* 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.
---------
Co-authored-by: Claude Opus 4.8 (1M context) <[email protected]>
A timestamp set to 1 means an immediate timestamp, and so the `int` version of `timestamp_elapsed` should account for that, just as it does in the `TIMESTAMP` and `UI_TIMESTAMP` versions. Normally the number comparison means the check will still work, but during mission initialization the timestamp code is not running. This caused destroy-before-mission ships to be added to the arrival list when they shouldn't have been.
Also fix logic in `timestamp_elapsed_safe`, where the `TIMESTAMP` and `UI_TIMESTAMP` versions were correct, but the `int` version had a bug dating back to retail that caused it to return true for uninitialized (zero) timestamps rather than false. Practically speaking, this fix has no effect because the function is only used in multiplayer and none of the instances use integer-0 to indicate uninitialized, but this will at least fix any uses in the future.
1. Make sure the legacy `timestamp_until()` and `timestamp_since()` functions check for any type of invalid timestamp
2. Add a useful `isFinite()` function
3. A timestamp delta on an immediate timestamp is more properly the actual delta, rather than another immediate timestamp
Because time compression adjusts the raw timestamp to be 0, it must use the exact value, not the snapshotted value, or the mission time will be slightly off. So this commit fixes that problem, as well as making sure that changes in time compression always occur at the start of a frame.
Prior to the timer upgrade, all simulation timestamps shared identical timer and timestamp values for the duration of the frame, since they were only updated within the `game_set_frametime` function. Since the timer upgrade depends on the system clock, timestamps evaluated near the end of the frame will be very slightly later than timestamps evaluated near the beginning of the frame. It is desirable to keep them all in sync.
This PR tweaks the timestamp system to take a snapshot at the beginning of the frame, then use that snapshot for the entire duration of the frame. This only affects simulation timestamps; real-time timestamps still use the live timer.
* Revert "synchronize simulation timestamps across the entire frame"
* try a proper fix instead of revert
* make sure nothing is reverted
* and back to full revert
Originally the check for event delay was this:
```
if ( (fix) Mission_events[i].timestamp + delay >= Missiontime )
return SEXP_FALSE;
```
This returns false even when the mission time is equal to the timestamp. Therefore the timestamp check needs to use >, not >=.
Thanks to Durandal and ShivanSpS for helping to track this down.
Prior to the timer upgrade, all simulation timestamps shared identical timer and timestamp values for the duration of the frame, since they were only updated within the `game_set_frametime` function. Since the timer upgrade depends on the system clock, timestamps evaluated near the end of the frame will be very slightly later than timestamps evaluated near the beginning of the frame. It is desirable to keep them all in sync.
This PR tweaks the timestamp system to take a snapshot at the beginning of the frame, then use that snapshot for the entire duration of the frame. This only affects simulation timestamps; real-time timestamps still use the live timer.
For all POFs that use animated textures, if no starting timestamp is specified, assume animation started at the beginning of the mission. This fixes a bug reported in Starfox: Event Horizon where weapon POF animated textures stopped animating after the texture timestamp upgrade.
These fix up the in-game confirm packet and help sync client and server through a few timing fixes.
Co-Authored-By: Taylor Richards <[email protected]>
The movie player code was missing some important functionality, in particular:
1) There was only one timing method to get real-time elapsed time, which was not suitable for pausing or time compression
2) There was an improper cast for the FPS property, causing a script error
3) The `getSeconds` method lost precision during casting
This patches those deficiencies.
A bit overkill for some of this but just covering the bases.
* fix issues with in-game join
* fix multi messaging and multi pause screen
* make sure maintenance stuff (pings, voice, file xfer, etc.) isn't
affected by pausing or time compression
The new timestamps should use the timestamp ticker, which accounts for pauses and time compression, not the standard timer, which measures absolute elapsed time. This fixes the bug reported on Discord where the supernova timer did not pause when the game was paused.
This adds a type-safe TIMESTAMP, similar to UI_TIMESTAMP. Eventually all of the FSO codebase will be switched over to this new type. In the meantime, just the supernova code is switched over.
If a breakpoint is hit in the code, the SDL time will keep running even though FSO doesn't realize things are effectively, if not actually, paused. Detect this situation and adjust the timestamp offset to compensate.
Previously, the game used a dead-reckoning system for measuring time, where several time counters were incremented as long as time was running. This unfortunately has no way to synchronize time in the long term, and therefore in-game time will tend to run faster or slower than real time by a few percent, depending on various factors.
This PR redesigns the timestamp system to use the SDL time counter which will always keep it in sync with real time. However this necessarily involves a bit of clever handling when the game is paused and unpaused. It also revealed several minor bugs in several places in the code where timestamps were handled.
This PR is currently in draft status until the design can be updated to handle time compression. In all other respects it should be working.
* Object Update Refactor
1. Keeps the object update packet aligned, even if the ship is dying or has not yet arrived on the client.
2. Properly handles model point shields (yes, that's what was causing multi to crash the most!)
3. Reworks positional interpolation timing and adds rotational interpolation, by sending timing information with every object update packet in a header shared between objects.
4. Saves a lot of bandwidth by only sending data that is changing. (no more sending all subsystems once per second!)
5. Better handles out of order packets (but can still use their information if recent enough!)
6. Builds the basis for Rollback by beginning to record the positions and orientations and velocities of ships for the last 30 frames.
7. Adds subsystem rotation -- Yeah, you saw that right, subsystems will now spin in multi.
8. Waypoint movement is now enabled via sexp, and time to arrival of waypoints is updated on the target info gauge.
* Fix edge case crash and Incorporate feedback
* Clean Up Interpolate Angles Quick
* Restrain the client
* How was this still here???
* Make sure every part of OO uses OOC_INDEX_NULLPTR_SUBSYSTEM define
* Fix Way to Store Return Values
* Ok travis, we get it
* Ok travis.........
Taylor Richards