Neighbor!
}
}
// Link our Right Neighbor to the new children
if (tri.getRightNeighbor() != null)
{
if (tri.getRightNeighbor().getBaseNeighbor() == tri)
{
tri.getRightNeighbor().setBaseNeighbor(tri.getRightChild());
}
else if (tri.getRightNeighbor().getRightNeighbor() == tri)
{
tri.getRightNeighbor().setRightNeighbor(tri.getRightChild());
}
else if (tri.getRightNeighbor().getLeftNeighbor() == tri)
{
tri.getRightNeighbor().setLeftNeighbor(tri.getRightChild());
}
else
{
;// Illegal Right Neighbor!
}
}
// Link our Base Neighbor to the new children
if (tri.getBaseNeighbor() != null)
{
if (tri.getBaseNeighbor().getLeftChild() != null)
{
tri.getBaseNeighbor().getLeftChild().setRightNeighbor(tri.getRightChild());
tri.getBaseNeighbor().getRightChild().setLeftNeighbor(tri.getLeftChild());
tri.getLeftChild().setRightNeighbor(tri.getBaseNeighbor().getRightChild());
tri.getRightChild().setLeftNeighbor(tri.getBaseNeighbor().getLeftChild());
}
else
{
split(tri.getBaseNeighbor()); // Base Neighbor (in a diamond with us) was not split yet, so do that now.
}
}
else
{
// An edge triangle, trivial case.
tri.getLeftChild().setRightNeighbor(null);
tri.getRightChild().setLeftNeighbor(null);
}
}
}
