On Wed, Feb 16, 2005 at 12:43:14PM -0500, Dan Streetman wrote: > > On Wed, 16 Feb 2005, Vojtech Pavlik wrote: > > >It doesn't flip them while it should flip the Y coordinate. This is > >because many touchscreens have [0,0] in their bottom left corner by > >hardware, being in the 1st quadrant, which is considered most logical by > >many. > > > >I fixed it in my tree. > > Thanks!! :) > > >> Or, can an app not rely on evdev's coordinate origin being > >> upper-left? > > > >Yes and no. You can rely that the driver will try to have [0,0] in the > >upper left corner, however this can be marred by the user turning the > >touchscreen 180 degrees on the monitor to get the cables on a more > >convenient side. This happens quite often. > > > >A complete matrix axis transformation is necessary then. > > Ok. Hmm. There is a field in the touchscreen report indicating what > the screen orientation is,
The 3M may have it, but not everyone else. There is simply no way to tell from the kernel, and it's much easier to configure this in the calibration config file than to have to pass a kernel parameter to the driver module. > although I have no idea how the screen would > know what orientation it's in :) A jumper on the controller board, that's the only way. And often it's not jumpered correctly even on touchscreens which do support this bit of information. > Maybe that could be used (get/set) to > determine how to handle the axis transformation. I'll see if I can figure > anything out. Or, maybe the system (X) should handle translating screen > rotation, since it seems to me the user would have to indicate rotation, > the hardware really can't know... Exactly. If you're using X, the calibration parameters will all be likely in XF86Config. And if some are negative, the axis flipping happens automagically as a result of the matrix operation. -- Vojtech Pavlik SuSE Labs, SuSE CR ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
