fix: bug of RandomlyTurnNPC

Author: kt3k

model/character.ts

@@ -383,7 +383,8 @@ export abstract class Character implements IActor {
         }
         return this.#getNextMovePlanWrap(field)
       } else if (nextAction.type === "turn") {
-        switch (nextAction.dir) {
+        const dir = nextAction.dir
+        switch (dir) {
           case "north":
             this.setDir("up")
             break
@@ -396,6 +397,17 @@ export abstract class Character implements IActor {
           case "east":
             this.setDir("right")
             break
+          case "left":
+            this.setDir(turnLeft(this.dir))
+            break
+          case "right":
+            this.setDir(turnRight(this.dir))
+            break
+          case "back":
+            this.setDir(opposite(this.dir))
+            break
+          default:
+            dir satisfies never
         }
         return this.#getNextMovePlanWrap(field)
       } else if (nextAction.type === "wait") {
@@ -705,7 +717,7 @@ export class RandomlyTurnNPC extends Character {
   override getNextMovePlan(field: IField): MovePlan {
     this.#counter -= 1
     if (this.#counter <= 0) {
-      const { randomInt, choice } = seed(this.age.toString())
+      const { randomInt, choice } = seed(field.time.toString())
       this.#counter = randomInt(8) + 4
       // If the character can keep going in the current direction,
       // it will keep going with 96% probability.
@@ -718,12 +730,17 @@ export class RandomlyTurnNPC extends Character {
       if (randomInt(2) === 0) {
         return { type: "jump" }
       }
-      const nextCandidate = [UP, DOWN, LEFT, RIGHT] as Dir[]
+      const nextCandidate = DIRS.filter((d) => this.canGo(d, field))
+      if (nextCandidate.length === 0) {
+        this.enqueueAction({
+          type: "turn",
+          dir: choice(["left", "right"]),
+        })
+        return undefined
+      }
       return {
         type: "go",
-        dir: choice(nextCandidate.filter((d) => {
-          return this.canGo(d, field)
-        })),
+        dir: choice(nextCandidate),
       }
     }
     return undefined

model/types.ts

@@ -90,5 +90,15 @@ export type MovePlan =
 export type Action =
   | MovePlan
   | { readonly type: "speed"; readonly change: "2x" | "4x" | "reset" }
-  | { readonly type: "turn"; readonly dir: "north" | "south" | "west" | "east" }
+  | {
+    readonly type: "turn"
+    readonly dir:
+      | "north"
+      | "south"
+      | "west"
+      | "east"
+      | "left"
+      | "right"
+      | "back"
+  }
   | { readonly type: "wait"; readonly until: number }

static/map/block_0.0.json

@@ -9016,11 +9016,11 @@
     "00010022220000201121200000000000000000000333333333333333333000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000033330033000000111000000000100003300000000000000",
     "00010000000010001202000333333333333333333333333333333333333330000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003333033000000100101110101000003300000000000000",
     "10020000000010001000003333333333333333333000000000000000033333000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000033333000010100100000101000003300000000000000",
-    "11000000001110101000033300300000000000000000000000000000000333000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003333000000111001010010000003300000000000000",
-    "22101011102220202000333000300000000000000000000000000000000033333333333333333333333333333333333333333333333333333000000000000000003333000000000000000000000000033000000001000011100000003300000000000000",
-    "00202022100000000003330000300000000000000000000000000000000033333333333333333333333333333333333333333333333333333333333333333333333333333000000000000000000000033000000100001001100110003300000000011100",
-    "01000000210001000033300001311111111111111111111111011000000000000000000000330000000000000000000000000000444444333333333333333333333333333330000000000000000000033000000011000000000100003300000000011200",
-    "02110000020012104333000001322222222222222221222222021110000000000000000000330000000000000440444000000000440004444044400000000000000000003333300000000000000000033000000110101101100010003300000100111010",
+    "11000000001110101000033300300000000000000000000000000000000333000000000000000000000111000000000000000000000000000000000000000000000000000000000000000000000003333000000111001010010000003300000000000000",
+    "22101011102220202000333000300000000000000000000000000000000033333333333333333333333121333333333333333333333333333000000000000000003333000000000000000000000000033000000001000011100000003300000000000000",
+    "00202022100000000003330000300000000000000000000000000000000033333333333333333333333131333333333333333333333333333333333333333333333333333000000000000000000000033000000100001001100110003300000000011100",
+    "01000000210001000033300001311111111111111111111111011000000000000000000000330000000111000000000000000000444444333333333333333333333333333330000000000000000000033000000011000000000100003300000000011200",
+    "02110000020012104333000001322222222222222221222222021110000000000000000000330000000222000440444000000000440004444044400000000000000000003333300000000000000000033000000110101101100010003300000100111010",
     "00210111000110204330000001555555555555555551555555552220110000000000000000330000444444444444000444000000044404444444400000000000000000000033333330000000000000033000001010010000110010003300000110222010",
     "00010111010220044330000001555555555555555551555555555551121110000000000000330000044444444000444440440000044444444100000000000000000000000000033333330000000000033000001000000110000000003300000221000010",
     "00010221010000044330000001555555555555555551555555555552251211100000000000330000044444444444444414014440000444000110000000000000000000000000000033333300000000033000000000010001100140003300000001100111",
@@ -9204,4 +9204,4 @@
     "00000000000000000033000000000000000000000001000000000000000000000000000000000000000000000010000000330000000001100000000010010000000100100110000010001101001010100000033333000000000110001100000011000001",
     "00000000000000000033000000000000000000000001000000000000000000000000000000000000000000000010000000330000000000100001010010011010101001000100000111010001011011110000033333000000001100000000101100111100"
   ]
-}
+}

util/random.ts

@@ -11,6 +11,9 @@ export function seed(seed: string) {
   }
 
   const choice = <T>(arr: T[]) => {
+    if (arr.length === 0) {
+      throw new Error("Cannot choose from an empty array")
+    }
     return arr[randomInt(arr.length)]
   }