'InkServices' is Microsoft's implementation of the interface between your input hardware (graphics tablet, mouse, tabletPC screen, touch pad, or whatever) and how the software reacts to that information.
InkServices has many features such as gesture recognition, handwriting recognition, right-click helpers, press-and-hold helpers, and so on.
Because of the wide array of hardware and software combinations, relying on third-party providers to write the drivers, there can sometimes be inconsitencies in the way each piece of hardware reports the properties of the user input at any time. Also there are widely varying ways the hardware manufacturers report the capabilities of their hardware.
This means that sometimes ArtRage thinks your tablet is doing something, when in reality it is doing something else.
Take the example of someone with a touch-enabled TabletPC. At any time they could be using a finger on their display (no pressure support), the stylus on their display (pressure support), their touchpad on the keyboard (no pressure support), or an attached mouse (no pressure support) or something else! Each means of getting those coordinates and pressure and other information from the user relies on ArtRage knowing whether the input means supports pressure, and avoiding the interaction of all the 'helper' services that could be throwing their support into the mix.
The upshot is that we dont always end up with the results we expect. So we give the option to disable parts of the way we interpret the input data. If 'InkServices' is enabled, you can switch on 'Precise Tablet' mode to use the absolute mouse coordinates, and discard the tablet packet data. (Some hardware vendors have strange data packets which they clean up later in their mouse drivers). Or you can disable InkServices entirely. In that case we treat all the data input as simple mouse coordinates.
Then there is WinTab, which is the Windows interface to Graphics Tablets which doesn't use InkServices. It is the standard most Wacom tablets use on XP and earlier operating systems. WinTab is generally very reliable - it has been around for decades. But sometimes it interacts badly with other running applications.
We have to use InkServices to get stylus pressure support out of some devices. And we have to use WinTab to get stylus pressure support out of some other devices. The option of switching off InkServices allows users to bypass problems on devices which dont support pressure anyway.
(Just so you know, yes there *are* input devices which tell ArtRage they support pressure, and then they return no pressure information on a stroke)
AndyRage's mantra for graphics engine code:
"Sure - how hard can it be?"