internal virtual bool FixRingSelfTangency_()
{
com.epl.geometry.AttributeStreamOfInt32 self_tangent_paths = new com.epl.geometry.AttributeStreamOfInt32(0);
com.epl.geometry.AttributeStreamOfInt32 self_tangency_clusters = new com.epl.geometry.AttributeStreamOfInt32(0);
int tangent_path_first_vertex_index = -1;
int tangent_vertex_cluster_index = -1;
com.epl.geometry.Point2D pt_prev = new com.epl.geometry.Point2D();
pt_prev.SetNaN();
int prev_vertex = -1;
int old_path = -1;
int current_cluster = -1;
com.epl.geometry.Point2D pt = new com.epl.geometry.Point2D();
for (int ivertex = m_sorted_vertices.GetFirst(m_sorted_vertices.GetFirstList()); ivertex != -1; ivertex = m_sorted_vertices.GetNext(ivertex))
{
int vertex = m_sorted_vertices.GetData(ivertex);
m_shape.GetXY(vertex, pt);
int path = m_shape.GetPathFromVertex(vertex);
if (pt_prev.IsEqual(pt) && old_path == path)
{
if (tangent_vertex_cluster_index == -1)
{
tangent_path_first_vertex_index = m_shape.CreatePathUserIndex();
tangent_vertex_cluster_index = m_shape.CreateUserIndex();
}
if (current_cluster == -1)
{
current_cluster = self_tangency_clusters.Size();
m_shape.SetUserIndex(prev_vertex, tangent_vertex_cluster_index, current_cluster);
self_tangency_clusters.Add(1);
int p = m_shape.GetPathUserIndex(path, tangent_path_first_vertex_index);
if (p == -1)
{
m_shape.SetPathUserIndex(path, tangent_path_first_vertex_index, prev_vertex);
self_tangent_paths.Add(path);
}
}
m_shape.SetUserIndex(vertex, tangent_vertex_cluster_index, current_cluster);
self_tangency_clusters.SetLast(self_tangency_clusters.GetLast() + 1);
}
else
{
current_cluster = -1;
pt_prev.SetCoords(pt);
}
prev_vertex = vertex;
old_path = path;
}
if (self_tangent_paths.Size() == 0)
{
return(false);
}
// Now self_tangent_paths contains list of clusters of tangency for each
// path.
// The clusters contains list of clusters and for each cluster it
// contains a list of vertices.
com.epl.geometry.AttributeStreamOfInt32 vertex_stack = new com.epl.geometry.AttributeStreamOfInt32(0);
com.epl.geometry.AttributeStreamOfInt32 cluster_stack = new com.epl.geometry.AttributeStreamOfInt32(0);
for (int ipath = 0, npath = self_tangent_paths.Size(); ipath < npath; ipath++)
{
int path = self_tangent_paths.Get(ipath);
int first_vertex = m_shape.GetPathUserIndex(path, tangent_path_first_vertex_index);
int cluster = m_shape.GetUserIndex(first_vertex, tangent_vertex_cluster_index);
vertex_stack.Clear(false);
cluster_stack.Clear(false);
vertex_stack.Add(first_vertex);
cluster_stack.Add(cluster);
for (int vertex = m_shape.GetNextVertex(first_vertex); vertex != first_vertex; vertex = m_shape.GetNextVertex(vertex))
{
int vertex_to = vertex;
int cluster_to = m_shape.GetUserIndex(vertex_to, tangent_vertex_cluster_index);
if (cluster_to != -1)
{
if (cluster_stack.Size() == 0)
{
cluster_stack.Add(cluster_to);
vertex_stack.Add(vertex_to);
continue;
}
if (cluster_stack.GetLast() == cluster_to)
{
int vertex_from = vertex_stack.GetLast();
// peel the loop from path
int from_next = m_shape.GetNextVertex(vertex_from);
int from_prev = m_shape.GetPrevVertex(vertex_from);
int to_next = m_shape.GetNextVertex(vertex_to);
int to_prev = m_shape.GetPrevVertex(vertex_to);
m_shape.SetNextVertex_(vertex_from, to_next);
m_shape.SetPrevVertex_(to_next, vertex_from);
m_shape.SetNextVertex_(vertex_to, from_next);
m_shape.SetPrevVertex_(from_next, vertex_to);
// vertex_from is left in the path we are processing,
// while the vertex_to is in the loop being teared off.
bool[] first_vertex_correction_requied = new bool[] { false };
int new_path = m_shape.InsertClosedPath_(m_geometry, -1, from_next, m_shape.GetFirstVertex(path), first_vertex_correction_requied);
m_shape.SetUserIndex(vertex, tangent_vertex_cluster_index, -1);
// Fix the path after peeling if the peeled loop had the
// first path vertex in it
if (first_vertex_correction_requied[0])
{
m_shape.SetFirstVertex_(path, to_next);
}
int path_size = m_shape.GetPathSize(path);
int new_path_size = m_shape.GetPathSize(new_path);
path_size -= new_path_size;
System.Diagnostics.Debug.Assert((path_size >= 3));
m_shape.SetPathSize_(path, path_size);
self_tangency_clusters.Set(cluster_to, self_tangency_clusters.Get(cluster_to) - 1);
if (self_tangency_clusters.Get(cluster_to) == 1)
{
self_tangency_clusters.Set(cluster_to, 0);
cluster_stack.RemoveLast();
vertex_stack.RemoveLast();
}
// this cluster has more than two vertices in it.
first_vertex = vertex_from;
// reset the counter to
// ensure we find all loops.
vertex = vertex_from;
}
else
{
vertex_stack.Add(vertex);
cluster_stack.Add(cluster_to);
}
}
}
}
m_shape.RemovePathUserIndex(tangent_path_first_vertex_index);
m_shape.RemoveUserIndex(tangent_vertex_cluster_index);
return(true);
}