OGRBoolean OGRCurve::IsConvex() const
{
OGRBoolean bRet = TRUE;
OGRPointIterator* poPointIter = getPointIterator();
OGRPoint p1, p2, p3;
if( poPointIter->getNextPoint(&p1) &&
poPointIter->getNextPoint(&p2) )
{
while( poPointIter->getNextPoint(&p3) )
{
double crossproduct = (p2.getX() - p1.getX()) * (p3.getY() - p2.getY()) -
(p2.getY() - p1.getY()) * (p3.getX() - p2.getX());
if( crossproduct > 0 )
{
bRet = FALSE;
break;
}
p1.setX(p2.getX());
p1.setY(p2.getY());
p2.setX(p3.getX());
p2.setY(p3.getY());
}
}
delete poPointIter;
return bRet;
}
double OGRCompoundCurve::get_Area() const
{
if( IsEmpty() || !get_IsClosed() )
return 0;
// Optimization for convex rings.
if( IsConvex() )
{
// Compute area of shape without the circular segments.
OGRPointIterator* poIter = getPointIterator();
OGRLineString oLS;
oLS.setNumPoints( getNumPoints() );
OGRPoint p;
for( int i = 0; poIter->getNextPoint(&p); i++ )
{
oLS.setPoint( i, p.getX(), p.getY() );
}
double dfArea = oLS.get_Area();
delete poIter;
// Add the area of the spherical segments.
dfArea += get_AreaOfCurveSegments();
return dfArea;
}
OGRLineString* poLS = CurveToLine();
double dfArea = poLS->get_Area();
delete poLS;
return dfArea;
}
