问题描述

cocos2D的Box2d项目中弹球问题

做到第二个弹球时，弹球没有弹起来，穿过地板了。不知道怎么解决？第二个弹球和第一个弹球完全一样啊。请好心人帮忙看看。

代码：

#import ""HelloWorldLayer.h""@implementation HelloWorldLayer+ (id)scene {    CCScene *scene = [CCScene node];    HelloWorldLayer *layer = [HelloWorldLayer node];    [scene addChild:layer];    return scene;}- (id)init {    if ((self=[super init])) {        CGSize winSize = [CCDirector sharedDirector].winSize;        // Create sprite and add it to the layer        _ball = [CCSprite spriteWithFile:@""ball.png"" rect:CGRectMake(0 0 52 52)];        _ball.position = ccp(100 300);        [self addChild:_ball];        _ball2 = [CCSprite spriteWithFile:@""ball.png"" rect:CGRectMake(0 0 52 52)];        _ball2.position = ccp(300 300);        [self addChild:_ball2];        // Create a world        b2Vec2 gravity = b2Vec2(0.0f -8.0f);        _world = new b2World(gravity);        // Create BALL 1 body and shape        b2BodyDef ballBodyDef;        ballBodyDef.type = b2_dynamicBody;        ballBodyDef.position.Set(100/PTM_RATIO 300/PTM_RATIO);        ballBodyDef.userData = _ball;        _body = _world->CreateBody(&ballBodyDef);        b2CircleShape circle;        circle.m_radius = 26.0/PTM_RATIO;        b2FixtureDef ballShapeDef;        ballShapeDef.shape = &circle;        ballShapeDef.density = 2.0f;        ballShapeDef.friction = 0.1f;        ballShapeDef.restitution = 0.4f;        _body->CreateFixture(&ballShapeDef);        [self schedule:@selector(tick:)];        // Create BALL 2 body and shape        b2BodyDef ballBodyDef2;        ballBodyDef2.type = b2_dynamicBody;        ballBodyDef2.position.Set(300/PTM_RATIO 300/PTM_RATIO);        ballBodyDef2.userData = _ball2;        _body2 = _world->CreateBody(&ballBodyDef2);        b2CircleShape circle2;        circle2.m_radius = 26.0/PTM_RATIO;        b2FixtureDef ballShapeDef2;        ballShapeDef2.shape = &circle2;        ballShapeDef2.density = 2.0f;        ballShapeDef2.friction = 0.1f;        ballShapeDef2.restitution = 0.4f;        _body->CreateFixture(&ballShapeDef2);        // Create edges around the entire screen        b2BodyDef groundBodyDef;        groundBodyDef.position.Set(00);        b2Body *groundBody = _world->CreateBody(&groundBodyDef);        b2EdgeShape groundEdge;        b2FixtureDef boxShapeDef;        boxShapeDef.shape = &groundEdge;        //WALL DEFINITIONS        //floor wall        groundEdge.Set(b2Vec2(00) b2Vec2(winSize.width/PTM_RATIO 0));        groundBody->CreateFixture(&boxShapeDef);        //roof wall        groundEdge.Set(b2Vec2(00) b2Vec2(0winSize.height/PTM_RATIO));        groundBody->CreateFixture(&boxShapeDef);        //left wall        groundEdge.Set(b2Vec2(0 winSize.height/PTM_RATIO)                       b2Vec2(winSize.width/PTM_RATIO winSize.height/PTM_RATIO));        groundBody->CreateFixture(&boxShapeDef);        //right wall        groundEdge.Set(b2Vec2(winSize.width/PTM_RATIO winSize.height/PTM_RATIO)                       b2Vec2(winSize.width/PTM_RATIO 0));        groundBody->CreateFixture(&boxShapeDef);         //Do the kick every 5 seconds         //[self schedule:@selector(kick) interval:5.0];        [self setTouchEnabled:YES];    }    return self;}- (void)tick:(ccTime) dt {    _world->Step(dt 10 10);    for(b2Body *b = _world->GetBodyList(); b; b=b->GetNext()) {        if (b->GetUserData() != NULL) {            CCSprite *ballData = (CCSprite *)b->GetUserData();            ballData.position = ccp(b->GetPosition().x * PTM_RATIO                                    b->GetPosition().y * PTM_RATIO);            ballData.rotation = -1 * CC_RADIANS_TO_DEGREES(b->GetAngle());        }    }}- (void)dealloc {    delete _world;    _body = NULL;    _world = NULL;    [super dealloc];}@end

解决方案

将这行

_body->CreateFixture(&ballShapeDef2);

改为这行：

_body2->CreateFixture(&ballShapeDef2);