On Sat, 2011-11-26 at 13:43 +0100, Philipp Knechtges wrote: > Hi folks, > > time has passed since the initial proposal [1] of _NET_WM_OPAQUE_REGION but > here > it is finally :) > > Support for it has recently been added to kwin [2] and I hope that more > compositing managers will adapt it.
I'm certainly open to adding this to Mutter ... it's a useful addition. + + <sect2><title>_NET_WM_OPAQUE_REGION</title> + <programlisting><![CDATA[ +_NET_WM_OPAQUE_REGION, x, y, width, height, CARDINAL[][4]/32 +]]></programlisting> + <para> +The Client MAY set this property to a list of 4-tuples [x, y, width, height], +each representing a rectangle in window coordinates that is occluding the +background. I think this would be a little clearer as: rectangle in window coordinates which has a fully-opaque alpha value in the window's pixel contents. If the window is drawn by the compositor without adding any transparency, then such a rectangle will occlude whatever is drawn behind it. + Inherent in this definition is that the property information is only +considered to be meaningful if the window is an ARGB visual. This is a pretty obscure sentence .... is the intent here that it's simply informative, not normative? similar to: If the window has an RGB visual rather than an ARGB visual, this property is not typically useful, since the opaque region of a window is exactly the bounding region of the window as set via the shape extension. Which then raises the question of the relationship between this and the shape extension for an ARGB window; since I've rewritten things above to specify things in terms of alpha value in the windows pixel contents, that would imply that: For windows with an ARGB visual, and also a bounding region set via the shape extension, the effective opaque region is given by the intersection of the region set by this property and the bounding region set via the shape extension. > The compositing manager MAY ignore this hint. + </para> + <para> +Rationale: This gives the compositing manager more room for optimizations, e.g. by not +drawing the occluded background. Maybe "occluded portions behind the window." (background to me means root window background) + </para> + </sect2> Do those edits seem reasonable? - Owen _______________________________________________ wm-spec-list mailing list wm-spec-list@gnome.org http://mail.gnome.org/mailman/listinfo/wm-spec-list
