Esempi in C++ (Cpp) per QPolygonF::subtracted

Esempio n. 1

File: qgshighlight.cpp Progetto: coyotte508/Quantum-GIS

void QgsHighlight::paintPolygon( QPainter *p, QgsPolygon polygon )
{
  QPolygonF poly;

  // just ring outlines, no fill
  p->setPen( mPen );
  p->setBrush( Qt::NoBrush );

  for ( int i = 0; i < polygon.size(); i++ )
  {
    QPolygonF ring( polygon[i].size() + 1 );

    for ( int j = 0; j < polygon[i].size(); j++ )
    {
      ring[ j ] = toCanvasCoordinates( polygon[i][j] ) - pos();
    }

    ring[ polygon[i].size()] = ring[ 0 ];

    p->drawPolygon( ring );

    if ( i == 0 )
      poly = ring;
    else
      poly = poly.subtracted( ring );
  }

  // just fill, no outline
  p->setPen( Qt::NoPen );
  p->setBrush( mBrush );
  p->drawPolygon( poly );
}