The per-AI "start_date" is a lot of custom code, and was rarely
used in the way it was meant.
While at it, also ported this part over to the new timer system.
Previously, on a straight line of a one corner up slope with the adjacent
steep sloop the Z would increase one step every two sub pixels, except for one
case where one sub pixel is skipped. Similarly, a steep slope with two
adjacent one corner up slopes, would have a bump in the height line along the
diagonal whenever it enters/leaves the steep slope tile.
Previously it checked the position in non-driving direction to "guess" whether
a ground vehicle was using the function, so on tunnels/bridges it could either
return the Z of the (virtual) ground compared to the Z of the path the vehicle
would take.
IsSavegameVersionUntil() did a [0, N] check, not [0, N) as the
name suggests.
Until can be a confusing word, where people consider it to be
including the upperbound. Dictionary states it means "before",
excluding the upperbound. There are long debates about who is right.
So, simply remove away from this ambiguity, and call it "before"
and "before or at". This makes the world easier for everyone.
It now follows very simple rules:
0 - Fatal, user should know about this
1 - Error, but we are recovering
2 - Warning, wrong but okay if you don't know
3 - Info, information you might care about
4 -
5 - Debug #1 - High level debug messages
6 - Debug #2 - Low level debug messages
7 - Trace information
This better reflects what it is, and hopefully removes a bit of
the confusion people are having what this setting actually does.
Additionally, update the text on the setting to better inform
users what it is doing exactly, so they can make an educated
decision on how to change it.
Next commit will introduce an "auto" value, which should be the
new default. The rename has as added benefit that everyone will
start out on the "auto" value.
Despite what it looked like, you could never really change the
ending-year (it was always reset to 2050 on start-up). See commit
683b65ee1 for details. As a side-effect, the variable that was
suppose to store the ending-year was just zero, never containing
a real ending-year.
