Re: gdi+ and XOR of fill area

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"Keven Corazza" <KevenCorazza@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:FE824302-3C67-469A-A224-C8C02E587196@xxxxxxxxxxxxxxxx
Thank you for the answer but the real problem for me is how to update the
selected area while mouse is moving.

I mean, I draw the first filled rectangle between the starting point and
the
current mouse position; then the mouse change its position, and I've to
update the rectangle.

If the new rectangle is lower how can I remove the previous rectangle ?

With the standard GDI and Pen I can set XOR mode so if I draw a line over
existing line this will be removed.

I hope to have explained better the result that I would like to obtain.

As Grzegorz said, you can't "undraw" what you've drawn. You could
potentially do this with the alpha blended area but the result would not be
exactly what you started with (due to integer rounding color value that are
only from 0 to 255). I believe MS would be double buffering the area and
drawing the whole lot again, that's how I did the same thing anyway.

Michael


.

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