#include "stdafx.h"
#include "RubberLine.h"

RubberLine::RubberLine()
	:m_firstDraw(false)
{
}

void RubberLine::SetOriginPoint(const CPoint & originPt)
{
	m_originPt = originPt;
	m_firstDraw = true;
}

void RubberLine::Draw(CDC * pDC, CPoint & motionPt)
{
	int nOldRop = pDC->SetROP2(R2_NOTXORPEN);
	if (m_firstDraw)
	{
		pDC->MoveTo(m_originPt);
		pDC->LineTo(motionPt);

		m_oldMotionPt = motionPt;
		m_firstDraw = false;
		pDC->SetROP2(nOldRop);
		return;
	}

	//擦除原来的橡皮线
	pDC->MoveTo(m_originPt);
	pDC->LineTo(m_oldMotionPt);
	m_oldMotionPt = motionPt;

	//绘制新的橡皮线
	pDC->MoveTo(m_originPt);
	pDC->LineTo(motionPt);

	pDC->SetROP2(nOldRop);
}

void RubberLine::Erease(CDC * pDC)
{
	//擦除原来的橡皮线
	int nOldRop = pDC->SetROP2(R2_NOTXORPEN);
	pDC->MoveTo(m_originPt);
	pDC->LineTo(m_oldMotionPt);
	pDC->SetROP2(nOldRop);
}