objective-c - Cocos2D : Gap in scrolling background

Question

我见过很多人遇到这个问题，但我似乎找不到适合我的案例的解决方案。正如标题所解释的那样，我有一个滚动背景，使用两个包含相同图像的 Sprite 。我将高度设置为 321 (321x480)，以为这样可以解决问题，天哪，但事实并非如此。

好吧，这是我在 init 中的设置:

 background = [CCSprite spriteWithFile:@"level1BG.png"];
        background.position = ccp(background.contentSize.width/2, background.contentSize.height/2);
        [self addChild:background];

        background2 = [CCSprite spriteWithFile:@"level1BG.png"];
        background2.position = ccp(background2.contentSize.width/2, -background2.contentSize.height/2);
        [self addChild:background2];

这里没什么特别的，只是一个设置。

这是我的日程表滚动条(当然有一个 ccTime 参数): 哦，背景向上滚动，增加了 y 值。

-(void)scroll:(ccTime)dt{
    background.position = ccp(background.position.x, background.position.y + GAME_SPEED*dt);
    background2.position = ccp(background2.position.x, background2.position.y + GAME_SPEED*dt);

    if(background.position.y >= background.contentSize.width){
        background.position = ccp(background.position.x, -background.contentSize.height/2 + 1);
    }else if(background2.position.y >= background2.contentSize.width){
        background2.position = ccp(background2.position.x, -background2.contentSize.height/2 + 1);

    }
}

GAME_SPEED 定义为 50.0。我添加了“+ 1”，相信这会解决问题，但又错了!

那么，对于这个问题，有人知道在这种情况下消除差距的方法吗？将永远感激不已!

问候

Answer 1

这是我用来使云出现在场景上的一些旧代码

Clouds.h

#import <Foundation/Foundation.h>
#import "cocos2d.h"

@interface Clouds : CCLayer {
    CCSprite *first;
    CCSprite *second;
    float firstX0;
    float secondX0;
    float firstXf;
    float secondXf;
    float height;
    float firstWidth;
    float secondWidth;
    float Yvalue;
    float duration;
    id moveFirstDone;
    id moveSecondDone;  
}

@end

Clouds.m

#import "Clouds.h"

@implementation Clouds
-(id) init{
    if( (self=[super init] )) {
        first = [CCSprite spriteWithFile:@"clouds_1.png"];
        firstWidth = first.contentSize.width;
        height = first.contentSize.height;
        second = [CCSprite spriteWithFile:@"clouds_2.png"];
        secondWidth = second.contentSize.width;
        Yvalue = 220.0f;
        duration = 200.0f;
        CGSize size = [[CCDirector sharedDirector] winSize];
        firstXf = -1 * (secondWidth - size.width + firstWidth/2);
        secondXf = -1 * (firstWidth + secondWidth/2);
        firstX0 = size.width + firstWidth/2;
        secondX0 = size.width + secondWidth/2;

        moveFirstDone = [CCCallFuncN actionWithTarget:self selector:@selector(callFirstDone:)];
        moveSecondDone = [CCCallFuncN actionWithTarget:self selector:@selector(callSecondDone:)];

        first.position = ccp(firstX0 + -1*firstX0,Yvalue);
        second.position = ccp(secondX0,Yvalue);
        [self addChild:first];
        [self addChild:second];
        [first runAction:[CCSequence actions:[CCMoveTo actionWithDuration:duration position:ccp(firstXf,Yvalue)],moveFirstDone,nil]];
        [second runAction:[CCSequence actions:[CCMoveTo actionWithDuration:duration*2 position:ccp(secondXf,Yvalue)],moveSecondDone,nil]];
    }
    return self;
}

-(void)callSecondDone:(id)sender{
    second.position = ccp(secondX0,Yvalue);
    [second runAction:[CCSequence actions:[CCMoveTo actionWithDuration:duration*2 position:ccp(secondXf,Yvalue)],moveSecondDone,nil]];
}

-(void)callFirstDone:(id)sender{
    first.position = ccp(firstX0,Yvalue);
    [first runAction:[CCSequence actions:[CCMoveTo actionWithDuration:duration*2 position:ccp(firstXf,Yvalue)],moveFirstDone,nil]];
}
@end

使用

    Clouds *clouds = [Clouds node];
    [self addChild: clouds z:0];

将节点添加到主层/场景

我不知道这是否正是您所需要的，但也许它有帮助。观看我使用这种方法获得的效果的视频 https://rapidshare.com/files/3478655240/2012-02-14_1458.swf