Question

当无限背景滚动完成时，我有一个问题，对象是否保持固定（如涂鸦跳转中的涂鸦，papi跳跃中的papy）或这些对象真正移动。只有背景移动或两者（背景和对象）移动。 PLZ有人帮我。我正在寻找这个解决方案4/5天，但无法得到解决方案。所以有人帮助我。如果对象不移动如何创建这样一个对象移动的错觉。

Answer 1

如果将对象添加到与滚动背景相同的图层，则它将在背景滚动时滚动。

如果你在涂鸦中寻找像英雄一样的效果，你可能想要看一下场景中有两层或更多层。

第1层：滚动背景图层
第2层：精灵层

SomeScene.m

CCLayer *backgroundLayer = [[CCLayer alloc] init];
CCLayer *spriteLayer= [[CCLayer alloc] init];

[self addChild:backgroundLayer z:0];
[self addChild:spriteLayer z:1];

//Hero stays in one spot regardless of background scrolling.
CCSprite *squidHero = [[CCSprite alloc] initWithFile:@"squid.png"];
[spriteLayer addChild:squidHero];

如果您希望对象以背景滚动，请将其添加到背景图层：

//Platform moves with background.
CCSprite *bouncePlatform= [[CCSprite alloc] initWithFile:@"bouncePlatform.png"];
[backgroundLayer addChild:bouncePlatform];

Answer 2

另一种方法是使用CCFollow操作。你会编写代码，好像背景是静态的（它将是）并且玩家正在移动（它将会移动），但是向玩家添加CCFollow动作。这基本上会移动相机，以便跟踪您的播放器。

你也可以修改这些类，这样你就可以得到CCFollow动作跟随一个偏移（即，所以玩家不在屏幕中间）以及对它有平滑效果，这样当玩家移动时，跟随动作不是生涩的。请参阅以下代码：

*注意我使用的是cocos2d-x，即c ++端口。 cocos2d中的方法类似，您应该能够修改这些方法以适应cocos2d语法。或者四处搜索 - 我发现了这些用于cocos2d，然后移植到c ++。

//defines the action to constantly follow the player (in my case, "runner.p_sprite is the sprite pointing to the player)
FollowWithOffset* followAction = FollowWithOffset::create(runner.p_sprite, CCRectZero);
runAction(followAction);

另外，我已经复制了CCFollow的类定义来创建我自己的类CCFollowWithAction。这也有平滑效果（你可以在网上查看更多），这样当玩家移动时，动作不会生涩。我修改了“initWithTarget”以考虑偏移量，并修改了“步骤”以添加平滑动作。您可以在下面的评论中看到修改。

bool FollowWithOffset::initWithTarget(CCNode *pFollowedNode, const CCRect& rect/* = CCRectZero*/)
{
    CCAssert(pFollowedNode != NULL, "");

    pFollowedNode->retain();
    m_pobFollowedNode = pFollowedNode;
    if (rect.equals(CCRectZero))
    {
        m_bBoundarySet = false;
    }
    else
    {
        m_bBoundarySet = true;
    }

    m_bBoundaryFullyCovered = false;

    CCSize winSize = CCDirector::sharedDirector()->getWinSize();
    m_obFullScreenSize = CCPointMake(winSize.width, winSize.height);

    //m_obHalfScreenSize = ccpMult(m_obFullScreenSize, 0.5f);
    m_obHalfScreenSize = CCPointMake(m_obFullScreenSize.x/2 + RUNNER_FOLLOW_OFFSET_X,
                                     m_obFullScreenSize.y/2 + RUNNER_FOLLOW_OFFSET_Y);

    if (m_bBoundarySet)
    {
        m_fLeftBoundary = -((rect.origin.x+rect.size.width) - m_obFullScreenSize.x);
        m_fRightBoundary = -rect.origin.x ;
        m_fTopBoundary = -rect.origin.y;
        m_fBottomBoundary = -((rect.origin.y+rect.size.height) - m_obFullScreenSize.y);

        if(m_fRightBoundary < m_fLeftBoundary)
        {
            // screen width is larger than world's boundary width
            //set both in the middle of the world
            m_fRightBoundary = m_fLeftBoundary = (m_fLeftBoundary + m_fRightBoundary) / 2;
        }
        if(m_fTopBoundary < m_fBottomBoundary)
        {
            // screen width is larger than world's boundary width
            //set both in the middle of the world
            m_fTopBoundary = m_fBottomBoundary = (m_fTopBoundary + m_fBottomBoundary) / 2;
        }

        if( (m_fTopBoundary == m_fBottomBoundary) && (m_fLeftBoundary == m_fRightBoundary) )
        {
            m_bBoundaryFullyCovered = true;
        }
    }

    return true;
}

void FollowWithOffset::step(float dt)
{
    CC_UNUSED_PARAM(dt);

    if(m_bBoundarySet){
        // whole map fits inside a single screen, no need to modify the position - unless map boundaries are increased
        if(m_bBoundaryFullyCovered)
            return;

        CCPoint tempPos = ccpSub( m_obHalfScreenSize, m_pobFollowedNode->getPosition());

        m_pTarget->setPosition(ccp(clampf(tempPos.x, m_fLeftBoundary, m_fRightBoundary), 
                                   clampf(tempPos.y, m_fBottomBoundary, m_fTopBoundary)));
    }
    else{
        //custom written code to add in support for a smooth ccfollow action
        CCPoint tempPos = ccpSub( m_obHalfScreenSize, m_pobFollowedNode->getPosition());
        CCPoint moveVect = ccpMult(ccpSub(tempPos,m_pTarget->getPosition()),0.25); //0.25 is the smooth constant.
        CCPoint newPos = ccpAdd(m_pTarget->getPosition(), moveVect);
        m_pTarget->setPosition(newPos);
    }
}

在cocos2d中滚动背景时，对象是否保持固定

2 个答案: