DrawOneKLine如何畫單根K線

//函數實現畫單根K線的功能,坐標為普通坐標,而非對數坐標

void CStockGraph::DrawOneKLine(CDC * pDC, int nIndexPos, int nIndexKD, CKData * pKData, double dMin, double dMax, BOOL bGreyed )
{
 DECLARE_COLOR_DEFINATION

 // Check Valid

 //判斷當前位置的序列號是否有效,指的是顯示窗口,在當前的m_nIndexStart 和 m_nIndexEnd之間
 ASSERT( pDC && nIndexPos >= m_nIndexStart && nIndexPos <= m_nIndexEnd && nIndexPos >= 0 );
 if( !(pDC && nIndexPos >= m_nIndexStart && nIndexPos <= m_nIndexEnd && nIndexPos >= 0) )
  return;

 //判斷當前位置的序列號是否有效,序列號是否是小于零或大于當前序列的長度
 if( !pKData || nIndexKD < 0 || nIndexKD >= pKData->GetSize() )
  return;
 if( dMax-dMin < 1e-4 )
  return;

 // Get Region

 //關于GetOneKLineRect請參看下面關于這個函數的分析

 //這里需要注意的一個問題就是rectK, rcEntity,是有不同的含義的,rectK是指顯示的K線矩形區(qū)域,實際的畫K線的區(qū)域是rcEntity,指的是畫K線實體的區(qū)域
 CRect rectK, rcEntity;
 long xMedium = 0;
 if( !GetOneKLineRect( nIndexPos, &rectK, &rcEntity.left, &rcEntity.right, &xMedium ) )//參數xMedium 為K線實體的中間位置,對應畫K線的圖形
  return;

 int xStart = rectK.left;
 int xEnd = rectK.right;
 ASSERT( xEnd <= m_rectKLineCenter.right );
 if( xEnd > m_rectKLineCenter.right )
  return;

 KDATA kd = pKData->ElementAt(nIndexKD);

//根據當前最低價格/最高價格/收盤價格/開盤價格的計算出K線實體在當前顯示區(qū)域中坐標.(等比例的計算)

 // Set rcEntity's top and bottom, set yLow, yHigh
 int yLow = int( m_rectKLineCenter.bottom - m_rectKLineCenter.Height() * (kd.m_fLow - dMin) / (dMax-dMin) );
 int yHigh = int( m_rectKLineCenter.bottom - m_rectKLineCenter.Height() * (kd.m_fHigh - dMin) / (dMax-dMin) );
 int yOpen = int( m_rectKLineCenter.bottom - m_rectKLineCenter.Height() * (kd.m_fOpen - dMin) / (dMax-dMin) );
 int yClose = int( m_rectKLineCenter.bottom - m_rectKLineCenter.Height() * (kd.m_fClose - dMin) / (dMax-dMin) );

 //計算出實體區(qū)域的上下坐標,左右坐標已經根據序列位置計算出來了,到這個地方,已經計算出了要畫K線的試題區(qū)域的具體坐標了.

 rcEntity.top = min( yOpen, yClose );
 rcEntity.bottom = max( yOpen, yClose ) + 1;

 //上面已經計算出了要畫的K線的坐標了,下面就開始畫K線了

 if( CStockGraph::klineCandle == m_nCurKLineMode )
 {
  // Draw Entity

  //畫實體區(qū)域了
  COLORREF clr = clrRise;
  if( kd.m_fClose < kd.m_fOpen )
   clr = clrFallEntity;
  if( kd.m_date > m_dwLatestDate )
   clr = clrNewKLine;
  if( bGreyed )
   clr = clrDJ;
  pDC->SetBkColor( clrBK );
  if( kd.m_fClose < kd.m_fOpen )
   pDC->FillSolidRect( &rcEntity, clr );
  else
   pDC->Draw3dRect( &rcEntity, clr, clr );
 
  // Draw Line

  //畫K線上的最高和最低價格的線
  CPen pen( PS_SOLID, 1, clr );
  CPen *pOldPen = pDC->SelectObject( &pen );
  pDC->MoveTo( xMedium, yHigh );
  pDC->LineTo( xMedium, rcEntity.top );
  pDC->MoveTo( xMedium, rcEntity.bottom );
  pDC->LineTo( xMedium, yLow );

  pDC->SelectObject( pOldPen );
 }
 else if( CStockGraph::klineAmerica == m_nCurKLineMode )
 {
  // Draw Entity
  COLORREF clr = clrRise;
  if( kd.m_date > m_dwLatestDate )
   clr = clrNewKLine;
  if( bGreyed )
   clr = clrDJ;
  pDC->SetBkColor( clrBK );
 
  // Draw Line
  CPen pen( PS_SOLID, 1, clr );
  CPen *pOldPen = pDC->SelectObject( &pen );
  pDC->MoveTo( xStart, yHigh );
  pDC->LineTo( xStart, yLow );
  pDC->MoveTo( xStart, yClose );
  pDC->LineTo( xEnd, yClose );

  pDC->SelectObject( pOldPen );
 }
 else if( CStockGraph::klineTower == m_nCurKLineMode )
 {
 
  // Draw Entity
  COLORREF clr = clrRise;
  if( kd.m_fClose < kd.m_fOpen )
   clr = clrFallEntity;
  if( kd.m_date > m_dwLatestDate )
   clr = clrNewKLine;
  if( bGreyed )
   clr = clrDJ;
  pDC->SetBkColor( clrBK );
  if( kd.m_fClose < kd.m_fOpen )
   pDC->FillSolidRect( &rcEntity, clr );
  else
   pDC->Draw3dRect( &rcEntity, clr, clr );

  if( nIndexKD > 0 )
  {
   KDATA kdLast = pKData->ElementAt(nIndexKD-1);
   int yOpenLast = int( m_rectKLineCenter.bottom - m_rectKLineCenter.Height() * (kdLast.m_fOpen - dMin) / (dMax-dMin) );
   int yCloseLast = int( m_rectKLineCenter.bottom - m_rectKLineCenter.Height() * (kdLast.m_fClose - dMin) / (dMax-dMin) );
   if( kdLast.m_fClose > kdLast.m_fOpen && kd.m_fClose < kd.m_fOpen )
   {
    rcEntity.bottom = min(yOpenLast,rcEntity.bottom);
    if( rcEntity.bottom > rcEntity.top )
    {
     pDC->FillSolidRect( &rcEntity, clrBK );
     clr = clrRise;
     if( kd.m_date > m_dwLatestDate )
      clr = clrNewKLine;
     if( bGreyed )
      clr = clrDJ;
     pDC->Draw3dRect( &rcEntity, clr, clr );
    }
   }
   else if( kdLast.m_fClose < kdLast.m_fOpen && kd.m_fClose > kd.m_fOpen )
   {
    rcEntity.top = max(yOpenLast,rcEntity.top);
    if( rcEntity.bottom > rcEntity.top )
    {
     clr = clrFallEntity;
     if( kd.m_date > m_dwLatestDate )
      clr = clrNewKLine;
     if( bGreyed )
      clr = clrDJ;
     pDC->FillSolidRect( &rcEntity, clr );
    }
   }
  }
 }
}

//函數GetOneKLineRect的分析,得到當前序列位置處要畫K線的區(qū)域

BOOL CStockGraph::GetOneKLineRect( int nIndex, LPRECT lpRect, long *pxEntityLeft, long *pxEntityRight, long *pxMedium )
{

 //判斷當前的序列位置是在當前顯示的窗口區(qū)域中
 if( nIndex == -1 || nIndex < m_nIndexStart || nIndex > m_nIndexEnd )
  return FALSE;

 //初始化畫K線的位置的矩形區(qū)域

 CRect rectK = m_rectCenter;

 //計算出K線位置的左右寬度的坐標,上下的坐標沒有給出,只是初始化為m_rectCenter中的參數

 //左邊的起誓位置為,從K線顯示區(qū)域的左邊開始m_rectKLineCenter.left,加上已經顯示了nIndex-m_nIndexStart點的距離就是當前序列處的坐標
 rectK.left = m_rectKLineCenter.left + (nIndex-m_nIndexStart) * m_nThickness;

//右邊的坐標最簡單,就是左邊左邊加上寬度就可以了.
 rectK.right = rectK.left + m_nThickness;

 if( rectK.Width() <= 0 || rectK.Height() <= 0 )
  return FALSE;

//傳出參數lpRect
 if( lpRect )
  *lpRect = rectK;

 int xStart = rectK.left;

 CRect rcEntity;

 //根據當前的K線的寬度計算出序列的右邊的坐標點,并傳出參數
 switch( m_nThickness )
 {
 case 1:
 case 2:
  rcEntity.left = xStart;
  rcEntity.right = xStart + 1;
  break;
 case 4:
 case 5:
  rcEntity.left = xStart;
  rcEntity.right = xStart + 3;
  break;
 case 6:
 case 7:
  rcEntity.left = xStart;
  rcEntity.right = xStart + 5;
  break;
 case 9:
 case 10:
  rcEntity.left = xStart;
  rcEntity.right = xStart + 7;
  break;
 case 13:
 case 15:
  rcEntity.left = xStart;
  rcEntity.right = xStart + 11;
  break;
 default:
  ASSERT( FALSE );
  rcEntity.left = xStart;
  rcEntity.right = xStart + 3;
  return FALSE;
 }
 if( pxEntityLeft )
  *pxEntityLeft = rcEntity.left;
 if( pxEntityRight )
  *pxEntityRight = rcEntity.right;
 if( pxMedium )
  *pxMedium = rcEntity.left + rcEntity.Width() / 2;

 return TRUE;
}