Quoting Monge Maurizio ([EMAIL PROTECTED]): > Alle 15:43, luned� 28 luglio 2003, hai scritto: > > Quoting Monge Maurizio ([EMAIL PROTECTED]): > > > Third, it could be nice that a window with alpha channel could decide of > > > not receiving mouse event where alpha = 0, with this shaped window can be > > > implemented in Qt and receive selected events. Al that can be realized > > > with the attached patch, that add the "DWOP_SHAPED" flag (to be used with > > > DWOP_ALPHACHANNEL) > > > > I was thinking of that some time ago. Unfortunately the locking to read one > > pixel for each mouse movement may be too much overhead and a faster > > solution should be thought about. > > Anyway for each mouse movent there is "rebuild_stack" for the mouse window, > that i guess to be much more exepensive, isn't it?
Of course, you are right. I forgot about that ;) > If the surface is in system mem reading pixels is not expensive. I only worried about the locking, but I'm no longer concerned. > Since reading a pixel is so fast, for every surface there could be lock flag > (just a var in mem, no locking object) that if set lock will lock the surface > manager. If a surface has to be moved and the flag is set the surface manager > will shed_yield until the var is unset again (that should happan immediately). > This solution makes expensive waiting for lock, but makes very fast > lock/unlock, and this could be perfect for reading 1 pixel. The surfaces already have a soft (var) lock counter. The surface manager won't kick out buffers with a non-zero lock counter. Doing shed_yield() is unwise, especially with Linux 2.5, but the possibility of long-time locks forbids this anyways. > > I will apply the patch now. However, DWOP_SHAPED has to be implemented for > > color keyed windows, too. You should think about using the primary > > pixelformat (pixel format of the layer, i.e. no DWCAPS_ALPHACHANNEL). You > > can implement shaped windows via color keying then which is way faster and > > consumes less video memory. XDirectFB uses color keying for shaped windows. > > True. -- Best regards, Denis Oliver Kropp .------------------------------------------. | DirectFB - Hardware accelerated graphics | | http://www.directfb.org/ | "------------------------------------------" Convergence GmbH -- Info: To unsubscribe send a mail to [EMAIL PROTECTED] with "unsubscribe directfb-dev" as subject.
