Consider having two lines given by their start points ($A$ and $B$) and their angle with respect to the $x$-axis.
These are half-open lines, and the intersection may occur only after the starting points. For example, they do not intersect in the given image if $a>b$ or $a$ is negative.
- How can we tell if they cross from their angles?
- What is the fastest way to find the intersection?
I have two options: First, using an imaginary far endpoint, calculate the intersection of line segments. Second, treat them as two vectors.
But I think both are overkill, as a simpler solution might be available using the angles (instead of the endpoints).