1 /*这个方法是spritekit 的场景自带的，每过一秒就会被调用*/
  2 -(void)update:(CFTimeInterval)currentTime {
  3     [self BackMove:1];
  4
  5     [self initEnemySprite];//本次增加的创建敌对飞机的方法
  6
  7
  8 }
  9 /*创建敌对飞机*/
 10 -(void)initEnemySprite
 11 {
 12     /*此方法是放在update里面的所以是每秒执行一次，下面三个变量就是控制飞机刷新速度的，如果不控制,屏幕就会每秒都刷新一个飞机出来，那么不一会屏幕就会爆满， 这里每35秒刷新一架小型地址每400秒刷新一架中型飞机， 每700秒刷行一架大飞机*/
 13     _smallPlaneTime++;
 14     _mediumPlaneTime++;
 15     _bigPlaneTime++;
 16
 17
 18     //int RadomNumber=   (arc4random() % 100) + 0;
 19     int SpriteX=DEVICE_Width;
 20     /*随机精灵在x轴的位置*/
 21       int x = (arc4random() % (SpriteX-90)) + 45;
 22
 23     int speed = 0;
 24
 25
 26     if (_smallPlaneTime>35) {
 27         UIImage  *farTextureImageThree=[UIImage imageNamed:@"MemberTwo"];
 28         SKTexture *farTextureThree = [SKTexture  textureWithImage:farTextureImageThree];
 29
 30
 31         SKSpriteNode *foePlane = [SKSpriteNode spriteNodeWithTexture: farTextureThree size:CGSizeMake(farTextureThree.size.width/2.5, farTextureThree.size.height/2.5)];
 32         //增加敌对飞机受动力感应的范围
 33         foePlane.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:foePlane.size];
 34           /*飞机向下移动速度*/
 35          speed= (arc4random() % 5) + 2;
 36
 37          foePlane.position = CGPointMake(x, self.size.height);
 38          foePlane.zPosition=1;
 39         /*下面三个属性是设置敌对飞机的重力检测属性，之后它们都会用到，比如之后用户操作的飞机发射子弹打在它们上面，下面这属性就起作用了*/
 40         foePlane.physicsBody.categoryBitMask = SKRoleCategoryFoePlane;
 41         foePlane.physicsBody.collisionBitMask = SKRoleCategoryBullet;
 42         foePlane.physicsBody.contactTestBitMask = SKRoleCategoryBullet;
 43         [self addChild:foePlane];
 44         /*当精灵的y坐标为0时将精灵从父节点移出*/
 45         [foePlane runAction:[SKAction sequence:@[[SKAction moveToY:0 duration:speed],[SKAction removeFromParent]]] completion:^{
 46             [foePlane removeFromParent];
 47         }];
 48        _smallPlaneTime=0;
 49
 50     }
 51
 52     if (_mediumPlaneTime>400) {
 53
 54
 55
 56         UIImage  *farTextureImageThree=[UIImage imageNamed:@"Teamer"];
 57         SKTexture *farTextureThree = [SKTexture  textureWithImage:farTextureImageThree];
 58          SKSpriteNode *foePlane = [SKSpriteNode spriteNodeWithTexture: farTextureThree size:CGSizeMake(farTextureThree.size.width/2.5, farTextureThree.size.height/2.5)];
 59         //增加敌对飞机受动力感应的范围
 60          foePlane.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:foePlane.size];
 61           /*飞机向下移动速度*/
 62           speed = (arc4random() % 2) + 2;
 63
 64         foePlane.position = CGPointMake(x, self.size.height);
 65
 66         foePlane.zPosition=1;
 67         /*下面三个属性是设置敌对飞机的重力检测属性，之后它们都会用到，比如之后用户操作的飞机发射子弹打在它们上面，下面这属性就起作用了*/
 68         foePlane.physicsBody.categoryBitMask = SKRoleCategoryFoePlane;
 69         foePlane.physicsBody.collisionBitMask = SKRoleCategoryBullet;
 70         foePlane.physicsBody.contactTestBitMask = SKRoleCategoryBullet;
 71         [self addChild:foePlane];
 72         /*当精灵的y坐标为0时将精灵从父节点移出*/
 73         [foePlane runAction:[SKAction sequence:@[[SKAction moveToY:0 duration:speed],[SKAction removeFromParent]]] completion:^{
 74             [foePlane removeFromParent];
 75         }];
 76               _mediumPlaneTime=0;
 77
 78       }
 79
 80
 81        if (_bigPlaneTime>700) {
 82
 83
 84
 85
 86
 87
 88            UIImage  *farTextureImageThree=[UIImage imageNamed:@"Unknown"];
 89            SKTexture *farTextureThree = [SKTexture  textureWithImage:farTextureImageThree];
 90
 91
 92            SKSpriteNode *foePlane = [SKSpriteNode spriteNodeWithTexture: farTextureThree size:CGSizeMake(farTextureThree.size.width/2.5, farTextureThree.size.height/2.5)];
 93
 94
 95            //增加敌对飞机受动力感应的范围
 96            foePlane.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:foePlane.size];
 97
 98            /*飞机向下移动速度*/
 99             speed = (arc4random() % 5) + 3;
100            foePlane.position = CGPointMake(x, self.size.height);
101            foePlane.zPosition=1;
102            /*下面三个属性是设置敌对飞机的重力检测属性，之后它们都会用到，比如之后用户操作的飞机发射子弹打在它们上面，下面这属性就起作用了*/
103            foePlane.physicsBody.categoryBitMask = SKRoleCategoryFoePlane;
104            foePlane.physicsBody.collisionBitMask = SKRoleCategoryBullet;
105            foePlane.physicsBody.contactTestBitMask = SKRoleCategoryBullet;
106            [self addChild:foePlane];
107            /*当精灵的y坐标为0时将精灵从父节点移出*/
108            [foePlane runAction:[SKAction sequence:@[[SKAction moveToY:5 duration:speed],[SKAction removeFromParent]]] completion:^{
109                [foePlane removeFromParent];
110            }];
111            _bigPlaneTime=0;
112
113        }
114
115
116
117
118
119 }