private bool IsVerticesLinear()
{
List <Vector3D> list = new List <Vector3D>();
double maxDist = 0;
int maxIndexFrom = -1;
int maxIndexTo = -1;
var hes = Circulate();
for (int i = 0; i < hes.Count; i++)
{
var pos = hes[i].vert.positionD;
if (list.Count > 2)
{
for (int j = 0; j < list.Count; j++)
{
double dist = Vector3D.Distance(pos, list[j]);
if (dist > maxDist)
{
maxDist = dist;
maxIndexFrom = i;
maxIndexTo = j;
}
}
}
list.Add(pos);
}
if (maxIndexFrom == maxIndexTo)
{
// all same position
return(true);
}
RayD r = new RayD(list[maxIndexFrom], list[maxIndexFrom] - list[maxIndexTo]);
foreach (var p in list)
{
if (r.LinePointDistance(p) > hmesh.zeroMagnitudeTreshold)
{
// not linear
return(false);
}
}
return(true);
}
public CollapsePreconditionReason CollapsePrecondition(Vector3D newPosition, CollapsePreconditionReason bits = CollapsePreconditionReason.All)
{
if ((bits & CollapsePreconditionReason.EdgeIsBoundary) == CollapsePreconditionReason.EdgeIsBoundary)
{
if (IsBoundary())
{
return(CollapsePreconditionReason.EdgeIsBoundary);
}
}
if ((bits & CollapsePreconditionReason.VertexIsBoundary) == CollapsePreconditionReason.VertexIsBoundary)
{
if (vert.IsBoundary())
{
return(CollapsePreconditionReason.VertexIsBoundary);
}
if (prev.vert.IsBoundary())
{
return(CollapsePreconditionReason.VertexIsBoundary);
}
}
var prevVert = prev.vert;
Vector3D prevVertPos = prevVert.positionD;
bool checkForNormalFlipped =
(bits & CollapsePreconditionReason.NormalFlipped) == CollapsePreconditionReason.NormalFlipped;
bool checkCollapsePointTooCloseToLine =
(bits & CollapsePreconditionReason.CollapsePointTooCloseToLine) == CollapsePreconditionReason.CollapsePointTooCloseToLine;
// test for flipped normal
var hes = prevVert.Circulate();
foreach (var he in hes)
{
if (he == this || he.prev.opp == this)
{
continue;
}
Vector3D dirA = he.vert.positionD - prevVertPos;
Vector3D dirB = he.prev.prev.vert.positionD - prevVertPos;
Vector3D dirC = Vector3D.Cross(dirA, dirB);
Vector3D dirMovedA = he.vert.positionD - newPosition;
Vector3D dirMovedB = he.prev.prev.vert.positionD - newPosition;
Vector3D dirMovedC = Vector3D.Cross(dirMovedA, dirMovedB);
if (checkForNormalFlipped)
{
bool isNormalFlipped = Vector3D.Dot(dirC, dirMovedC) < 0;
if (isNormalFlipped)
{
return(CollapsePreconditionReason.NormalFlipped);
}
}
if (checkCollapsePointTooCloseToLine)
{
// test for tree points line up
RayD ray = new RayD(he.vert.positionD, (he.vert.positionD - he.prev.prev.vert.positionD));
double distToLine = ray.LinePointDistance(newPosition);
if (distToLine < hmesh.zeroMagnitudeTreshold)
{
return(CollapsePreconditionReason.CollapsePointTooCloseToLine);
}
}
}
return(CollapsePreconditionReason.Ok);
}
private static double VertexDistOnDissolve(Vertex toDissolve, Vertex neighbour1, Vertex neighbour2)
{
RayD r = new RayD(neighbour1.positionD, neighbour2.positionD - neighbour1.positionD);
return(r.LinePointDistance(toDissolve.positionD));
}