/// <summary>
/// True if <paramref name="pos"/> inside the convex hull formed by the triangulation.
/// </summary>
/// <param name="pos">The position to test</param>
public bool InsideConvexHull(Vec3 pos)
{
QuadEdge <T> boundEdge = RightMostEdge;
foreach (QuadEdge <T> hullEdge in boundEdge.RightEdges(CCW:false))
{
if (Geometry.RightOf(pos, hullEdge))
{
// Must be outside because hullEdge right face is outside
return(false);
}
}
return(true);
}
/// <summary>
/// Construct triangles based on Delaunay triangulation.
/// </summary>
protected override IEnumerable <Vec3> ExportTriangles()
{
// FIFO
var queue = new Queue <QuadEdge <TEdge> >();
// Start at the far right
QuadEdge <TEdge> first = _mesh.RightMostEdge;
queue.Enqueue(first);
// Visit all edge of the convex hull in CW order and
// add opposite edges to queue
foreach (QuadEdge <TEdge> hullEdge in first.RightEdges(CCW:false))
{
// Enqueue same edge but with opposite direction
queue.Enqueue(hullEdge.Sym);
hullEdge.Tag = !_mesh.VisitedTagState;
// Because mesh does not have any boundary this is also a triangle
yield return(hullEdge.Origin);
}
// Convex hull now closed. Start triangles construction
while (queue.Count > 0)
{
QuadEdge <TEdge> edge = queue.Dequeue();
if (edge.Tag == _mesh.VisitedTagState)
{
foreach (QuadEdge <TEdge> current in edge.RightEdges(CCW:false))
{
if (current.Sym.Tag == _mesh.VisitedTagState)
{
queue.Enqueue(current.Sym);
}
current.Tag = !_mesh.VisitedTagState;
yield return(current.Origin);
}
}
}
// Inverse flag to be able to traverse again at next call
_mesh.SwitchInternalFlag();
}