public bool StepThree(ref UniqueEdgeList edges)
{
foreach (Edge edge_outer in edges.edgeList)
{
foreach (Edge edge_inner in edges.edgeList)
{
if (!Edge.SameEdge(edge_inner, edge_outer))
{
float[] shared_vertex = Edge.HasSharedVertex(edge_inner, edge_outer);
bool is_parallel = Edge.AreParallelOrAntiParallel(edge_inner, edge_outer);
if (shared_vertex != null && is_parallel)
{
// Case 1.
float[] start_vertex = new float[] { edge_inner.x1, edge_inner.y1, edge_inner.z1 };
// Case 2.
if (edge_inner.x1 == shared_vertex[0] &&
edge_inner.y1 == shared_vertex[1] &&
edge_inner.z1 == shared_vertex[2])
{
start_vertex = new float[] { edge_inner.x2, edge_inner.y2, edge_inner.z2 };
}
// Case 3.
float[] end_vertex = new float[] { edge_outer.x1, edge_outer.y1, edge_outer.z1 };
// Case 4.
if (edge_outer.x1 == shared_vertex[0] &&
edge_outer.y1 == shared_vertex[1] &&
edge_outer.z1 == shared_vertex[2])
{
end_vertex = new float[] { edge_outer.x2, edge_outer.y2, edge_outer.z2 };
}
edges.edgeList.Remove(edge_outer);
edges.edgeList.Remove(edge_inner);
edges.Add(
new Edge(
start_vertex[0], start_vertex[1], start_vertex[2], // Edge Start
end_vertex[0], end_vertex[1], end_vertex[2] // Edge end
));
return(StepThree(ref edges));
}
}
}
}
return(true);
}
/// <summary>
/// This is a - b, not b - a
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
/// <returns></returns>
public static UniqueEdgeList SetDifference(UniqueEdgeList a, UniqueEdgeList b)
{
UniqueEdgeList result = new UniqueEdgeList();
foreach (Edge edge_a in a.edgeList)
{
bool found = false;
foreach (Edge edge_b in b.edgeList)
{
if (Edge.SameEdge(edge_a, edge_b))
{
found = true;
}
}
if (!found)
{
result.Add(edge_a);
}
}
return(result);
}
/// <summary>
/// Sorting the edges that are contiguous into boundary groups/buckets.
/// </summary>
public void StepThreePartTwo()
{
// Add first bucket.
UniqueEdgeList first_bucket = new UniqueEdgeList();
first_bucket.Add(outline_edges_refined.edgeList[0]);
grouped_edges.Add(first_bucket);
foreach (Edge edge in outline_edges_refined.edgeList)
{
bool found = false;
foreach (UniqueEdgeList group in grouped_edges)
{
foreach (Edge edge_from_bucket in group.edgeList)
{
if (Edge.HasSharedVertex(edge, edge_from_bucket) != null)
{
group.Add(edge);
found = true;
break;
}
}
if (found)
{
break;
}
}
if (!found)
{
UniqueEdgeList new_bucket = new UniqueEdgeList();
new_bucket.Add(edge);
grouped_edges.Add(new_bucket);
}
}
return;
}
// Step 2. Remove shared edges.
// Input: List of triangles.
// Output: List of edges that were not shared by other edges in the triangles.
void StepTwo()
{
// Check every triangle against all other triangles.
for (int m = 0; m < input_triangles.GetLength(0); ++m)
{
for (int n = 0; n < input_triangles.GetLength(0); ++n)
{
// Not the same triangle.
if (m != n)
{
for (int i = 0; i < 3; ++i)
{
int j = i + 1;
if (i == 2)
{
j = 0;
}
Edge tri1_edge = new Edge(
input_triangles[m, i, 0], input_triangles[m, i, 1], input_triangles[m, i, 2],
input_triangles[m, j, 0], input_triangles[m, j, 1], input_triangles[m, j, 2]);
all_edges.Add(tri1_edge);
// a --> b == (b - a)
Edge tri2_edge01 = new Edge(
input_triangles[n, 0, 0], input_triangles[n, 0, 1], input_triangles[n, 0, 2],
input_triangles[n, 1, 0], input_triangles[n, 1, 1], input_triangles[n, 1, 2]);
Edge tri2_edge12 = new Edge(
input_triangles[n, 1, 0], input_triangles[n, 1, 1], input_triangles[n, 1, 2],
input_triangles[n, 2, 0], input_triangles[n, 2, 1], input_triangles[n, 2, 2]);
Edge tri2_edge20 = new Edge(
input_triangles[n, 2, 0], input_triangles[n, 2, 1], input_triangles[n, 2, 2],
input_triangles[n, 0, 0], input_triangles[n, 0, 1], input_triangles[n, 0, 2]);
if (Edge.AreOverlappingEdges(tri1_edge, tri2_edge01))
{
shared_edges.Add(tri1_edge);
}
if (Edge.AreOverlappingEdges(tri1_edge, tri2_edge12))
{
shared_edges.Add(tri1_edge);
}
if (Edge.AreOverlappingEdges(tri1_edge, tri2_edge20))
{
shared_edges.Add(tri1_edge);
}
}
}
}
}
outline_edges = UniqueEdgeList.SetDifference(all_edges, shared_edges);
//shared_edges.Print();
//Debug.Log("OUTLINE EDGES");
//outline_edges.Print();
//all_edges.Print();
return;
}