I have a confusion related to an algorithm for finding the orientation given three points, i.e., determining whether one line is clockwise or counter-clockwise of another.
Let's say the points are $P_1=(x_1,y_1)$, $P_2=(x_2,y_2)$, $P_3(x_3,y_3)$. The algorithm says
- Let the slope of line $P_1P_2$ be $m_1$ and slope of $P_2P_3$ be $m_2$.
- If $m_2 > m_1$, the orientation is counterclockwise and if $m_1 > m_2$ it is clockwise.
However lets say the points are $(0,0)$, $(4,4)$ and $(2,4)$. This give $m_1=1$, $m_2=0$. The orientation is counter clockwise but $m_2 < m_1$. So I am wondering if there is any issue with the algorithm.