The algorithm relied on the assumption that the points were
ordered anti-clockwise. When ordered in a clockwise fashion, the
result was correct but negative.
Refer to https://www.mathopenref.com/coordpolygonarea2.html
for more information.
The log viewer tool lets you inspect all the intermediate stages of the routing algorithms. This patch:
- Adds source location tracking of the debug calls (need to use the PNS_DBG macro, sorry)
- Moves some wxLogTrace calls to DEBUG_DECORATOR::Message() so that messages can be displayed alongside the corresponding geometric shapes