MaskBlt

[V(ery) Basic]

Does anybody know what the:

ByVal hbmMask As Long, ByVal xMask As Long, ByVal yMask As Long

part of MaskBlt does, and what the various options are
for each one (or a sample code snippet).

Not essential, just out of curiosity.

Thanks,

Me

[Cougar0119]

Well, I turned to Mr. Dan Appleman and I asked him...and this is what he said....

hbmMask - This is a handle to a monochrome bitmap (that's gonna be your mask). Then he goes on to telling us about the dwROP - if it has a source, it must be same size, otherwise match the destination size...

xMask/yMask - those are offsets so you can use one large bitmap with multiple masks

And just FYI - the dwROP code is nonstandard - it says to create it with the agMakeROP4 function in APIGID32.DLL --- Good luck with that 'cause this is difficult to do in VB... Why? It is very likely that there will be an overflow in the shift...

Good Luck!

[V(ery) Basic]

But does good old Mr Appleman have some source code that
good Mr Me could use, just so I could 'play' with it and
see how it works? You see, I still dont get it: does my
app fail because I use vbSrcInvert in the dwRop part?

Thanks to anyone who can shed light on this matter,
or anyone who can give me an answer :D

Thanks, again.

And again.

And once mor for luck.

Bye!

[Cougar0119]

My guess is yes - vbSrcInvert is a standard raster operation code. He specifically says that dwROP is nonstandard...nonstandard being made up of two regular raster operations: a foreground and a background code. You need to create this code with the agMakeROP4 function as previously stated... According to him, "This function shifts the background raster-op left by 8 bits then ORs in the foreground raster operation. This is difficult to do in Visual Basic due to the likelihood of an overflow during the shift." In other words - try something else! :)

You can use BitBlt and masks - create a Black and white of your source image...Black where you want the image to show through - white where you want it to be masked. Then BitBlt the mask using SRCAND - then BitBlt the source image using SRCPAINT... that should do it for you...

Good Luck!

[V(ery) Basic]

Thanks, that's what I was looking for. I'm still very
confused my Mr Dan Appleman (couldn't he speak English? :) )
Thanks again,

Cheers,

(is a great TV show)

Me