public double OpeningAngleDeg(int iVertex)
{
Vector2d e0 = Vector2d.Zero, e1 = Vector2d.Zero;
NeighboursV(iVertex, ref e0, ref e1, true);
return(Vector2d.AngleD(e0, e1));
}
/// <summary>
/// Compute opening angle at vertex vID.
/// If not a vertex, or valence != 2, returns invalidValue argument.
/// If either edge is degenerate, returns invalidValue argument.
/// </summary>
public double OpeningAngle(int vID, double invalidValue = double.MaxValue)
{
if (vertices_refcount.isValid(vID) == false)
{
return(invalidValue);
}
List <int> vedges = vertex_edges[vID];
if (vedges.Count != 2)
{
return(invalidValue);
}
int nbra = edge_other_v(vedges[0], vID);
int nbrb = edge_other_v(vedges[1], vID);
Vector2d v = new Vector2d(vertices[2 * vID], vertices[2 * vID + 1]);
Vector2d a = new Vector2d(vertices[2 * nbra], vertices[2 * nbra + 1]);
Vector2d b = new Vector2d(vertices[2 * nbrb], vertices[2 * nbrb + 1]);
a -= v;
if (a.Normalize() == 0)
{
return(invalidValue);
}
b -= v;
if (b.Normalize() == 0)
{
return(invalidValue);
}
return(Vector2d.AngleD(a, b));
}
/// <summary>
/// Find and remove any junction (ie valence>2) vertices of the graph.
/// At a junction, the pair of best-aligned (ie straightest) edges are left
/// connected, and all the other edges are disconnected
///
/// [TODO] currently there is no DGraph2.SetEdge(), so the 'other' edges
/// are deleted and new edges inserted. Hence, edge IDs are not preserved.
/// </summary>
public static int DisconnectJunctions(DGraph2 graph)
{
var junctions = new List <int>();
// find all junctions
foreach (int vid in graph.VertexIndices())
{
if (graph.IsJunctionVertex(vid))
{
junctions.Add(vid);
}
}
foreach (int vid in junctions)
{
Vector2d v = graph.GetVertex(vid);
int[] nbr_verts = graph.VtxVerticesItr(vid).ToArray();
// find best-aligned pair of edges connected to vid
Index2i best_aligned = Index2i.Max; double max_angle = 0;
for (int i = 0; i < nbr_verts.Length; ++i)
{
for (int j = i + 1; j < nbr_verts.Length; ++j)
{
double angle = Vector2d.AngleD(
(graph.GetVertex(nbr_verts[i]) - v).Normalized,
(graph.GetVertex(nbr_verts[j]) - v).Normalized);
angle = Math.Abs(angle);
if (angle > max_angle)
{
max_angle = angle;
best_aligned = new Index2i(nbr_verts[i], nbr_verts[j]);
}
}
}
// for nbr verts that are not part of the best_aligned edges,
// we remove those edges and add a new one connected to a new vertex
for (int k = 0; k < nbr_verts.Length; ++k)
{
if (nbr_verts[k] == best_aligned.a || nbr_verts[k] == best_aligned.b)
{
continue;
}
int eid = graph.FindEdge(vid, nbr_verts[k]);
graph.RemoveEdge(eid, true);
if (graph.IsVertex(nbr_verts[k]))
{
var newpos = Vector2d.Lerp(graph.GetVertex(nbr_verts[k]), v, 0.99);
int newv = graph.AppendVertex(newpos);
graph.AppendEdge(nbr_verts[k], newv);
}
}
}
return(junctions.Count);
}
public static double PlaneAngleSignedD(Vector2d vFrom, Vector2d vTo)
{
vFrom.Normalize();
vTo.Normalize();
double fSign = Math.Sign(vFrom.Cross(vTo));
double fAngle = fSign * Vector2d.AngleD(vFrom, vTo);
return(fAngle);
}
public void Chamfer(double chamfer_dist, double minConvexAngleDeg = 30, double minConcaveAngleDeg = 30)
{
if (IsClockwise)
{
throw new Exception("must be ccw?");
}
List <Vector2d> NewV = new List <Vector2d>();
int N = Vertices.Count;
int iCur = 0;
do
{
Vector2d center = Vertices[iCur];
int iPrev = (iCur == 0) ? N - 1 : iCur - 1;
Vector2d prev = Vertices[iPrev];
int iNext = (iCur + 1) % N;
Vector2d next = Vertices[iNext];
Vector2d cp = prev - center;
double cpdist = cp.Normalize();
Vector2d cn = next - center;
double cndist = cn.Normalize();
// if degenerate, skip this vert
if (cpdist < MathUtil.ZeroTolerancef || cndist < MathUtil.ZeroTolerancef)
{
iCur = iNext;
continue;
}
double angle = Vector2d.AngleD(cp, cn);
// TODO document what this means sign-wise
double sign = cp.Perp.Dot(cn);
bool bConcave = (sign > 0);
double thresh = (bConcave) ? minConcaveAngleDeg : minConvexAngleDeg;
// ok not too sharp
if (angle > thresh)
{
NewV.Add(center);
iCur = iNext;
continue;
}
double prev_cut_dist = Math.Min(chamfer_dist, cpdist * 0.5);
Vector2d prev_cut = center + prev_cut_dist * cp;
double next_cut_dist = Math.Min(chamfer_dist, cndist * 0.5);
Vector2d next_cut = center + next_cut_dist * cn;
NewV.Add(prev_cut);
NewV.Add(next_cut);
iCur = iNext;
} while (iCur != 0);
vertices = NewV;
Timestamp++;
}