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KateLegend2_proj/assets/scripts/logic/EnemyAI.ts
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2026-06-07 22:10:03 +08:00

372 lines
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TypeScript

import { AttackType, EnemyType, IEnemyConfig, IReinforcementRule } from '../data/Interfaces';
/**
* Enemy AI base class + four concrete subclasses (req 6.1-6.7).
*
* Each enemy is modelled as a tiny state machine that ticks on `update(dt)`
* and emits an `IEnemyAction[]` the level manager then spawns into the world
* (bullets / smoke bombs / fireballs / sword swings).
*
* Enemies outside the camera's culling rect can be frozen by simply skipping
* `update()` — see `EnemyManager.update()` below (requirement 6.7 / 18.5).
*/
export interface IEnemyAction {
kind: 'fire_bullet' | 'melee_swing' | 'spawn_item' | 'drop_item';
attackType?: AttackType;
/** Origin of the projectile, world coords. */
originX?: number;
originY?: number;
/** Velocity of the projectile. */
velX?: number;
velY?: number;
/** For drop_item only — item id + world coords. */
itemId?: string;
}
export interface IPlayerSense {
x: number;
y: number;
isGrounded: boolean;
}
export interface IEnemyAABB {
x: number;
y: number;
w: number;
h: number;
}
export interface IEnemyUpdateCtx {
dtSec: number;
nowMs: number;
player: IPlayerSense;
}
export abstract class EnemyAIBase {
public readonly type: EnemyType;
public pos: { x: number; y: number };
public alive = true;
public hp: number;
protected cooldownSec = 0;
protected readonly cfg: IEnemyConfig;
constructor(cfg: IEnemyConfig, spawnX: number, spawnY: number) {
this.cfg = cfg;
this.type = cfg.id;
this.pos = { x: spawnX, y: spawnY };
this.hp = cfg.hp;
}
public abstract update(ctx: IEnemyUpdateCtx): IEnemyAction[];
public get aabb(): IEnemyAABB {
return { x: this.pos.x, y: this.pos.y, w: this.cfg.size.w, h: this.cfg.size.h };
}
protected decrementCooldown(dtSec: number): boolean {
this.cooldownSec -= dtSec;
if (this.cooldownSec > 0) return false;
this.cooldownSec = this.cfg.attackIntervalSec;
return true;
}
}
// ---------- Qing Ren (req 6.1) --------------------------------------------
export class QingRenAI extends EnemyAIBase {
public update(ctx: IEnemyUpdateCtx): IEnemyAction[] {
if (!this.decrementCooldown(ctx.dtSec)) return [];
const dx = ctx.player.x - this.pos.x;
const horizontalDistance = Math.abs(dx);
const direction = dx >= 0 ? 1 : -1;
if (horizontalDistance < 64) {
return [{ kind: 'melee_swing', attackType: 'sword' }];
}
return [
{
kind: 'fire_bullet',
attackType: 'shuriken',
originX: this.pos.x,
originY: this.pos.y,
velX: 240 * direction,
velY: 0,
},
];
}
}
// ---------- Chi Ren (req 6.2-6.4) -----------------------------------------
export class ChiRenAI extends EnemyAIBase {
private interceptCooldown = 0;
public update(ctx: IEnemyUpdateCtx): IEnemyAction[] {
// Patrol horizontally toward the player at 120px/s (req 6.2).
const dx = ctx.player.x - this.pos.x;
const direction = dx >= 0 ? 1 : -1;
this.pos.x += direction * this.cfg.moveSpeed * ctx.dtSec;
// Proactive intercept jump when player stands still within vision (req 6.3).
if (this.interceptCooldown > 0) this.interceptCooldown -= ctx.dtSec;
const playerIdle = Math.abs(ctx.player.x - this.pos.x) < 200 && ctx.player.isGrounded;
if (playerIdle && this.interceptCooldown <= 0) {
this.interceptCooldown = 3;
// Intercept arc: +X velocity + upward bounce, treated as position warp.
this.pos.y += 48;
}
if (!this.decrementCooldown(ctx.dtSec)) return [];
return [
{
kind: 'fire_bullet',
attackType: 'smoke_bomb',
originX: this.pos.x,
originY: this.pos.y,
velX: 140 * direction,
velY: 0,
},
];
}
}
// ---------- Hei Ren (req 6.5) ---------------------------------------------
export class HeiRenAI extends EnemyAIBase {
private hasDroppedMagicFlute = false;
public update(ctx: IEnemyUpdateCtx): IEnemyAction[] {
if (!this.decrementCooldown(ctx.dtSec)) return [];
const dx = ctx.player.x - this.pos.x;
const direction = dx >= 0 ? 1 : -1;
if (Math.abs(dx) < 96) {
return [{ kind: 'melee_swing', attackType: 'sword' }];
}
return [
{
kind: 'fire_bullet',
attackType: 'shuriken',
originX: this.pos.x,
originY: this.pos.y,
velX: 200 * direction,
velY: 0,
},
];
}
/** Called by EnemyManager on death — yields at most one magic flute. */
public onKilled(): IEnemyAction[] {
if (this.hasDroppedMagicFlute) return [];
this.hasDroppedMagicFlute = true;
return [{ kind: 'drop_item', itemId: 'mo_di', originX: this.pos.x, originY: this.pos.y }];
}
}
// ---------- Yao Fang (req 6.6) --------------------------------------------
export class YaoFangAI extends EnemyAIBase {
public update(ctx: IEnemyUpdateCtx): IEnemyAction[] {
if (!this.decrementCooldown(ctx.dtSec)) return [];
const dx = ctx.player.x - this.pos.x;
const direction = dx >= 0 ? 1 : -1;
return [
{
kind: 'fire_bullet',
attackType: 'fireball',
originX: this.pos.x,
originY: this.pos.y,
velX: 260 * direction,
velY: 0,
},
];
}
}
// ---------- Manager with camera-culling (req 6.7) -------------------------
export interface ICullingRect {
leftX: number;
rightX: number;
topY: number;
bottomY: number;
}
export class EnemyManager {
private readonly enemies: EnemyAIBase[] = [];
public spawn(enemy: EnemyAIBase): void {
this.enemies.push(enemy);
}
public get all(): ReadonlyArray<EnemyAIBase> {
return this.enemies;
}
/**
* Update all live enemies that intersect `cull` (with optional margin).
* Returns the concatenated list of actions emitted so the caller
* (LevelMgr) can instantiate projectiles, drops, etc.
*
* @param cullingMargin Extra pixels beyond `cull` to still activate enemies.
* Used for reinforcements that spawn just outside the screen.
*/
public update(dtSec: number, nowMs: number, player: IPlayerSense, cull: ICullingRect, cullingMargin = 0): IEnemyAction[] {
const actions: IEnemyAction[] = [];
for (const e of this.enemies) {
if (!e.alive) continue;
if (!this.inside(e, cull, cullingMargin)) continue;
const ctx: IEnemyUpdateCtx = { dtSec, nowMs, player };
actions.push(...e.update(ctx));
}
return actions;
}
public kill(enemy: EnemyAIBase): IEnemyAction[] {
enemy.alive = false;
if (enemy instanceof HeiRenAI) return enemy.onKilled();
return [];
}
public clear(): void {
this.enemies.length = 0;
}
private inside(e: EnemyAIBase, cull: ICullingRect, margin = 0): boolean {
return (
e.pos.x + e.aabb.w / 2 >= cull.leftX - margin &&
e.pos.x - e.aabb.w / 2 <= cull.rightX + margin &&
e.pos.y + e.aabb.h / 2 >= cull.bottomY - margin &&
e.pos.y - e.aabb.h / 2 <= cull.topY + margin
);
}
}
// ---------- Reinforcement Scheduler (dynamic edge spawns) -----------------
/** An enemy spawned by the reinforcement scheduler, with a jump-in arc. */
export interface IReinforcementSpawn {
enemy: EnemyAIBase;
/** The edge the enemy is jumping in from. */
edge: 'left' | 'right';
}
/**
* Manages periodic reinforcement waves — enemies that jump in from screen
* edges even when the player is standing still. Each rule specifies an
* enemy type, interval, count, and which edge(s) they appear from.
*
* Usage: call `tick()` every frame. It returns newly-spawned enemies that
* the caller must register with `EnemyManager.spawn()` and create visual
* nodes for.
*/
export class ReinforcementScheduler {
private readonly timers = new Map<number, number>();
private readonly totals = new Map<number, number>();
constructor(private readonly rules: IReinforcementRule[]) {}
/**
* Tick the scheduler. Returns enemies that should be spawned this frame.
* The caller is responsible for:
* 1. Passing the new enemies to `EnemyManager.spawn()`
* 2. Creating visual nodes for them
* 3. Calling `EnemyManager.update()` as usual
*
* @param dtSec Frame delta in seconds.
* @param elapsedSec Total elapsed seconds since level start.
* @param cull Current camera culling rect (used to determine edge positions).
* @param groundY Ground Y in physics coords (feet surface).
* @param enemyCfgFactory A function that returns the IEnemyConfig for a given EnemyType.
*/
public tick(
dtSec: number,
elapsedSec: number,
cull: ICullingRect,
groundY: number,
enemyCfgFactory: (type: EnemyType) => { moveSpeed: number; attackIntervalSec: number; size: { w: number; h: number } },
): IReinforcementSpawn[] {
const spawns: IReinforcementSpawn[] = [];
for (let i = 0; i < this.rules.length; i++) {
const rule = this.rules[i];
// Check delay
if (rule.delaySec && elapsedSec < rule.delaySec) continue;
// Check max total
const total = this.totals.get(i) ?? 0;
if (rule.maxTotal && rule.maxTotal > 0 && total >= rule.maxTotal) continue;
// Accumulate timer
const timer = this.timers.get(i) ?? 0;
const newTimer = timer + dtSec;
this.timers.set(i, newTimer);
if (newTimer < rule.intervalSec) continue;
// Reset timer (keep remainder for smoother intervals)
this.timers.set(i, newTimer - rule.intervalSec);
// Determine edge(s)
const edges: Array<'left' | 'right'> = rule.edge === 'both'
? (Math.random() < 0.5 ? ['left'] : ['right'])
: [rule.edge];
for (const edge of edges) {
for (let j = 0; j < rule.count; j++) {
const cfg = enemyCfgFactory(rule.type);
// Spawn position: just outside the culling rect on the chosen edge.
// Moving enemies (moveSpeed > 0) start farther out and walk in;
// stationary enemies (YaoFang) start just inside the visible edge.
const margin = cfg.moveSpeed > 0 ? 60 : -30; // negative = inside screen
const spawnX = edge === 'left'
? cull.leftX - margin - j * 50
: cull.rightX + margin + j * 50;
const spawnY = groundY + cfg.size.h / 2;
const enemy = createReinforcementEnemy(rule.type, cfg, spawnX, spawnY, edge);
spawns.push({ enemy, edge });
this.totals.set(i, (this.totals.get(i) ?? 0) + 1);
}
}
}
return spawns;
}
/** Reset all timers and counters (e.g. on level restart). */
public reset(): void {
this.timers.clear();
this.totals.clear();
}
}
/**
* Create an enemy AI instance for a reinforcement spawn.
* Reuses the same AI classes as static spawns. The enemy spawns at ground
* level on the chosen edge; moving enemies (ChiRen) will walk into the
* screen automatically, while stationary enemies (YaoFang) are placed
* just inside the visible edge so they're immediately active.
*/
function createReinforcementEnemy(
type: EnemyType,
cfg: { moveSpeed: number; attackIntervalSec: number; size: { w: number; h: number } },
spawnX: number,
spawnY: number,
_edge: 'left' | 'right',
): EnemyAIBase {
const fullCfg = {
id: type,
displayName: type,
size: cfg.size,
moveSpeed: cfg.moveSpeed,
attackIntervalSec: cfg.attackIntervalSec,
attacks: [] as never[],
hp: type === EnemyType.HeiRen ? 2 : 1,
};
switch (type) {
case EnemyType.ChiRen: return new ChiRenAI(fullCfg, spawnX, spawnY);
case EnemyType.HeiRen: return new HeiRenAI(fullCfg, spawnX, spawnY);
case EnemyType.YaoFang: return new YaoFangAI(fullCfg, spawnX, spawnY);
case EnemyType.QingRen:
default: return new QingRenAI(fullCfg, spawnX, spawnY);
}
}