%\ccHtmlNoRefLinks
\begin{ccRefFunction}{orientation}

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\ccFunction{Orientation orientation(const Point_2<Kernel>& p,
                                    const Point_2<Kernel>& q,
                                    const Point_2<Kernel>& r);}
{returns \ccStyle{LEFT_TURN}, if $r$ lies to the left of the oriented 
line $l$ defined by $p$ and $q$, returns \ccStyle{RIGHT_TURN} if $r$ 
lies to the right of $l$, and returns \ccStyle{COLLINEAR} if $r$ lies
on $l$.}

\ccHtmlNoLinks
\ccFunction{Orientation orientation(const Vector_2<Kernel>& u,
                                    const Vector_2<Kernel>& v);}
{returns \ccStyle{LEFT_TURN} if $u$ and $v$ form a left turn,
returns \ccStyle{RIGHT_TURN} if $u$ and $v$ form a right turn,
and returns \ccStyle{COLLINEAR} if $u$ and $v$ are collinear.}


\ccHtmlNoLinks
\ccFunction{Orientation orientation(const Point_3<Kernel> &p,
                                   const Point_3<Kernel>&q,
                                   const Point_3<Kernel>&r,
                                   const Point_3<Kernel>&s);}
{returns \ccStyle{POSITIVE}, if $s$ lies on the positive side of the oriented 
plane $h$ defined by $p$, $q$, and $r$, returns \ccStyle{NEGATIVE} if $s$ 
lies on the negative side of $h$, and returns \ccStyle{COPLANAR} if $s$ lies
on $h$.}

\ccHtmlNoLinks
\ccFunction{Orientation orientation(const Vector_3<Kernel> &u,
                                    const Vector_3<Kernel> &v,
                                    const Vector_3<Kernel> &w);}
{returns \ccStyle{POSITIVE} if $u$, $v$ and $w$ are positively oriented,
returns \ccStyle{NEGATIVE} if $u$, $v$ and $w$ are negatively oriented,
and returns \ccStyle{COPLANAR} if $u$, $v$ and $w$ are coplanar.}


\ccSeeAlso
\ccRefIdfierPage{CGAL::collinear}\\
\ccRefIdfierPage{CGAL::left_turn}\\
\ccRefIdfierPage{CGAL::right_turn}

\end{ccRefFunction}