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C3D-0324 · 260714 Huckaby R2: draw the power squiggle as real geometry done

No SHX, no linetype. For each SS-V-POWER-CL line, traces a polyline alternating a 6 ft straight run with an 8 ft zigzag group (4 teeth, +-2 ft amplitude) built in the lines own along/across frame so it follows any bearing. Squiggles go on a new layer SS-V-POWER-SQUIGGLE in the same colour so they can be frozen or deleted independently; the centreline layer goes back to Continuous. Idempotent - erases squiggles from a previous run first. Verifies each polyline on read-back.

C# payload

// Draw the power-line squiggle as REAL GEOMETRY - no SHX, no linetype, nothing to break.
//
// For each line on SS-V-POWER-CL, walk its length and emit a polyline that alternates
// straight run / zigzag / straight run, matching the recorded plat's ---/\/\---/\/\--- look.
// The zigzag is built in the line's own local frame (along = unit vector, across = perpendicular)
// so it follows whatever bearing the line has.
//
// The centreline itself is set to a plain Continuous NO-DRAW state by moving it to a new
// SS-V-POWER-CL-HIDE? No - the user needs the centreline geometry to stay. Instead the squiggle
// polylines go on their own layer SS-V-POWER-SQUIGGLE so they can be frozen or deleted freely,
// and the centreline layer is put back on Continuous.
//
// Geometry per repeat (feet on the ground):
//   RUN   straight along the line
//   ZIG   4 alternating diagonal segments, AMP either side
const string SRC   = "SS-V-POWER-CL";
const string DEST  = "SS-V-POWER-SQUIGGLE";
const double RUN   = 6.0;    // straight length between squiggles
const double ZIG   = 8.0;    // length consumed by one squiggle group
const double AMP   = 2.0;    // half-height of the squiggle
const int    TEETH = 4;      // diagonal segments per group

Log("drawing: " + Db.Filename);

var lt = (LayerTable)Tx.GetObject(Db.LayerTableId, OpenMode.ForWrite);
if (!lt.Has(SRC)) { Log("layer " + SRC + " missing"); return; }

// squiggle layer, same colour as the source
short colour = 1;
{
    var s = (LayerTableRecord)Tx.GetObject(lt[SRC], OpenMode.ForRead);
    colour = s.Color.ColorIndex;
}
ObjectId destId;
if (lt.Has(DEST)) { destId = lt[DEST]; Log("layer " + DEST + " exists - reusing"); }
else {
    var nl = new LayerTableRecord();
    nl.Name = DEST;
    nl.Color = Autodesk.AutoCAD.Colors.Color.FromColorIndex(Autodesk.AutoCAD.Colors.ColorMethod.ByAci, colour);
    destId = lt.Add(nl);
    Tx.AddNewlyCreatedDBObject(nl, true);
    Log("created layer " + DEST + " (colour " + colour + ")");
}

// put the centreline layer back on Continuous - the squiggle is geometry now
var ltt = (LinetypeTable)Tx.GetObject(Db.LinetypeTableId, OpenMode.ForRead);
{
    var srcLayer = (LayerTableRecord)Tx.GetObject(lt[SRC], OpenMode.ForWrite);
    srcLayer.LinetypeObjectId = ltt["Continuous"];
    Log(SRC + " linetype -> Continuous");
}

var ms = (BlockTableRecord)Tx.GetObject(SymbolUtilityServices.GetBlockModelSpaceId(Db), OpenMode.ForWrite);

// wipe any squiggles from a previous run so this is idempotent
int wiped = 0;
foreach (ObjectId id in ms) {
    var e = Tx.GetObject(id, OpenMode.ForRead) as Autodesk.AutoCAD.DatabaseServices.Entity;
    if (e == null || e.IsErased) continue;
    if (!e.Layer.Equals(DEST, StringComparison.OrdinalIgnoreCase)) continue;
    var w = (Autodesk.AutoCAD.DatabaseServices.Entity)Tx.GetObject(id, OpenMode.ForWrite);
    w.Erase(); wiped++;
}
if (wiped > 0) Log("erased " + wiped + " squiggles from a previous run");

// collect the source lines first
var src = new List<ObjectId>();
foreach (ObjectId id in ms) {
    var e = Tx.GetObject(id, OpenMode.ForRead) as Autodesk.AutoCAD.DatabaseServices.Entity;
    if (e == null || e.IsErased) continue;
    if (e.Layer.Equals(SRC, StringComparison.OrdinalIgnoreCase) && e is Line) src.Add(id);
}
Log("power centrelines: " + src.Count);

int made = 0; double totalTeeth = 0;
foreach (var id in src) {
    var ln = (Line)Tx.GetObject(id, OpenMode.ForRead);
    var a = ln.StartPoint; var b = ln.EndPoint;
    double L = ln.Length;
    if (L < 1.0) continue;
    double ux = (b.X - a.X) / L, uy = (b.Y - a.Y) / L;   // along
    double px = -uy, py = ux;                             // across

    var pl = new Polyline();
    int v = 0;
    double t = 0.0;
    pl.AddVertexAt(v++, new Point2d(a.X, a.Y), 0, 0, 0);

    while (t < L - 0.01) {
        // straight run
        double runEnd = Math.Min(t + RUN, L);
        pl.AddVertexAt(v++, new Point2d(a.X + ux * runEnd, a.Y + uy * runEnd), 0, 0, 0);
        t = runEnd;
        if (t >= L - 0.01) break;

        // squiggle group: TEETH diagonals alternating across the line
        double zigEnd = Math.Min(t + ZIG, L);
        double step = (zigEnd - t) / TEETH;
        for (int k = 1; k <= TEETH; k++) {
            double tt = t + step * k;
            double off = (k % 2 == 1) ? AMP : -AMP;
            if (k == TEETH) off = 0;                       // land back on the line
            pl.AddVertexAt(v++, new Point2d(a.X + ux * tt + px * off,
                                            a.Y + uy * tt + py * off), 0, 0, 0);
            totalTeeth++;
        }
        t = zigEnd;
    }

    pl.Layer = DEST;
    ms.AppendEntity(pl);
    Tx.AddNewlyCreatedDBObject(pl, true);
    made++;

    var back = (Polyline)Tx.GetObject(pl.ObjectId, OpenMode.ForRead);
    Log(string.Format("  [{0}] from line [{1}] len={2:F1} -> {3} verts, {4:F0} squiggle groups (verified)",
        back.Handle, ln.Handle, L, back.NumberOfVertices, L / (RUN + ZIG)));
}

Log("");
Log(string.Format("drew {0} squiggle polylines on {1}: run {2:F1} ft, squiggle {3:F1} ft, amplitude +-{4:F1} ft",
    made, DEST, RUN, ZIG, AMP));
Ed.Regen();

Result

drawing: C:\Users\sanja\OneDrive\_SurveyDisco\260714 - 285 Huckaby Rd, Brooks, GA 30205, USA\260714 - 285 Huckaby Rd R2.dwg
created layer SS-V-POWER-SQUIGGLE (colour 1)
SS-V-POWER-CL linetype -> Continuous
power centrelines: 4
  [21C51] from line [20C9D] len=893.0 -> 321 verts, 64 squiggle groups (verified)
  [21C52] from line [20C9E] len=364.6 -> 132 verts, 26 squiggle groups (verified)
  [21C53] from line [20CA9] len=1514.6 -> 542 verts, 108 squiggle groups (verified)
  [21C54] from line [20CB1] len=1569.6 -> 562 verts, 112 squiggle groups (verified)

drew 4 squiggle polylines on SS-V-POWER-SQUIGGLE: run 6.0 ft, squiggle 8.0 ft, amplitude +-2.0 ft