FUNCTIONS

   1 /*
   2     SDL - Simple DirectMedia Layer
   3     Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
   4 
   5     This library is free software; you can redistribute it and/or
   6     modify it under the terms of the GNU Library General Public
   7     License as published by the Free Software Foundation; either
   8     version 2 of the License, or (at your option) any later version.
   9 
  10     This library is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13     Library General Public License for more details.
  14 
  15     You should have received a copy of the GNU Library General Public
  16     License along with this library; if not, write to the Free
  17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 
  19     Sam Lantinga
  20     slouken@devolution.com
  21 */
  23 #ifdef SAVE_RCSID
  24 static char rcsid =
  25  "@(#) $Id: SDL_bejoystick.cc,v 1.1.2.2 2001/02/10 07:20:04 hercules Exp $";
  26 #endif
  28 /* This is the system specific header for the SDL joystick API */
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  34 #include <be/support/String.h>
  35 #include <be/device/Joystick.h>
  37 extern "C" {
  39 #include "SDL_error.h"
  40 #include "SDL_joystick.h"
  41 #include "SDL_sysjoystick.h"
  42 #include "SDL_joystick_c.h"
  45 /* The maximum number of joysticks we'll detect */
  46 #define MAX_JOYSTICKS   16      
  48 /* A list of available joysticks */
  49 static char *SDL_joyport[MAX_JOYSTICKS];
  50 static char *SDL_joyname[MAX_JOYSTICKS];
  52 /* The private structure used to keep track of a joystick */
  53 struct joystick_hwdata {
  54         BJoystick *stick;
  55         uint8 *new_hats;
  56         int16 *new_axes;
  57 };
  59 /* Function to scan the system for joysticks.
  60  * This function should set SDL_numjoysticks to the number of available
  61  * joysticks.  Joystick 0 should be the system default joystick.
  62  * It should return 0, or -1 on an unrecoverable fatal error.
  63  */
  64 int SDL_SYS_JoystickInit(void)
  65 {
  66         BJoystick joystick;
  67         int numjoysticks;
  68         int i;
  69         int32 nports;
  70         char name[B_OS_NAME_LENGTH];
  72         /* Search for attached joysticks */
  73         nports = joystick.CountDevices();
  74         numjoysticks = 0;
  75         memset(SDL_joyport, 0, (sizeof SDL_joyport));
  76         memset(SDL_joyname, 0, (sizeof SDL_joyname));
  77         for ( i=0; (SDL_numjoysticks < MAX_JOYSTICKS) && (i < nports); ++i ) {
  78                 if ( joystick.GetDeviceName(i, name) == B_OK ) {
  79                         if ( joystick.Open(name) != B_ERROR ) {
  80                                 BString stick_name;
  81                                 joystick.GetControllerName(&stick_name);
  82                                 SDL_joyport[numjoysticks] = strdup(name);
  83                                 SDL_joyname[numjoysticks] =
  84                                                    strdup(stick_name.String());
  85                                 numjoysticks++;
  86                                 joystick.Close();
  87                         }
  88                 }
  89         }
  90         return(numjoysticks);
  91 }
  93 /* Function to get the device-dependent name of a joystick */
  94 const char *SDL_SYS_JoystickName(int index)
  95 {
  96         return SDL_joyname[index];
  97 }
  99 /* Function to open a joystick for use.
 100    The joystick to open is specified by the index field of the joystick.
 101    This should fill the nbuttons and naxes fields of the joystick structure.
 102    It returns 0, or -1 if there is an error.
 103  */
 104 int SDL_SYS_JoystickOpen(SDL_Joystick *joystick)
 105 {
 106         BJoystick *stick;
 108         /* Create the joystick data structure */
 109         joystick->hwdata = (struct joystick_hwdata *)
 110                            malloc(sizeof(*joystick->hwdata));
 111         if ( joystick->hwdata == NULL ) {
SDL_OutOfMemory();
 113                 return(-1);
 114         }
 115         memset(joystick->hwdata, 0, sizeof(*joystick->hwdata));
 116         stick = new BJoystick;
 117         joystick->hwdata->stick = stick;
 119         /* Open the requested joystick for use */
 120         if ( stick->Open(SDL_joyport[joystick->index]) == B_ERROR ) {
SDL_SetError("Unable to open joystick");
SDL_SYS_JoystickClose(joystick);
 123                 return(-1);
 124         }
 126         /* Set the joystick to calibrated mode */
 127         stick->EnableCalibration();
 129         /* Get the number of buttons, hats, and axes on the joystick */
 130         joystick->nbuttons = stick->CountButtons();
 131         joystick->naxes = stick->CountAxes();
 132         joystick->nhats = stick->CountHats();
 134         joystick->hwdata->new_axes = (int16 *)
 135                           malloc(joystick->naxes*sizeof(int16));
 136         joystick->hwdata->new_hats = (uint8 *)
 137                           malloc(joystick->nhats*sizeof(uint8));
 138         if ( ! joystick->hwdata->new_hats || ! joystick->hwdata->new_axes ) {
SDL_OutOfMemory();
SDL_SYS_JoystickClose(joystick);
 141                 return(-1);
 142         }
 144         /* We're done! */
 145         return(0);
 146 }
 148 /* Function to update the state of a joystick - called as a device poll.
 149  * This function shouldn't update the joystick structure directly,
 150  * but instead should call SDL_PrivateJoystick*() to deliver events
 151  * and update joystick device state.
 152  */
 153 void SDL_SYS_JoystickUpdate(SDL_Joystick *joystick)
 154 {
 155         static const Uint8 hat_map[9] = {
 156              SDL_HAT_CENTERED,
 157              SDL_HAT_UP,
 158              SDL_HAT_RIGHTUP,
 159              SDL_HAT_RIGHT,
 160              SDL_HAT_RIGHTDOWN,
 161              SDL_HAT_DOWN,
 162              SDL_HAT_LEFTDOWN,
 163              SDL_HAT_LEFT,
 164              SDL_HAT_LEFTUP
 165         };
 166         const int JITTER = (32768/10);  /* 10% jitter threshold (ok?) */
 168         BJoystick *stick;
 169         int i, change;
 170         int16 *axes;
 171         uint8 *hats;
 172         uint32 buttons;
 174         /* Set up data pointers */
 175         stick = joystick->hwdata->stick;
 176         axes = joystick->hwdata->new_axes;
 177         hats = joystick->hwdata->new_hats;
 179         /* Get the new joystick state */
 180         stick->Update();
 181         stick->GetAxisValues(axes);
 182         stick->GetHatValues(hats);
 183         buttons = stick->ButtonValues();
 185         /* Generate axis motion events */
 186         for ( i=0; i<joystick->naxes; ++i ) {
 187                 change = ((int32)axes[i] - joystick->axes[i]);
 188                 if ( (change > JITTER) || (change < -JITTER) ) {
SDL_PrivateJoystickAxis(joystick, i, axes[i]);
 190                 }
 191         }
 193         /* Generate hat change events */
 194         for ( i=0; i<joystick->nhats; ++i ) {
 195                 if ( hats[i] != joystick->hats[i] ) {
SDL_PrivateJoystickHat(joystick, i, hat_map[hats[i]]);
 197                 }
 198         }
 200         /* Generate button events */
 201         for ( i=0; i<joystick->nbuttons; ++i ) {
 202                 if ( (buttons&0x01) != joystick->buttons[i] ) {
SDL_PrivateJoystickButton(joystick, i, (buttons&0x01));
 204                 }
 205                 buttons >>= 1;
 206         }
 207 }
 209 /* Function to close a joystick after use */
 210 void SDL_SYS_JoystickClose(SDL_Joystick *joystick)
 211 {
 212         if ( joystick->hwdata ) {
 213                 joystick->hwdata->stick->Close();
 214                 delete joystick->hwdata->stick;
 215                 if ( joystick->hwdata->new_hats ) {
 216                         free(joystick->hwdata->new_hats);
 217                 }
 218                 if ( joystick->hwdata->new_axes ) {
 219                         free(joystick->hwdata->new_axes);
 220                 }
 221                 free(joystick->hwdata);
 222                 joystick->hwdata = NULL;
 223         }
 224 }
 226 /* Function to perform any system-specific joystick related cleanup */
 227 void SDL_SYS_JoystickQuit(void)
 228 {
 229         int i;
 231         for ( i=0; SDL_joyport[i]; ++i ) {
 232                 free(SDL_joyport[i]);
 233         }
 234         SDL_joyport[0] = NULL;
 236         for ( i=0; SDL_joyname[i]; ++i ) {
 237                 free(SDL_joyname[i]);
 238         }
 239         SDL_joyname[0] = NULL;
 240 }
 242 }; // extern "C"