cocos2d-iphone - 带有 Cocos2d-x 球的 Box2d 不会被加速度计反弹

Question

球没有反弹我做错了什么？

这是课程

   #include "GameLayer.h"

USING_NS_CC;

GameLayer::GameLayer(){
    mWorld = NULL;
    mBody=NULL;
    mBall=NULL;

}

GameLayer::~GameLayer(){

       delete mWorld;
       mBody=NULL;
        delete mBall;
            mBall=NULL;
}

bool GameLayer::init()
{
    if ( !CCLayer::init() )
    {
        return false;
    }

    CCSize winSize = CCDirector::sharedDirector()->getWinSize();
    // Create sprite and add it to the layer
    mBall = CCSprite::spriteWithFile("Ball.jpg",CCRectMake(0,0,52,52));
    mBall->setPosition(ccp(100,100));
    addChild(mBall);

    // Create a world
    b2Vec2 gravity;
    gravity.Set(0.0f,-10.0f);

    mWorld = new b2World(gravity);

    // Do we want to let bodies sleep?
   // mWorld->SetAllowSleeping(true);

   // mWorld->SetContinuousPhysics(true);

    //Definition of the body
    // body definition to specify initial properties of the body such as position or velocity.
    b2BodyDef  groundBodyDef;
    groundBodyDef.position.Set(0,0);

    // use the world object to create a body object by specifying the body definition.
    b2Body *groundBody = mWorld->CreateBody(&groundBodyDef);

    //Create the shape as needed   (for ground all the sides)
    b2EdgeShape groundEdge;
    groundEdge.Set(b2Vec2_zero,b2Vec2(winSize.width/PTM_RATIO,0));
    groundBody->CreateFixture(&groundEdge,0);
    groundEdge.Set(b2Vec2(0,0), b2Vec2(0, winSize.height/PTM_RATIO));
    groundBody->CreateFixture(&groundEdge,0);
    groundEdge.Set(b2Vec2(0, winSize.height/PTM_RATIO),
                        b2Vec2(winSize.width/PTM_RATIO, winSize.height/PTM_RATIO));
    groundBody->CreateFixture(&groundEdge,0);
    groundEdge.Set(b2Vec2(winSize.width/PTM_RATIO,
                               winSize.height/PTM_RATIO), b2Vec2(winSize.width/PTM_RATIO, 0));
    groundBody->CreateFixture(&groundEdge,0);

    // Create the another body
        //1. body defn
        //2. create body from game world
        // 3. define shape and create fixtures
     b2BodyDef ballBodyDef;
     ballBodyDef.position.Set(100/PTM_RATIO,100/PTM_RATIO);
     // applying sprite as userdata to the bodydef
     ballBodyDef.userData = mBall;
     mBody = mWorld->CreateBody(&ballBodyDef);

     // created different shapes as you want
     b2CircleShape circle;
     circle.m_radius = 26.0/PTM_RATIO;

     //create the fixturedef
     b2FixtureDef ballShapeDef;
     ballShapeDef.shape = &circle;
     ballShapeDef.density=1.0f;
     ballShapeDef.friction=0.2f;
     ballShapeDef.restitution=0.8f;

     mBody->CreateFixture(&ballShapeDef);

     setAccelerometerEnabled(true);

    scheduleUpdate();

    return true;
}


void GameLayer::update(float dt){

    mWorld->Step(dt,10,10);

     for(b2Body *b = mWorld->GetBodyList(); b; b=b->GetNext()) {
            if (b->GetUserData() != NULL) {
                CCSprite *ballData = (CCSprite *)b->GetUserData();
                ballData->setPosition(ccp(b->GetPosition().x * PTM_RATIO,
                        b->GetPosition().y * PTM_RATIO));
                ballData->setRotation(-1 * CC_RADIANS_TO_DEGREES(b->GetAngle()));

            }
        }

}

void GameLayer::didAccelerate(CCAcceleration* pAccelerationValue)
{

    b2Vec2 gravity(-pAccelerationValue->y * 15,pAccelerationValue->x *15);
       mWorld->SetGravity(gravity);


}

Answer 1

b2BodyDef 默认具有 b2_staticBody 类型。尝试设置

ballBodyDef.type = b2_dynamicBody;