* avoid undefined behavior from UNREACHABLE on reachable code paths
UNREACHABLE expands to __assume(false) / __builtin_unreachable() in
release builds, which is undefined behavior if the code is ever actually
reached. Many UNREACHABLE sites only guard against unexpected-but-
possible runtime states (values from tables, mission/save files, network
packets, scripting, or user input), so reaching them should degrade
gracefully rather than invoke UB.
Replace UNREACHABLE with Assertion(false, ...) at all such sites. It
still pops an error in debug builds, but in release it is a harmless
no-op that simply falls through to the following code. Sites that are
genuinely unreachable by local invariants (e.g. a switch over a bounded
random number) are left as UNREACHABLE.
A few converted sites had no safe fall-through -- an uninitialized read,
null dereference, or null call would have followed -- so they also get a
minimal recovery: initialize the value, guard the dereference, return
early, or skip the offending item.
Where the converted site was a simple guard of the form
if (x) { Assertion(false, ...); return; }
hoist the check onto the invariant instead:
Assertion(!x, ...);
if (x) { return; }
This states the expectation directly and shows the offending value in
the debug popup, while keeping the same graceful runtime degradation.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
* addendum
After consultation with Lafiel, use UNREACHABLE in situations that are effectively impossible even if not provably impossible. UNREACHABLE = "this shouldn't ever happen"; Assertion = "if this ever happens, it's a coding error". Also fix a few other sites and change a couple to Warnings.
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Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]>
* rename misleading variable check_again to never_check_again
The first element of collision_result means "never check again" per the
typedef comment, but was destructured as check_again (opposite meaning).
Rename to never_check_again to match the actual semantics and prevent
future confusion.
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
* fix data races in ship-weapon collision threading
Two thread-safety bugs in ship_weapon_check_collision, which runs on
worker threads:
1. update_danger_weapon() wrote to Ai_info[] (danger_weapon_objnum,
danger_weapon_signature) without synchronization. Multiple weapons
targeting the same ship would race on the same Ai_info entry.
2. Homing missile detonation logic wrote wp->lifeleft and
wp->weapon_flags directly on the Weapons[] global array.
Fix: defer both writes to the main-thread post-processing phase via
new flags in ship_weapon_collision_data. Also convert the collision
data from a 6-element tuple to a named struct for readability.
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
* fix data race in ship-ship collision submodel checking
ship_ship_check_collision() toggled pmi->submodel[].collision_checked
flags on the heavy ship's polymodel_instance to selectively enable/
disable submodel collision checks. When two collision pairs shared the
same heavy ship, worker threads would race on the same pmi entries.
Fix: add a collision_checked_override pointer to mc_info that lets
callers provide a thread-local array of collision_checked values.
model_collide() uses the override when set, falling back to the
pmi->submodel[] field otherwise. ship_ship_check_collision() now
builds a local SCP_vector<char> and passes it via the override,
completely avoiding writes to shared polymodel_instance state.
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
* Ensure threads have spun down before continuing non-threaded execution
* address review feedback for ship-weapon collision threading
- postproc flag now accumulates incrementally instead of being OR'd
at the final return, ensuring all return paths respect it
- early return for predictive collisions now preserves the
should_update_danger_weapon flag in the collision data
- moved nprintf detonation debug print to the main-thread process
pass for thread safety
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
* move collision_checked from pmi into mc_info for thread safety
collision_checked flags were transient per-collision-pass state that
didn't belong in the shared polymodel_instance. Now mc_info owns an
SCP_vector<char> that model_collide auto-initializes from pmi when
empty. All collision callers (ship-ship, asteroid, debris, prop)
updated to manipulate mc.collision_checked instead of pmi->submodel[].
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
* Convert to CV and spinup counter
* Update comment
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Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>
Co-authored-by: BMagnu <[email protected]>
* First draft of prop object type
* Add prop editor dialog in FRED
* prop sexps
* lua table prop support
* lab support
* lua mission access to props
* prop collision support
* use std::optional so the object->instance id is always valid
* allow props to block suns
* minor cleanup and remove arbitrary limit. Still limited to 500 objects.
* Sort props by category
* cleanup
* implement collision hooks
* parse prop flags and further ensure props are inited and closed correctly
* Add Cyborg's multi suggestions
* fix missing header
* add props to empty slots if available
* add multi signature
* fix rebase issues and match collisions to the new multithread style
* appease Clang the Conquerer
* save/parse mission prop classes by name
* Clean up comments and finish TODOs
* fix string errors
* clang wants this to be static now
* address feedback
* address feedback
* Use model num from prop info instead
* merge prop and ship collision group sexps together
* fix rebase bug
* address feedback
* fix name shadowing
* ship heavy submodel
* clang
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Co-authored-by: Asteroth <[email protected]>
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.
* Add the submodel that was hit to the On Ship Collision scripting hook. (This will only be non-nil if the ship was the "heavy object".)
* Add a `getModel()` function to the scripted submodel object.
* Fix some incorrect documentation in `OnShipCollision`.
* fast version of setting position and orientation
* preliminary stale collide time
* add global collision cache stale flag instead
* clean up
* more clean up
* no periods >.>
* bring back single object version
* rename and bring back stale object list
* use a set
1. Add a function to retime *only* the collision pairs involving a specific object. This is useful when only one object has moved, since only collisions involving that object are affected.
2. Use this function when objects are moved for autopilot, via sexp, and via script.
Previously collision pairs were not retimed when objects were moved via script, leading to bugs. This fixes that.
Take into account the collision flag and collision groups when spawning a ship. Should fix#5357.
Also clean up the code a bit, including setting a few `int`s to `bool`s and adding a missing axis case.
This initializes `mc_info` to the correct values when it is constructed, removing the need for `mc_info_init`.
This PR also fixes a group of incorrectly inverted assignments in beam.cpp.
Follow-up to #5040. This extends the checks to most iterations over `obj_used_list` in FSO. There are a few exceptions such as `waypoint_add` and `waypoint_remove`, plus a few others. And none of the object iterations in FRED have the guard because FRED does not use the same object life cycle as FSO.
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.
It's theoretically possible for `parent_type` to get out of sync with the parent's type, particularly if the parent is destroyed. Since the field is almost never used, it can be removed.
Should fix#4105.
Mostly renaming of fields and functions, and moving some modelread sections into functions. This reorganization will put the code on a better footing for the model translation feature. No model translation code is included yet, and there should be no change in functionality.
* Prevent Crashes from Weapons being deleted during the collision process
This puts in some safety checks to keep FSO from crashing while doing collision detection when close to the object limit.
* Remove Problematic Assertions and INT3's
Keeps FSO from crashing when low on Object slots from failed weapon and beam creations.
* Simplify Code with a good suggestion
Co-authored-by: Asteroth <[email protected]>
Co-authored-by: Asteroth <[email protected]>
* Multiplayer Dumbfire Rollback
This creates a packet that sends the relative position and orientation info for a primary or dumbfire missle shot. The client creates this packet when firing those two types of weapons and sends it to the server. The server goes back to the frame that the client fired the weapon and quicky resimulates all the frames in-between.
This includes collision detection, restoring positions, orientations and veloicties, but not subsystem orientations.
* Address Feedback
* allow clients to send subsystem info
* Check for object number not weapon number
* Readability Adjustment
A bit of small cleanups in preparation of larger scale refactoring.
remove unused member heavy_collision_cm_pos of collision info struct,
which was set in several places but never used.
The new design is centered around the Event Trace JSON format but it
should still be possible to adapt it for other profiling tools. The old
profiling system has been removed.
The codebase had quite a few instances of .size() being called and then checked to see if it was 0 or not (or less than 1, or greater-than-or-equal-to 1, which are basically equivalent), when .empty() could be called instead (negated or not, depending on what the original condition was).
This introduces a new mechanism for handling bit flags. Instead of using an int (or two, or three) to write bits into, this uses the std::bitset in a wrapper class that accepts an enum class as input. This means that certain classes of errors we've had a few of in the engine, where a coder used the wrong set of flags or checked them against the wrong variable (SF_STEALTH vs SIF_STEALTH, for example) can now be detected at a compiler level rather than not at all.
This expands the existing system which only worked on Windows to all
supported platforms.
If the MSVC debug runtime is not present then its behavior is emulated
by adding a header to each allocated memory block.
Somewhat related to PR #528, this changes the branch that assumes constant velocity from checking for an absence of the WIF_TURNS flag to checking for the presence of the PF_CONST_VEL flag (because non-turning weapons can be given an acceleration time).
Could cause problems with recycled objects (specifically, I had a crash once because "Objects[B->parent].instance" was well over MAX_SHIPS due to being a weapon instead of a ship, causing the "Ships[Objects[B->parent].instance].team" reference to fail hard).
