/// <summary>
/// Helper to walk a polygon, starting from a pair of intersection points.
/// increment determines the direction we are walking.
/// NOTE: when walking from i1 -> i2 along c, we should be moving through the interior of the polygon.
/// </summary>
private static Polygon WalkPolygon(Polygon parent, Polygon walking, Circle c, int pair, List <IntersectionPoint> iPoints, bool increment)
{
Polygon newPoly = new Polygon();
IntersectionPoint iPoint1, iPoint2;
GetPairPoints(iPoints, pair, increment, out iPoint1, out iPoint2);
Vector3D startLocation = iPoint1.Location;
int iSeg = 0;
Segment current = SplicedArc(parent, c, iPoints, ref pair, increment, ref iSeg);
newPoly.Segments.Add(current.Clone());
while (true)
{
// NOTE: Since we don't allow tangent intersections, there will never
// be multiple spliced arcs added in succession.
// Add in the next one.
current = walking.Segments[iSeg];
newPoly.Segments.Add(current.Clone());
iSeg = GetNextSegmentIndex(walking, iSeg);
if (current.P2.Compare(startLocation))
{
break;
}
// Do we need to splice in at this point?
Vector3D segEnd = current.P2;
if (iPoints.Select(p => p.Location).Contains(segEnd)) // ZZZ - Performance
{
current = SplicedArc(parent, c, iPoints, ref pair, increment, ref iSeg);
newPoly.Segments.Add(current.Clone());
if (current.P2.Compare(startLocation))
{
break;
}
}
}
return(newPoly);
}
private static void MeshEdges(Mesh mesh, Tile tile, HashSet <Vector3D> completed, Polygon boundary)
{
for (int i = 0; i < tile.Boundary.Segments.Count; i++)
{
Segment boundarySeg = tile.Boundary.Segments[i];
Segment d1 = tile.Drawn.Segments[i];
if (completed.Contains(boundarySeg.Midpoint))
{
continue;
}
// Find the incident segment.
Segment seg2 = null, d2 = null;
foreach (Tile incident in tile.EdgeIncidences)
{
for (int j = 0; j < incident.Boundary.Segments.Count; j++)
{
if (boundarySeg.Midpoint == incident.Boundary.Segments[j].Midpoint)
{
seg2 = incident.Boundary.Segments[j];
d2 = incident.Drawn.Segments[j];
break;
}
}
if (seg2 != null)
{
break;
}
}
// Found our incident edge?
bool foundIncident = seg2 != null;
if (!foundIncident)
{
seg2 = d2 = boundarySeg;
}
// Do the endpoints mismatch?
if (boundarySeg.P1 != seg2.P1)
{
Segment clone = d2.Clone();
clone.Reverse();
d2 = clone;
}
// Add the two vertices (careful of orientation).
if (foundIncident)
{
CheckAndAdd(mesh, new Mesh.Triangle(boundarySeg.P1, d1.P1, d2.P1), boundary);
CheckAndAdd(mesh, new Mesh.Triangle(boundarySeg.P2, d2.P2, d1.P2), boundary);
}
int num = 1 + (int)(d1.Length * m_divisions);
Vector3D[] list1 = d1.Subdivide(num);
Vector3D[] list2 = d2.Subdivide(num);
for (int j = 0; j < num; j++)
{
CheckAndAdd(mesh, new Mesh.Triangle(list1[j], list1[j + 1], list2[j + 1]), boundary);
CheckAndAdd(mesh, new Mesh.Triangle(list2[j], list1[j], list2[j + 1]), boundary);
}
completed.Add(boundarySeg.Midpoint);
}
}
