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dwinkler

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CreateIconIndirect

I have two bitmaps which I am passing.  One is the mask (monochrome bitmap, 1 being the ON bit and 0 being the OFF bit).  The other is the real bitmap image (actually a DIB created with CreateDIBSection).  When the icon is displayed everything which is supposed to be transparent still comes up inverted.  Any suggestions on this?
Avatar of robpitt
robpitt
Heres a fragment of code that I've used that works:

   //Create color bitmap
    hdc=GetDC(NULL);
    ii.hbmColor=CreateDIBitmap(hdc,pBmih,CBM_INIT,pColorData,pBmi,DIB_RGB_COLORS);    

    //Create mask bitmap (monochrome)
    pBmih->biBitCount=1;
    pBmih->biClrUsed=0;
    ii.hbmMask=CreateBitmap(pBmih->biWidth,pBmih->biHeight,1,1,NULL);
    SetDIBits(hdc,ii.hbmMask,0,32,pMaskData,pBmi,DIB_RGB_COLORS);    
    ReleaseDC(NULL,hdc);
       
    //Create the icon
    ii.fIcon=TRUE;
    ii.xHotspot=ii.yHotspot=0;
    hIcon=CreateIconIndirect(&ii);


In the above I'm initialising the contents of the bitmaps directly from raw data but thats should be irelevant. How similar is the above to your code?

Avatar of pjknibbs
pjknibbs
As I recall, transparency doesn't just depend on the mask--it also depends on the colour of the image bitmap at the same position. It's something like white is inverse and black is transparent, or possibly the other way round--anyway, you need to check what colour the "transparent" pixels are on your icon bitmap.
Avatar of dwinkler
dwinkler

ASKER

So how do you use the mask?  I want a certain color of the original bitmap to be transparent.  Lets say, hypothetically, that RGB(255,0,255) is the background color.  I want to create a icon that has that color as the transparency.
Avatar of Madshi
Madshi
I think the background color is not important when using CreateIconIndirect.

Here comes an extract how I am using CreateIconIndirect. It's Delphi code, but I'm sure you can see the important things:

  zeroMemory(@bi, sizeOf(TBitmapInfo));
  with bi.bmiColors[1] do begin
    rgbBlue  := 255;
    rgbGreen := 255;
    rgbRed   := 255;
  end;
  with bi.bmiHeader do begin
    biSize      :=  sizeOf(TBitmapInfoHeader);
    biWidth     :=  32;
    biHeight    :=  64;
    biPlanes    :=   1;
    biBitCount  :=   1;
    biSizeImage := 256;
  end;

This is how I prepare the monochrome bitmap. Please note that you have to set the bmiColors to the right values. bmiColors[0] must be all zero, while bmiColors[1] must be all $FF.

Regards, Madshi.
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dwinkler

ASKER

That's what I was missing...

I knew the mask should be a monochrome bitmap, but the doc didn't make it clear that the bitmap had to be the XOr image.  BTW pImage is a generic class to hold bitmap info.  The following code converts a standard bitmap with RGB(255,0,255) background into an icon with correct mask and image.

BITMAPINFO bmpInfoMem = { '\0' };
bmpInfoMem.bmiHeader.biSize               = sizeof(BITMAPINFOHEADER);
bmpInfoMem.bmiHeader.biWidth          = pImage->GetWidth( );
bmpInfoMem.bmiHeader.biHeight          = -(MOSINT32)pImage->GetHeight( );
bmpInfoMem.bmiHeader.biPlanes          = 1;
bmpInfoMem.bmiHeader.biBitCount          = 32;
bmpInfoMem.bmiHeader.biCompression     = BI_RGB;

HDC hClientDC          = ::GetDC( NULL );

HDC hDCCreate          = ::CreateCompatibleDC( hClientDC );
HDC hDCImage          = ::CreateCompatibleDC( hClientDC );
HDC hDCAnd               = ::CreateCompatibleDC( hClientDC );
HDC hDCXOr               = ::CreateCompatibleDC( hClientDC );

HBITMAP hDDB          = ::CreateCompatibleBitmap( hClientDC, pImage->GetWidth( ), pImage->GetHeight( ) );
HBITMAP hXOrBitmap     = ::CreateCompatibleBitmap( hClientDC, pImage->GetWidth( ), pImage->GetHeight( ) );
HBITMAP hAndBitmap     = ::CreateBitmap( pImage->GetWidth( ), pImage->GetHeight( ), 1, 1, NULL );

::SetDIBits( hDCCreate,
                hDDB,
                0,
                pImage->GetHeight( ),
                pImage->GetBuffer( ),
                &bmpInfoMem,
                DIB_RGB_COLORS );

::DeleteDC( hDCCreate );

// Create the AND Mask bitmap
HBITMAP hOldAndBitmap     = (HBITMAP)::SelectObject( hDCAnd, hAndBitmap );
HBITMAP hOldImageBitmap     = (HBITMAP)::SelectObject( hDCImage, hDDB );
HBITMAP hOldXorBitmap     = (HBITMAP)::SelectObject( hDCXOr, hXOrBitmap );

// Create the monochrome mask bitmap from the source image using the background color
COLORREF crOld = ::SetBkColor( hDCImage, RGB(255,0,255) );
::BitBlt( hDCAnd, 0, 0, pImage->GetWidth( ), pImage->GetHeight( ), hDCImage, 0, 0, SRCCOPY );
::SetBkColor( hDCImage, crOld );

// Create the XOR color bitmap
::BitBlt( hDCXOr, 0, 0, pImage->GetWidth( ), pImage->GetHeight( ), hDCImage, 0, 0, SRCCOPY );

::BitBlt( hDCXOr, 0, 0, pImage->GetWidth( ), pImage->GetHeight( ), hDCAnd, 0, 0, 0x220326);

::SelectObject( hDCImage, hOldImageBitmap );
::SelectObject( hDCAnd, hOldAndBitmap );
::SelectObject( hDCXOr, hOldXorBitmap );

::DeleteDC( hDCXOr );
::DeleteDC( hDCImage );
::DeleteDC( hDCAnd );

::ReleaseDC( NULL, hClientDC );

ICONINFO iconInfo;
iconInfo.fIcon          = TRUE;
iconInfo.xHotspot     = 0;
iconInfo.yHotspot     = 0;
iconInfo.hbmMask     = hAndBitmap;
iconInfo.hbmColor     = hXOrBitmap;

hIcon = ::CreateIconIndirect( &iconInfo );

::DeleteObject( hDDB );

::DeleteObject( hAndBitmap );

::DeleteObject( hXOrBitmap );
Avatar of dwinkler
dwinkler

ASKER

That's what I was missing...

I knew the mask should be a monochrome bitmap, but the doc didn't make it clear that the bitmap had to be the XOr image.  BTW pImage is a generic class to hold bitmap info.  The following code converts a standard bitmap with RGB(255,0,255) background into an icon with correct mask and image.

BITMAPINFO bmpInfoMem = { '\0' };
bmpInfoMem.bmiHeader.biSize               = sizeof(BITMAPINFOHEADER);
bmpInfoMem.bmiHeader.biWidth          = pImage->GetWidth( );
bmpInfoMem.bmiHeader.biHeight          = -(MOSINT32)pImage->GetHeight( );
bmpInfoMem.bmiHeader.biPlanes          = 1;
bmpInfoMem.bmiHeader.biBitCount          = 32;
bmpInfoMem.bmiHeader.biCompression     = BI_RGB;

HDC hClientDC          = ::GetDC( NULL );

HDC hDCCreate          = ::CreateCompatibleDC( hClientDC );
HDC hDCImage          = ::CreateCompatibleDC( hClientDC );
HDC hDCAnd               = ::CreateCompatibleDC( hClientDC );
HDC hDCXOr               = ::CreateCompatibleDC( hClientDC );

HBITMAP hDDB          = ::CreateCompatibleBitmap( hClientDC, pImage->GetWidth( ), pImage->GetHeight( ) );
HBITMAP hXOrBitmap     = ::CreateCompatibleBitmap( hClientDC, pImage->GetWidth( ), pImage->GetHeight( ) );
HBITMAP hAndBitmap     = ::CreateBitmap( pImage->GetWidth( ), pImage->GetHeight( ), 1, 1, NULL );

::SetDIBits( hDCCreate,
                hDDB,
                0,
                pImage->GetHeight( ),
                pImage->GetBuffer( ),
                &bmpInfoMem,
                DIB_RGB_COLORS );

::DeleteDC( hDCCreate );

// Create the AND Mask bitmap
HBITMAP hOldAndBitmap     = (HBITMAP)::SelectObject( hDCAnd, hAndBitmap );
HBITMAP hOldImageBitmap     = (HBITMAP)::SelectObject( hDCImage, hDDB );
HBITMAP hOldXorBitmap     = (HBITMAP)::SelectObject( hDCXOr, hXOrBitmap );

// Create the monochrome mask bitmap from the source image using the background color
COLORREF crOld = ::SetBkColor( hDCImage, RGB(255,0,255) );
::BitBlt( hDCAnd, 0, 0, pImage->GetWidth( ), pImage->GetHeight( ), hDCImage, 0, 0, SRCCOPY );
::SetBkColor( hDCImage, crOld );

// Create the XOR color bitmap
::BitBlt( hDCXOr, 0, 0, pImage->GetWidth( ), pImage->GetHeight( ), hDCImage, 0, 0, SRCCOPY );

::BitBlt( hDCXOr, 0, 0, pImage->GetWidth( ), pImage->GetHeight( ), hDCAnd, 0, 0, 0x220326);

::SelectObject( hDCImage, hOldImageBitmap );
::SelectObject( hDCAnd, hOldAndBitmap );
::SelectObject( hDCXOr, hOldXorBitmap );

::DeleteDC( hDCXOr );
::DeleteDC( hDCImage );
::DeleteDC( hDCAnd );

::ReleaseDC( NULL, hClientDC );

ICONINFO iconInfo;
iconInfo.fIcon          = TRUE;
iconInfo.xHotspot     = 0;
iconInfo.yHotspot     = 0;
iconInfo.hbmMask     = hAndBitmap;
iconInfo.hbmColor     = hXOrBitmap;

hIcon = ::CreateIconIndirect( &iconInfo );

::DeleteObject( hDDB );

::DeleteObject( hAndBitmap );

::DeleteObject( hXOrBitmap );