Thread: BitBlt transparancy question?

  1. #1
    julie lexx... btq's Avatar
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    BitBlt transparancy question?

    I've been searchin for 3 hours now with no result so I figured it was time to ask..
    I have a color bitmap, picturing a dog on a blue background.
    The window, which I want to copy the dog into, pictures a nice lawn with many many nice green trees.
    The question is, can I copy the dog into the window *without* changing the background, that is, everything blue in the bitmap with the dog will not contribute to anything in the window it is copied into...
    I mean as a result I will have a nice picture of a dog walkin around in the park, and not a park and a "cut in" dog in a little square in the middle...?

    ...cause this is all I get from the BitBlt-func.

    thanks a bunch

    /btq

  2. #2
    erstwhile
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    Yes you can. You need to create a monochrome mask of the source bitmap, either separately or programmatically, blit the mask first using the SRCAND flag for the last parameter of BitBlt and then BitBlt the source image with the SRCPAINT flag.

    Hope that helps.

  3. #3
    julie lexx... btq's Avatar
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    he..thanks man. that did help!

    /btq

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