Hi.
I am working on an xinput driver for my older serial tablet under FreeBSD. My main question is, how do you post tilt and pressure events to Xwindows and is there any complete up to date API documentation anywhere for it? I originally wrote the driver a number of years ago and have finally gotten it updated to compile and work with Xorg-7.7. I have cursor motion and buttons working by calling xf86PostMotionEvent() and xf86PostButtonEvent() so that it can be used as a core pointer, but I can find no API documentation on posting tilt and pressure events. The only documentation I have found with examples is https://www.x.org/wiki/Development/Documentation/XorgInputHOWTO/ which apparently was mostly written around 10 years ago and is very out of date. It says right at the top of the page, "Warning: This tutorial is outdated and refers to APIs that have since been changed." No links or mention of any docs for the updated APIs. I have been pulling my hair out for days dealing with changes that seem to be completely undocumented. For example: I had this call from the example in my driver. xf86InitValuatorAxisStruct(device, i, *pIdev->labels, -1, -1, 1, 1, 1); which produced this compilation error: error: too few arguments to function call, expected 9, have 8 xf86InitValuatorAxisStruct(device, i, *pIdev->labels, -1, -1, 1, 1, 1); Not only can I find no API docs mentioning this but nowhere in the ChangeLog for xorg-server-1.18.4 does it even mention adding a 9th argument or what it is. They are making significant compatibility changes and staying completely quiet about it. I found a prototype for it in the Xorg source tree that showed that it now had a mode parameter but, like most of the rest of the sources, it was completely uncommented. So what the hell is mode? After much digging, I finally found an uncommented call to it in the mouse.c file from the xf86-input-mouse-1.7.2 sources where I discovered an extra argument of Relative being added under #if GET_ABI_MAJOR(ABI_XINPUT_VERSION) >= 12 So, after digging through all the headers, I came to the conclusion that it now accepts either Absolute or Relative value as the parameter. This is just one example of many issues that I had. The Xorg developers are making all kinds of changes without putting out updated API reference documentation or howtos, commenting their code, or in cases like above, even mentioning it in the change logs. I have searched with google and various other major search engines for days and have found no up to date or complete xinput API documentation. It has been frustrating. Am I overlooking something obvious or have the Xwindows developers lost the ability to communicate in recent years? I have always griped and complained about hardware vendors, such as Wacom, ignoring open source platforms like Linux and FreeBSD and only putting out drivers for Microshaft. Now I may be beginning to understand one of the reasons why. It's hard to write drivers or debug code for a poorly documented platform, where most of the documentation either does not exist or is wrong or incomplete or hasn't been updated in 10 years. BTW, before anybody points out that there are existing Xwindows drivers for Wacom and other tablets, I do realize that. 1, I have never had much luck getting them to work on FreeBSD. This is getting too long to go into those issues. And 2, I am taking a very different approach than the existing drivers to provide features and capabilities, that we wanted for in-house use, that the existing drivers do not have. I will document it if I get it working well enough to release to the public. _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel
