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joystick_getaxis(3)           Svgalib User Manual          joystick_getaxis(3)


NAME

       joystick_getaxis, joystick_getbutton - query the current state of a
       joystick.


SYNOPSIS

       #include <vgajoystick.h>

       char joystick_getaxis(int joydev, int a);
       char joystick_getbutton(int joydev, int b);


DESCRIPTION

       These functions query the current state of the joystick joydev.
       Actually this is the state found during the last call to
       joystick_update(3) with the default joystick event handler active.

       joystick_getaxis(joydev, a) return the current state of the given axis
       (usually it is x - 0, y - 1, z - 1, ...) in range -128 .. 127.  Some
       effort is made such that the center position is close to 0.

       Note that especially the version 0.* protocol joystick calibration is
       very bad. You won't usually see the extrem values on the extreme
       position. Also, the center position will be close to zero but often not
       be exactly zero and return values will also vary slightly from call to
       call even when the user did not move the joystick.

       joystick_getbutton(joydev, b) returns the state of a button. It returns
       1 for pressed button and 0 else. Note that no hardware checks for
       button clicks. The button press is only detected during a call to
       joystick_update(3) (at least in the 0.* protocol).

       NOTE: The functions simply return the data passed to the default
       joystick event handler!

       For your convenience, the following stortcuts have been established by
       use of the preprocessor:

              joystick_button1(i) for joystick_getbutton(i, 0).
              joystick_button2(i) for joystick_getbutton(i, 1).
              joystick_button3(i) for joystick_getbutton(i, 2).
              joystick_button4(i) for joystick_getbutton(i, 3).

              joystick_x(i) for joystick_getaxis(i, 0).
              joystick_y(i) for joystick_getaxis(i, 1).
              joystick_z(i) for joystick_getaxis(i, 2).

              joystick_getb1() for joystick_getbutton(0, 0).
              joystick_getb2() for joystick_getbutton(0, 1).
              joystick_getb3() for joystick_getbutton(0, 2).
              joystick_getb4() for joystick_getbutton(0, 3).

              joystick_getx() for joystick_getaxis(0, 0).
              joystick_gety() for joystick_getaxis(0, 1).
              joystick_getz() for joystick_getaxis(0, 2).


CAVEATS

       This function is only available in ELF versions of svgalib. Due to
       backwards compatibility issues it cannot be used with shared a.out
       libs.


SEE ALSO

       svgalib(7), vgagl(7), libvga.config(5), joytest(6), mjoytest(6),
       joystick_init(3), joystick_close(3), joystick_update(3),
       joystick_sethandler(3), joystick_setdefaulthandler(3),
       joystick_getnumaxes(3), joystick_getnumbuttons(3).


AUTHOR

       The svgalib joystick handler was mostly done by Daniel Engstr\"om
       <daniel.engstrom@riksnett.no>.  Multiple joystick, VC switching support
       and code to glue it into svgalib by Michael Weller <eowmob@exp-
       math.uni-essen.de>. Part of the code is based on code from C. Smith and
       Vojtech Pavlik.

Svgalib 1.3.0                    14 April 1998             joystick_getaxis(3)

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