BitBlt

[SLH]

Firstly, sorry about starting a thread for this, i know this sort of thing has been answered many times, but i just can not get it to work.


I'm making an tile based game editor. I'm currently bitblting the pictures on to the form, then using SRCAND to overlay the current object to place (which follows the cursor, and only changes the 'map' when the user clicks.

Instead of blending the images together i want to overlay the current object on top of the form.

As i already had all the SRCAND bitblt commands set up correctly, i decided to make a sub that instead of doing and, did a mask & picture.

Here is the Sub i'm using:

Public Sub MskBlt(DestDC, X, Y, Width, Height, SrcDC)
    BitBlt DestDC, X, Y, Width, Height, SrcDC, Width, 0, SRCPAINT
    BitBlt DestDC, X, Y, Width, Height, SrcDC, 0, 0, SRCAND
End Sub

All the parameters are the same as the ones i used for bitblt (which worked), except the last 3, which arn't needed any more.


The trouble is that this still blends the pictures together instead of overlaying them. What have i don't wrong?


Thanks for any replies.

[Fox]

Sorry if I misunderstood your problem but what I suppose is:

Did you generate a mask for your picture or not?

[SLH]

I sure did, infact i used your program to do so

For those who arn't familiar with Fox's brillient program, it created a bitmap, with the picture on the left, and the mask on the right (how i used it anyway).

[Sastraxi]

Switch SrcAnd and SrcPaint.

[SLH]

Thanks for the reply, but i've already tried that already, and for some reason, it does nothing (nothing is drawn on the form).

I have checked the bitmap is in the correct place etc...

[Sastraxi]

There's the remote possibility that this could help:

(What colour is the sprite's background? If it's black use SrcAnd/Paint. If it's white, use MergePaint/SrcAnd (in those orders))

[SLH]

It's a black background.

[Fox]

Whoah there's anyone using my Mask Generator? ^^*

Uhm, however it should work.. make sure AutoRedraw of the picturebox holding your source bitmap is true or post the project..

Err I'm not sure whether my old MaskGen uses black or white backgrounds.. but if you're using Paint/And (as you do, the drawing code seems correct btw) the colored bitmap part needs a white background and the mask would have a black one...

[SLH]

Ok, didn't want to resort to this, but here it is.


The sub is in the module (with a tempory solution so you can see what's going on), and all the code that calls it is in a procedure called RedrawArea (at the top).

When you run it, an open dialog will appear, choose test.gnr in the maps directory.

[Fox]

Public Sub MskBlt(DestDC, X, Y, Width, Height, SrcDC)
    'Draw
    BitBlt DestDC, X, Y, Width, Height, SrcDC, Width, 0, vbSrcPaint
    BitBlt DestDC, X, Y, Width, Height, SrcDC, 0, 0, vbSrcAnd
End Sub

I had no problem running it with this function.. I could move around the objects in placement mode and they were drawn with transparency... That's it.

[SLH]

Great, that's fixed it. Thanks.