C++ DPoint::getLength方法代码示例

void CAScrollView::deaccelerateScrolling(float dt)
{
    dt = MIN(dt, 1/30.0f);
    dt = MAX(dt, 1/100.0f);

    if (m_tInertia.getLength() > maxSpeedCache(dt))
    {
        m_tInertia = ccpMult(m_tInertia, maxSpeedCache(dt) / m_tInertia.getLength());
    }
    
    DPoint speed = DPointZero;
    if (m_tInertia.getLength() > maxSpeed(dt))
    {
        speed = ccpMult(m_tInertia, maxSpeed(dt) / m_tInertia.getLength());
    }
    else
    {
        speed = m_tInertia;
    }
    
    DPoint point = m_pContainer->getFrameOrigin();

    if (m_bBounces)
    {
        DPoint resilience = DPointZero;
        DSize size = this->getBounds().size;
        DPoint curr_point = m_pContainer->getFrameOrigin();
        DPoint relust_point = curr_point;
        this->getScrollWindowNotOutPoint(relust_point);
        float off_x = relust_point.x - curr_point.x;
        float off_y = relust_point.y - curr_point.y;
        
        if (fabsf(off_x) > FLT_EPSILON)
        {
            resilience.x = off_x / size.width;
        }
        
        if (fabsf(off_y) > FLT_EPSILON)
        {
            resilience.y = off_y / size.height;
        }
        
        resilience = ccpMult(resilience, maxSpeed(dt));
        
        if (speed.getLength() < resilience.getLength())
        {
            speed = resilience;
            m_tInertia = DPointZero;
        }
    }
    
    if (speed.getLength() < 0.25f)
    {
        m_tInertia = DPointZero;
        this->getScrollWindowNotOutPoint(point);
        this->setContainerFrame(point);
        this->update(0);
        this->hideIndicator();
        this->stopDeaccelerateScroll();
        
        if (m_pScrollViewDelegate)
        {
            m_pScrollViewDelegate->scrollViewStopMoved(this);
        }
        
    }
    else
    {
        point = ccpAdd(point, speed);

        if (this->isScrollWindowNotMaxOutSide(point))
        {
            m_tInertia = DPointZero;
        }
        
        if (m_bBounces == false)
        {
            this->getScrollWindowNotOutPoint(point);
        }
        else
        {
            if (m_bBounceHorizontal == false)
            {
                point.x = this->getScrollWindowNotOutHorizontal(point.x);
            }
            
            if (m_bBounceVertical == false)
            {
                point.y = this->getScrollWindowNotOutVertical(point.y);
            }
        }

        if (point.equals(m_pContainer->getFrameOrigin()))
        {
            m_tInertia = DPointZero;
        }
        else
        {
            this->showIndicator();
            this->setContainerFrame(point);
//.........这里部分代码省略.........

void CAScrollView::ccTouchMoved(CATouch *pTouch, CAEvent *pEvent)
{
    CC_RETURN_IF(m_bPCMode);
    CC_RETURN_IF(m_vTouches.contains(pTouch) == false);
    DPoint p_container = m_pContainer->getFrameOrigin();
    DPoint p_off = DPointZero;
    
    if (m_vTouches.size() == 1)
    {
        p_off = ccpSub(this->convertToNodeSpace(pTouch->getLocation()),
                       this->convertToNodeSpace(pTouch->getPreviousLocation()));
        
        DPoint off = p_off;
        if (off.getLength() <= 5)
        {
            off = DPointZero;
        }
        
        m_tPointOffset.push_back(off);
    }
    else if (m_vTouches.size() == 2)
    {
        CATouch* touch0 = dynamic_cast<CATouch*>(m_vTouches.at(0));
        CATouch* touch1 = dynamic_cast<CATouch*>(m_vTouches.at(1));
        DPoint mid_point = ccpMidpoint(this->convertToNodeSpace(touch0->getLocation()),
                                        this->convertToNodeSpace(touch1->getLocation()));
        p_off = ccpSub(mid_point, ccpAdd(p_container, m_pContainer->getAnchorPointInPoints() * m_fZoomScale));
        
        if (m_fMinimumZoomScale < m_fMaximumZoomScale)
        {
            float touch_lenght = ccpDistance(this->convertToNodeSpace(touch0->getLocation()) ,
                                             this->convertToNodeSpace(touch1->getLocation()));
            float scale_off = (touch_lenght - m_fTouchLength) * 0.0020f;
            
            m_fZoomScale = m_pContainer->getScale();
            m_fZoomScale += m_fZoomScale * scale_off;
            
            m_fZoomScale = MIN(m_fZoomScale, m_fMaximumZoomScale);
            m_fZoomScale = MAX(m_fZoomScale, m_fMinimumZoomScale);
            
            m_pContainer->setScale(m_fZoomScale);
            m_fTouchLength = touch_lenght;
        }
    }

    if (m_bBounces)
    {
        DSize size = this->getBounds().size;
        DPoint curr_point = m_pContainer->getFrameOrigin();
        DPoint relust_point = curr_point;
        this->getScrollWindowNotOutPoint(relust_point);
        
        float lenght_x = fabsf(curr_point.x - relust_point.x);
        float lenght_y = fabsf(curr_point.y - relust_point.y);
        
        DPoint scale = DPoint(1.0f, 1.0f);
        
        if (!(lenght_x < FLT_EPSILON))
        {
            scale.x = (0.5f - MIN(lenght_x / size.width, 0.5f));
            p_off.x *= scale.x;
        }
        
        if (!(lenght_y < FLT_EPSILON))
        {
            scale.y = (0.5f - MIN(lenght_y / size.height, 0.5f));
            p_off.y *= scale.y;
        }
    }
    
    p_container = ccpAdd(p_container, p_off);

    if (m_bBounces == false)
    {
        this->getScrollWindowNotOutPoint(p_container);
    }
    else
    {
        if (m_bBounceHorizontal == false)
        {
            p_container.x = this->getScrollWindowNotOutHorizontal(p_container.x);
        }
        
        if (m_bBounceVertical == false)
        {
            p_container.y = this->getScrollWindowNotOutVertical(p_container.y);
        }
    }
    
    if (p_container.equals(m_pContainer->getFrameOrigin()) == false)
    {
        if (m_bTouchEnabledAtSubviews)
        {
            m_pContainer->setTouchEnabled(false);
        }
        this->setContainerFrame(p_container);
        this->showIndicator();
        
        if (m_bTracking == false)
        {
//.........这里部分代码省略.........