//Track contour line with BFS.
private void bfs(int s, ContourLine line)
{
Queue <int> queue = new Queue <int>();
queue.Enqueue(s);
while (queue.Count != 0)
{
Element e = elements[queue.Dequeue()];
e.Flag = true;
if (e.Type == ContourType.T011 || e.Type == ContourType.T100)
{
line.Points.Add(e.Intersections[1]);
line.Points.Add(e.Intersections[2]);
}
if (e.Type == ContourType.T101 || e.Type == ContourType.T010)
{
line.Points.Add(e.Intersections[0]);
line.Points.Add(e.Intersections[1]);
}
if (e.Type == ContourType.T110 || e.Type == ContourType.T001)
{
line.Points.Add(e.Intersections[0]);
line.Points.Add(e.Intersections[2]);
}
for (int i = 0; i < 3; i++)
{
if (e.NeighborIndices[i] != -1 && (elements[e.NeighborIndices[i]].Flag == false))
{
queue.Enqueue(e.NeighborIndices[i]);
}
}
}
}
private void GetLines(float value)
{
//init all elements
foreach (var v in elements)
{
v.Flag = false;
int t = 0;
for (int i = 2; i >= 0; i--)
{
t <<= 1;
if (values[v.VertIndices[i]] > value)
{
t += 1;
}
}
v.Type = (ContourType)t;
//Ignore no-contour element.
if (v.Type == ContourType.T000 || v.Type == ContourType.T111)
{
v.Flag = true;
}
//Interpolate contour point.
if (v.Type == ContourType.T011 || v.Type == ContourType.T100)
{
v.Intersections[1] = Linear(points[v.VertIndices[1]], values[v.VertIndices[1]], points[v.VertIndices[2]], values[v.VertIndices[2]], value);
v.Intersections[2] = Linear(points[v.VertIndices[0]], values[v.VertIndices[0]], points[v.VertIndices[2]], values[v.VertIndices[2]], value);
}
if (v.Type == ContourType.T101 || v.Type == ContourType.T010)
{
v.Intersections[1] = Linear(points[v.VertIndices[1]], values[v.VertIndices[1]], points[v.VertIndices[2]], values[v.VertIndices[2]], value);
v.Intersections[0] = Linear(points[v.VertIndices[0]], values[v.VertIndices[0]], points[v.VertIndices[1]], values[v.VertIndices[1]], value);
}
if (v.Type == ContourType.T110 || v.Type == ContourType.T001)
{
v.Intersections[0] = Linear(points[v.VertIndices[0]], values[v.VertIndices[0]], points[v.VertIndices[1]], values[v.VertIndices[1]], value);
v.Intersections[2] = Linear(points[v.VertIndices[0]], values[v.VertIndices[0]], points[v.VertIndices[2]], values[v.VertIndices[2]], value);
}
}
//Find all contour lines.
for (int l = 0; l < elemCount; l++)
{
if (elements[l].Flag)
{
continue;
}
Element e = elements[l];
if (e.Type == ContourType.T000 || e.Type == ContourType.T111)
{
e.Flag = true;
continue;
}
ContourLine line = new ContourLine(Color.Black);
bfs(l, line);
line.GeneVertList();
if (line.Verts.Length >= 2)
{
lines.Add(line);
}
}
}
