Edge flowline

[changliao1025]

There is a chance that a flowline passes through a bay cell like this:

This will cause a bug for the intersection algorithm.

[changliao1025]

In a reasonable scenario, the user should provide a flowline that "sticks out" of the study domain, which is defined by the boundary file. However, because the mesh resolution cannot fully describe the boundary file, such as the coastal line, it is possible to have this type of data quality issue.

[changliao1025]

To fix this issue programmingly instead of manually, it is possible to let the intersection algorithm automatically cut off the tail.

[changliao1025]

The requirement to fix this includes that the algorithm must know which flowline is the last one that sticks out, this information is stored within the "simplified flowline".

[changliao1025]

Multiple functions ensure that the first flowline is the last segment flows out of the domain.
We can also use the max segment index as the indicator.