feat(ModularBot): KNN gun, gunheat tracker, bullet shadows — inspired by DrussGT

New DrussGT-inspired modules:
- KNNGun: K-nearest-neighbor statistical targeting using GF density peaks
- GunheatTracker: dual-heat system (predicted + confirmed) for 1-2 tick lead
- ShadowTracker: computes GF regions safe from in-flight bullets (enemy wave dodge)

VirtualBodyTracker now integrates gunheat for earlier fire detection and shadows
for safe-zone multiplier (90% reduction in danger zones).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
2026-09-20 11:58:57 +02:00
parent 6d16081fcc
commit 651ce80620
4 changed files with 495 additions and 20 deletions
+259
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@@ -0,0 +1,259 @@
## KNN gun: K-nearest-neighbor statistical targeting inspired by DrussGT's DC gun.
## Builds a feature vector per scan, stores resolved GF outcomes, queries KNN at
## predict time and picks the GF with the highest Gaussian-weighted density.
## ponytail: linear scan O(n*k), cap at 2000 obs — KD-tree if perf matters at scale.
import std/[math]
import gun_harness/gun_interface
const
MaxObs = 2000 # ring-buffer cap
KCap = 50 # hard ceiling on K
KernelW = 0.3 # Gaussian kernel width multiplier
DensityBins = 60 # scan resolution for peak-GF search
type
Obs = object
feat: array[7, float] # normalized feature vector
gf: float # observed GF at wave resolution
KNNWave = object
fireX, fireY: float
fireBearing: float
feat: array[7, float]
KNNGun* = object
obs: seq[Obs]
obsHead: int # ring-buffer write index
waves: seq[KNNWave]
# per-tick cache
cachedTick: int
cachedWaveStored: bool
# rolling normalization ranges
featMin: array[7, float]
featMax: array[7, float]
# state for feature extraction
lastSpeed: float
lastDirection: float # +1 or -1
timeSinceDirChange: int
proc initKNNGun*(): KNNGun =
result.cachedTick = -1
result.lastDirection = 1.0
for i in 0..6:
result.featMin[i] = 1e18
result.featMax[i] = -1e18
# ── helpers ──────────────────────────────────────────────────────────────────
proc normFeat(g: KNNGun, raw: array[7, float]): array[7, float] =
for i in 0..6:
let span = g.featMax[i] - g.featMin[i]
result[i] = if span > 1e-9: (raw[i] - g.featMin[i]) / span else: 0.0
proc updateMinMax(g: var KNNGun, raw: array[7, float]) =
for i in 0..6:
if raw[i] < g.featMin[i]: g.featMin[i] = raw[i]
if raw[i] > g.featMax[i]: g.featMax[i] = raw[i]
proc buildFeatures(state: WorldState, lastSpeed, lastDir: float,
tsdc: int): array[7, float] =
let dx = state.enemyX - state.selfX
let dy = state.enemyY - state.selfY
let dist = sqrt(dx*dx + dy*dy)
let arenaDiag = sqrt(state.arenaWidth*state.arenaWidth + state.arenaHeight*state.arenaHeight)
# bearing to enemy (0°=East, standard Tank Royale)
let bearing = arctan2(dy, dx)
# angle of enemy heading relative to bearing
let relHead = state.enemyHeading - bearing
let latVel = state.enemySpeed * sin(relHead)
let advVel = state.enemySpeed * (-cos(relHead))
let accel = state.enemySpeed - lastSpeed # signed delta
# wall distances: how far enemy can travel fwd/bwd before hitting wall
# approximate: project enemy heading to nearest wall in each axis
let ex = state.enemyX
let ey = state.enemyY
let eh = state.enemyHeading
# forward distances to each wall in heading direction
let fwdX = if cos(eh) > 0: (state.arenaWidth - ex) / max(abs(cos(eh)), 1e-9)
else: ex / max(abs(cos(eh)), 1e-9)
let fwdY = if sin(eh) > 0: (state.arenaHeight - ey) / max(abs(sin(eh)), 1e-9)
else: ey / max(abs(sin(eh)), 1e-9)
let fwdDist = min(fwdX, fwdY)
# backward = forward in opposite direction
let bwdX = if cos(eh) < 0: (state.arenaWidth - ex) / max(abs(cos(eh)), 1e-9)
else: ex / max(abs(cos(eh)), 1e-9)
let bwdY = if sin(eh) < 0: (state.arenaHeight - ey) / max(abs(sin(eh)), 1e-9)
else: ey / max(abs(sin(eh)), 1e-9)
let bwdDist = min(bwdX, bwdY)
result[0] = abs(latVel) / 8.0
result[1] = clamp(advVel / 8.0, -1.0, 1.0) * 0.5 + 0.5 # shift to [0,1]
result[2] = clamp(dist / arenaDiag, 0.0, 1.0)
result[3] = clamp(accel / 2.0, -1.0, 1.0) * 0.5 + 0.5
result[4] = clamp(float(tsdc) / 100.0, 0.0, 1.0)
result[5] = clamp(fwdDist / arenaDiag, 0.0, 1.0)
result[6] = clamp(bwdDist / arenaDiag, 0.0, 1.0)
proc euclidean(a, b: array[7, float]): float {.inline.} =
for i in 0..6:
let d = a[i] - b[i]
result += d * d
result = sqrt(result)
# ── Gun interface ─────────────────────────────────────────────────────────────
proc predict*(g: var KNNGun, state: WorldState, bulletSpd: float): GunPrediction =
if bulletSpd <= 0.0:
return GunPrediction(x: state.enemyX, y: state.enemyY)
let dx = state.enemyX - state.selfX
let dy = state.enemyY - state.selfY
let dist = sqrt(dx*dx + dy*dy)
let bearing = arctan2(dy, dx)
let mea = arcsin(clamp(8.0 / bulletSpd, -1.0, 1.0))
# Track direction change — update state once per tick
if state.tick != g.cachedTick:
g.cachedTick = state.tick
g.cachedWaveStored = false
let relHead = state.enemyHeading - bearing
let latVel = state.enemySpeed * sin(relHead)
let newDir = if latVel >= 0: 1.0 else: -1.0
if newDir != g.lastDirection and abs(latVel) > 0.01:
g.timeSinceDirChange = 0
g.lastDirection = newDir
else:
inc g.timeSinceDirChange
# Store wave once per tick
if not g.cachedWaveStored:
let feat = buildFeatures(state, g.lastSpeed, g.lastDirection, g.timeSinceDirChange)
g.updateMinMax(feat)
g.waves.add KNNWave(
fireX: state.selfX,
fireY: state.selfY,
fireBearing: bearing,
feat: feat,
)
g.lastSpeed = state.enemySpeed
g.cachedWaveStored = true
# Cold start — no data yet
if g.obs.len == 0:
return GunPrediction(
x: clamp(state.selfX + cos(bearing) * dist, BotRadius, state.arenaWidth - BotRadius),
y: clamp(state.selfY + sin(bearing) * dist, BotRadius, state.arenaHeight - BotRadius),
)
# Build query feature vector (use current state)
let queryRaw = buildFeatures(state, g.lastSpeed, g.lastDirection, g.timeSinceDirChange)
let query = g.normFeat(queryRaw)
# KNN: linear scan, pick k = max(5, min(sqrt(n), KCap))
# Fall back to head-on when not enough neighbors to be meaningful
let n = g.obs.len
if n < 5:
return GunPrediction(
x: clamp(state.selfX + cos(bearing) * dist, BotRadius, state.arenaWidth - BotRadius),
y: clamp(state.selfY + sin(bearing) * dist, BotRadius, state.arenaHeight - BotRadius),
)
let k = max(5, min(int(sqrt(float(n))), KCap))
# Partial selection: maintain k-best by tracking max distance in result set
# ponytail: O(n*k) insertion; fine for n<=2000, k<=50
var bestDists = newSeq[float](k)
var bestGFs = newSeq[float](k)
var worstIdx = 0
var filled = 0
for i in 0..<n:
let normFeat = g.normFeat(g.obs[i].feat)
let d = euclidean(query, normFeat)
if filled < k:
bestDists[filled] = d
bestGFs[filled] = g.obs[i].gf
inc filled
if filled == k:
# find worst
worstIdx = 0
for j in 1..<k:
if bestDists[j] > bestDists[worstIdx]: worstIdx = j
elif d < bestDists[worstIdx]:
bestDists[worstIdx] = d
bestGFs[worstIdx] = g.obs[i].gf
worstIdx = 0
for j in 1..<k:
if bestDists[j] > bestDists[worstIdx]: worstIdx = j
if filled == 0:
return GunPrediction(
x: clamp(state.selfX + cos(bearing) * dist, BotRadius, state.arenaWidth - BotRadius),
y: clamp(state.selfY + sin(bearing) * dist, BotRadius, state.arenaHeight - BotRadius),
)
# Inverse-distance weights, Gaussian (same as DrussGT getBearingGaussian)
var sumDist = 1e-30
for i in 0..<filled: sumDist += bestDists[i]
let invAvg = float(filled) / sumDist
# Find GF range of neighbors
var gfMin = bestGFs[0]
var gfMax = bestGFs[0]
for i in 1..<filled:
if bestGFs[i] < gfMin: gfMin = bestGFs[i]
if bestGFs[i] > gfMax: gfMax = bestGFs[i]
# Scan DensityBins points in [gfMin, gfMax] for peak density
let span = max(gfMax - gfMin, 1e-9)
let step = span / float(DensityBins - 1)
var bestGF = gfMin
var bestScore = -1.0
for b in 0..<DensityBins:
let testGF = gfMin + float(b) * step
var score = 0.0
for i in 0..<filled:
let w = exp(-0.5 * (bestDists[i] * invAvg) * (bestDists[i] * invAvg))
let dg = (testGF - bestGFs[i]) / max(span * KernelW, 1e-9)
score += w * exp(-0.5 * dg * dg)
if score > bestScore:
bestScore = score
bestGF = testGF
let aimAngle = bearing + clamp(bestGF, -1.0, 1.0) * mea
let px = state.selfX + cos(aimAngle) * dist
let py = state.selfY + sin(aimAngle) * dist
GunPrediction(
x: clamp(px, BotRadius, state.arenaWidth - BotRadius),
y: clamp(py, BotRadius, state.arenaHeight - BotRadius),
)
proc onResult*(g: var KNNGun, e: FeedbackEvent) =
if g.waves.len == 0: return
let w = g.waves[0]
g.waves.delete(0)
let speed = bulletSpeed(e.bulletPower)
let mea = arcsin(clamp(8.0 / speed, -1.0, 1.0))
let ax = e.actualX - w.fireX
let ay = e.actualY - w.fireY
var delta = arctan2(ay, ax) - w.fireBearing
while delta > PI: delta -= 2.0 * PI
while delta < -PI: delta += 2.0 * PI
let gf = if mea > 1e-10: clamp(delta / mea, -1.0, 1.0) else: 0.0
g.updateMinMax(w.feat)
if g.obs.len < MaxObs:
g.obs.add Obs(feat: w.feat, gf: gf)
else:
# ring buffer
g.obs[g.obsHead] = Obs(feat: w.feat, gf: gf)
g.obsHead = (g.obsHead + 1) mod MaxObs
@@ -0,0 +1,121 @@
## Bullet shadow tracker — computes GF regions guaranteed safe because
## our in-flight bullets would intercept an enemy bullet traveling there.
##
## Geometry: 0° = East, X = East, Y = North (Tank Royale).
## Algorithm mirrors DrussGT EnemyWave.logShadow: simulate each of our bullets
## forward tick-by-tick, find where it intersects the expanding enemy wave ring,
## convert intersection points to GF values.
import std/math
import gun_harness/gun_interface
const
MaxBullets* = 32 ## slots; ponytail: simple array, 1 bullet/tick max
type
MyBullet* = object
x*, y*: float
headingRad*: float
speed*: float
alive*: bool
ShadowTracker* = object
bullets*: array[MaxBullets, MyBullet]
numSlots: int ## high-water mark
BulletShadow* = object
## GF range [gfLow, gfHigh] shadowed by one of our bullets for a wave.
gfLow*, gfHigh*: float
# ── bullet lifecycle ──────────────────────────────────────────────────────────
proc addBullet*(st: var ShadowTracker, x, y, headingRad, power: float) =
for i in 0..<MaxBullets:
if not st.bullets[i].alive:
st.bullets[i] = MyBullet(x: x, y: y, headingRad: headingRad,
speed: bulletSpeed(power), alive: true)
if i >= st.numSlots: st.numSlots = i + 1
return
proc removeBullet*(st: var ShadowTracker, idx: int) {.inline.} =
if idx >= 0 and idx < MaxBullets:
st.bullets[idx].alive = false
proc removeBulletNear*(st: var ShadowTracker, x, y: float) =
## Kill the live bullet slot closest to (x, y). Used when a hit event fires
## with the bullet's last known position.
var bestIdx = -1
var bestDist = 1e18
for i in 0..<st.numSlots:
if not st.bullets[i].alive: continue
let d = hypot(st.bullets[i].x - x, st.bullets[i].y - y)
if d < bestDist:
bestDist = d
bestIdx = i
if bestIdx >= 0:
st.bullets[bestIdx].alive = false
proc tick*(st: var ShadowTracker) =
## Advance all live bullets one tick (call once per game tick).
for i in 0..<st.numSlots:
if st.bullets[i].alive:
st.bullets[i].x += st.bullets[i].speed * cos(st.bullets[i].headingRad)
st.bullets[i].y += st.bullets[i].speed * sin(st.bullets[i].headingRad)
# ── shadow computation ────────────────────────────────────────────────────────
proc getShadows*(st: ShadowTracker,
waveFireX, waveFireY: float,
waveBearingRad: float, ## bearing from enemy to us at fire time
waveRadius: float, ## current radius of the wave (px)
waveSpeed: float): seq[BulletShadow] =
## For each live bullet, simulate it forward against the expanding wave ring.
## Returns GF ranges [gfLow, gfHigh] that are shadowed.
##
## Caller supplies wave parameters directly to avoid coupling to VBWave.
let maxEA = arcsin(min(8.0 / waveSpeed, 1.0))
if maxEA < 1e-9: return
for bi in 0..<st.numSlots:
let b = st.bullets[bi]
if not b.alive: continue
let dx = b.speed * cos(b.headingRad)
let dy = b.speed * sin(b.headingRad)
var prevDist = hypot(b.x - waveFireX, b.y - waveFireY)
# ponytail: 300-tick horizon covers arena diagonal / min bullet speed
for step in 1..300:
let bx = b.x + float(step) * dx
let by = b.y + float(step) * dy
let curDist = hypot(bx - waveFireX, by - waveFireY)
let waveAt = waveRadius + float(step - 1) * waveSpeed
let waveNext = waveRadius + float(step) * waveSpeed
# Bullet crossed the ring: was outside at step-1, inside at step, and approaching
if curDist < waveNext and prevDist > waveAt and curDist < prevDist:
# Angular half-width of bot at crossing distance
let ringR = (waveAt + waveNext) * 0.5
let angHalf = arctan(BotRadius / max(ringR, 1.0))
# Center angle of intersection point (absolute bearing from wave origin)
let centerAngle = arctan2(by - waveFireY, bx - waveFireX)
# Convert to GF
var off = centerAngle - waveBearingRad
while off > PI: off -= 2.0 * PI
while off < -PI: off += 2.0 * PI
let gfCenter = clamp(off / maxEA, -1.0, 1.0)
let gfHalf = angHalf / maxEA
result.add BulletShadow(
gfLow: clamp(gfCenter - gfHalf, -1.0, 1.0),
gfHigh: clamp(gfCenter + gfHalf, -1.0, 1.0),
)
break # one shadow per bullet per wave
if curDist > prevDist: break # bullet diverging — no future crossing
prevDist = curDist
proc isShadowed*(shadows: openArray[BulletShadow], gf: float): bool {.inline.} =
for s in shadows:
if gf >= s.gfLow and gf <= s.gfHigh: return true
false
@@ -0,0 +1,85 @@
## Gunheat wave prediction — mirrors DrussGT's enemyGunHeat / imaginaryGunHeat pattern.
## Tracks two heat values:
## confirmedHeat — reset from actual energy-drop fire detections
## predictedHeat — reset speculatively when enemy COULD fire (heat near 0)
## This lets us create a "predicted" wave 1-2 ticks before energy drop confirms it.
##
## Gun cooling rate in Tank Royale: 0.1/tick.
## Initial gun heat at round start: 3.0 → first possible fire at tick 30.
import std/math
import gun_harness/gun_interface
const
GunCoolingRate* = 0.1
InitialGunHeat* = 3.0
type
WaveEventKind* = enum
wePredicted ## enemy CAN fire this tick (heat just reached 0)
weConfirmed ## energy drop confirmed a fire last tick
WaveEvent* = object
kind*: WaveEventKind
fireX*, fireY*: float ## enemy position at (predicted/confirmed) fire time
bulletPower*: float
tick*: int
GunheatTracker* = object
confirmedHeat*: float ## heat from last confirmed fire (energy drop)
predictedHeat*: float ## heat from last predicted fire (imaginary wave)
prevEnemyEnergy*: float
canFireTick*: int ## tick when enemy next confirmed able to fire
proc initGunheatTracker*(): GunheatTracker =
result.confirmedHeat = InitialGunHeat
result.predictedHeat = InitialGunHeat
result.prevEnemyEnergy = 100.0
result.canFireTick = -1
proc resetRound*(gt: var GunheatTracker) =
gt.confirmedHeat = InitialGunHeat
gt.predictedHeat = InitialGunHeat
gt.prevEnemyEnergy = 100.0
gt.canFireTick = -1
proc tick*(gt: var GunheatTracker, state: WorldState): seq[WaveEvent] =
## Call once per tick with current world state.
## Returns any wave events created this tick (0, 1, or 2 entries).
# Cool both heat values
gt.confirmedHeat = max(0.0, gt.confirmedHeat - GunCoolingRate)
gt.predictedHeat = max(gt.confirmedHeat, gt.predictedHeat - GunCoolingRate)
# Check energy drop for confirmed fire (fired last tick)
let drop = gt.prevEnemyEnergy - state.enemyEnergy
gt.prevEnemyEnergy = state.enemyEnergy
if drop >= 0.1 and drop <= 3.0 and gt.confirmedHeat == 0.0:
let power = drop
# ponytail: subtract one coolingRate because they fired last tick, not this tick
gt.confirmedHeat = 1.0 + power / 5.0 - GunCoolingRate
gt.predictedHeat = gt.confirmedHeat
gt.canFireTick = state.tick
result.add WaveEvent(
kind: weConfirmed,
fireX: state.enemyX,
fireY: state.enemyY,
bulletPower: power,
tick: state.tick,
)
# Predicted wave: confirmedHeat just reached 0 AND no confirmed fire this tick
elif gt.confirmedHeat == 0.0 and gt.predictedHeat == 0.0:
# Enemy CAN fire. Guess power = 2.0 (sensible default, caller can override).
# ponytail: flat prior on power; upgrade to BulletPowerPredictor if needed
let guessedPower = 2.0
gt.predictedHeat = 1.0 + guessedPower / 5.0 + GunCoolingRate # +cooling: fire next tick
gt.canFireTick = state.tick
result.add WaveEvent(
kind: wePredicted,
fireX: state.enemyX,
fireY: state.enemyY,
bulletPower: guessedPower,
tick: state.tick,
)
+30 -20
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@@ -6,6 +6,8 @@
import std/math
import gun_harness/gun_interface
import movement_harness/movement_interface
import movement_harness/gunheat_tracker
import movement_harness/bullet_shadows
const
VB_BINS* = 31 ## GF bins from -1 to +1
@@ -34,12 +36,13 @@ type
waves: array[MaxWaves, VBWave]
waveCount: int
waveHead: int ## ring buffer head
prevEnemyEnergy: float
gunheat: GunheatTracker
shadows*: ShadowTracker ## our bullets in flight for shadow computation
arenaW, arenaH: float
proc initVirtualBodyTracker*(numModules: int): VirtualBodyTracker =
result.numModules = numModules
result.prevEnemyEnergy = 100.0
result.numModules = numModules
result.gunheat = initGunheatTracker()
# Seed bins so we have a uniform prior before any real hits
for i in 0..<VB_BINS: result.dangerBins[i] = 1.0
@@ -48,9 +51,9 @@ proc resetRound*(t: var VirtualBodyTracker, startX, startY, startHeading, startS
for i in 0..<t.numModules:
t.bodies[i] = VirtualBody(x: startX, y: startY,
heading: startHeading, speed: startSpeed)
t.waveCount = 0
t.waveHead = 0
t.prevEnemyEnergy = 100.0
t.waveCount = 0
t.waveHead = 0
t.gunheat.resetRound()
proc registerHit*(t: var VirtualBodyTracker, bulletPower: float, bulletHeadingDeg: float,
realX, realY: float) =
@@ -92,22 +95,21 @@ proc tick*[N: static int](t: var VirtualBodyTracker, state: WorldState,
## Per-tick update. cmds[i] is computeMove() output of module i.
## Call AFTER collecting all module commands for this tick.
# --- Fire detection ---
let drop = t.prevEnemyEnergy - state.enemyEnergy
t.prevEnemyEnergy = state.enemyEnergy
if drop >= 0.1 and drop <= 3.0:
let bspeed = 20.0 - 3.0 * drop
let bearingRad = arctan2(state.selfY - state.enemyY, state.selfX - state.enemyX)
let d = hypot(state.selfX - state.enemyX, state.selfY - state.enemyY)
# --- Fire detection via gunheat tracker ---
let waveEvents = t.gunheat.tick(state)
for ev in waveEvents:
let bspeed = 20.0 - 3.0 * ev.bulletPower
let bearingRad = arctan2(state.selfY - ev.fireY, state.selfX - ev.fireX)
let d = hypot(state.selfX - ev.fireX, state.selfY - ev.fireY)
let slot = t.waveHead mod MaxWaves
t.waves[slot] = VBWave(
fireX: state.enemyX,
fireY: state.enemyY,
fireX: ev.fireX,
fireY: ev.fireY,
fireBearingRad: bearingRad,
speed: bspeed,
radius: 0.0,
fireTick: state.tick,
startDist: d,
speed: bspeed,
radius: 0.0,
fireTick: ev.tick,
startDist: d,
)
t.waveHead = (t.waveHead + 1) mod MaxWaves
if t.waveCount < MaxWaves: inc t.waveCount
@@ -119,6 +121,9 @@ proc tick*[N: static int](t: var VirtualBodyTracker, state: WorldState,
if i < N:
advanceBody(t.bodies[i], cmds[i], state.arenaWidth, state.arenaHeight)
# --- Advance our bullets (for shadow tracking) ---
t.shadows.tick()
# --- Advance waves and score ---
# ponytail: O(waves * modules), small counts, fine
for wi in 0..<t.waveCount:
@@ -126,6 +131,9 @@ proc tick*[N: static int](t: var VirtualBodyTracker, state: WorldState,
var w = addr t.waves[idx]
if w.speed <= 0.0: continue
w.radius += w.speed
# Compute bullet shadows for this wave once; reuse across all virtual bodies
let waveShadows = t.shadows.getShadows(w.fireX, w.fireY,
w.fireBearingRad, w.radius, w.speed)
for mi in 0..<t.numModules:
let bx = t.bodies[mi].x
let by = t.bodies[mi].y
@@ -140,7 +148,9 @@ proc tick*[N: static int](t: var VirtualBodyTracker, state: WorldState,
if maxA >= 1e-9:
let gf = clamp(off / maxA, -1.0, 1.0)
let bin = gfToBin(gf)
t.dangerScore[mi] += t.dangerBins[bin]
# Shadow zones are guaranteed safe — reduce danger by 90%
let shadowMul = if isShadowed(waveShadows, gf): 0.1 else: 1.0
t.dangerScore[mi] += t.dangerBins[bin] * shadowMul
proc bestMovement*(t: VirtualBodyTracker): int =
## Returns index of module with lowest accumulated danger score.