Using the `No_shields` flag for ships is common usage in multiple mods, and as it turns out ships with that flag set will not have the AI manage ETS values due to an early return in the `ai_manage_ets` function. This PR adds an AI flag to allow ships with no shields to manage ETS regarding weapons and engines. This flag was tested and works as expected.
Previously, the default distance for determining if a ship had finished a point in a model path was only 5. This worked fine for ships with low damp or no Newtonian physics. However, it did not work well with ships that use higher damps or Newtonian physics, becuase those ships contiunatlly overshoot that 5 meter distance and get stuck flying in a large circle trying to reach that point. This fix allows modders to set an AI flag to specify that the path distance check uses a larger value of 775 for points that are not the last point in the path. If desired I can add a game settings option that allows modders to set this value.
This adds an ai_profiles flag that checks comm systems for non-player ships. If their comm system is damaged, they will not send messages and you will not be able to issue squadmsg orders.
See also:
http://scp.indiegames.us/mantis/view.php?id=1947
By enabling the "$Use Actual Primary Range:" profile flag (which can also be set on a per-AI-class basis), the code to determine if the AI should fire its primary weapons will not only perform its current "range based on speed of weapon and target" calculation, but it will also compute the weapon's actual range and not fire if the target is outside of it.
By making parse_ai_profiles_tbl() actually check the return value of skip_to_start_of_string_either() (and break if the appropriate characters aren't found), AI profile tables should no longer keep parsing past the end of the file and into invalid memory, until they either find an "#End" in memory somewhere or just plain crash.
As a pleasant bonus, a missing "#End" should now generate an appropriate error message.
Most AI profile-related five-value lists are related to the number of difficulty levels. "$Detail Distance Multiplier:", however, is related to the number of detail levels (MAX_DETAIL_LEVEL + 1, because detail levels go from 0-MAX_DETAIL_LEVEL; MAX_DETAIL_LEVEL + 1 is also the size the detail_distance_mult array is defined with). Those two numbers happen to be the same (5); however, this may not always be the case in the future, and this way it's explicit that this field isn't related to difficulty at all.
Coverity defects 1320483, 1320484, 1320485, and 1320486 noted that several values were being set and then immediately overwritten before they could do anything. These appear to be related to behavior that Volition disabled before release that would allow the AI to slow down while attacking capital ships. It seemed a shame to waste this code, so I've added a flag to enable the behavior.
The CMake merge changed the default files system to include individual files instead of use a bunch of hardcoded strings, but the old file got left behind for some reason. Also, the same merge added some spurious extra imports of def_files.h which I removed at the same time (although if somebody wanted to go through and clean up all of our imports again, it'd probably be a good time for it).
Goober5000