New engine movements/strafe.nim, selected by TR_MOVEMENT=strafe (default stays
tfil, byte-identical — test_tfil_commit_env.nim's 30 checks still pass).
Design (the owner's):
- AXIS = incoming bullet's direction when a bullet is in flight, else the
perpendicular of the enemy bearing. The body heading is kept inside a band
(TR_STRAFE_BAND, default 20 deg) around the perpendicular LINE; it turns only
when outside the band, and never turns to face a movement target.
- Candidate tiles on the perpendicular line through our position, both forward
and backward, within TR_STRAFE_REACH px, with a perpendicular jitter of
+/- TR_STRAFE_SPREAD tiles. A tile is acceptable when its path max heat is
<= PathDangerThreshold, the SAME safety rule TFIL uses.
- Move by SIGN only: setForward(+/-MaxSpeed>). Dwell is re-picked after a random
number of ticks in [TR_STRAFE_DWELL_MIN, TR_STRAFE_DWELL_MAX], on arrival, or
on a serious threat spike.
- Heat machinery is REUSED from the shipped mover, not re-implemented: the
exported heatDecay()/bulletMagScale() (j105 time-indexed model) and the
PillarHotness/PillarRadiance globals (j106 pillar-free default). The heat
shape is overridable via TR_STRAFE_CORRIDOR_HEAT/WALL_HOTNESS/WALL_RADIANCE
(defaults = the shipped TFIL field).
- GUI overlay: strafe line, threat axis, candidate tiles (safe/unsafe), chosen
target, sign-coloured movement ray, and the heading band.
Gates (offline, recorded DrussGT fixture, 20026 ticks):
- A TILE AVAILABILITY: shipped heat field -> a safe tile exists on only 36.6%
of picks (63.4% fall back to the least-hot tile); the ring retune
(corridor 5, wall 10/5) raises it to 91.9%.
- B PREDICTABILITY: reversal-interval entropy 5.84 bits vs TFIL 5.09; direction
entropy 1.00 both; long-lag autocorrelation ~0 for both (no periodic
component). Fewer reversals (710 vs 1453) and more full-speed ticks.
measurements: common_libs/tests/measure_strafe_gates.nim
Also registers TR_STRAFE_* in the boot env report (ModularBot_garage/src/
env_report.nim) and wires the engine into ModularBot.nim (hold -> strafe,
ram trigger -> rammer).
The default mover painted a 30/10 radiance blob on the arena centre even
though the arena has NO physical pillar there, creating a 4x4 tile
(144x144 px) exclusion zone over open centre floor. Set
PillarHotness/PillarRadiance to 0/0 in the shipped default (matching the
ring variant) and add TR_TFIL_PILLAR_ON=1 to restore the old 30/10 field
for A/B without a rebuild; registered in env_report.
Because the shipped default legitimately changed, the default-path parity
golden (fixtures/tfil_commit_default.golden) was regenerated from the NEW
default, with an explicit 'deliberate default change' note in the test so
a future failure is treated as a real regression.
Also register the three env reads job j102 added in common_libs/bitbrain
(TR_BITBRAIN_MODE / _DECAY_EVERY / _DECAY_SHIFT), which the env-report
guard was failing on.
Verification: test_env_report all green; test_tfil_commit_env 30/30.
Make danger a function of time-to-arrival instead of flat distance. Bullet
core/aura/corridor heat becomes magnitude(power) * decay(dt), dt = along/speed:
* decay(dt) = exp(-dt/tau) is a function of TIME; a fixed tau projects a
pixel reach of speed*tau, so fast/weak bullets get a longer slope and slow
ones a shorter one — derived from speed = 20 - 3*power, not hand-tuned.
tau = TR_TFIL_HEAT_TAU.
* magnitude(power) scales the near-end heat with power from DAMAGE
(calcBulletDamage = 4p, linear in p; SCORE_PER_BULLET_DAMAGE = 1.0). Hit
probability is FLAT across power (docs/env_reference.md), so risk does not
justify power scaling — the cost of the hit does. Floored at 1.0 so a weak
bullet's near end is never less dangerous than the flat model.
Gain = TR_TFIL_HEAT_POWER_GAIN.
Every source is already f(dt), so the time-indexed planner (evaluate a cell at
the tick the bot would ARRIVE, i.e. heatDecay(dt - arrivalDelay)) is a one-line
change. It is intentionally NOT implemented here.
Default path is byte-identical: with TR_TFIL_HEAT_TIME unset both factors are
exactly 1.0 (IEEE x*1.0 is exact), and the committed golden replay in
common_libs/tests/test_tfil_commit_env.nim (20,026 ticks) still passes
byte-for-byte against the pre-change mover. The debug corridor outline is also
drawn only to the model's reach when enabled, so the GUI shows the shortening.
Offline field measurement (common_libs/tests/measure_tfil_heat_time.nim,
46,054 fixture ticks, tau=9/gain=1): corridor reach drops from 443px
wall-to-wall to 143px mean (32% retained); fraction of tiles > 10 goes
0.61 -> 0.57; largest contiguous safe region 118 -> 140 tiles; mean
distance-to-nearest-safe-tile 49 -> 42px. Saturation stays high because wall
radiance + pillar alone are 44% of tiles over threshold and are untouched.
Registers the three knobs in env_report (report + known-name set).
The tile-change replan cancels the 15-tick movement commitment whenever OUR
tile changes. With GridSize=36 and speed up to 8 px/tick that is every ~5
ticks, so the commitment is cancelled by the motion it commands (measured:
96.9% of picks were tile-change replans, 33.8% of picks reversed direction).
Adds four env knobs, every default reproducing the shipped mover
byte-for-byte:
TR_TFIL_TILE_REPLAN self (default) | off | enemy
TR_TFIL_COMMIT_TICKS 15 (default)
TR_TFIL_NO_REV 0 (default)
TR_TFIL_COMMIT_LOG off (default, JSONL per-tick diagnostics)
- `off` honours the commitment; the danger replan stays the safety valve.
- `enemy` keys the cancel to the TARGET's tile displacement (the intent the
original comment claimed).
- `TR_TFIL_NO_REV` down-weights (never filters) tiles >90 deg from the travel
direction; the pool can never be emptied.
Default-path parity is guarded by test_tfil_commit_env.nim, which replays
tools/fixtures/tr_drussgt_vs_modularbot.jsonl and diffs every move command
against a golden generated from the pre-change build (git archive f842ac0).
env_report known-name list updated for the four new names.
re-plan 3x more often
Uncommitted working-tree change in `the_floor_is_lava_ring.nim`, confirmed by the
user as theirs. Committing it so it stops appearing in every job's `git status`.
WHAT IT DOES - a coherent "be far more afraid of bullets" strategy:
- BULLETS 2x hotter: BulletCore 10 -> 20, BulletAura 5 -> 10.
- Walls weaker and thinner: WallRadiance 10 -> 5; the `WallHotness` default
10 -> 15 (so the heat falls off over ~3 tiles instead of 1, with a higher peak).
- CENTRE PILLAR DISABLED: PillarHotness 30 -> 0, PillarRadiance 10 -> 0, so the
bot may now use the middle of the arena instead of treating it as a no-go zone.
- MUCH more reactive: CommitTicks 15 -> 5 and MinCommitTicks 5 -> 0, i.e. the
dodge target is re-chosen 3x more often and a replan is allowed immediately.
- `CorridorHeat` default 5 -> 10.
This applies ONLY to the ring mover, which is NOT the shipped movement (the default
is `tfil`), so the shipped bot is unaffected.
TWO FACTS RECORDED, not objections - it is the user's call:
1. `CorridorHeat = 10` now EQUALS `PathDangerThreshold = 10`. The earlier measured
taming set it to 5 precisely so a single corridor could no longer poison a path
on its own (a corridor at 10 puts every tile along it at/over the threshold).
That is part of what lifted the "band-weightable" fraction from 10.8% to 26.5%.
At 10 the range weighting gets less to work with.
2. UNMEASURED: this retune has not been A/B'd. The ring mover it modifies was
itself measured as a glass cannon (best offline hit rate, but round wins
16/49 -> 6/49, p=0.012). The two changes push in the same direction - hotter
bullets and more frequent replanning mean MORE dodging and LESS time spent
closing to the 100-200px band where our hit rate peaks (27% vs 5% at 450px).
Worth an A/B before drawing conclusions, but it is an experiment, not a
shipped change.
Follows the diagnosis that proactive straight-line ramming CANNOT work: both bots
have MAX_SPEED=8, so a pursuit cannot catch an evading equal-speed opponent.
Measured over 49 rounds per arm, opportunity -> contact was **0/6** (base), 0/40
(ring), 0/12 (ringhot). The only proactive conversion in the whole corpus came
from a FINISHER, and only because a <20-energy DrussGT stops fleeing (that episode
closed at 6-8 px/tick). Opportunity episodes never got below ~80px; one ran the
full 60-tick duration cap and closed only 198->171px; a perfectly aligned
full-speed one closed 195->114px then plateaued.
CHANGES
- **Finisher-only default.** `finisher` (<20 energy, dist<300, we are healthier)
and the rare `desperation` (both <5, dist<150) are kept; `opportunity` and the
speculative `plan` are OFF. Both are env-reenableable with no rebuild:
`TR_RAM_OPPORTUNITY=1` (tune via TR_RAM_OPP_DIST/MARGIN) and `TR_RAM_PLAN=1`.
Justification: it removes 100+ non-converting episodes per fixture at zero
measured loss (oldram vs base was p=0.69, damage 279 vs 284, survival 17/49 vs
16/49) - and each of those episodes spent up to 60 ticks driving STRAIGHT at
the enemy, abandoning the mover's dodging and disrupting aim.
- **`desperation` KEPT** deliberately: it is cheap and rare, fires only when both
bots are nearly dead at short range (a coin-flip where 0.6 contact can decide
it), and it is not the refuted straight-line pursuit.
- **THE BULLET-RAIN ABORT WAS DEAD CODE AND IS NOW FIXED.** `onHitByBullet`
accumulated raw bullet FIREPOWER while `TR_RAM_ABORT_DMG = 0.5` was documented
as a DAMAGE rate - so the bar was implicitly "sum of power > 7.5 over 15 turns"
and the maximum rate ever observed was 0.27. It now accumulates REAL ENERGY via
a `bulletDamage(power)` helper matching the server's `4p` / `6p-2` formula, and
`TR_RAM_ABORT_DMG` defaults to **2.0 energy/turn** (~30 HP over 15 turns):
"abort an in-progress ram if we take > 2.0 energy per turn". Same effective bar
for normal firepower, and it can now actually fire - the live run reports
`dmgRate=1.07/turn` where the old units said 0.27.
- **`ramStuckTicks` REMOVED.** It required `dist < 5px`; contact occurs at ~36px
(two 18px radii) and position rewind prevents getting closer, so it could never
increment. Only the 60-tick duration cap can now self-end a ram.
LIVENESS (measured, default config, vs a charging Java RamFire, 3 rounds):
default -> `[ram] ON reason=finisher` x3, `reason=opportunity` x0
TR_RAM_OPPORTUNITY=1 -> `reason=opportunity` x4, `reason=finisher` x2
So the opportunity states DID occur and are suppressed by the new default - the
removal is real, not an arm that never fires. A line also read
`[ram] OFF reason=duration dmgRate=1.07/turn`, confirming the new energy units.
Adds docs/ramming_negative_result.md (70 lines) recording the question, the five
diagnostic answers, the geometric reason, the finisher exception, the two dead
code paths, and an explicit "do not re-attempt a proactive straight-line ram; if
point-blank forcing is ever wanted it is an INTERCEPTION/cornering movement
problem" note - the same pattern that stopped the corpse bug recurring.
Guards: test_ram_decision 40 (was 28), test_gun_harness 39, test_vbullet_metric 11,
test_power_selection 3, test_adaptive_radar 41, test_tfil_ring_weights 24,
test_power_policy 26, test_rack_membership 48, test_selector_tiebreak 19,
test_tm_pattern_registration 20, test_vbullet_admit_gate 12,
acceptance_offline_vs_online 12/12. ModularBot compiles.
Honest note: the abort-threshold fix is a real (tiny) behaviour change, NOT
measured-neutral - it only bites while a finisher ram is under sustained fire,
which is exactly the user's stated wish. The finisher-only removal itself is
measured-neutral per the given A/B.
The user watched 1v1 and melee runs and saw ram opportunities arise that the bot
declined: "there were moments where the bot could jump over the enemy and shred
it but shot it down instead."
DIAGNOSIS - a chicken-and-egg loop. `ramOpportunity` required dist < 50px, but
an offline measurement over 15 rounds vs DrussGT found the closest approach was
118.7px and the <50px trigger had NEVER fired: the mover has no reason to close,
so the trigger waited for a proximity nothing created. The MECHANISM to close
already existed (the ring mover expresses a ram as band=(0,50)); what was
missing was a decision that fires at a range the bot can actually close from.
Changes:
- opportunity gate relaxed: dist 50 -> TR_RAM_OPP_DIST (200), energy margin
+30 -> TR_RAM_OPP_MARGIN (15). Both env-tunable, no rebuild needed.
- New pure module `common_libs/movements/ram_decision.nim` holding the trigger
and abort logic (no battle/API deps), so it is unit-testable.
- BULLET-RAIN ABORT (the user asked for this earlier): `onHitByBullet` now
accumulates `e.bullet.power` into a 15-turn ring; damageRatePerTurn = sum/15;
an in-progress ram aborts when rate > TR_RAM_ABORT_DMG (0.5/turn). On abort:
isRamming=false, cooldown 30, TARGET KEPT, and the mover returns to the normal
range band. It never stops the bot.
- Opt-in, DEFAULT-OFF `plan` trigger for "change of plan when the gun duel is
failing" (dist<250, margin+20, selected gun's pooled virtual rate < 0.05).
Left off because a cold gun reads 0.0 and would qualify - speculative.
- `TR_RAM_LOG=1` change-gated line: `[ram] ON reason=opportunity dist=143
selfE=78 enemyE=41 cap=3.0 band=[0,50]` / `[ram] OFF reason=bulletRain`.
- Existing cooldown/duration/stuck machinery untouched (stuck>10 or duration>60
-> abort + cooldown 30). A refactor bug that briefly DROPPED the
`ramCooldownTicks == 0` gate was caught and fixed.
Trigger set (first match wins): finisher (dist<300, enemy<20, we are healthier);
opportunity (dist<200, we lead by 15+); desperation (both <5, dist<150); plan
(off). All require enemy>0, a valid target, and no cooldown.
Proof the intent now fires at a closable distance (28/28 unit checks):
PASS: opportunity fires at dist 143 with a 37-energy lead <- the exact case
PASS: old gate (dist<50, margin+30) does NOT fire at 143 <- the old bug
PASS: fires at 199px / does NOT fire at 201px
+ margin, finisher priority, desperation, plan on/off, window mean, abort
threshold checks.
HONEST FRAMING: ram damage is 0.6 per CONTACT EVENT, one-shot (collision
resolution rewinds positions so contacts do not stream) - small next to a p=3.0
bullet hit (16). The payoff is that point-blank forces hit probability toward 1,
so heavy bullets stop missing and E[dE]=p(3P-1) turns positive above P=1/3; ram
damage also scores 2.0/point (highest in the game) and a ram kill carries a 0.30
bonus vs 0.20. So this is "force the fight to point-blank", not "the ram shreds
them". Base rate is rare (2 collisions in the whole fixture corpus).
Guards: test_ram_decision 28 (new), test_power_policy 26, test_gun_harness 39,
test_vbullet_metric 11, test_power_selection 3, test_adaptive_radar 41,
test_tfil_ring_weights 24. Compiles (release).
UNVERIFIED: the live effect. No A/B has run, and whether the mover actually
reaches contact is unproven.
New mover `the_floor_is_lava_ring.nim`, a COPY of `the_floor_is_lava.nim` (which
stays byte-identical - the user explicitly wants the current TFIL preserved).
Selected only via `TR_MOVEMENT=tfil_ring`; the default stays `tfil`.
WHY: our measured real hit rate vs DrussGT is strongly range-dependent - 21.6%
at 0-100px, 27.1% at 100-200px, 19.3% at 200-300, 10.9% at 300-400, 6.8% at
400-600, 5.4% at 600-800 - but we shoot from ~450px on average. Plain TFIL has
no range preference at all.
THE ONE CHANGE: the final tile draw is re-weighted toward a target band.
rangeW(d) = 1.0 if lo<=d<=hi; exp(-((lo-d)/K)^2) if d<lo; exp(-((d-hi)/K)^2) if d>hi
w_i = rangeW(d_i)^(1/T); chosen ~ Categorical(w)
FLAT TOP on purpose: a Gaussian centred on the band midpoint would collapse the
band to a point and destroy the within-band hedge. `T` is the only knob;
`TR_TFIL_RANGE_TEMP=0` gives plain `rand(candidates.high)` - the exact control
arm. Safety stays a HARD constraint: the weighting only reorders the draw among
the pool the old code already accepted, so it can never pick a tile the old code
rejected (monotone refinement). Small pools (<4) stay uniform.
Randomness is deliberately KEPT: a measured A/B showed committing to the "best"
tile made real hit rate WORSE (7.02% -> 5.10%), so the distribution is tilted,
never removed.
HEAT TAMING (ring copy only; env-overridable):
TR_TFIL_CORRIDOR_HEAT 20.0 -> 5.0
TR_TFIL_WALL_HOTNESS 30.0 -> 10.0
Rationale, measured: `CorridorHeat=20` is TWICE `PathDangerThreshold=10`, so a
single corridor could poison a path by itself; `WallHotness=30` with
`WallRadiance=10` put the outer two tile rings over threshold on their own.
Per-source shares of total lava: wall 60.6%, corridor 25.4%, pillar 7.4%,
everything else <3%.
MEASURED EFFECT (primary fixture, 20,026 ticks / 15 rounds, field identity
verified max diff 0.000e+00):
metric original(20/30) ring(5/10)
band-weightable ticks 10.79% 26.45%
mean safeTiles/tick 15.19 85.04
ticks with 0 safe (pre-fallback) 58.5% 7.5%
safePool >= 4 39.05% 92.47%
>=1 safe tile in 100-200px 11.84% 26.64%
MEAN CLOSEST-SAFE-TILE DISTANCE 397.78px 284.84px
tiles > 10 threshold 0.61 0.15
The 397.78px figure is why the bot stayed far away: the safety filter left
nothing safe near the target, and 397px is our WORST range. Control: setting
corridor=20 wall=30 reproduces the original baseline exactly.
CEILING, honestly: even at corridor 0 / wall 0 only ~40% of ticks are
band-weightable, so no constant tweak fully unlocks the range weighting.
Ram unification: the ring mover takes a `band` field; ramming becomes just
`band=(0,50)`, so there is one movement engine. The `tfil` path is unchanged.
Observability: magenta annulus at the band edges, candidates tinted by weight,
chosen tile marked; one `[tfil_ring]` log line on change (now including
corridorHeat/wallHotness).
Guards: test_tfil_ring_weights 24/24 (new, pure, no battle), test_gun_harness 39,
test_vbullet_metric 11, test_power_selection 3, test_adaptive_radar 41.
UNVERIFIED: the mover's live effect. It has not been run in a battle yet.
- 30-tick cooldown after ghost-stuck/timeout ram exit prevents re-entry loop
- enemy_tracker.update() skips dead bots to prevent same-tick scan resurrection
- TFIL graphics cleared when ramming is active movement
- [config] logs: white base with green-highlighted changes only
- [ram:enter] logs trigger reason and key values on false→true transition
- [death] and [target-invalid] logs retained for diagnostics
PhantomMeteor:
- Ram finisher: charge at enemy when <200px and their energy <10
- Ram opportunity: charge when <60px and we have >20 energy advantage
- Integrated gunheat tracker for 1-2 tick earlier wave detection
- Distance control: smooth linear ramp toward preferred engagement distance
- Phantom range expanded 150→250px to catch closer threats
WaveSurfer:
- Wall-aware dodge bin selection: penalize bins leading off-arena
- Dodge timing: predict future position 15 ticks ahead for safety
- Distance control: radial blend when outside deadband (350±50px)
- Wall escape: invert strafe if pushing further into wall, blend toward center
ModularBot:
- Wired KNN gun (purple/magenta)
- Shadows tracked for movement (safer GF prediction)
- Bullet lifecycle management (onBulletFired/onBulletHitBot/onBulletHitWall)
- Unified phantom_meteor movement (wave_surfer unplugged)
- Config logging on round start + gun switch
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
SirStone