On Fri, 25 Oct 2002, Luugi Marsan wrote: > Hi, > > I don't understand how X11 implements overlay. I'm trying to understand > the xf8_32bpp module. Is their any documentation on this? I would like > to get an explanation on how this module was implemented. Is it > anything like how Window does Overlay? If I want to go through the code > where should I start? Seems to me that the xf86overlay.c file is a good > starting point. But how is this code structured. Is there anywhere I > could find something to explain the big picture of the code?
There is a bit more in xaaOverl/xc/programs/Xserver/hw/xfree86/xaa/xaaInit.c xaaOverlay.c and xaaImage.c - look for overlayFlags and OVERLAY_8_32_PLANAR. How does windoes do overlays ? For the big picture I'd be guessing, but my impression is that most of the overlay code is there to persuade XAA to draw in the top byte of each pixmap, sometimes with planemasks and sometimes by using a depth 8 pixmap with 32 bit pixels (xf86overlay:512 OverlayRefreshPixmap). I'd be interested in anything you find out, since I expect I'll need to duplicate much of it for PseudoColor on DirectColor. -- Dr. Andrew C. Aitchison Computer Officer, DPMMS, Cambridge [EMAIL PROTECTED] http://www.dpmms.cam.ac.uk/~werdna _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert
