Public Type IMAGELISTDRAWPARAMS
    cbSize As Long
    himl As Long
    i As Long
    hdcDst As Long
    x As Long
    y As Long
    cx As Long
    cy As Long
    xBitmap As Long '        // x offest from the upperleft of bitmap
    yBitmap As Long '        // y offset from the upperleft of bitmap
    rgbBk As Long
    rgbFg As Long
    fStyle As Long
    dwRop As Long
    fState As Long
    Frame As Long
    crEffect As Long
End Type
' image list states (fState field in IMAGELISTDRAWPARAMS)
Public Const ILS_ALPHA As Long = &H8&
Public Declare Function ImageList_DrawIndirect Lib "COMCTL32.DLL" (pimldp As IMAGELISTDRAWPARAMS) As Long

Public Sub DrawImageAlpha( _
        ByVal vKey As Variant, _
        ByVal hdc As Long, _
        ByVal xPixels As Integer, _
        ByVal yPixels As Integer, _
        ByVal btAlpha As Byte _
    )
Dim idp As IMAGELISTDRAWPARAMS
Dim iImgIndex As Long

   iImgIndex = flItemIndex(vKey)

   idp.cbSize = Len(idp)
   idp.himl = m_hIml
   idp.hdcDst = hdc
   idp.x = xPixels
   idp.y = yPixels
   idp.i = iImgIndex
   idp.fState = ILS_ALPHA
   idp.Frame = btAlpha
   
   ImageList_DrawIndirect idp
End Sub

HIMAGELIST ImageList_Create(
    int cx,
    int cy,
    UINT flags,
    int cInitial,
    int cGrow
);

      
      ' saturate (only ever seems to result in unsaturated image?)
      idp.y = idp.y + (m_cIml.IconSizeY +  4 )
      idp.fState = ILS_SATURATE
      idp.Frame = - 128 
      ImageList_DrawIndirect idp
            
      ' glow (does not appear to work)
      'idp.x = idp.x + (m_cIml.IconSizeX + 2)
      'idp.fState = ILS_GLOW
      'idp.crEffect = &HFFFFFF
      'ImageList_DrawIndirect idp
      
      ' shadow (does not appear to work)
      'idp.x = idp.x + (m_cIml.IconSizeX + 2)
      'idp.fState = ILS_SHADOW
      'idp.crEffect = &HFF0000
      'ImageList_DrawIndirect idp
      
      ' alpha (does not appear to work)
      'idp.x = idp.x + (m_cIml.IconSizeX + 2)
      'idp.fState = ILS_ALPHA
      'idp.Frame = 128
      'ImageList_DrawIndirect idp

Call SetWindowLong(Me.hwnd, GWL_EXSTYLE, lOldLong Or WS_EX_LAYERED)

Sub SetAlpha(Optional Alpha As Byte =  255 )
    With BF
        .AlphaFormat = AC_SRC_ALPHA
        .BlendFlags =  0 
        .BlendOp = AC_SRC_OVER
        .SourceConstantAlpha = Alpha
    End With
    Call UpdateLayeredWindow(Me.hwnd, Me.hdc, PAD, SZ, hCDC, PAS,  0 , BF, ULW_ALPHA)
End Sub

void CTranspBitmapsDoc::CreateDIB()
{
	BITMAPINFO bmi;
	BITMAP bm;
	int sx, sy;

	HDC tempDC = GetDC( 0 );
	m_fgBmp.GetBitmap(&bm);
	sx = bm.bmWidth;
	sy = bm.bmHeight;
	bmi.bmiHeader.biSize = sizeof bmi.bmiHeader;
	bmi.bmiHeader.biWidth = sx;
	bmi.bmiHeader.biHeight = sy;
	bmi.bmiHeader.biPlanes =  1 ;
	bmi.bmiHeader.biBitCount =  32 ;
	bmi.bmiHeader.biCompression = BI_RGB;
	bmi.bmiHeader.biSizeImage =  0 ;
	RGBQUAD *buffer, pixel;
	RGBTRIPLE *t1, *t2;
	HBITMAP hDIB = CreateDIBSection(tempDC, &bmi, DIB_RGB_COLORS, 
									(void**)&buffer,  0 ,  0 );
	bmi.bmiHeader.biBitCount= 24 ;
	bmi.bmiHeader.biClrUsed= 0 ;
	int widthBytes = sx* 3  + (sx* 3 )% 4 ;
	char* bits1 = new char[widthBytes*sy];
	char* bits2 = new char[widthBytes*sy];
	GetDIBits(tempDC, m_fgBmp,  0 , sy, bits1, &bmi, DIB_RGB_COLORS);		
	GetDIBits(tempDC, m_bgBmp,  0 , sy, bits2, &bmi, DIB_RGB_COLORS);		
	for (int i= 0 ; i<sy; i++) 
	{
		t1 = (RGBTRIPLE*)(bits1+widthBytes*i);
		t2 = (RGBTRIPLE*)(bits2+widthBytes*i);
		for (int j= 0 ; j<sx; j++)
		{
			if(isWhite(t1))
			{
				BYTE alpha=isWhite(t2)? 0 : 255 -intensity(t2)/ 2 ;
				pixel.rgbBlue  = alpha?t2->rgbtBlue/ 2 : 0 ;
				pixel.rgbGreen = alpha?t2->rgbtGreen/ 2 : 0 ;
				pixel.rgbRed   = alpha?t2->rgbtRed/ 2 : 0 ;
				pixel.rgbReserved = alpha;
			}
			else
			{
				pixel.rgbBlue  = t1->rgbtBlue;
				pixel.rgbGreen = t1->rgbtGreen;
				pixel.rgbRed   = t1->rgbtRed;
				pixel.rgbReserved =  255 ;
			}
			*buffer++ = pixel;
			t1++; t2++;
		}
	}
	m_alphaBmp.Attach(hDIB);
	ReleaseDC( 0 , tempDC);
	delete[] bits1;
	delete[] bits2;
}

Dim hdcAlphaBlend As Long
Dim hbmpImageTemp As Long
Dim hbmpAlphaBlendOld As Long

' Prepare temp drawing surface
hdcAlphaBlend = CreateCompatibleDC(hdc)
hbmpImageTemp = CreateCompatibleBitmap(hdc, m_lImageWidth, m_lImageHeight)
hbmpAlphaBlendOld = SelectObject(hdcAlphaBlend, hbmpImageTemp)

' First copy the real part of hdc we will draw to
BitBlt hdcAlphaBlend,  0 ,  0 , m_lImageWidth, m_lImageHeight, _
   hdc, xPixels, yPixels, SRCCOPY
   
' Put the icon into the temp drawing surface
ImageList_Draw _
    m_hIml, _
    iImgIndex, _
    hdcAlphaBlend, _
     0 , _
     0 , _
    ILD_TRANSPARENT

' Blending the icon with global transparent effect onto the dest surface
Dim Blendfunc As BLENDFUNCTION
Blendfunc.BlendOp = AC_SRC_OVER
Blendfunc.SourceConstantAlpha = btAlpha
Dim lBF As Long
CopyMemory lBF, Blendfunc,  4 

AlphaBlend hdc, xPixels, yPixels, m_lImageWidth, m_lImageHeight, _
   hdcAlphaBlend,  0 ,  0 , m_lImageWidth, m_lImageHeight, lBF

 
' Cleanup code
SelectObject hdcAlphaBlend, hbmpAlphaBlendOld
DeleteObject hbmpImageTemp
DeleteDC hdcAlphaBlend