* Adds safety checks to scripting orders with waypoints
Turns out setting a waypoint order then trying to get to target of that order in the same frame triggers a crash in the scripting API for ship orders (`order.cpp` line 295). This was due to invalid lookups which lacked safety checks.
This PR adds those safety checks. Now, if this situation is encountered, it leaves `objnum` at -1 and thus returns an object for which `isValid` is false.
Fix is tested and works as expected. Also fixes#5172
* appease clang
* cleanup thanks to Goober
* clang again
* forgot to re-add the nullptr
* remove redundant checks
When iterating through `Ship_obj_list`, check the `Should_be_dead` flag before using the object. This fixes#4990 and adds defense-in-depth checks to guard against similar errors elsewhere.
I considered moving the `Ship_obj_list` removal from `obj_delete` to `ship_cleanup`, but decided it would be prudent to avoid fundamental changes to lifecycle management.
When iterating through various object collections, check for the should-be-dead flag to avoid returning objects that are on the verge of being deleted.
Separately, this adds the `isExpiring` function to check for should-be-dead objects.
This PR also makes object iteration consistent across all object types, both to reduce code duplication and to ensure that the length and iteration are done using the same algorithm. Furthermore, if the number of should-be-dead objects is nonzero, the Lua array count for that frame will be different from the internal array count for that frame.
Fixes#5034.
- fix crash bug when path only contains dir separators
- fix error handling when no path is specified in write mode
- clarify function documentation
Fixes#5028
Much like a previous instance (fixed in #3281, although the function in question was later removed), `std::isdigit()` without a locale argument prevents MSVC 2017 from compiling FSO.
* Fixes CTD with decals on dying ships
If a ship was getting shot with weapons that used decals, the decal code would hit an assertation, because the invalid decals were not being all removed.
This PR updates the decal cleanup loop, to ensure that no decals are missed and all invalid ones are removed. Tests confirm this fixes the issue.
Also cleaned up some comments and moved another assertation before setting of variables.
* Exposes modder useful options to decals
Now that decals are very stable, this PR exposes two options that are very useful for using decals, a random range for the radius along with the option to have a random rotation when the decal is created.
Tested and everything works as expected.
* add script ability to toggle decals
* properly use set arg not func
* fix two minor things in decal shader
* one more cleanup line
* fixes
Allow `mn.sendMessage` to send from a ship source, not only a string source, by allowing the ship object to be specified as the first argument. Also add `ship:sendMessage` which is a more streamlined version of the same thing.
Adds gravity! Applies on a per-mission basis, and weapons, ships, debris, and asteroids now have a configurable "gravity const" which multiplies the effect of gravity on them, by default everything except debris is 0 (meaning no effect even when the mission has gravity). AI and the lead indicator will also lead for ballistic trajectories as well, given a gravity-affected weapon. No FRED support or gravity direction control yet, to come in later PRs.
wookieejedi