Esempi in C++ (Cpp) per QgsVector::lengthSquared

Esempio n. 1

File: qgsinternalgeometryengine.cpp Progetto: dbaston/QGIS

bool QgsClockwiseAngleComparer::operator()( const QgsPointXY &a, const QgsPointXY &b ) const
{
  const bool aIsLeft = a.x() < mVertex.x();
  const bool bIsLeft = b.x() < mVertex.x();
  if ( aIsLeft != bIsLeft )
    return bIsLeft;

  if ( qgsDoubleNear( a.x(), mVertex.x() ) && qgsDoubleNear( b.x(), mVertex.x() ) )
  {
    if ( a.y() >= mVertex.y() || b.y() >= mVertex.y() )
    {
      return b.y() < a.y();
    }
    else
    {
      return a.y() < b.y();
    }
  }
  else
  {
    const QgsVector oa = a - mVertex;
    const QgsVector ob = b - mVertex;
    const double det = oa.crossProduct( ob );
    if ( qgsDoubleNear( det, 0.0 ) )
    {
      return oa.lengthSquared() < ob.lengthSquared();
    }
    else
    {
      return det < 0;
    }
  }
}