;
; Conversion for PB of a Vegard Fiksdal Technologies code
; http://www.codeguru.com/vb/gen/vb_graphics/transparency/article.php/c5329/
;
Procedure DrawTransparentImage(DC, Bitmap, x, y, Width, Height, TransparentColor)

    ; First, create some DC's. These are our gateways To associated
    ; bitmaps in RAM
    maskDC = CreateCompatibleDC_(DC)
    tempDC = CreateCompatibleDC_(DC)
   
    SourceDC = CreateCompatibleDC_(DC)
    SelectObject_(SourceDC, Bitmap)
   

    ; Then, we need the bitmaps. Note that we create a monochrome
    ; bitmap here!
    ; This is a trick we use For creating a mask fast enough.
    hMaskBmp = CreateBitmap_(Width, Height, 1, 1, 0)
    hTempBmp = CreateCompatibleBitmap_(DC, Width, Height)

    ; Then we can assign the bitmaps to the DCs
    ;
    hMaskBmp = SelectObject_(maskDC, hMaskBmp)
    hTempBmp = SelectObject_(tempDC, hTempBmp)

    ; Now we can create a mask. First, we set the background color
    ; To the transparent color; then we copy the image into the
    ; monochrome bitmap.
    ; When we are done, we reset the background color of the
    ; original source.
    TransparentColor = SetBkColor_(SourceDC, TransparentColor)
    BitBlt_(maskDC, 0, 0, Width, Height, SourceDC, 0, 0, #SrcCopy)
    SetBkColor_(SourceDC, TransparentColor)

    ; The first we do with the mask is To MergePaint it into the
    ; destination.
    ; This will punch a WHITE hole in the background exactly were
    ; we want the graphics To be painted in.
    BitBlt_(tempDC, 0, 0, Width, Height, maskDC, 0, 0, #SrcCopy)
    BitBlt_(DC, X, Y, Width, Height, tempDC, 0, 0, #MergePaint)

    ; Now we delete the transparent part of our source image. To do
    ; this, we must invert the mask And MergePaint it into the
    ; source image. The transparent area will now appear as WHITE.
    BitBlt_(maskDC, 0, 0, Width, Height, maskDC, 0, 0, #NotSrcCopy)
    BitBlt_(tempDC, 0, 0, Width, Height, SourceDC, 0, 0, #SrcCopy)
    BitBlt_(tempDC, 0, 0, Width, Height, maskDC, 0, 0, #MergePaint)

    ; Both target And source are clean. All we have To do is To And
    ; them together!
    BitBlt_(DC, X, Y, Width, Height, tempDC, 0, 0, #SrcAnd)

    ; Now all we have To do is To clean up after us And free system
    ; resources..
    DeleteObject_(hMaskBmp)
    DeleteObject_(hTempBmp)
    DeleteDC_(maskDC)
    DeleteDC_(tempDC)
    DeleteDC_(SourceDC)

EndProcedure



OpenWindow(0, 100, 100, 200, 200, #PB_Window_SystemMenu, "FastTransparency")

LoadImage(0, "BackGround.bmp") ; Background
LoadImage(1, "ForeGround.bmp") ; Image to be drawn as transparent

UseImage(0)
DC = StartDrawing(ImageOutput())
If DC
  DrawTransparentimage(DC, UseImage(1), 0, 0, 97, 97, RGB(255, 255, 255))
  StopDrawing()
EndIf


CreateGadgetList(WindowID())
ImageGadget(0, 10, 10, 100, 100, UseImage(0))

Repeat
  Event = WaitWindowEvent()
 
Until Event = #PB_Event_CloseWindow