/// <summary>
/// build polygons from given list of segments
/// if want to represent arcs, add them as dummy lines to segs
/// polys returned are ordered anticlockwise
/// </summary>
public static IEnumerable <IReadOnlyList <Vector3D> > ClosedPolys2D(this IEnumerable <Line3D> segs, double tolLen,
int polyMaxPoints = 0)
{
var minCoord = new BBox3D(segs.SelectMany(r => new[] { r.From, r.To })).Min;
var vcmp = new Vector3DEqualityComparer(tolLen);
var lcmp = new Line3DEqualityComparer(tolLen);
var segsDict = segs.ToDictionary(k => k.ToString(tolLen), v => v);
var segsFromDict = segs.GroupBy(g => g.From, v => v, vcmp).ToDictionary(k => k.Key, v => v.ToList(), vcmp);
var segsToDict = segs.GroupBy(g => g.To, v => v, vcmp).ToDictionary(k => k.Key, v => v.ToList(), vcmp);
var segsLeft = segs.OrderBy(w => w.MidPoint.Distance(minCoord)).ToList();
var polys = new List <List <Vector3D> >();
var polyCentroidDone = new HashSet <Vector3D>(vcmp);
while (segsLeft.Count > 0)
{
Console.WriteLine($"segsLeft: {segsLeft.Count} polys:{polys.Count}");
var seg = segsLeft.First();
segsLeft.Remove(seg);
var poly = new List <Vector3D>()
{
seg.From, seg.To
};
var rotDir = 1.0; // 1=+Z, -1=-Z
while (true)
{
List <Line3D> segsNext = null;
{
var hs = new HashSet <Line3D>(lcmp);
{
List <Line3D> tmp = null;
if (segsFromDict.TryGetValue(seg.To, out tmp))
{
foreach (var x in tmp.Where(r => !r.EqualsTol(tolLen, seg)))
{
hs.Add(x);
}
}
if (segsToDict.TryGetValue(seg.To, out tmp))
{
foreach (var x in tmp.Where(r => !r.EqualsTol(tolLen, seg)))
{
hs.Add(x);
}
}
}
segsNext = hs.Select(w => w.EnsureFrom(tolLen, seg.To)).ToList();
}
Line3D segNext = null;
var force_close_poly = false;
if (polyMaxPoints > 0 && poly.Count > polyMaxPoints)
{
throw new Exception($"polygon [{poly.PolygonSegments(tolLen).ToCadScript()}] max point exceeded");
}
//#if DEBUG
// if (//poly.Count >= 2 &&
// poly.Any(r => r.EqualsTol(1e-2, 31.0626,-0.0018))
// //&&
// //poly.Any(r => r.EqualsTol(tolLen, -42.9561, 0))
// )
// ;
//#endif
if (poly.Count == 2)
{
if (segsNext.Count == 0)
{
throw new Exception($"check singular segment [{seg}] cadscript [{seg.CadScript}]");
}
segNext = segsNext
.OrderBy(w => (-seg.V).AngleRad(tolLen, w.V))
.First();
rotDir = seg.V.CrossProduct(segNext.V).Z > 0 ? 1 : -1;
}
else
{
var qSegsNext = segsNext
.Select(w => new
{
arad = (seg.V).AngleToward(tolLen, w.V, Vector3D.ZAxis * rotDir),
seg = w
})
.Where(r => r.arad <= PI).ToList();
if (qSegsNext.Count == 0)
{
force_close_poly = true;
}
else
{
// retrieve next segment with current rotation direction w/acutest angle
segNext = qSegsNext
.OrderByDescending(r => r.arad)
.First().seg;
}
}
if (force_close_poly)
{
break;
}
segsLeft.Remove(segNext);
if (segNext.To.EqualsTol(tolLen, poly[0]))
{
break;
}
poly.Add(segNext.To);
seg = segNext;
}
if (poly.Count > 2)
{
poly = poly.SortPoly(tolLen, Vector3D.ZAxis).ToList();
var polyCentroid = poly.Centroid(tolLen);
if (!polyCentroidDone.Contains(polyCentroid))
{
polys.Add(poly);
polyCentroidDone.Add(polyCentroid);
}
}
else
{
// todo warning
}
}
return(polys.OrderByDescending(w => w.Count));
}
/// <summary>
/// autointersect given list of segments
/// ( duplicates and overlapping are removed )
/// TODO : dummy function, optimize
/// </summary>
public static IReadOnlyList <Line3D> AutoIntersect(this IReadOnlyList <Line3D> segs, double tolLen,
bool mergeColinearSegments = true, IEnumerable <Vector3D> addictionalSplitPoints = null)
{
segs = segs.MergeColinearSegments(tolLen).ToList();
var segCmp = new Line3DEqualityComparer(tolLen);
var vecCmp = new Vector3DEqualityComparer(tolLen);
// line_hs -> split points
var splitPts = new Dictionary <Line3D, HashSet <Vector3D> >(segCmp);
// fill splitPts dictionary with list of segments split points
for (int i = 0; i < segs.Count; ++i)
{
for (int j = 0; j < segs.Count; ++j)
{
if (i == j)
{
continue;
}
var seg_i = segs[i];
var seg_j = segs[j];
var q = seg_i.Intersect(tolLen, seg_j, true, true);
if (q != null)
{
HashSet <Vector3D> i_hs = null;
HashSet <Vector3D> j_hs = null;
if (!q.EqualsTol(tolLen, seg_i.From) && !q.EqualsTol(tolLen, seg_i.To))
{
if (!splitPts.TryGetValue(seg_i, out i_hs))
{
i_hs = new HashSet <Vector3D>(vecCmp);
splitPts.Add(seg_i, i_hs);
}
i_hs.Add(q);
}
if (!q.EqualsTol(tolLen, seg_j.From) && !q.EqualsTol(tolLen, seg_j.To))
{
if (!splitPts.TryGetValue(seg_j, out j_hs))
{
j_hs = new HashSet <Vector3D>(vecCmp);
splitPts.Add(seg_j, j_hs);
}
j_hs.Add(q);
}
}
}
}
// process addictional split points
if (addictionalSplitPoints != null)
{
foreach (var pt in addictionalSplitPoints)
{
foreach (var seg in segs)
{
if (seg.SegmentContainsPoint(tolLen, pt, excludeExtreme: true))
{
HashSet <Vector3D> hs = null;
if (!splitPts.TryGetValue(seg, out hs))
{
hs = new HashSet <Vector3D>(vecCmp);
splitPts.Add(seg, hs);
}
hs.Add(pt);
}
}
}
}
// split segment by split points and rebuild res list
if (splitPts.Count > 0)
{
HashSet <Vector3D> qSplitPts = null;
var res = new List <Line3D>();
for (int i = 0; i < segs.Count; ++i)
{
if (splitPts.TryGetValue(segs[i], out qSplitPts))
{
res.AddRange(segs[i].Split(tolLen, qSplitPts.ToList()));
}
else
{
res.Add(segs[i]);
}
}
segs = res;
}
return(segs);
}
