Before, the GridNodes were stored in vector<vector<vector<T>>>,
and initialized in advance. Putting three vectors inside each other
puts lots of unneccessary stress onto the allocator, costs more memory,
and has worse cache locality than a flat vector<T>.
For larger search distances, an the array getting initialized means
essentially O(distance^3) complexity in both time and memory,
which makes the current path search a joke. In order to really
profit from the dijkstra/A* algorithms, other data structures
need to be used for larger distances.
For shorter distances, a map based GridNode storage may be slow as
it requires lots of levels of indirection, which is bad for things like
cache locality, and an array based storage may be faster.
This commit does:
1. remove the vector<vector<vector<T>>> based GridNodes storage that
is allocated and initialized in advance and for the whole
possible area.
2. Add a vector<T> based GridNodes storage that is allocated and
initialized in advance for the whole possible area.
3. Add a map<P,T> based GridNodes storage whose elements are
allocated and initialized, when the path search code
demands it.
4. Add code to decide between approach 2 and 3,
based on the length of the path.
5. Remove the unused "surfaces" member of the PathGridnode class.
Setting this isn't as easy anymore for the
map based GridNodes storage.
* Fix naming style for methods and classes:
Use camelCase for methods and PascalCase for classes as
code style demands it. And use sneak_case for methods that
are not member of a class.
* Replace "* " with " *" for Pointers
* Same for references
* Put function body opening braces on new line
* Other misc minor non functional style improvements
There is no need to put them into the header, they are solely used
inside the pathfinder.
Another advantage of this change is that only the pathfinder.cpp has
to be compiled if PATHFINDER_DEBUG gets defined or undefined, not
all files including the .h.
This commit moves the pathfinder classes to the cpp file without
modifications.
Also, the PATHFINDER_DEBUG macro gets moved to the cpp file and
the PATHFINDER_CALC_TIME macro gets moved to a plce where it
actually does work.
