XChangePointerControl(), XGetPointerControl() - control pointer
XChangePointerControl (Display *display, Bool do_accel,
Bool do_threshold, int accel_numerator,
int accel_denominator, int threshold)
XGetPointerControl (Display *display, int *accel_numerator_return,
int *accel_denominator_return,
int *threshold_return)
The XChangePointerControl(3) function defines how the pointing device moves. The acceleration, expressed as a fraction, is a multiplier for movement. For example, specifying 3/1 means the pointer moves three times as fast as normal. The fraction can be rounded arbitrarily by the X server. Acceleration only takes effect if the pointer moves more than threshold pixels at once and only applies to the amount beyond the value in the threshold argument. Setting a value to -1 restores the default. The values of the do_accel and do_threshold arguments must be True for the pointer values to be set, or the parameters are unchanged. Negative values (other than -1) generate a BadValue error, as does a zero value for the accel_denominator argument.
XChangePointerControl(3) can generate a BadValue error.
The XGetPointerControl(3) function returns the pointer's current acceleration multiplier and acceleration threshold.
Xlib