如何在iOS中無限移動背景圖片coco2d

Question

我必須在iOS Coco2d中移動背景圖片，但我遇到了一些困難。我嘗試了一些網站上提供的解決方案，但沒有成功讓他們正常工作。下面是我目前工作的代碼： -

背景平滑地移動第一次，但它沒有後正常工作： -

代碼在初始化函數： -

bg1 = [CCSprite spriteWithFile: @"bg1.png"]; 
bg1.anchorPoint = CGPointZero; 
[self addChild:bg1 z:-2]; 

bg2 = [CCSprite spriteWithFile: @"bg1.png"]; 
[self addChild:bg2 z:-3]; 
bg2.anchorPoint = CGPointMake(480, 0); 

// schedule a repeating callback on every frame 
[self schedule:@selector(nextFrame:) interval:.4f]; 

---

- (void) nextFrame:(ccTime)dt { 
    id actionMove = [CCMoveTo actionWithDuration:.4 position:ccp(bg1.position.x - 100 * dt, bg1.position.y)]; //winSize.height/2)]; 

    id actionMove1 = [CCMoveTo actionWithDuration:.4 position:ccp(bg2.position.x - 100 * dt, bg2.position.y)]; //winSize.height/2)]; 

    id actionMoveDone = [CCCallFuncN actionWithTarget:self selector:@selector(spriteMoveFinished:)]; 
    [bg1 runAction:[CCSequence actions:actionMove,actionMoveDone, nil]]; 
    [bg2 runAction:[CCSequence actions:actionMove1,actionMoveDone, nil]]; 
} 

-(void)spriteMoveFinished:(id)sender { 

    CCSprite *sprite = (CCSprite *)sender; 
    if(sprite == bg1) { 
     if (bg1.position.x < -480) { 
      [self removeChild:bg1 cleanup:NO]; 
      bg1.position = ccp(480 , bg1.position.y); 

      [self addChild:bg1 z:-2]; 
     } 
    } 
    else if(sprite == bg2) 
     if (bg2.position.x < -480) { 
      [self removeChild:bg2 cleanup:NO]; 
      bg2.position = ccp(bg1.position.x+ 480 , bg1.position.y); 
      [self addChild:bg2 z:-3]; 
     } 
    } 
} 

Answer 1

試試這個，一定要翻轉背景2.

#define IS_IPAD (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) 
#define MM_BG_SPEED_DUR       (IS_IPAD ? (6.0f) : (2.0f)) 

-(void)onEnter 
{ 
    [super onEnter]; 
    [self initBackground]; 

    [self schedule: @selector(tick:)]; 
} 

-(void)initBackground 
{ 
    NSString *tex = @"BG/Background.png";//[self getThemeBG]; 

    mBG1 = [CCSprite spriteWithFile:tex]; 
    mBG1.position = ccp(s.width*0.5f,s.height*0.5f); 
    [self addChild:mBG1 z:LAYER_BACKGROUND]; 

    mBG2 = [CCSprite spriteWithFile:tex]; 
    mBG2.position = ccp(s.width+s.width*0.5f,s.height*0.5f); 

    mBG2.flipX = true; 
    [self addChild:mBG2 z:LAYER_BACKGROUND]; 

} 


-(void)scrollBackground:(ccTime)dt 
{ 
    CGSize s = [[CCDirector sharedDirector] winSize]; 

    CGPoint pos1 = mBG1.position; 
    CGPoint pos2 = mBG2.position; 

    pos1.x -= MM_BG_SPEED_DUR; 
    pos2.x -= MM_BG_SPEED_DUR; 


    if(pos1.x <=-(s.width*0.5f)) 
    { 
     pos1.x = pos2.x + s.width; 
    } 

    if(pos2.x <=-(s.width*0.5f)) 
    { 
     pos2.x = pos1.x + s.width; 
    } 

    mBG1.position = pos1; 
    mBG2.position = pos2; 

} 

-(void)tick:(ccTime)dt 
{ 
    [self scrollBackground:dt]; 
} 

Answer 2

我覺得這種方式有點簡單。您初始化init中的背景並將它們移動到update。

在init方法：

// position backgrounds 
CCSprite *bg1 = [CCSprite spriteWithSpriteFrame:spriteFrame]; 
CCSprite *bg2 = [CCSprite spriteWithSpriteFrame:spriteFrame]; 
CCSprite *bg3 = [CCSprite spriteWithSpriteFrame:spriteFrame]; 
bg1.anchorPoint = ccp(0, 0); 
bg1.position = ccp(0, 0); 
bg2.anchorPoint = ccp(0, 0); 
bg2.position = ccp(bg1.contentSize.width-1, 0); 
bg3.anchorPoint = ccp(0, 0); 
bg3.position = ccp(2*bg1.contentSize.width-1, 0); 
_backgrounds = @[bg1, bg2, bg3]; 

[self addChild:bg1 z:INT_MIN]; 
[self addChild:bg2 z:INT_MIN]; 
[self addChild:bg3 z:INT_MIN]; 

在更新方法：

// endless scrolling for backgrounds 
for (CCSprite *bg in _backgrounds) { 
    bg.position = ccp(bg.position.x - 50 * delta, bg.position.y); 
    if (bg.position.x < -1 * (bg.contentSize.width)) { 
     bg.position = ccp(bg.position.x + (bg.contentSize.width*2)-2, 0); 
    } 
} 

注：代碼是cocos2d的3.0