#include "stdafx.h"
#include "ServoMemDC.h"

CServoMemDC::CServoMemDC(CDC* pDC, const CRect* pRect)
    : CDC(), m_pOldBitmap(nullptr), m_pDC(pDC), m_bMemDC(FALSE)
{
    ASSERT(pDC != nullptr);

    if (pRect == nullptr)
        pDC->GetClipBox(&m_rect);
    else
        m_rect = *pRect;

    if (CreateCompatibleDC(pDC)) {
        m_bMemDC = TRUE;
        m_bitmap.CreateCompatibleBitmap(pDC, m_rect.Width(), m_rect.Height());
        m_pOldBitmap = SelectObject(&m_bitmap);
        SetWindowOrg(m_rect.left, m_rect.top);
    }
}

CServoMemDC::~CServoMemDC()
{
    if (m_bMemDC) {
        // ½«ÄÚ´æ DC ¿½±´»Øԭʼ´°¿Ú DC
        m_pDC->BitBlt(m_rect.left, m_rect.top, m_rect.Width(), m_rect.Height(),
            this, m_rect.left, m_rect.top, SRCCOPY);
        SelectObject(m_pOldBitmap);
    }
}

CServoMemDC* CServoMemDC::operator->()
{
    return this;
}

CServoMemDC::operator CDC* ()
{
    return this;
}