tanqiu/assets/scripts/test/WeaponRandomSpawner.ts

import { _decorator, Component, Node, Sprite, SpriteFrame, resources, Prefab, instantiate, UITransform, Vec2, Vec3, RigidBody2D, macro } from 'cc';
const { ccclass, property } = _decorator;

@ccclass('WeaponRandomSpawner')
export class WeaponRandomSpawner extends Component {
    /**
     * Pellet prefab used as bullet. Drag the Pellet.prefab into this slot in the editor.
     */
    @property({ type: Prefab })
    public pelletPrefab: Prefab | null = null;

    /**
     * Time interval (seconds) between two shots.
     */
    @property
    public fireInterval: number = 1.0;

    /** Cached weapon sprite component (WeaponBlock/B1/Weapon) */
    private _weaponSprite: Sprite | null = null;
    /** The sprite frame chosen randomly at scene start */
    private _selectedFrame: SpriteFrame | null = null;

    onLoad() {
        // Locate the Weapon sprite component inside the prefab hierarchy
        const b1Node: Node | null = this.node.getChildByName('B1');
        if (!b1Node) {
            console.error('[WeaponRandomSpawner] Cannot find child node "B1"');
            return;
        }
        const weaponNode: Node | null = b1Node.getChildByName('Weapon');
        if (!weaponNode) {
            console.error('[WeaponRandomSpawner] Cannot find grand-child node "Weapon" under B1');
            return;
        }
        this._weaponSprite = weaponNode.getComponent(Sprite);
        if (!this._weaponSprite) {
            console.error('[WeaponRandomSpawner] Sprite component missing on Weapon node');
            return;
        }

        // Load all sprite frames under resources/images/PlantsSprite at runtime
        resources.loadDir('images/PlantsSprite', SpriteFrame, (err, assets) => {
            if (err) {
                console.error('[WeaponRandomSpawner] Failed to load PlantsSprite resources:', err);
                return;
            }
            if (!assets || assets.length === 0) {
                console.warn('[WeaponRandomSpawner] No sprite frames found in images/PlantsSprite');
                return;
            }

            // Pick one sprite frame randomly and apply to weapon
            this._selectedFrame = assets[Math.floor(Math.random() * assets.length)];
            // Add null safety check before setting spriteFrame
            if (this._weaponSprite && this._weaponSprite.isValid && this._weaponSprite.node && this._weaponSprite.node.isValid) {
                this._weaponSprite.spriteFrame = this._selectedFrame;
            }
        });
    }

    start() {
        // Start auto-fire schedule
        this.schedule(this._fire.bind(this), this.fireInterval);
    }

    onDestroy() {
        // Clear references to prevent operations on destroyed components
        this._weaponSprite = null;
        this._selectedFrame = null;
    }

    /**
     * Instantiate a bullet prefab, copy the weapon sprite frame to it (scaled to half size)
     * and give it an upward velocity.
     */
    private _fire() {
        if (!this.pelletPrefab || !this._selectedFrame) {
            return; // Not ready yet
        }

        const bullet: Node = instantiate(this.pelletPrefab);
        // Add to the same scene, at world position of the weapon muzzle (current node)
        this.node.scene?.addChild(bullet);
        bullet.setWorldPosition(this.node.worldPosition);

        // Set bullet sprite frame with null safety checks
        const bulletSprite = bullet.getComponent(Sprite);
        if (bulletSprite && bulletSprite.isValid && bullet && bullet.isValid) {
            bulletSprite.spriteFrame = this._selectedFrame;
        }

        // Match bullet size to half of weapon sprite size
        const weaponUi = this._weaponSprite?.node.getComponent(UITransform);
        const bulletUi = bullet.getComponent(UITransform);
        if (weaponUi && bulletUi) {
            const size = weaponUi.contentSize;
            bulletUi.setContentSize(size.width * 0.5, size.height * 0.5);
        } else {
            // Fallback: scale the whole node
            bullet.setScale(this.node.scale.x * 0.5, this.node.scale.y * 0.5, 1);
        }

        // Give the bullet an upward velocity if it has a RigidBody2D component
        const rb = bullet.getComponent(RigidBody2D);
        if (rb) {
            rb.linearVelocity = new Vec2(0, 600);
        }
    }
}