Editing Openai/694f5245-1110-800b-b182-7c2accd50046 (section)

=== Assistant: 哎呀又被「座標系鬼打牆」抓回去一次🤣🫠 ===
哎呀又被「座標系鬼打牆」抓回去一次🤣🫠
但這其實是好消息：代表它最近那次改動又把「world / screen / iso投影」混在一起了——左右反了跟房間 AREA 壞掉幾乎永遠是同一種病灶：用錯座標空間 or 反向套了兩次。

我直接給你一包「回歸修正 Patch 2.1」：專殺這兩個回歸 bug（Facing 反向＋Exit/Room bounds 壞），而且會加上 Debug 顯示，避免下次又默默壞掉 😈🛠️

==== 把下面整段貼給 GEMINI： ====

<syntaxhighlight lang="text">PATCH 2.1 / Regression Fix: Facing reversed + Room AREA broken (Isometric)

Goal:
* Prevent recurring regressions by enforcing a strict rule:
  ALL gameplay logic uses WORLD or TILE coordinates only.
  Screen/isometric projection is rendering-only.

A) Fix facing reversal (mouse aim)
* Do NOT decide facing using mouseX screen coords directly.
* Convert mouse screen position to aimWorld (inverse isometric projection), then:
  faceLeft  if (aimWorld.x < playerWorld.x)
  faceRight otherwise
* Inverse iso (with camera offset):
  sx = mouseX - camX
  sy = mouseY - camY
  worldX = ( sy/(tileH/2) + sx/(tileW/2) ) / 2
  worldY = ( sy/(tileH/2) - sx/(tileW/2) ) / 2
* Ensure sprite mirroring is applied in ONE place only (avoid double-flip):
  e.g., drawImage with scaleX = -1 OR choose mirrored frame, not both.

Debug (F2):
* Show: playerWorld.x, playerWorld.y
* Show: aimWorld.x, aimWorld.y
* Show: facing = LEFT/RIGHT
Acceptance:
* Aim mouse left of player => mech faces left (always).
* Aim mouse right of player => mech faces right (always).

B) Fix room AREA / exit trigger (after isometric changes)
* Exit triggers MUST be computed in WORLD/TILE coords, never screen coords.
* Best practice: define room size in TILE grid:
  roomTilesW, roomTilesH
  playerTile = worldToTile(playerWorld)
* Exit margins in tiles (e.g. 1~2 tiles):
  if playerTile.x <= 0 + margin => LEFT exit
  if playerTile.x >= roomTilesW-1 - margin => RIGHT exit
  if playerTile.y <= 0 + margin => UP exit
  if playerTile.y >= roomTilesH-1 - margin => DOWN exit
* Only render exit indicators for exits that exist in the room graph.

Debug (F1):
* Show current room coords (rx, ry)
* Show playerTile (tx, ty)
* Show roomTilesW/H and margin
* Print when trigger fires: "ENTER EXIT: LEFT/RIGHT/UP/DOWN"
Acceptance:
* Walking to an exit edge triggers transition reliably within 3 seconds.
* Indicators match actual exits (no fake arrows).

C) Regression guardrails (important)
* Never mix screenX/screenY into collision, exit, or facing logic.
* Keep a single source of truth:
  playerWorld, enemyWorld, bulletWorld, roomGraph in world/tile space.

</syntaxhighlight>

==== - Facing 反：就是它拿 mouseX（螢幕）去跟 playerX（世界）比，或 inverse 公式少了 cam offset / 係數，或 mirror 做了兩次 ====
* AREA 壞：就是 exit 判定還在用「菱形畫面邊緣」當作碰撞邊界，而不是用「tile/world」當邏輯邊界

➡️ 把 exit 改成「tile grid boundary」會超穩：不管你渲染怎麼歪、投影怎麼改，它都不會壞。

==== 你測試只要做兩個動作就行： ====
# 站著不動，滑鼠繞主角一圈 → 面向要跟著左右正確切
# 往任意邊緣一直走 → F1 必須跳出 “ENTER EXIT: …” 而且房間座標變化

如果這兩個過了，後面貼圖、敵人 sprite、特效就能安心堆上去🔥

你如果想更狠一點，我也可以再加一句「如果 F1/F2 debug 沒開就不算完成」——這種回歸 bug 只有用 debug 鐵欄杆才能永遠關住 🤣🧱