Retail has a hud_find_target_distance function that returns the distance between the player position and a bounding box. This is useful for the HUD because it shows the distance to the perimeter of an object like a jump node or a large ship. However, this function was re-used for the `distance` SEXP, resulting in the awkward situation where the distance is measured from one ship's center to another ship's bounding box. This can lead to unexpected results and it also means that the SEXP returns a different distance when the arguments are swapped.
This PR deprecates the original SEXP and introduces the new SEXPs `center-distance` and `bbox-distance` which use consistent methods for both ships. It also renames the `distance-ship-subystem` SEXP to `center-distance-subsystem` and adds a new `bbox-distance-subsystem` SEXP.
This PR upgrades the function, and the sexps that use it, to take advantage of the new sexp caching. It also makes `script_eval_multi` more robust in the face of players who might be respawning.
This will ensure that Lua functions will always be executed in the
correct Lua state. Since we now have multiple threads (which are
different lua_State objects) it is possible that the current code could
execute a Lua function in the main state instead of the thread that is
currently executing. This can lead to weird behavior and probably also
to issues inside Lua.
This PR uses `eval_ship` and `eval_wing` to optimize `object_ship_wing_point_team` and `sexp_deal_with_ship_flags`. The API changed a bit, but to ensure compatibility, there are fields and functions to support the old behavior. These are temporary and will be removed when all changes have been merged via PRs.
This is part of the ongoing sexp overhaul relating to performance and caching. This PR combines functions for several sexps that are very similar, and it also uses the `eval_ship` speedy lookup function. As a bonus, it allows `turret-tagged-only` and `turret-tagged-clear` to run for multiple ships at a time.
The `special_argument_appears_in_sexp_tree` function can run multiple times per event, especially for repeating events, so it's a good idea to cache the result. This avoids the need to iterate through potentially the entire tree, checking every single node.
Awhile back, the get_operator_const and get_operator_index functions were enhanced to cache the result of the operator lookup. But this only works when called on the node itself, not the text. So let's call these functions on the node whenever possible.
This code is highly inefficient (find_parent_operator() is O(n) for Num_sexp_nodes, and it runs every frame for all sexps with negative values) and should not actually be necessary. But it is useful as a debug tool, so I added some #ifdef's.
This adds the capability to have a Lua script that does not need to use
our table syntax at all but instead defines the hooks by calling API
functions. This also makes it possible to add hook functions at runtime
if the script requires that.
Also clean up some unused debug stuff.
In the SEXP parser, zero-length strings are valid, as are zero-length operators. But zero-length numbers are interpreted as missing arguments, since their only syntactic separators are spaces and the parser skips over whitespace. And in any case, zero-length numbers are not semantically valid anyway. This PR adds a sanity check to intercept all zero-length numbers, as well as malformed numbers, and convert them to 0.
This fixes issue #2314.
error_display shows the line where the error was detected. Warning
itself is pretty useless for parsing related errors so I replaced all
Warnings (where appropriate) with an equivalent error_display.
Per dicussion on Discord and and Github, `set-object-position` does not work properly and the fix would involve making it act the same way as `ship-maneuver`. With discussions with Goober (who originally made it), we have decided to deprecate the sexp. I have talked with folks who have used it thus I am not removing it from FRED with this PR but I am open to discussion on that point.
Goober5000