From bbc9e511667650009db4849ee62e1cdcf91137c8 Mon Sep 17 00:00:00 2001
From: Davide Cappellini <signorsasso@gmail.com>
Date: Sun, 16 Aug 2026 16:40:28 +0200
Subject: [PATCH] =?UTF-8?q?fix(PPO=5FBot):=20state=20vector=20bearing=20us?=
 =?UTF-8?q?es=20game=20coords=20(north=3D0=C2=B0=20CW)?=
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Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 PPO_Bot/state_vector.nim     |  2 +-
 PPO_Bot/tests/test_state.nim | 21 +++++++++++++++++----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/PPO_Bot/state_vector.nim b/PPO_Bot/state_vector.nim
index 831dcde..e25b9ef 100644
--- a/PPO_Bot/state_vector.nim
+++ b/PPO_Bot/state_vector.nim
@@ -61,7 +61,7 @@ proc buildStateVector*(bot: BotStateData; enemy: EnemyTracker): Tensor[float32]
     # Relative bearing to enemy (signed, from bot perspective)
     let dx = enemy.current.x - bot.x
     let dy = enemy.current.y - bot.y
-    let absDir = (180.0 * arctan2(dy, dx) / PI + 360.0) mod 360.0
+    let absDir = (180.0 * arctan2(dx, dy) / PI + 360.0) mod 360.0
     let relBearing = ((absDir - bot.direction) + 540.0) mod 360.0 - 180.0
     result[16] = float32(relBearing / 180.0)
     # Distance to enemy
diff --git a/PPO_Bot/tests/test_state.nim b/PPO_Bot/tests/test_state.nim
index 0c7e03e..401b8d3 100644
--- a/PPO_Bot/tests/test_state.nim
+++ b/PPO_Bot/tests/test_state.nim
@@ -119,9 +119,9 @@ block testWallDistances:
   check abs(sv[21] - 0.875f32) < 0.001f32,  "right wall = 0.875"
 
 block testRelativeBearing:
-  # Bot at (0,0) dir=0°. Enemy at (0,100) → arctan2(100,0)=90° absolute.
-  # relBearing = (90 - 0 + 540) mod 360 - 180 = 90°
-  # normalized = 90 / 180 = 0.5
+  # Game convention: north=0°, CW. arctan2(dx,dy) used.
+  # Bot at (0,0) dir=0°. Enemy at (0,100) → due north → absDir=0°.
+  # relBearing = (0 - 0 + 540) mod 360 - 180 = 0°. normalized = 0/180 = 0.0
   var t = initEnemyTracker()
   t.update(0.0, 100.0, 0.0, 0.0, 100.0)
   let bot = BotStateData(
@@ -130,7 +130,20 @@ block testRelativeBearing:
     arenaWidth: 800.0, arenaHeight: 600.0,
   )
   let sv = buildStateVector(bot, t)
-  check abs(sv[16] - 0.5f32) < 0.01f32, "relative bearing = 0.5, got " & $sv[16]
+  check abs(sv[16] - 0.0f32) < 0.01f32, "relative bearing = 0.0 (due north), got " & $sv[16]
+
+block testRelativeBearingEast:
+  # Enemy at (100,0) → due east → absDir=90°.
+  # relBearing = (90 - 0 + 540) mod 360 - 180 = 90°. normalized = 90/180 = 0.5
+  var t = initEnemyTracker()
+  t.update(100.0, 0.0, 0.0, 0.0, 100.0)
+  let bot = BotStateData(
+    x: 0.0, y: 0.0, direction: 0.0, speed: 0.0, energy: 100.0,
+    gunDirection: 0.0, gunHeat: 0.0,
+    arenaWidth: 800.0, arenaHeight: 600.0,
+  )
+  let sv = buildStateVector(bot, t)
+  check abs(sv[16] - 0.5f32) < 0.01f32, "relative bearing east = 0.5, got " & $sv[16]
 
 block testHistoryPaddedWhenEmpty:
   var t = initEnemyTracker()