freetype2灰色图渲染

BOOL DrawText(HDC hDC, LPSTR lpString, int nCount, LPRECT lpRect, UINT uFormat)
{
 int i, j;
 int x, y;
 int nUnderLineHei;
 BOOL bRet;
 PFT2FONT pFont;
 
 if((NULL == hDC) || (NULL == hDC->hFont) || (NULL == lpString) || ('\0' == lpString) || (NULL == lpRect))
  return FALSE;

 pFont = (PFT2FONT)hDC->hFont;

 bRet = FreeType2_GetFontData(pFont, lpString);
 if(bRet)
 {
  if((pFont->nRealWid > 0) && (pFont->nRealHei > 0))
  {
   int nDy;
   COLORREF clrD;
   BYTE dr, dg, db, mr, mg, mb;
   BYTE sr = fb_r(hDC->clrPen);
   BYTE sg = fb_g(hDC->clrPen);
   BYTE sb = fb_b(hDC->clrPen);

   x = lpRect->left;
   y = lpRect->top;

   nUnderLineHei = 0;
   
   if(pFont->bUnderline)
    nUnderLineHei = pFont->nRealHei / 10;
   
   switch(uFormat & 0xf0)
   {
    case DT_RIGHT:
     x += lpRect->right - pFont->nRealWid;
     break;

    case DT_HCENTER: 
     x = (lpRect->left + lpRect->right - pFont->nRealWid) / 2;
     break;
   }

   nDy = pFont->bUnderline ? (nUnderLineHei + 1) : 0;

   switch(uFormat & 0x0f)
   {
    case DT_VCENTER:
     y = (lpRect->top + lpRect->bottom - (pFont->nRealHei  + nDy)) / 2;
     break;

    case DT_BOTTOM:
     y += lpRect->bottom - (pFont->nRealHei + nDy);
     break;
   }
   
   if(x <= lpRect->left)
    x = lpRect->left;
    
   if(y <= lpRect->top)
    y = lpRect->top;
 
   RequestPaint();

   for(i=0; inRealHei; i++)
   {
    for(j=0; jnRealWid; j++)
    {
     if((x+j < lpRect->right) && (y+i < lpRect->bottom))
     {
      if(*(pFont->pucData + i*pFont->nRealWid + j) != 0xff)
      {       
       clrD = xgui_getpixel(x+j, y+i);
       
       mr = fb_r(clrD);
       mg = fb_g(clrD);
       mb = fb_b(clrD);

       if(!*(pFont->pucData + i*pFont->nRealWid + j))
       {
        dr = sr;
        dg = sg;
        db = sb;
       }
       
       else
       {
        dr = (*(pFont->pucData + i*pFont->nRealWid + j)*(mr - sr) >> 8) + sr;
        dg = (*(pFont->pucData + i*pFont->nRealWid + j)*(mg - sg) >> 8) + sg;
        db = (*(pFont->pucData + i*pFont->nRealWid + j)*(mb - sb) >> 8) + sb;
       }
       
       xgui_setpixel(hDC, x+j, y+i, fb_rgb(dr, dg, db));
      }
     }
    }
   }

   if(pFont->bUnderline)
   {
    y += pFont->nRealHei + 1;
    
    for(i=0; i    {
     for(j=0; jnRealWid; j++)
     {
      if((x+j < lpRect->right) && (y+i < lpRect->bottom))
       xgui_setpixel(hDC, x+j, y+i, hDC->clrPen);
     }
    }
   }
   
   CompletePaint();
  } 
 }

 return TRUE;
}