Пример #1
0
// TODO: move to geometry utils
double distance2D( const QgsPolylineXY &coords )
{
  int np = coords.count();
  if ( np == 0 )
    return 0;

  double x0 = coords[0].x(), y0 = coords[0].y();
  double x1, y1;
  double dist = 0;
  for ( int i = 1; i < np; ++i )
  {
    x1 = coords[i].x();
    y1 = coords[i].y();
    dist += std::sqrt( ( x1 - x0 ) * ( x1 - x0 ) + ( y1 - y0 ) * ( y1 - y0 ) );
    x0 = x1;
    y0 = y1;
  }
  return dist;
}
Пример #2
0
// TODO: move to geometry utils
double closestSegment( const QgsPolylineXY &pl, const QgsPointXY &pt, int &vertexAfter, double epsilon )
{
  double sqrDist = std::numeric_limits<double>::max();
  const QgsPointXY *pldata = pl.constData();
  int plcount = pl.count();
  double prevX = pldata[0].x(), prevY = pldata[0].y();
  double segmentPtX, segmentPtY;
  for ( int i = 1; i < plcount; ++i )
  {
    double currentX = pldata[i].x();
    double currentY = pldata[i].y();
    double testDist = QgsGeometryUtils::sqrDistToLine( pt.x(), pt.y(), prevX, prevY, currentX, currentY, segmentPtX, segmentPtY, epsilon );
    if ( testDist < sqrDist )
    {
      sqrDist = testDist;
      vertexAfter = i;
    }
    prevX = currentX;
    prevY = currentY;
  }
  return sqrDist;
}