feat: add RandomWalkNPC

Author: kt3k

model/character.test.ts

@@ -1,12 +1,12 @@
-import { MainCharacter, RandomWalkNPC } from "./character.ts"
+import { MainCharacter, RandomlyTurnNPC } from "./character.ts"
 import { assertEquals } from "@std/assert"
 
 Deno.test("Character", async (t) => {
   await t.step("physicalGridKey", () => {
     const mc = new MainCharacter(100, 100, "main/", "main")
     assertEquals(mc.physicalGridKey, "100.100")
 
-    const npc = new RandomWalkNPC(200, 200, "npc/", "npc")
+    const npc = new RandomlyTurnNPC(200, 200, "npc/", "npc")
     assertEquals(npc.physicalGridKey, "200.200")
   })
 

model/character.ts

@@ -83,15 +83,19 @@ export type ItemContainer = {
   remove(i: number, j: number): void
 }
 
+type NPCType = "random" | "random-walk" | "static"
+
 export function spawnCharacter(
   id: string,
-  type: "random" | "static",
+  type: NPCType,
   i: number,
   j: number,
   assetPrefix: string,
   { dir = "down", speed = 1 }: { dir?: Dir; speed?: 1 | 2 | 4 | 8 | 16 } = {},
 ): IChar {
   if (type === "random") {
+    return new RandomlyTurnNPC(i, j, assetPrefix, id, dir, speed)
+  } else if (type === "random-walk") {
     return new RandomWalkNPC(i, j, assetPrefix, id, dir, speed)
   } else if (type === "static") {
     return new StaticNPC(i, j, assetPrefix, id, dir, speed)
@@ -453,7 +457,7 @@ export abstract class Character implements IChar {
   }
 }
 
-export class RandomWalkNPC extends Character {
+export class RandomlyTurnNPC extends Character {
   #counter = 32
 
   override getNextAction(
@@ -483,5 +487,22 @@ export class RandomWalkNPC extends Character {
   }
 }
 
+export class RandomWalkNPC extends Character {
+  #counter = 32
+
+  override getNextAction(
+    fieldTester: IFieldTester,
+    collisionChecker: CollisionChecker,
+  ): NextAction {
+    const dirs = ([UP, DOWN, LEFT, RIGHT] as const).filter((d) => {
+      return this.canEnter(d, fieldTester, collisionChecker)
+    })
+    if (dirs.length === 0) {
+      return undefined
+    }
+    return choice(dirs)
+  }
+}
+
 export class StaticNPC extends Character {
 }