/* Joystick()                                                          */
/* Joystick() is a handy, easy and fast but naughty function that hits */
/* the hardware of the Amiga. It looks at either port 1 or port 2, and */
/* returns a bitfield containing the position of the stick and the     */
/* present state of the button. 				       */
/*								       */
/* Synopsis: value = Joystick( port );                                 */
/* value:    (UBYTE) If the fire button is pressed, the first bit is   */
/*	     set. If the stick is moved to the right, the second bit   */
/*	     is set, and if the stick is moved to the left, the third  */
/*	     bit is set. The fourth bit is set if the stick is moved   */
/*	     down, and the fifth bit is set if the stick is moved up.  */
/* port:     (UBYTE) Set the flag PORT1 if you want to check the first */
/*	     (mouse) port, or set the flag PORT2 if you want to check  */
/*	     the second (joystick) port.                               */

#include <hardware/custom.h>
#include <hardware/cia.h>

#define CIAAPRA 0xBFE001

#define FIRE   1
#define RIGHT  2
#define LEFT   4
#define DOWN   8
#define UP    16

#define PORT1 1
#define PORT2 2

extern __far struct Custom custom;
struct CIA *cia = (struct CIA *) CIAAPRA;

UBYTE Joystick();


UBYTE Joystick( port )
UBYTE port;
{
  UBYTE data = 0;
  UWORD joy;

  if( port == PORT1 )
  {
    /* PORT 1 ("MOUSE PORT") */
    joy = custom.joy0dat;
    data += !( cia->ciapra & 0x0040 ) ? FIRE : 0;
  }
  else
  {
    /* PORT 2 ("JOYSTICK PORT") */
    joy = custom.joy1dat;
    data += !( cia->ciapra & 0x0080 ) ? FIRE : 0;
  }

  data += joy & 0x0002 ? RIGHT : 0;
  data += joy & 0x0200 ? LEFT : 0;
  data += (joy >> 1 ^ joy) & 0x0001 ? DOWN : 0;
  data += (joy >> 1 ^ joy) & 0x0100 ? UP : 0;

  return( data );
}