47 lines
878 B
JavaScript
47 lines
878 B
JavaScript
import Sprite from '../base/sprite';
|
|
|
|
const BULLET_IMG_SRC = 'images/bullet.png';
|
|
const BULLET_WIDTH = 16;
|
|
const BULLET_HEIGHT = 30;
|
|
|
|
export default class Bullet extends Sprite {
|
|
constructor() {
|
|
super(BULLET_IMG_SRC, BULLET_WIDTH, BULLET_HEIGHT);
|
|
}
|
|
|
|
init(x, y, speed) {
|
|
this.x = x;
|
|
this.y = y;
|
|
this.speed = speed;
|
|
this.isActive = true;
|
|
this.visible = true;
|
|
}
|
|
|
|
// 每一帧更新子弹位置
|
|
update() {
|
|
if (GameGlobal.databus.isGameOver) {
|
|
return;
|
|
}
|
|
|
|
this.y -= this.speed;
|
|
|
|
// 超出屏幕外销毁
|
|
if (this.y < -this.height) {
|
|
this.destroy();
|
|
}
|
|
}
|
|
|
|
destroy() {
|
|
this.isActive = false;
|
|
// 子弹没有销毁动画，直接移除
|
|
this.remove();
|
|
}
|
|
|
|
remove() {
|
|
this.isActive = false;
|
|
this.visible = false;
|
|
// 回收子弹对象
|
|
GameGlobal.databus.removeBullets(this);
|
|
}
|
|
}
|