The `+Rotation Factor:` value in the ship collide section of the ships table has been around for many years, but raising that value beyond the default of 0.2 results in ship collisions that can result in the colliding ship spinning at ludicrous rotational velocities that last for over 10 seconds (this is especially evident with long ships with high speeds).
This PR adds a field after `+Rotation Factor:` called `+Rotation Magnitude Maximum:` which serves as a maximum for the resulting rotational velocity from a ship collision in degrees per second. By default this is -1 and thus disabled.
Tested and works as expected, and now properly allows mods to have ships spin out if they have collision while not spinning out at wild speeds that look immersion breaking.
Per #4294, this adds two new flag that, together, are equivalent to the legacy "immobile" flag but individually provide more fine-grained control. Since the physics for position and orientation have a bit of overlap, the new flag functionality simply reverts whatever position or orientation changes were done by the physics sim.
In the FRED and qtFRED ship flags dialogs, the "immobile" flag (aka "Does Not Move") is replaced by the two new flags, but in FSO the situation is more complicated. The old and new flags coexist and have overlapping functionality, so the mission designer must be careful to set and unset the appropriate flag (that is, it is possible for both "immobile" and "don't-change-position" to be set at the same time, in which case the ship cannot change position without both flags being unset). The `set-immobile` and `set-mobile` legacy SEXPs ensure that the new flags are removed so as not to conflict with the legacy flag, but the `alter-ship-flag` and `are-ship-flags-set` SEXPs and the `getFlag` and `setFlag` script functions use exactly what the FREDder/scripter specifies and nothing else.
(I attempted to completely replace "immobile" with the two newer flags, but it proved intractable to do this while maintaining reverse compatibility: retrofitting single-flag functions to apply dual flags for one particular situation made the functions harder to understand as well as introducing many edge cases and opportunities for bugs or "gotchas".)
Implements #4294.
* Remove old interpolate angles quick
* Remove old interpolate functions
These are no longer used.
* Add linear interpolate vm function
More clearing functions
* Add physics snapshot struct to silo interpolation
Two of these two functions require an object pointer, so they cannot be in physics_state.cpp
With doxygen documentation
* Try to placate Linux
* Address Feedback
* And update declaration, of course
* Attempt to appease linter
The three functions `physics_apply_whack`, `physics_apply_shock`, and `physics_collide_whack` limited speed after the physics had been applied, but they limited absolute speed, not the speed due to the physics. This modifies the process to limit the change in speed. It also adds an AI profiles flag to disable the limit if desired.
This also tweaks the three functions (by editing comments and moving lines) to be more consistent, since all three are doing very similar calculations near the end.
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.
In #4443, `fl_near_zero` was set to use default epsilon values in the `IS_VEC_NULL` check. In this comparison, epsilon is the wrong threshold because it used to have a much smaller threshold. The fix restores the previous definitions of `IS_VEC_NULL` and `IS_VEC_NULL_SQ_SAFE` by exposing the epsilon value as an optional parameter (similar to how `IS_NEAR_ZERO` used to work. This PR also restores `IS_VEC_NULL_SQ_SAFE` where it was replaced by `IS_VEC_NULL.`
* more cleanup in preparation for model translation
1) Clean up stepped rotation, fixing some logic, adding safeguards for invalid values, and allowing rotations to go in the opposite direction
2) Add more specific SEXP error checking for AWACS and rotating subsystems
3) Assorted refactoring and polishing
* address feedback, plus a bit of extra cleanup
Properly whacks all ships that are docked together when any are whacked, makes everything more consistent by calling ship_apply_whack instead of physics_apply_whack, whacking in general now unrotates its hit pos to get a world pos like physics whack was expecting and adds a few matrix helper functions.
Taylor Richards