飞机大战小游戏源码(微信小程序)

【实例截图】

【核心代码】

import Player     from './player/index'
import Enemy      from './npc/enemy'
import BackGround from './runtime/background'
import GameInfo   from './runtime/gameinfo'
import Music      from './runtime/music'
import DataBus    from './databus'

let ctx   = canvas.getContext('2d')
let databus = new DataBus()

/**
 * 游戏主函数
 */
export default class Main {
  constructor() {
    this.restart()
  }

  restart() {
    databus.reset()

    canvas.removeEventListener(
      'touchstart',
      this.touchHandler
    )

    this.bg       = new BackGround(ctx)
    this.player   = new Player(ctx)
    this.gameinfo = new GameInfo()
    this.music    = new Music()

    window.requestAnimationFrame(
      this.loop.bind(this),
      canvas
    )
  }

  /**
   * 随着帧数变化的敌机生成逻辑
   * 帧数取模定义成生成的频率
   */
  enemyGenerate() {
    if ( databus.frame % 30 === 0 ) {
      let enemy = databus.pool.getItemByClass('enemy', Enemy)
      enemy.init(6)
      databus.enemys.push(enemy)
    }
  }

  // 全局碰撞检测
  collisionDetection() {
    let that = this

    databus.bullets.forEach((bullet) => {
      for ( let i = 0, il = databus.enemys.length; i < il;i   ) {
        let enemy = databus.enemys[i]

        if ( !enemy.isPlaying && enemy.isCollideWith(bullet) ) {
          enemy.playAnimation()
          that.music.playExplosion()

          bullet.visible = false
          databus.score   = 1

          break
        }
      }
    })

    for ( let i = 0, il = databus.enemys.length; i < il;i   ) {
      let enemy = databus.enemys[i]

      if ( this.player.isCollideWith(enemy) ) {
        databus.gameOver = true

        break
      }
    }
  }

  //游戏结束后的触摸事件处理逻辑
  touchEventHandler(e) {
     e.preventDefault()

    let x = e.touches[0].clientX
    let y = e.touches[0].clientY

    let area = this.gameinfo.btnArea

    if (   x >= area.startX
        && x <= area.endX
        && y >= area.startY
        && y <= area.endY  )
      this.restart()
    }

    /**
     * canvas重绘函数
     * 每一帧重新绘制所有的需要展示的元素
     */
    render() {
    ctx.clearRect(0, 0, canvas.width, canvas.height)

    this.bg.render(ctx)

    databus.bullets
           .concat(databus.enemys)
           .forEach((item) => {
              item.drawToCanvas(ctx)
            })

    this.player.drawToCanvas(ctx)

    databus.animations.forEach((ani) => {
      if ( ani.isPlaying ) {
        ani.aniRender(ctx)
      }
    })

    this.gameinfo.renderGameScore(ctx, databus.score)
  }

  // 游戏逻辑更新主函数
  update() {
    this.bg.update()

    databus.bullets
           .concat(databus.enemys)
           .forEach((item) => {
              item.update()
            })

    this.enemyGenerate()

    this.collisionDetection()
  }

  // 实现游戏帧循环
  loop() {
    databus.frame  

    this.update()
    this.render()

    if ( databus.frame % 20 === 0 ) {
      this.player.shoot()
      this.music.playShoot()
    }

    // 游戏结束停止帧循环
    if ( databus.gameOver ) {
      this.gameinfo.renderGameOver(ctx, databus.score)

      this.touchHandler = this.touchEventHandler.bind(this)
      canvas.addEventListener('touchstart', this.touchHandler)

      return
    }

    window.requestAnimationFrame(
      this.loop.bind(this),
      canvas
    )
  }
}