Re: [gtk-list] Re: suggestions wanted for tricky shaped window problem

[Paul Barton-Davis <pbd op net>]

>Yep, XCopyPlane tends to be pessimized on standard PC hardware
>(which is not planar)
>
>It would probably be slightly more efficient to draw in a bitmap
>in parallel with drawing in the pixmap. I.e., draw each line
>in both places.

Yep, thats what I did last night. I know have a GtkTransparency class
(and its Gtk-- equivalent Gtk_Transparency) which comes with its own
complete set of the gdk_draw_*() routines. The window is completely
transparent except where you draw into it. Its pretty nice.  I'm now
working on a class that scribbles on such a thing to draw curved
"patchcords". I'll post them for perusal once I've got more experience
with them.

>Basically, it is an impossible thing to do in X and have
>it perform at all decently if you have complicated shapes;

Well, on a 450 PII with a Matrix G200+8MB, it runs pretty fine :)

>X's method of dealing with shaped windows is to store
>them as lists of rectangles.

Is this really true ? I had guessed that it did something clever than
that, but this was based on hope rather than source. I was expecting
there was a way to store the mask for the window and rapidly (probably
in h/w where possible) convolve the mask with the window. Sigh.

--p