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NAME

       XChangePointerControl, XGetPointerControl - control pointer

SYNTAX

       int XChangePointerControl(Display *display, Bool do_accel, Bool do_threshold, int
              accel_numerator, int accel_denominator, int threshold);

       int XGetPointerControl(Display *display, int *accel_numerator_return, int
              *accel_denominator_return, int *threshold_return);

ARGUMENTS

       accel_denominator
                 Specifies the denominator for the acceleration multiplier.

       accel_denominator_return
                 Returns the denominator for the acceleration multiplier.

       accel_numerator
                 Specifies the numerator for the acceleration multiplier.

       accel_numerator_return
                 Returns the numerator for the acceleration multiplier.

       display   Specifies the connection to the X server.

       do_accel  Specifies a Boolean value that controls whether the values for the
                 accel_numerator or accel_denominator are used.

       do_threshold
                 Specifies a Boolean value that controls whether the value for the threshold is
                 used.

       threshold Specifies the acceleration threshold.

       threshold_return
                 Returns the acceleration threshold.

DESCRIPTION

       The XChangePointerControl 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 may 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 can generate a BadValue error.

       The XGetPointerControl function returns the pointer's current acceleration multiplier and
       acceleration threshold.

DIAGNOSTICS

       BadValue  Some numeric value falls outside the range of values accepted by the request.
                 Unless a specific range is specified for an argument, the full range defined by
                 the argument's type is accepted.  Any argument defined as a set of alternatives
                 can generate this error.

SEE ALSO

       Xlib - C Language X Interface