The real cause of the ship/bullet separation, which the previous commit only
half-addressed. The server dropped inputs past a lead of 12 while the client
only re-synced past 16, so a client whose lead drifted into 13-16 had every
input silently rejected while believing its timing was fine. The server coasted
on held_input and then stopped; the client kept predicting. The two separated
permanently and the reconciler fought it every snapshot -- "shoved around".
It needed two independent clocks to drift, hence "only after some time", and
nothing in the loop could notice, hence "then persists". The listen-server
diagnostic could never reproduce it: one process, one physics tick, lead
constant by construction.
Two defences: INPUT_MAX_LEAD (40) is now far wider than the client's correction
band (3..20), asserted by tests/unit/test_input_lead.gd so narrowing it fails a
test; and an ack-stall detector re-syncs when last_input_tick stops advancing,
which catches the whole class regardless of cause -- lead alone cannot, because
a wrong lead looks normal from the client. diag_prediction.gd now injects a +14
tick drift and exits non-zero unless the gap recovers.
Also:
- No invulnerability frames. Every bullet that touches a player lands; i-frames
made dense patterns safer than sparse ones, which inverts the genre. Measured:
a stationary player survives ~13.6s of the Warden's opening phase, ~17.5s
drifting. spawn_grace remains the only invulnerable state.
- Death is exited with a HUD button, disabled for the first 3s. The lockout is
enforced in SimWorld, not just by graying the button -- a client that ignores
its own UI still waits. The interact key no longer respawns.
- Joining a server that is not there no longer drops the player into an empty
lobby they cannot act in. Net.join() only creates an ENet object; the game
scene now waits for the server to actually place us in an instance, with an
8s timeout, and headless runs exit non-zero instead of idling.
Protocol 2 -> 3. 98 tests; check.sh, test.sh and smoke.sh all pass.
(1) Bullets appeared to trail the ship. Two independent causes, measured with
the new tools/diag_prediction.gd rather than guessed at:
- ServerRuntime ticked before ClientRuntime, so input sampled on frame N was
not consumed until frame N+1, leaving the drawn ship a constant one tick
(4.00px at 240 u/s) ahead of the authoritative one that bullets spawn from.
ClientRuntime now sets process_physics_priority = -10. Gap on a listen
server: 4.00px -> 0.10px mean, 0.30px worst.
- PLAYER_MUZZLE_OFFSET was PLAYER_RADIUS + 6 = 12px against a 13px drawn
ship, so bullets were born inside the sprite. Regression from the previous
commit's hitbox shrink; it now derives from PLAYER_VISUAL_RADIUS.
(2) No more timed respawn. A downed player stays down until they ask for the
hub (E), which is an ordinary input -- the server has no "revive me" message.
(3) Escape channel 3s -> 1s, and damage no longer cancels it. An interruptible
channel makes killing the process strictly better than using the button, so a
dropped connection now runs the same channel: the player stays in the world as
linkdead, still killable, and is only released once it completes. Instances
refuse to close while a linkdead body is resolving, or a solo drop would delete
it on the next tick and hand the exploit straight back.
(4) Escape opens an in-game menu: return to hub (routed through the same held-
escape channel, not a new message), disconnect, quit.
(5) Server pushes a roster so the hub shows who is online and which dungeon
they are in. Entering a dungeon grants 2s arrival protection -- invulnerable
AND weapons-cold, since invulnerability alone would make the spawn a free
firing position -- flagged in the snapshot and drawn on every protected ship.
(6) Cleared dungeons hold the party 30s (was 5s) with a visible countdown.
(7) The hub's grey circle was a 100k-HP target dummy that read as scenery. Now
drawn as a bullseye so its purpose is legible.
Protocol version 1 -> 2. 91 tests (was 78); smoke.sh gains a bot that is
SIGKILLed mid-dungeon to prove the disconnect path end to end. check.sh,
test.sh and smoke.sh all pass.
The lobby connect menu and three pieces of the HUD (hit-flash overlay, boss
bar centering, death-message centering, hint label) were all silently broken
by the same Godot gotcha: set_anchors_preset(preset) with the default
keep_offsets=false does NOT zero the offsets to the preset's margins -- it
recomputes them to preserve the control's *current* rect, which for a
freshly constructed Control is (0,0). Anchors end up correct; the actual
rect stays pinned to the top-left corner regardless. Fixed by switching to
set_anchors_and_offsets_preset() everywhere a Control is built in code, and
by using offset_left/offset_top (anchor-relative) instead of .position
(absolute) for the HUD hint label. Documented as gotcha #5 in CLAUDE.md.
Also split PLAYER_RADIUS into two constants: PLAYER_RADIUS (6.0, the
authoritative hitbox used by SimWorld) and PLAYER_VISUAL_RADIUS (13.0,
view-only, used by world_view.gd). The client renders every ship a little
late relative to the server -- interpolation delay, reconciliation
smoothing -- so a hitbox that matched the sprite would let bullets connect
against a ship the player watched dodge clear of them. A smaller hitbox
means the occasional bullet visibly clips the sprite without a hit, which
reads as more forgiving of latency than the reverse.
Verified headlessly: a throwaway scene instantiating MainMenu/HUD under a
real 1280x720 viewport, asserting the panel is centered and _canvas.size /
hint position resolve correctly, before and after each fix. check.sh,
test.sh (78/78) and smoke.sh all pass.
Top-down twin-stick bullet-hell, Godot 4.7, server-authoritative dedicated
server with client-side prediction. Clients send input only; the server
resolves every hit for both players and enemies (no PvP).
- SimWorld: whole simulation as plain RefCounted objects (no nodes, no
physics server), ~0.24ms/tick at peak load -- runs headless for free and
drives 78 tests in under a second
- BulletPool: struct-of-arrays bullet storage, replicated as spawn/despawn
events rather than per-tick state
- Emitter framework (Ring/AimedSpread/WallGap/ArcSweep) shared by trash
enemies and bosses -- a new boss is data in src/content/content.gd, no
simulation changes
- The Warden of the Fold: stationary 4-phase boss built entirely on that
format
- Lobby hub with a portal into on-demand dungeon instances; one process
hosts the hub plus every concurrent dungeon
- Emergency escape: 3s server-owned channel, cancelled by damage
- tools/check.sh, test.sh (GUT), smoke.sh (real server + bot clients over
ENet), bench.gd; git hooks wired to the same scripts
- docs/ARCHITECTURE.md, NETCODE.md, WORKFLOW.md, ROADMAP.md
claude