//
// This ULP scans a board for wires that don't end any place 
// useful -- that is:
//   at an endpoint of another wire in the same layer,
//   at a via with at least one other connection, or
//   at a contact.
//
// Errors are displayed in a dialog box.  No box means no errors!
//
//  Written by vrs, 12/26/2014.
//
int points = 0;
int xp[];
int yp[];
int layerp[];
int refs[];
void EndPoint(int x, int y, int layer) {
  for (int i = 0; i < points; i++) {
    if ((x == xp[i]) && (y == yp[i]) && layer == layerp[i]) {
      refs[i]++;
      return;
    }
  }
  xp[points] = x;
  yp[points] = y;
  layerp[i] = layer;
  refs[points] = 1;
  points = points + 1;
  return;
}

int ViaCnt = 0;
int xv[];
int yv[];
void SetVia(int x, int y) {
  xv[ViaCnt] = x;
  yv[ViaCnt] = y;
  ViaCnt = ViaCnt + 1;
}
int IsVia(int x, int y) {
  for (int i = 0; i < ViaCnt; i++) {
    if ((x == xv[i]) && (y == yv[i])) {
      return 1;
    }
  }
  return 0;
}

if (!board) {
  dlgMessageBox("<hr><b>ERROR: No board!</b><p>\nThis program can only work in the board editor.");
  exit(1);
}

string outstr = "";
string tmp;
int errors = 0;
board(B) {
  B.signals(S){
    S.vias(V) {
      // A via causes all references to appear to be in layer 1.
      SetVia(V.x, V.y);
    }
    S.contactrefs(C) {
      // A contact appears as a via that needs no more traces.
      SetVia(C.contact.x, C.contact.y);
      EndPoint(C.contact.x, C.contact.y, 1);
      EndPoint(C.contact.x, C.contact.y, 1);
    }
    S.wires(W) {
      if (IsVia(W.x1, W.y1)) {
        EndPoint(W.x1, W.y1, 1);
      } else {
        EndPoint(W.x1, W.y1, W.layer);
      }
      if (IsVia(W.x2, W.y2)) {
        EndPoint(W.x2, W.y2, 1);
      } else {
        EndPoint(W.x2, W.y2, W.layer);
      }
    }
  }
}
for (int i = 0; i < points; i++) {
  if (refs[i] < 2) {
    sprintf(tmp, "Stub endpoint (%f %f) in layer %d\n",
           u2inch(xp[i]), u2inch(yp[i]), layerp[i]);
    outstr += tmp;
    errors++;
  }
}

if (errors) {
  dlgMessageBox(outstr);
  if (errors > 50) {
    output("stub.txt", "wt") {
      printf("%s", outstr);
    }
  }
  exit(1);
}
exit(0);