tpad_set_mode()

TPAD_$SET_MODE                    Domain/OS                     TPAD_$SET_MODE


NAME
     tpad_$set_mode - set pointing device response characteristics

SYNOPSIS (C)
     #include <apollo/base.h>
     #include <apollo/tpad.h>

     void tpad_$set_mode(
          tpad_$mode_t &mode,
          short &x_scale,
          short &y_scale,
          short &hysteresis,
          smd_$pos_t &origin)

SYNOPSIS (Pascal)
     %include '/sys/ins/base.ins.pas';
     %include '/sys/ins/tpad.ins.pas';

     procedure tpad_$set_mode(
          in mode: tpad_$mode_t;
          in x_scale: integer;
          in y_scale: integer;
          in hysteresis: integer;
          in origin: smd_$pos_t);

SYNOPSIS (FORTRAN)
     %include '/sys/ins/base.ins.ftn'
     %include '/sys/ins/tpad.ins.ftn'

           integer*2 mode, x_scale, y_scale, hysteresis
           integer*2 line, column, origin(2)

           equivalence (line, origin(1)), (column, origin(2))

           call tpad_$set_mode(mode, x_scale, y_scale, hysteresis, origin)

DESCRIPTION
     This call sets the mode, scale factors, and hysteresis factors of point-
     ing devices.  It can also change the origin for relative or
     absolute/relative mode.  Use the output from tpad_$inquire as the input
     to this call to change one aspect of pointing device response without
     changing any other aspects.

     A program can use this call with the touchpad, mouse, and bit pad point-
     ing devices, but the mouse uses only the scale and hysteresis factors and
     ignores the other mode settings, since it is inherently a relative dev-
     ice.

     mode The cursor mode to set.  Specify one of the following predefined
          values:

          tpad_$absolute
               Absolute mode maps the pointing space to a part of the screen
               dictated by the scaling factor and the origin value.  Thus,
               there is a one-to-one mapping between points in the pointing
               space and a subset of points on the screen.

          tpad_$relative
               In relative mode, the cursor responds only to device movement
               relative to the current position.  The response of the cursor
               simulates response to mouse movement.  This is the only mean-
               ingful mode to use with a mouse.

          tpad_$rel_abs
               In relative/absolute mode, the cursor responds as in absolute
               mode on first contact to establish a new current position.
               After first contact, the cursor responds as in relative mode.
               Momentary lifting of the finger from a touchpad (for less than
               about half a second) does not affect the cursor position.

     x_scale
          The scale factor in the x dimension.  Scale factors are not relevent
          to absolute mode.

     y_scale
          The scale factor in the y dimension.  Scale factors are not relevent
          to absolute mode.

     hysteresis
          The hysteresis factor, in pixels.

          The hysteresis factor prevents minor, unintentional movements from
          changing the cursor location.  It effectively defines a box around
          the current location.  The cursor does not move while the current
          location stays within the hysteresis box.

          If the current location moves beyond the box, the distance the cur-
          sor moves is the difference between the new location and the past
          location less the hysteresis factor.  The default hysteresis factor
          is 5.

     origin
          is scale origin for x- and y-dimensions in smd_$pos_t format.

SEE ALSO
     tpad_$inq_dtype.
Museum
