fix(guns): per-bin wave queues unbreak GF/DecayGF/KNN learning; fix vbullet drops

Wave queues (guess_factor, decay_gf, knn_gun): predict() stored ONE wave
per tick while onResult() popped one per resolved bullet (~4/tick), so the
queue drained to empty within a few dozen ticks, ~3 of every 4 resolutions
returned without learning, and the survivor paired with a same-tick wave
(bearingDelta ~= 0) pinning the histogram at centre. PROOF: GF.vHits ==
HeadOn.vHits and DecayGF.vHits == HeadOn.vHits byte-for-byte in every one
of 50 rounds — the guns had degenerated to HeadOn.

Now each gun keeps a per-bin FIFO with an O(1) head cursor. At most one
push per (tick, bin) so the fire site's 5th predict() call is a no-op, and
onResult pops the oldest wave of its OWN bin via e.bulletPower. Aiming
math untouched (it was already correct: 0 deg = East, CCW+).

maxBullets 2048 -> 8192: the rack spawns 52 bullets/tick so the ring wrapped
every ~39 ticks while a long power-3 shot needs ~90, silently discarding
unresolved bullets and biasing every measured hit rate by range. Added a
droppedBullets counter so a future overflow is measurable, and wavePushes/
waveStarved counters on the three guns. After the fix: vDropped = 0 and
vStarved = 0 across all 48 recorded rounds.

fitnessFor is now exported, deterministic (enemies iterated in ascending id
order) and shared by the selector and the stats dump, replacing a hand-rolled
merge in ModularBot that never advanced its window head.

Round lines gain additive keys: vDropped, vStarved.
This commit is contained in:
2026-09-20 22:27:52 +02:00
parent a90a0cc9b5
commit 0cc682152d
5 changed files with 205 additions and 75 deletions
+57 -25
View File
@@ -1,14 +1,16 @@
## Guess-factor gun: statistical targeting via GF histogram.
## Bins: 31, ranging GF -1 (max CW escape) to +1 (max CCW escape).
## Learns from virtual bullet outcomes; caches wave state per-tick.
## Learns from virtual bullet outcomes; queues one wave per (tick, power bin).
import std/[math, strformat]
import gun_harness/gun_interface
import gun_harness/virtual_bullets as vb # PowerBins: the four power bins the harness spawns
const
GFBins = 31
GFPrior = 0.1
DebugGF* = false
WaveCompactAt = 64 ## compact a bin's wave seq once this many entries are consumed
type
Wave = object
@@ -18,15 +20,20 @@ type
GFGun* = object
bins: array[GFBins, float]
waves: seq[Wave] # pending unresolved waves
# per-tick cache: store wave only once across multiple power-bin calls
cachedTick: int
cachedWaveStored: bool
# One wave queue per power bin. The owning bin is fixed at push time (from the
# bulletSpeed argument) and at pop time (from FeedbackEvent.bulletPower), so a
# resolved bullet is always paired with a wave from its own bin.
waves: array[len(vb.PowerBins), seq[Wave]]
waveHead: array[len(vb.PowerBins), int] # O(1) pop cursor into waves[bin]
waveStoredTick: array[len(vb.PowerBins), int] # last tick a wave was queued for this bin
wavePushes*: int # total waves enqueued (== one per (tick, bin))
waveStarved*: int # onResult found an empty queue for its own bin
debugGraphics*: bool
proc initGFGun*(): GFGun =
result.cachedTick = -1
result.debugGraphics = false
for b in 0..<len(vb.PowerBins):
result.waveStoredTick[b] = -1
# Seed with a head-on prior: triangular bump at bin 15 (GF=0).
# Prevents the cold-start tie-break to GF=-1 (bin 0) that poisons early fitness.
let center = (GFBins - 1) div 2 # = 15
@@ -47,6 +54,34 @@ proc peakBin(g: GFGun): int =
best = i
best
proc binForSpeed(spd: float): int {.inline.} =
## Map a virtual-bullet speed back to its power-bin index. All four bin speeds
## are exactly representable floats; the epsilon is belt-and-braces only.
for i in 0..<len(vb.PowerBins):
if abs(spd - bulletSpeed(vb.PowerBins[i])) < 1e-6:
return i
-1
proc binForPower(power: float): int {.inline.} =
## Map a FeedbackEvent.bulletPower back to its power-bin index.
for i in 0..<len(vb.PowerBins):
if abs(power - vb.PowerBins[i]) < 1e-6:
return i
-1
proc takeOldestWave(g: var GFGun, binIdx: int): (bool, Wave) =
## Pop the oldest unresolved wave for this bin (O(1) amortized via waveHead).
## Returns (false, default) when the bin's queue is empty.
if binIdx < 0 or g.waveHead[binIdx] >= g.waves[binIdx].len:
return (false, Wave())
result = (true, g.waves[binIdx][g.waveHead[binIdx]])
inc g.waveHead[binIdx]
# Amortized O(1): drop the consumed prefix once it dominates the queue.
if g.waveHead[binIdx] >= WaveCompactAt and
g.waveHead[binIdx] * 2 >= g.waves[binIdx].len:
g.waves[binIdx] = g.waves[binIdx][g.waveHead[binIdx] .. g.waves[binIdx].high]
g.waveHead[binIdx] = 0
proc predict*(g: var GFGun, state: WorldState, bulletSpeed: float): GunPrediction =
if bulletSpeed <= 0.0:
return GunPrediction(x: state.enemyX, y: state.enemyY)
@@ -57,18 +92,17 @@ proc predict*(g: var GFGun, state: WorldState, bulletSpeed: float): GunPredictio
let bearing = arctan2(dy, dx)
let mea = arcsin(clamp(8.0 / bulletSpeed, -1.0, 1.0))
# Store one wave per tick regardless of how many power bins call us
if state.tick != g.cachedTick:
g.cachedTick = state.tick
g.cachedWaveStored = false
if not g.cachedWaveStored:
g.waves.add Wave(
# Queue at most one wave per (tick, power bin). The fire site's extra predict()
# call for the selected bin lands on the same tick and reuses the queued wave.
let binIdx = binForSpeed(bulletSpeed)
if binIdx >= 0 and g.waveStoredTick[binIdx] != state.tick:
g.waves[binIdx].add Wave(
fireX: state.selfX,
fireY: state.selfY,
fireBearing: bearing,
)
g.cachedWaveStored = true
g.waveStoredTick[binIdx] = state.tick
inc g.wavePushes
let peak = g.peakBin()
let peakGF = indexToGF(peak)
@@ -78,7 +112,7 @@ proc predict*(g: var GFGun, state: WorldState, bulletSpeed: float): GunPredictio
let py = state.selfY + sin(gfAngle) * dist
when DebugGF:
echo fmt"[gf-dbg] predict: peakGF={peakGF:.2f} peakBin={peak} mea={radToDeg(mea):.1f}° aimAngle={radToDeg(gfAngle):.1f}° waves={g.waves.len}"
echo fmt"[gf-dbg] predict: peakGF={peakGF:.2f} peakBin={peak} mea={radToDeg(mea):.1f}° aimAngle={radToDeg(gfAngle):.1f}° waves={g.waves[binIdx].len}"
GunPrediction(
x: clamp(px, BotRadius, state.arenaWidth - BotRadius),
@@ -86,17 +120,15 @@ proc predict*(g: var GFGun, state: WorldState, bulletSpeed: float): GunPredictio
)
proc onResult*(g: var GFGun, e: FeedbackEvent) =
## Called when a virtual bullet resolves. Match the wave by predicted point,
## compute actual GF, and increment the histogram with a smoothing kernel.
## We don't have the original wave tick here, so we use the prediction coords
## to identify and remove the matching wave.
## ponytail: O(n) scan over waves; waves list stays tiny (< a dozen at a time)
if g.waves.len == 0:
return
## Called when a virtual bullet resolves. Pop the OLDEST unresolved wave from
## this bullet's own power-bin queue, compute the actual GF, and smooth-add it.
let binIdx = binForPower(e.bulletPower)
if binIdx < 0: return
# Pop the oldest wave (FIFO matches bullet resolution order)
let w = g.waves[0]
g.waves.delete(0)
let (found, w) = g.takeOldestWave(binIdx)
if not found:
inc g.waveStarved
return
# Recompute mea from the actual bullet power (correct per-bin, not the cached first-bin mea)
let speed = bulletSpeed(e.bulletPower)