/*** thinlib (c) 2000 Matthew Conte (matt@conte.com)****** This program is free software; you can redistribute it and/or** modify it under the terms of version 2 of the GNU Library General ** Public License as published by the Free Software Foundation.**** This program is distributed in the hope that it will be useful, ** but WITHOUT ANY WARRANTY; without even the implied warranty of** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU ** Library General Public License for more details.  To obtain a ** copy of the GNU Library General Public License, write to the Free ** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.**** Any permitted reproduction of these routines, in whole or in part,** must bear this legend.****** tl_joy.c**** DOS joystick reading routines** $Id: tl_joy.c,v 1.3 2000/12/16 21:18:11 matt Exp $*/#include <dos.h>#include "tl_types.h"#include "tl_djgpp.h"#include "tl_joy.h"#define  JOY_PORT          0x201#define  JOY_TIMEOUT       10000#define  J1_A              0x10#define  J1_B              0x20#define  J2_A              0x40#define  J2_B              0x80#define  J1_X              0x01#define  J1_Y              0x02#define  J2_X              0x04#define  J2_Y              0x08#define  JOY_CENTER        0xAA#define  JOY_MIN_THRESH    0.7#define  JOY_MAX_THRESH    1.3static struct{   int x_minthresh, x_maxthresh;   int y_minthresh, y_maxthresh;   int x_read, y_read;   uint8 button_state;} joystate;/* Read data in from joy port */static int joy_portread(void){   /* Set timeout to max number of samples */   int timeout = JOY_TIMEOUT;   uint8 port_val;   joystate.x_read = 0;   joystate.y_read = 0;   THIN_DISABLE_INTS();   /* Clear the latch and request a sample */   port_val = inportb(JOY_PORT);   outportb(JOY_PORT, port_val);   do   {      port_val = inportb(JOY_PORT);      if (port_val & J1_X)         joystate.x_read++;      if (port_val & J1_Y)         joystate.y_read++;   }   while (--timeout && (port_val & 3));   joystate.button_state = port_val;   THIN_ENABLE_INTS();   if (0 == timeout)      return -1;   else      return 0;}int thin_joy_read(joy_t *joy){   if (joy_portread())      return -1;   /* Calc X axis */   joy->left = (joystate.x_read < joystate.x_minthresh) ? true : false;   joy->right = (joystate.x_read > joystate.x_maxthresh) ? true : false;   /* Calc Y axis */   joy->up = (joystate.y_read < joystate.y_minthresh) ? true : false;   joy->down = (joystate.y_read > joystate.y_maxthresh) ? true : false;   /* Get button status */   /* note that buttons returned by hardware are inverted logic */   joy->button[0] = (joystate.button_state & J1_A) ? false : true;   joy->button[1] = (joystate.button_state & J2_A) ? false : true;   joy->button[2] = (joystate.button_state & J1_B) ? false : true;   joy->button[3] = (joystate.button_state & J2_B) ? false : true;   return 0;}/* Detect presence of joystick */int thin_joy_init(void){   if (joy_portread())      return -1;   /* Set the threshhold */   joystate.x_minthresh = JOY_MIN_THRESH * joystate.x_read;   joystate.x_maxthresh = JOY_MAX_THRESH * joystate.x_read;   joystate.y_minthresh = JOY_MIN_THRESH * joystate.y_read;   joystate.y_maxthresh = JOY_MAX_THRESH * joystate.y_read;   return 0;}void thin_joy_shutdown(void){}/*** $Log: tl_joy.c,v $** Revision 1.3  2000/12/16 21:18:11  matt** thinlib cleanups**** Revision 1.2  2000/11/05 16:32:36  matt** thinlib round 2**** Revision 1.1  2000/11/05 06:29:03  matt** initial revision***/