Question

我使用这种方法初始化我的精灵：

-(id)initAttackerWithType:(ShapeType)type withPosition:(CGPoint)pos world:(b2World*)world andEnergy:(float)energy {
    if(([self initWithTexture:[[CCTextureCache sharedTextureCache]addImage:@"circle.png"]])){
        self.tag=type;
        self.color= type == Enemy ? ccc3(255, 0, 0) : ccc3(0, 255, 0);

        self.scale=energy *.22/PTM_RATIO; //scale depending on energy
                                       // 0.22 gets the sprite scale to synchronize with shape radius  
        self.position=pos;

        b2BodyDef bodyDef;
        bodyDef.type = b2_dynamicBody;
        bodyDef.position.Set(pos.x/PTM_RATIO, pos.y/PTM_RATIO);
        _body = world->CreateBody(&bodyDef);

        b2CircleShape dynamicCircle;
        dynamicCircle.m_radius=energy/PTM_RATIO;  //radius depending on energy 

        b2FixtureDef fixtureDef;
        fixtureDef.shape = &dynamicCircle;
        fixtureDef.density = 1.0f;
        fixtureDef.friction = 0;
        fixtureDef.restitution = 1;
        _body->CreateFixture(&fixtureDef);
        fixtureDef.userData=self;
        _body->SetUserData(self);



    }else self = nil;
    return self ? self : nil;
}

关于力学，碰撞的一切都很有效。唯一的问题是精灵比例不会根据能量而变化。不要误解我的意思，它应该在屏幕上添加，但只能在规模1上。

当我记录刻度时，它会以应有的刻度记录，但实际图像不是。

我确信我忽略了一些简单易行的东西，但我无法弄清楚是什么。

Answer 1

我认为你使用的是CCPhysicsSprite？然后检查nodeToParentTransform代码，查看x / y坐标是否与scaleX / Y相乘。我相信早期版本没有使用规模，至少评论似乎表明了这一点。作为参考，我将从v2.1 rc1发布方法，以便您可以比较和更新版本的转换代码：

-(CGAffineTransform) nodeToParentTransform
{
    // Although scale is not used by physics engines, it is calculated in case
    // the sprite is animated (scaled up/down) using actions.
    // For more info see: http://www.cocos2d-iphone.org/forum/topic/68990
    cpVect rot = (_ignoreBodyRotation ? 
                  cpvforangle(-CC_DEGREES_TO_RADIANS(_rotationX)) : 
                  _cpBody->rot);
    CGFloat x = _cpBody->p.x + rot.x * -_anchorPointInPoints.x * _scaleX - 
                rot.y * -_anchorPointInPoints.y * _scaleY;
    CGFloat y = _cpBody->p.y + rot.y * -_anchorPointInPoints.x * _scaleX + 
                rot.x * -_anchorPointInPoints.y * _scaleY;

    if (_ignoreAnchorPointForPosition)
    {
        x += _anchorPointInPoints.x;
        y += _anchorPointInPoints.y;
    }

    return _transform = CGAffineTransformMake(rot.x * _scaleX, rot.y * _scaleX,
                                              -rot.y * _scaleY, rot.x * _scaleY,
                                              x,   y);
}

与box2d一起使用时，精灵不会改变比例

1 个答案: