dibhelp.c

Windows Programming source code

     iNumColors = DibNumColors (hdib) ;

     for (i = 0 ; i < iNumColors ; i++)
          DibGetColor (hdib, i, prgb + i) ;

     return pbmi ;
}

/*-------------------------------------------------------------------
   DibCopy:  Creates a new DIB section from an existing DIB section,
     possibly swapping the DIB width and height.
  -------------------------------------------------------------------*/

HDIB DibCopy (HDIB hdibSrc, BOOL fRotate)
{
     BITMAPINFO * pbmi ;
     BYTE       * pBitsSrc, * pBitsDst ;
     HDIB         hdibDst ;

     if (!DibIsValid (hdibSrc))
          return NULL ;

     if (NULL == (pbmi = DibCopyToInfo (hdibSrc)))
          return NULL ;

     if (fRotate)
     {
          pbmi->bmiHeader.biWidth = DibHeight (hdibSrc) ;
          pbmi->bmiHeader.biHeight = DibWidth (hdibSrc) ;
     }

     hdibDst = DibCreateFromInfo (pbmi) ;
     free (pbmi) ;

     if (hdibDst == NULL)
          return NULL ;

          // Copy the bits

     if (!fRotate)
     {
          pBitsSrc = DibBitsPtr (hdibSrc) ;
          pBitsDst = DibBitsPtr (hdibDst) ;

          CopyMemory (pBitsDst, pBitsSrc, DibBitsSize (hdibSrc)) ;
     }
     return hdibDst ;
}

/*----------------------------------------------------------------------
   DibCopyToPackedDib is generally used for saving DIBs and for 
     transferring DIBs to the clipboard. In the second case, the second 
     argument should be set to TRUE so that the memory is allocated 
     with the GMEM_SHARE flag.
  ----------------------------------------------------------------------*/

BITMAPINFO * DibCopyToPackedDib (HDIB hdib, BOOL fUseGlobal)
{
     BITMAPINFO * pPackedDib ;
     BYTE       * pBits ;
     DWORD        dwDibSize ;
     HDC          hdcMem ;
     HGLOBAL      hGlobal ;
     int          iNumColors ;
     PDIBSTRUCT   pdib = hdib ;
     RGBQUAD    * prgb ;

     if (!DibIsValid (hdib))
          return NULL ;

          // Allocate memory for packed DIB

     dwDibSize = DibTotalSize (hdib) ;

     if (fUseGlobal)
     {
          hGlobal = GlobalAlloc (GHND | GMEM_SHARE, dwDibSize) ;
          pPackedDib = GlobalLock (hGlobal) ;
     }
     else
     {
          pPackedDib = malloc (dwDibSize) ;
     }

     if (pPackedDib == NULL) 
          return NULL ;

          // Copy the information header

     CopyMemory (pPackedDib, &pdib->ds.dsBmih, sizeof (BITMAPINFOHEADER)) ;

     prgb = (RGBQUAD *) ((BYTE *) pPackedDib + sizeof (BITMAPINFOHEADER)) ;

          // Copy the possible color masks

     if (pdib->ds.dsBmih.biCompression == BI_BITFIELDS)
     {
          CopyMemory (prgb, pdib->ds.dsBitfields, 3 * sizeof (DWORD)) ;

          prgb = (RGBQUAD *) ((BYTE *) prgb + 3 * sizeof (DWORD)) ;
     }
          // Copy the color table

     if (iNumColors = DibNumColors (hdib))
     {
          hdcMem = CreateCompatibleDC (NULL) ;
          SelectObject (hdcMem, pdib->hBitmap) ;
          GetDIBColorTable (hdcMem, 0, iNumColors, prgb) ;
          DeleteDC (hdcMem) ;
     }

     pBits = (BYTE *) (prgb + iNumColors) ;

          // Copy the bits

     CopyMemory (pBits, pdib->pBits, DibBitsSize (pdib)) ;

          // If last argument is TRUE, unlock global memory block and 
          //   cast it to pointer in preparation for return

     if (fUseGlobal)
     {
          GlobalUnlock (hGlobal) ;
          pPackedDib = (BITMAPINFO *) hGlobal ;     
     }
     return pPackedDib ;
}

/*------------------------------------------------------------------
   DibCopyFromPackedDib is generally used for pasting DIBs from the 
     clipboard.
  ------------------------------------------------------------------*/

HDIB DibCopyFromPackedDib (BITMAPINFO * pPackedDib)
{
     BYTE     * pBits ;     
     DWORD      dwInfoSize, dwMaskSize, dwColorSize ;
     int        iBitCount ;
     PDIBSTRUCT pdib ;

          // Get the size of the information header and do validity check
     
     dwInfoSize = pPackedDib->bmiHeader.biSize ;

     if (dwInfoSize != sizeof (BITMAPCOREHEADER) &&
         dwInfoSize != sizeof (BITMAPINFOHEADER) &&
         dwInfoSize != sizeof (BITMAPV4HEADER) &&
         dwInfoSize != sizeof (BITMAPV5HEADER))
     {
          return NULL ;
     }
          // Get the possible size of the color masks

     if (dwInfoSize == sizeof (BITMAPINFOHEADER) &&
          pPackedDib->bmiHeader.biCompression == BI_BITFIELDS)
     {
          dwMaskSize = 3 * sizeof (DWORD) ;
     }
     else
     {
          dwMaskSize = 0 ;
     }
          // Get the size of the color table

     if (dwInfoSize == sizeof (BITMAPCOREHEADER))
     {
          iBitCount = ((BITMAPCOREHEADER *) pPackedDib)->bcBitCount ;

          if (iBitCount <= 8)
          {
               dwColorSize = (1 << iBitCount) * sizeof (RGBTRIPLE) ;
          }
          else
               dwColorSize = 0 ;
     }
     else           // all non-OS/2 compatible DIBs
     {
          if (pPackedDib->bmiHeader.biClrUsed > 0)
          {
               dwColorSize = pPackedDib->bmiHeader.biClrUsed * sizeof (RGBQUAD);
          }
          else if (pPackedDib->bmiHeader.biBitCount <= 8)
          {
               dwColorSize = (1 << pPackedDib->bmiHeader.biBitCount) * 
                                                       sizeof (RGBQUAD) ;
          }
          else
          {
               dwColorSize = 0 ;
          }
     }
          // Finally, get the pointer to the bits in the packed-DIB

     pBits = (BYTE *) pPackedDib + dwInfoSize + dwMaskSize + dwColorSize ;

          // Create the HDIB from the packed DIB pointer

     pdib = DibCreateFromInfo (pPackedDib) ;

          // Copy the pixel bits

     CopyMemory (pdib->pBits, pBits, DibBitsSize (pdib)) ;

     return pdib ;
}

/*-----------------------------------------------------
   DibFileLoad:  Creates a DIB section from a DIB file
  -----------------------------------------------------*/

HDIB DibFileLoad (const TCHAR * szFileName)
{
     BITMAPFILEHEADER bmfh ;
     BITMAPINFO     * pbmi ;
     BOOL             bSuccess ;
     DWORD            dwInfoSize, dwBitsSize, dwBytesRead ;
     HANDLE           hFile ;
     HDIB             hDib ;

          // Open the file: read access, prohibit write access

     hFile = CreateFile (szFileName, GENERIC_READ, FILE_SHARE_READ, NULL, 
                         OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL) ;

     if (hFile == INVALID_HANDLE_VALUE)
          return NULL ;

          // Read in the BITMAPFILEHEADER

     bSuccess = ReadFile (hFile, &bmfh, sizeof (BITMAPFILEHEADER), 
                          &dwBytesRead, NULL) ;

     if (!bSuccess || (dwBytesRead != sizeof (BITMAPFILEHEADER))         
                   || (bmfh.bfType != * (WORD *) "BM"))
     {
          CloseHandle (hFile) ;
          return NULL ;
     }
          // Allocate memory for the information structure & read it in

     dwInfoSize = bmfh.bfOffBits - sizeof (BITMAPFILEHEADER) ;

     if (NULL == (pbmi = malloc (dwInfoSize)))
     {
          CloseHandle (hFile) ;
          return NULL ;
     }

     bSuccess = ReadFile (hFile, pbmi, dwInfoSize, &dwBytesRead, NULL) ;

     if (!bSuccess || (dwBytesRead != dwInfoSize))
     {
          CloseHandle (hFile) ;
          free (pbmi) ;
          return NULL ;
     }
          // Create the DIB

     hDib = DibCreateFromInfo (pbmi) ;
     free (pbmi) ;

     if (hDib == NULL)
     {
          CloseHandle (hFile) ;
          return NULL ;
     }
          // Read in the bits

     dwBitsSize = bmfh.bfSize - bmfh.bfOffBits ;

     bSuccess = ReadFile (hFile, ((PDIBSTRUCT) hDib)->pBits, 
                          dwBitsSize, &dwBytesRead, NULL) ;
     CloseHandle (hFile) ;

     if (!bSuccess || (dwBytesRead != dwBitsSize))
     {
          DibDelete (hDib) ;
          return NULL ;
     }
     return hDib ;
}

/*---------------------------------------------
   DibFileSave:  Saves a DIB section to a file
  ---------------------------------------------*/

BOOL DibFileSave (HDIB hdib, const TCHAR * szFileName)
{
     BITMAPFILEHEADER bmfh ;
     BITMAPINFO     * pbmi ;
     BOOL             bSuccess ;
     DWORD            dwTotalSize, dwBytesWritten ;
     HANDLE           hFile ;

     hFile = CreateFile (szFileName, GENERIC_WRITE, 0, NULL,
                         CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL) ;

     if (hFile == INVALID_HANDLE_VALUE)
          return FALSE ;

     dwTotalSize  = DibTotalSize (hdib) ;

     bmfh.bfType      = * (WORD *) "BM" ;
     bmfh.bfSize      = sizeof (BITMAPFILEHEADER) + dwTotalSize ;
     bmfh.bfReserved1 = 0 ;
     bmfh.bfReserved2 = 0 ;
     bmfh.bfOffBits   = bmfh.bfSize - DibBitsSize (hdib) ;

          // Write the BITMAPFILEHEADER

     bSuccess = WriteFile (hFile, &bmfh, sizeof (BITMAPFILEHEADER), 
                           &dwBytesWritten, NULL) ;

     if (!bSuccess || (dwBytesWritten != sizeof (BITMAPFILEHEADER)))
     {
          CloseHandle (hFile) ;
          DeleteFile (szFileName) ;
          return FALSE ;
     }
          // Get entire DIB in packed DIB format

     if (NULL == (pbmi = DibCopyToPackedDib (hdib, FALSE)))
     {
          CloseHandle (hFile) ;
          DeleteFile (szFileName) ;
          return FALSE ;
     }
          // Write out the packed-DIB

     bSuccess = WriteFile (hFile, pbmi, dwTotalSize, &dwBytesWritten, NULL) ;
     CloseHandle (hFile) ;
     free (pbmi) ;

     if (!bSuccess || (dwBytesWritten != dwTotalSize))
     {
          DeleteFile (szFileName) ;
          return FALSE ;
     }
     return TRUE ;
}

/*---------------------------------------------------
   DibCopyToDdb:  For more efficient screen displays
  ---------------------------------------------------*/

HBITMAP DibCopyToDdb (HDIB hdib, HWND hwnd, HPALETTE hPalette)
{
     BITMAPINFO * pbmi ;
     HBITMAP      hBitmap ;
     HDC          hdc ;

     if (!DibIsValid (hdib))
          return NULL ;

     if (NULL == (pbmi = DibCopyToInfo (hdib)))
          return NULL ;

     hdc = GetDC (hwnd) ;

     if (hPalette)
     {
          SelectPalette (hdc, hPalette, FALSE) ;
          RealizePalette (hdc) ;
     }
     
     hBitmap = CreateDIBitmap (hdc, DibInfoHeaderPtr (hdib), CBM_INIT,
                               DibBitsPtr (hdib), pbmi, DIB_RGB_COLORS) ;

     ReleaseDC (hwnd, hdc) ;
     free (pbmi) ;

     return hBitmap ;
}