Quoting Marcus Gustafsson ([EMAIL PROTECTED]): > Im running XDirectFB and DirectFB in software mode in ARGB mode on hardware > where the alpha value in the framebuffer controls the visibility of the > graphics plane over an video underlay. Ie, a alpha value of 255 in the > framebuffer will make the graphics pixel fully opaque.
Are you using the CyberPro layering? > My problem is that when running XDirectFB the X applications are invisible. > X seems to zero the alpha value. However if I also start another DirectFB > application that also creates windows on the primary display and blend the > windows, the X applications is seen though the windows. X indeed writes '0' to the alpha channel ;( I could add a workaround that creates windows in RGB32 if the layer is ARGB to have them converted to valid ARGB data. > What I dont really understand is the relation between the alpha values in > layers(mainly the primary display layer) and the alpha value that is written > in /dev/fb and how layers are blended together. Is this up to driver to > decide? Please explain this. The alpha values of the primary layer are stored in /dev/fb along with the RGB values. Layers are blended by the hardware using this equation: dst = src * src.alpha + dst * (1.0 - src.alpha) Where dst is the layer below src. -- 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.
