Create "layers" like Photoshop/Paint shop pro **resolved**

OK. I got a webcam program that I'm writing. I got everything I need including the camera capture, and the upload portion. I just want to do one thing.

I want to add a watermark based on an image and a position that the user specifies. I have the underlying image on a picturebox and I want to put the watermark image overtop of it like another layer, then add it to the picture property.

Anybody have any good methods of doing this?

look up the BitBlt function in the search box. look up the raster op codes also for it, i forget which ones will give you that transparent watermark effect

VB Code:

hdcWatermark = LoadImage(0, strPath, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE)
 
    lResult = BitBlt(frmCapture.Picture1.hdc, 0, 0, _
        96 * 15, _
        11 * 15, _
        hdcWatermark, 0, 0, vbSrcCopy)

No effect

* 15 is for..? BitBlt uses pixels, so you needn't worry about Twips. And, SrcCopy will give you a big ol' rectangle around the image...

LoadImage doesnt reaturn an HDC.

Z.

Create a DC with CreateCompatibleDC, and use SelectObject to select the bitmap you get from LoadImage into it.

Quote:

---

Originally posted by Sastraxi
Create a DC with CreateCompatibleDC, and use SelectObject to select the bitmap you get from LoadImage into it.

---

VB Code:

lResult = LoadImage(0, strPath, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE)
    hdcWatermark = CreateCompatibleDC(0)
    Call SelectObject(hdcWatermark, lResult)
 
lResult = BitBlt(frmCapture.Picture1.hdc, 0, 0, _
        96 * 15, _
        11 * 15, _
        hdcWatermark, 0, 0, vbSrcCopy)

don't forget to delete the object or you'll crash after about 15-20 iterations depending on your memory. This code might help you delete it properly:

Dim hMemDC As Long
Dim hOldBMP As Long

' Create memory DC
hMemDC = CreateCompatibleDC(Me.hdc)

' Select bitmap into it, storing the previous value
' (SelectObject returns the previous bitmap which
' was selected into the DC)
hOldBMP = SelectObject(hMemDC, CreateCompatibleBitmap(Me.hdc, Width, Height))

'
' Now you can draw...
'

' First, select the old bitmap back into the DC and delete our bitmap
DeleteObject(SelectObject(hMemDC, hOldBMP))

' Now delete the DC
DeleteDC(hMemDC)

good to know