C++ CDC::BeginPath方法代码示例

void CClock::DrawTime( CDC *pDc )
{
	CRect  rtClient;
	GetClientRect(&rtClient);
	CDC  dcTransparent;
	dcTransparent.CreateCompatibleDC(pDc);
	CBitmap bitTransParent;
	bitTransParent.CreateCompatibleBitmap(pDc, rtClient.Width(),rtClient.Height());
	dcTransparent.SelectObject(&bitTransParent);

	// 		CRect rectReal(ix1, iy1, ix2, iy2);
	dcTransparent.FillSolidRect(rtClient, RGB(255, 255, 255));
	// 		dcTransparent.Draw3dRect(rectReal, RGB(111, 147, 188), RGB(111, 147, 188));

	dcTransparent.BeginPath();
	dcTransparent.MoveTo(rtClient.Width()/2, rtClient.Height()/2);
	dcTransparent.LineTo(rtClient.Width()/2-80, rtClient.Height()/2);

	float   fEnd = 90.0f;
	dcTransparent.AngleArc(rtClient.Width()/2, rtClient.Height()/2, 120, -180.0f, 270.0f);
	dcTransparent.LineTo(rtClient.Width()/2, rtClient.Height()/2);

	dcTransparent.EndPath();
	CRgn rgn;
	rgn.CreateFromPath(&dcTransparent);
	dcTransparent.FillRgn(&rgn, &CBrush(RGB(188, 199, 216)));

	//内
	dcTransparent.BeginPath();
	dcTransparent.MoveTo(rtClient.Width()/2, rtClient.Height()/2);
	dcTransparent.LineTo(rtClient.Width()/2-40, rtClient.Height()/2);

	dcTransparent.AngleArc(rtClient.Width()/2, rtClient.Height()/2, 40, -180.0f, 270.0f);
	dcTransparent.LineTo(rtClient.Width()/2, rtClient.Height()/2);

	dcTransparent.EndPath();
	CRgn rgn1;
	rgn1.CreateFromPath(&dcTransparent);
	dcTransparent.FillRgn(&rgn1, &CBrush(RGB(255, 255, 0)));

	if( ::AlphaBlend == 0 )
	{
		pDc->StretchBlt(0, 0, rtClient.Width(), rtClient.Height(), 
			&dcTransparent, 0, 0, rtClient.Width(), rtClient.Height(), SRCINVERT );

	}else{

		BLENDFUNCTION bf;    
		memset( &bf, 0, sizeof( bf ) );
		bf.SourceConstantAlpha = 0x9f; //半透明
		bf.BlendOp = AC_SRC_OVER;

		::TransparentBlt(pDc->GetSafeHdc(), 0, 0, rtClient.Width(), rtClient.Height(), 
			dcTransparent.GetSafeHdc( ), 0, 0, rtClient.Width(), rtClient.Height(), RGB(255, 255, 255));
		// 			::AlphaBlend( memDC.GetSafeHdc(), 0, 0, rtClient.Width(), rtClient.Height(), 
		// 				dcTransparent.GetSafeHdc( ), 0, 0, rtClient.Width(), rtClient.Height(), bf );  
	}
	bitTransParent.DeleteObject();
	dcTransparent.DeleteDC();
}

void CHexagon::Draw(CDC &dc)
{
	dc.BeginPath();
	dc.MoveTo(m_dCenterX - m_A, m_dCenterY);
	dc.LineTo(m_dCenterX - m_A * 1/2, m_dCenterY - m_A * sqrt(3.)/2);
	dc.LineTo(m_dCenterX + m_A * 1/2, m_dCenterY - m_A * sqrt(3.)/2);
	dc.LineTo(m_dCenterX + m_A, m_dCenterY);
	dc.LineTo(m_dCenterX + m_A * 1/2, m_dCenterY + m_A * sqrt(3.)/2);
	dc.LineTo(m_dCenterX - m_A * 1/2, m_dCenterY + m_A * sqrt(3.)/2);
	dc.LineTo(m_dCenterX - m_A, m_dCenterY);
	dc.EndPath();
	dc.StrokeAndFillPath();
}

bool CAddCamDlg::GenerateMskImg(CString& mstr)
{
	if (mRangeIndex==0 && mWarnRange[mRangeIndex].size()<3)
	{
		return false;
	}
	if (maskimg.IsNull())
	{
		return false;
	}
	vector<CPoint>::iterator it;
	CPen *pPen = new CPen(PS_SOLID, 1, RGB(255, 255, 255));
	CBrush *pBr = new CBrush(RGB(255, 255, 255));
	CDC *pDC = CDC::FromHandle(maskimg.GetDC());

	pDC->FillSolidRect(CRect(0, 0, maskimg.GetWidth(), maskimg.GetHeight()), RGB(0, 0, 0));
	pDC->SelectObject(pPen);
	pDC->SelectObject(pBr);
	//memDC.SetBkColor(RGB(255,255,255));
	CPoint mPt;
	for (int i = 0; i <= mRangeIndex; i++)
	{
		it = mWarnRange[i].begin();
		pDC->BeginPath();
		mPt = *it;
		mPt.x = mPt.x*double(maskimg.GetWidth()) / mImgRect.Width();
		mPt.y = mPt.y*double(maskimg.GetHeight()) / mImgRect.Height();
		pDC->MoveTo(mPt);
		for (it++; it != mWarnRange[i].end(); it++)
		{
			mPt = *it;
			mPt.x = mPt.x*double(maskimg.GetWidth()) / mImgRect.Width();
			mPt.y = mPt.y*double(maskimg.GetHeight()) / mImgRect.Height();
			pDC->LineTo(mPt);
		}
		pDC->EndPath();
		pDC->StrokeAndFillPath();
	}
	delete pPen;
	delete pBr;
	maskimg.ReleaseDC();
	maskimg.Save(mstr);
	return true;
}

void CWmPaintTestView::OnMenuGMJoin() 
{
	CDC* pDC = GetDC();
	int nStyle[3];
	nStyle[0] = PS_GEOMETRIC | PS_SOLID | PS_ENDCAP_FLAT | PS_JOIN_BEVEL;
	nStyle[1] = PS_GEOMETRIC | PS_SOLID | PS_ENDCAP_FLAT | PS_JOIN_ROUND;
	nStyle[2] = PS_GEOMETRIC | PS_SOLID | PS_ENDCAP_FLAT | PS_JOIN_MITER;

	CPen* pNewPen = NULL;
	CPen* pOldPen = NULL;

	LOGBRUSH lb;
	lb.lbStyle = BS_SOLID;
	lb.lbColor = RGB(0, 0, 255);

	for(int i = 0; i < 3; i++)
	{
		pNewPen = new CPen(nStyle[i], 16, &lb);
		pOldPen = pDC->SelectObject(pNewPen);

		//ㄱ자 모양으로 선을 그리되 이 두 선을 서로 패스로 묶어준다.
		// BeginPath EndPath의 역할 : 사이의 선이 연결선음을 암시 
		pDC->BeginPath();
		pDC->MoveTo(100 + i * 120, 200);
		pDC->LineTo(200 + i * 120, 200);
		pDC->LineTo(200 + i * 120, 200 + 50);
		pDC->EndPath();
		//두 연결된 선의 꺽어진 부분에 대해 Join 스타일을 적용하여 랜더링한다.
		// 여기서 그려주게 됨 
		pDC->StrokePath();

		pDC->SelectObject(pOldPen);
		delete pNewPen;
	}

	ReleaseDC(pDC);
}

//.........这里部分代码省略.........
	int nRadius((int) (nSeriesSpace * INTERSERIES_PERCENT_USED / 2.0));
	POSITION pos(m_olMyGraphSeries.GetHeadPosition());

	while (pos) {

		MyGraphSeries* pSeries = m_olMyGraphSeries.GetNext(pos);
		ASSERT_VALID(pSeries);

		// Don't leave a space for empty pies.
		if (0 < pSeries->GetNonZeroElementCount()) {

			// Locate this pie.
			CPoint ptCenter;
			ptCenter.x = xOrigin + (nSeriesSpace * nPie) + nSeriesSpace / 2;
			ptCenter.y = m_ptOrigin.y - m_nYAxisHeight / 2;

			CRect rcPie;
			rcPie.left = ptCenter.x - nRadius;
			rcPie.right = ptCenter.x + nRadius;
			rcPie.top = ptCenter.y - nRadius;
			rcPie.bottom = ptCenter.y + nRadius;

			// Draw series label.
			CSize sizPieLabel(dc.GetTextExtent(pSeries->GetLabel()));

			VERIFY(dc.TextOut(ptCenter.x - (sizPieLabel.cx / 2),
			  ptCenter.y + nRadius + GAP_PIXELS, pSeries->GetLabel()));

			// How much do the wedges total to?
			double dPieTotal(pSeries->GetDataTotal());

			// Draw each wedge in this pie.
			CPoint ptStart(rcPie.left, ptCenter.y);
			double dRunningWedgeTotal(0.0);

			for (int nGroup = 0; nGroup < m_saLegendLabels.GetSize(); ++nGroup) {

				// Ignore empty wedges.
				if (0 < pSeries->GetData(nGroup)) {

					// Get the degrees of this wedge.
					dRunningWedgeTotal += pSeries->GetData(nGroup);
					double dPercent(dRunningWedgeTotal * 100.0 / dPieTotal);
					double degrees(360.0 * dPercent / 100.0);

					// Find the location of the wedge's endpoint.
					CPoint ptEnd(WedgeEndFromDegrees(degrees, ptCenter, nRadius));

					// Special case: a wedge that takes up the whole pie would
					// otherwise be confused with an empty wedge.
					bool drawEmptyWedges = false;
					if (1 == pSeries->GetNonZeroElementCount()) {
						_ASSERTE(360 == (int)degrees  &&  ptStart == ptEnd  &&  "This is the problem we're correcting");
						--ptEnd.y;
						drawEmptyWedges = true;
					}

					// If the wedge is zero size or very narrow, don't paint it.
					// If pie is small, and wedge data is small, we might get a wedges
					// where center and both endpoints lie on the same coordinate,
					// and endpoints differ only in one pixel. GDI draws such pie as whole pie,
					// so we just skip them instead.
					int distance = abs(ptStart.x-ptEnd.x) + abs(ptStart.y-ptEnd.y);
					if (drawEmptyWedges || distance > 1) {

						// Draw wedge.
						COLORREF crWedge(m_dwaColors.GetAt(nGroup));
						CBrush br(crWedge);
						CBrush* pBrushOld = dc.SelectObject(&br);
						ASSERT_VALID(pBrushOld);
						VERIFY(dc.Pie(rcPie, ptStart, ptEnd));

						// Create a region from the path we create.
						VERIFY(dc.BeginPath());
						VERIFY(dc.Pie(rcPie, ptStart, ptEnd));
						VERIFY(dc.EndPath());
						CRgn * prgnWedge = new CRgn;
						VERIFY(prgnWedge->CreateFromPath(&dc));
						pSeries->SetTipRegion(nGroup, prgnWedge);

						// Cleanup.
						dc.SelectObject(pBrushOld);
						br.DeleteObject();
						ptStart = ptEnd;
					}
				}
			}

			++nPie;
		}
	}

	// Draw X axis title
	CSize sizXLabel(dc.GetTextExtent(m_sXAxisLabel));
	VERIFY(dc.TextOut(xOrigin + (nSeriesSpace * nPie - sizXLabel.cx)/2,
		m_ptOrigin.y - m_nYAxisHeight/2 + nRadius + GAP_PIXELS*2 + sizXLabel.cy, m_sXAxisLabel));

	VERIFY(dc.SelectObject(pFontOld));
	fontLabels.DeleteObject();
}