CreateGrayscaleIcon()

Sample Image

SoftechSoftware homepage
SoftechSoftware Email

Environment: VC++ 6.0, XP, Win2k, NT 4.0, Win9x/ME

Abstract

CreateGrayscaleIcon is a Win32 function that creates a grayscale icon starting from a given icon. The resulting icon will have the same size of the original one. This function is written using only Win32 APIs to make possible to be used either in MFC and pure Win32 applications.

Function description

Just add in your project a function like the following:


// This function creates a grayscale icon starting
// from a given icon. The resulting icon will have
// the same size of the original one.
//
// Parameters:
//      [IN]    hIcon
//              Handle to the original icon.
//
// Return value:
//      If the function succeeds, the return value is 
//      the handle to the newly created grayscale icon.
//      If the function fails, the return value is NULL.
//
HICON CreateGrayscaleIcon(HICON hIcon)
{
  HICON       hGrayIcon = NULL;
  HDC         hMainDC = NULL, 
              hMemDC1 = NULL, 
              hMemDC2 = NULL;
  BITMAP      bmp;
  HBITMAP     hOldBmp1 = NULL,
              hOldBmp2 = NULL;
  ICONINFO    csII, csGrayII;
  BOOL        bRetValue = FALSE;

  bRetValue = ::GetIconInfo(hIcon, &csII);
  if (bRetValue == FALSE) return NULL;

  hMainDC = ::GetDC(m_hWnd);
  hMemDC1 = ::CreateCompatibleDC(hMainDC);
  hMemDC2 = ::CreateCompatibleDC(hMainDC);
  if (hMainDC == NULL || 
    hMemDC1 == NULL ||
    hMemDC2 == NULL) 
      return NULL;

  if (::GetObject(csII.hbmColor, 
                sizeof(BITMAP), &
                amp;bmp))
  {
    csGrayII.hbmColor = 
         ::CreateBitmap(csII.xHotspot*2,
                        csII.yHotspot*2, 
                        bmp.bmPlanes, 
                        bmp.bmBitsPixel, 
                        NULL);
    if (csGrayII.hbmColor)
    {
      hOldBmp1 =
         (HBITMAP)::SelectObject(hMemDC1,
                                 csII.hbmColor);
      hOldBmp2 = 
         (HBITMAP)::SelectObject(hMemDC2,
                                 csGrayII.hbmColor);

      ::BitBlt(hMemDC2, 0, 0, csII.xHotspot*2,
               csII.yHotspot*2, hMemDC1, 0, 0,
               SRCCOPY);

      DWORD    dwLoopY = 0, dwLoopX = 0;
      COLORREF crPixel = 0;
      BYTE     byNewPixel = 0;

      for (dwLoopY = 0; dwLoopY < csII.yHotspot*2; dwLoopY++)
      {
        for (dwLoopX = 0; dwLoopX < csII.xHotspot*2; dwLoopX++)
        {
          crPixel = ::GetPixel(hMemDC2, dwLoopX, dwLoopY);

          byNewPixel = (BYTE)((GetRValue(crPixel) * 0.299) +
               (GetGValue(crPixel) * 0.587) +
               (GetBValue(crPixel) * 0.114));
          if (crPixel) ::SetPixel(hMemDC2,
                                  dwLoopX,
                                  dwLoopY,
                                  RGB(byNewPixel,
                                  byNewPixel,
                                  byNewPixel));
        } // for
      } // for

      ::SelectObject(hMemDC1, hOldBmp1);
      ::SelectObject(hMemDC2, hOldBmp2);

      csGrayII.hbmMask = csII.hbmMask;

      csGrayII.fIcon = TRUE;
      hGrayIcon = ::CreateIconIndirect(&csGrayII);
    } // if

    ::DeleteObject(csGrayII.hbmColor);
    //::DeleteObject(csGrayII.hbmMask);
  } // if

  ::DeleteObject(csII.hbmColor);
  ::DeleteObject(csII.hbmMask);
  ::DeleteDC(hMemDC1);
  ::DeleteDC(hMemDC2);
  ::ReleaseDC(m_hWnd, hMainDC);

  return hGrayIcon;
} // End of CreateGrayscaleIcon

  • Date Published: April 23, 2002
    First release (4/16)

Downloads

Download source code & demo project - 123 Kb


Comments

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: August 14, 2014 @ 2:00 p.m. ET / 11:00 a.m. PT Data protection has long been considered "overhead" by many organizations in the past, many chalking it up to an insurance policy or an extended warranty you may never use. The realities of today makes data protection a must-have, as we live in a data-driven society -- the digital assets we create, share, and collaborate with others on must be managed and protected for many purposes. Check out this upcoming eSeminar and join Seagate Cloud …

  • Java developers know that testing code changes can be a huge pain, and waiting for an application to redeploy after a code fix can take an eternity. Wouldn't it be great if you could see your code changes immediately, fine-tune, debug, explore and deploy code without waiting for ages? In this white paper, find out how that's possible with a Java plugin that drastically changes the way you develop, test and run Java applications. Discover the advantages of this plugin, and the changes you can expect to see …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds