在cocos2d中銷毀box2d主體

Question

我有一個網和一些昆蟲，我正在投擲網，並與昆蟲進行碰撞檢測並將其破壞。 我已經將bod2d用於碰撞檢測。

世界方法

-(void)createWorld
{

 // Define the gravity vector.
    b2Vec2 b_gravity;
    b_gravity.Set(0.0f, -9.8f);

 // Do we want to let bodies sleep?
 // This will speed up the physics simulation
    bool doSleep = true;

 // Construct a world object, which will hold and simulate the rigid bodies.
    world = new b2World(b_gravity);
    world->SetAllowSleeping(doSleep);

    world->SetContinuousPhysics(true);

}

建立網站

-(void) createWeb
{
    freeBodySprite = [CCSprite spriteWithFile:@"web1.png"];
        [self addChild:freeBodySprite z:2 tag:TAG_WEB];

    CGPoint startPos = CGPointMake(100, 320/1.25);

    bodyDef.type = b2_staticBody;
    bodyDef.position = [self toMeters:startPos];
    bodyDef.userData = freeBodySprite;

    float radiusInMeters = ((freeBodySprite.contentSize.width * freeBodySprite.scale/PTM_RATIO) * 1.0f);
    shape.m_radius = radiusInMeters;

    fixtureDef.shape = &shape;
    fixtureDef.density = 0.01f;
    fixtureDef.friction = 0.1f;
    fixtureDef.restitution = 0.1f;

    circularObstacleBody = world->CreateBody(&bodyDef);
    stoneFixture = circularObstacleBody->CreateFixture(&fixtureDef);
        freeBody = circularObstacleBody;
}

我用spritesheet創建了昆蟲動畫，然后為該Sprite創建了b2body

-(b2Body *) createMovingBoxObstacle
{


    //set this to avoid updating this object in the tick schedule
        _ants.userData = (void *)YES;

    b2BodyDef bodyDef_Ant;
    bodyDef_Ant.type = b2_dynamicBody;
    CGPoint startPos = ccp(520,winSize.height/7.6);
    bodyDef_Ant.position = [self toMeters:startPos];
    bodyDef_Ant.userData = _ants;

    b2PolygonShape dynamicBox;
    float tileWidth = ((_ants.contentSize.width * _ants.scale/PTM_RATIO) * 0.5f);
    float tileHeight = ((_ants.contentSize.height * _ants.scale/PTM_RATIO) * 0.5f);
    dynamicBox.SetAsBox(tileWidth, tileHeight);

    b2FixtureDef fixtureDef_Ant;
    fixtureDef_Ant.shape = &dynamicBox;
    fixtureDef_Ant.friction = 0.7;
    fixtureDef_Ant.density = 0.1f;
    fixtureDef_Ant.restitution = 0.7;


    staticBody = world->CreateBody(&bodyDef_Ant);
    staticBody->CreateFixture(&fixtureDef_Ant);

       VAMovingObstacle* moveableObject = [[VAMovingObstacle alloc] init];
       moveableObject.startPoint = ccp(520,winSize.height/7.6);
       moveableObject.endPoint = ccp(-50,winSize.height/7.6);
       moveableObject.transitionTime = 20.0;
       moveableObject.breakTime = 1.0;

    moveableObject.obstacleSprite = _ants;
    moveableObject.physicalBody = staticBody;
    [moveableObject startMovement];

    if (!movingObstacles) {
        movingObstacles = [[NSMutableArray alloc] init];
    }
    [movingObstacles addObject:moveableObject];
    [moveableObject release];
    return staticBody;
}

VAMovingObstacle是一個類，可幫助精靈與b2body一起從左向右移動（運行）

這是我的聯系人列表器EndContact方法

void ContactListener::EndContact(b2Contact* contact)
{
    b2Body* bodyA = contact->GetFixtureA()->GetBody();
    b2Body* bodyB = contact->GetFixtureB()->GetBody();

    if (bodyA->GetUserData() != NULL && bodyB->GetUserData() != NULL) {
        CCSprite *spriteA = (CCSprite *) bodyA->GetUserData();
        CCSprite *spriteB = (CCSprite *) bodyB->GetUserData();


        if (spriteA.tag == TAG_WEB && spriteB.tag >= TAG_ANT) {

        }

        else if (spriteA.tag >= TAG_ANT && spriteB.tag == TAG_WEB) {

            [spriteA removeFromParentAndCleanup:YES];
            [[HelloWorldLayer sharedLevel] WebCollisionWithInsect:bodyA];
        }
    }
}

每當發生碰撞時，EndContact方法都會調用WebCollisionWithInsect：bodyA

-(void) WebCollisionWithInsect:(b2Body*) bodyT{
            world->DestroyBody(bodyT);
}

在world-> DestroyBody（bodyT）行上給出錯誤

斷言失敗：（IsLocked（）== false），函數DestroyBody，文件/Users/libs/Box2D/Dynamics/b2World.cpp，第134行。

任何想法我在做什么錯。 ？

編輯我已在EndContact中添加此行

destroyCollisionDetectionBody = objBody;
didInsectCollideWithWeb = YES;

保持引用我要破壞的身體。 現在我可以在tick方法中破壞我的身體，如果選中在tick方法中添加了這些行

if(didInsectCollideWithWeb)
    {
        [self unschedule:@selector(tick:)];
        [freeBodySprite removeFromParentAndCleanup:YES]; // this is my web
        world->DestroyBody(destroyCollisionDetectionBody);
        world->DestroyBody(freeBody);
        [self createWeb];
        [self schedule:@selector(tick:)];
        didInsectCollideWithWeb = NO;

    }

但是現在的問題是，當我破壞我的網站時，即自由人。 我無法重新創建它。 就像我以前通過調用[self createWeb]所做的那樣；

Answer 1

您正試圖摧毀一個box2d對象，而其在模擬階段使用（如EndContact是在該階段的稱呼）。 仿真階段是調用世界的step方法時執行的step 。

因此，您應該做的是保留對要刪除的主體對象的引用，然后在box2d模擬階段（在step方法返回之后）用所需的主體執行WebCollisionWithInsect