Closes Phase 4's outstanding action-sequence-correctness invariant, then
fixes two server-side bugs an adversarial review of that work uncovered.
Server simulation, bot observations, collision resources and tick rate are
unchanged: the server_physics_parity trace is byte-for-byte identical to
HEAD across 360 ticks including both ships' full observation vectors.
4.11 - prediction history filed under the ISSUING sequence
_send_local_input filed each post-step predicted state under the timeline's
estimate of the sequence the server would consume this tick, trailing
issuance by input_lead. The body had integrated the intent issued under
_input_seq, so predicted[S] held "state after the intent from now" while
the server's authority for S is "state after action(S)". They agree only
while the stick is still. Filing under _input_seq costs nothing: which
action the ship uses is decided in LocalNetShipController.get_action() and
is untouched.
Every prior Phase 4 gate held its input steady, and a steady input cannot
falsify a sequence label - the 60s runs honestly reported marker=0/3784.
New --exercise-input-transitions role toggles thrust every 6 ticks; it is
the only gate that can catch a label regression. Verified non-vacuous: the
old label fails it at 50%.
4.12 - issued-but-unsimulated sequences, and the release path
An attack (delta > 1) issues and sends several sequences for one local
physics step. Those gap sequences had no recorded prediction, so a server
ack of one reported missing_not_recorded - indistinguishable from ring
loss, costing a teleport and resync suppression several times a minute.
They are now recorded stateless via record_unsimulated() and answered with
a new "skip" decision mode. Free-flight hard snaps: 25/8/4 -> 0/0/0.
A release (delta == 0) re-recorded at the unchanged _input_seq, filing the
current intent under a sequence that went out carrying a different action;
LocalInputTimeline deliberately refuses to mutate an issued sequence, so
the ring contradicted the wire. Recording is now skipped on release ticks.
4.13 - two Phase 3 bugs silently killing player input
(a) InputJitterBuffer.consume() advanced last_applied_seq on every tick
including a starve. Since ingest() discards seq <= last_applied_seq, one
starve on a sequence the client had not sent yet stranded the stream one
ahead of arrivals permanently - both sides advancing in lockstep, every
honest packet discarded on arrival. The client's own input_lead release is
enough to trigger it, so input died for ~30 ticks roughly every 6.5s on a
clean LAN. Now only gives up on a sequence once strictly newer data proves
it lost. Silent-client stall and ring-overflow resync are unchanged.
(b) The seq-range guard bounded incoming seq against highest_ingested_seq,
which only advances inside ingest(), which that guard gates. After a ~2s
host hitch every packet was rejected forever with no diagnostic (600+
consecutive rejections reproduced via SIGSTOP). Third iteration of this
guard; each previous version bounded against a value only the accepted
path could advance. Adds an escape after 10 consecutive rejections, which
grants an attacker nothing the rate limiter does not already bound.
(c) The transitions gate reported PASS at 3.76% while input was completely
dead, because suppression stops _record_metrics - a worse outage yields
fewer samples and a LOWER rate. Now scales the required sample count with
run length and asserts the wire's server_stalled bit. Reverting both fixes
makes it fail at samples 292/600, server_stalled=true, input_lead=12.
Fixing (a) also explained a residual the review had already traced: 151 of
151 action-marker mismatches were the server repeating a stale action on a
starve, not a prediction defect. Marker is now 0.00% in all three
conditions (was 1.7-2.5%), and free-flight p99 improved to
0.141/0.168/0.154m from 0.170/0.176/0.184m.
Two pre-existing test defects fixed alongside: the ball gate asserted
RTT-masking on a link with no RTT (flaked 2 in 5; now asserted only at
rtt >= 20ms, 5/5 under latency), and the two-bot CI compared scores across
a 3-5s window (now polls the scores the server actually held; note
score_changed is emitted only on the client path).
QA: 72 unit tests; 60s free-flight at LAN/80+-20ms/5% loss; transition
gate in all three; 2.0s and 3.5s host-freeze recovery; ball contact x5;
two-bot CI x3; all three abuse roles; net/match_net/clock/lobby smokes.
Phase 4 sign-off still pending a human playtest at ~100ms RTT - the
milestone asks how it feels, which no gate here answers.
Lands the non-networked Phase 0 tasks from multiplayer-todo.md (ship/camera/
arena refactors, sim constants, background FPS handling) plus a first pass
at exposing graphics/performance settings (presets, resolution scaling,
vsync, FPS cap, perf overlay) and a GPU profiling harness for the
real-hardware follow-up in task 0.15b.
Retraining from scratch removes the constraint that blocked these: the
existing checkpoints in Game/bots/promoted/ no longer need byte-identical
geometry.
- Fix the goal aperture constants (were 1.85/1.65, now match
objects/goal.tscn's actual sensor exactly at 1.75/1.5) so a ball crossing
the visible edge can't fail to score.
- Cut a real navigable hole in each end wall's collision
(_build_end_wall_colliders), replacing the previous solid box — the ball
now genuinely enters the net instead of triggering the sensor a hair
before hitting a solid wall. Correct for both FLOOR and ELEVATED goal
modes via _goal_surround_bounds. A separate, slightly wider
GOAL_VISUAL_APERTURE_* pair keeps the collision hole exact while still
giving goal.gd's bezel/rim frame clearance to be seen against the hull cut.
- Resize the play volume 1.5x (INNER_HALF_X/Z/HEIGHT 12/18/12 -> 18/27/18) to
comfortably fit a 5v5 roster: updates every hand-authored literal in
arena_boundary.tscn/arena_base.tscn/the elevated arena variants that
doesn't derive from those constants, adds 5 spawn markers per team, and
rescales ship_observations.gd's normalization scales and arena_02's
cosmetic decoration/nebula-dust shader uniforms to match.
- Bake the ~170 runtime-generated CollisionShape3D nodes into the scene via
a new bake_colliders()/tools/bake_arena_boundary.gd instead of rebuilding
them on every load — a real load-time cost repeated in every parallel
headless training env. Colliders must be direct children of the
StaticBody3D to register at all, so bake_colliders() parents them onto
self and tags them with a group for idempotent re-baking, rather than
grouping them under an intermediate container node. _ready() self-heals:
it skips regenerating only when an existing bake's goal_mode metadata
matches the current one, so the FLOOR-mode bake in the shared scene is
never silently reused by an ELEVATED arena variant.
Josh Creek