1 #import "GameScene.h"
  2 @implementation GameScene
  3
  4 {
  5    //场景背景节点精灵存放数组
  6     NSMutableArray *NearbyArray;
  7
  8 }
  9
 10 /*初始化场景的方法，在uiviwecontroller 初始化场景时调用的方法*/
 11 - (instancetype)initWithSize:(CGSize)size
 12 {
 13      if (self = [super initWithSize:size]) {
 14
 15         NearbyArray=[[NSMutableArray alloc]init];
 16           /*第一个场景背景节点*/
 17         UIImage  *farTextureImage=[UIImage imageNamed:@"planeBack"];
 18         SKTexture *farTexture = [SKTexture  textureWithImage:farTextureImage];
 19
 20         SKSpriteNode  *farTextureSpriteOne = [SKSpriteNode spriteNodeWithTexture:farTexture size:self.size];
 21         // farTextureSpriteOne.anchorPoint=CGPointMake(DEVICE_Width/2, DEVICE_Height/2);
 22         farTextureSpriteOne.zPosition=0;
 23          farTextureSpriteOne.position=CGPointMake(self.frame.size.width/2, self.frame.size.height/2 );
 24
 25
 26
 27
 28             /*第二个场景背景节点*/
 29          UIImage  *farTextureImageTwo=[UIImage imageNamed:@"planeBack"];
 30          SKTexture *farTextureTwo = [SKTexture  textureWithImage:farTextureImageTwo];
 31             SKSpriteNode  *farTextureSpriteTwo = [SKSpriteNode spriteNodeWithTexture:farTextureTwo size:self.size];
 32         //farTextureSpriteTwo.anchorPoint=CGPointMake(0, 0);
 33         farTextureSpriteTwo.zPosition=0;
 34         farTextureSpriteTwo.position=CGPointMake(farTextureSpriteOne.position.x, -(self.frame.size.height/2-10));
 35
 36
 37
 38         /*第三个场景背景节点*/
 39          UIImage  *farTextureImageThree=[UIImage imageNamed:@"planeBack"];
 40         SKTexture *farTextureThree = [SKTexture  textureWithImage:farTextureImageThree];
 41
 42         SKSpriteNode  *farTextureSpriteThree =[SKSpriteNode spriteNodeWithTexture:farTextureThree size:self.size];
 43
 44          farTextureSpriteThree.zPosition=0;
 45         farTextureSpriteThree.position=CGPointMake(farTextureSpriteOne.position.x, -(self.frame.size.height/2+self.frame.size.height-20));
 46
 47
 48
 49
 50         [self addChild:farTextureSpriteOne];
 51         [self addChild:farTextureSpriteTwo];
 52           [self addChild:farTextureSpriteThree];
 53
 54         /*把三个场景背景节点加到一个数组中去，等会滚动之后，才好快速获取每个节点，重置postion*/
 55         [NearbyArray addObject:farTextureSpriteOne];
 56          [NearbyArray addObject:farTextureSpriteTwo];
 57         [NearbyArray addObject:farTextureSpriteThree];
 58
 59
 60     }
 61     return self;
 62
 63 }
 64
 65 /*设置背景图片滚动的方法*/
 66 -(void)BackMove:(CGFloat)moveSpeed
 67 {
 68
 69     for (int i=0; i<NearbyArray.count; i++) {
 70         SKSpriteNode *TempSprite=[NearbyArray objectAtIndex:i];
 71
 72
 73         [TempSprite setPosition:CGPointMake(TempSprite.position.x,TempSprite.position.y+moveSpeed)];
 74     }
 75
 76     //循环滚动算法
 77     SKSpriteNode *RollOneSprite=[NearbyArray objectAtIndex:0];
 78     SKSpriteNode *RollTwoSprite=[NearbyArray objectAtIndex:1];
 79      SKSpriteNode *ThreeBackSprit=[NearbyArray objectAtIndex:2];
 80
 81     if (RollOneSprite.position.y>(self.frame.size.height/2+self.frame.size.height))
 82        {
 83          RollOneSprite.position=CGPointMake(RollOneSprite.position.x, -(self.frame.size.height/2+self.frame.size.height-30));
 84
 85     }
 86       if (RollTwoSprite.position.y>(self.frame.size.height/2+self.frame.size.height)) {
 87             RollTwoSprite.position=CGPointMake(RollOneSprite.position.x, -(self.frame.size.height/2+self.frame.size.height-30));
 88
 89     }
 90     if (ThreeBackSprit.position.y>(self.frame.size.height/2+self.frame.size.height)) {
 91           ThreeBackSprit.position=CGPointMake(RollOneSprite.position.x, -(self.frame.size.height/2+self.frame.size.height-30));
 92
 93     }
 94 }
 95
 96 /*这个方法是spritekit 的场景自带的，每过一秒就会被调用*/
 97 -(void)update:(CFTimeInterval)currentTime {
 98     [self BackMove:2];
 99
100
101 }
102
103 @end

 1 - (void)viewDidLoad
 2 {
 3     [super viewDidLoad];
 4
 5     // Configure the view.
 6     SKView * skView = (SKView *)self.view;
 7     skView.showsFPS = YES;
 8     skView.showsNodeCount = YES;
 9     /* Sprite Kit applies additional optimizations to improve rendering performance */
10     skView.ignoresSiblingOrder = YES;
11
12
13    GameScene *scene = [[GameScene alloc]initWithSize:skView.bounds.size];
14
15     scene.scaleMode = SKSceneScaleModeAspectFill;
16
17     [skView presentScene:scene];
18
19 }