| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2009 Sam Lantinga |
| 4 | |
| 5 | This library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 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 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with this library; if not, write to the Free Software |
| 17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | |
| 19 | Sam Lantinga |
| 20 | slouken@libsdl.org |
| 21 | */ |
| 22 | #include "SDL_config.h" |
| 23 | |
| 24 | #ifdef SDL_JOYSTICK_RISCOS |
| 25 | |
| 26 | /* |
| 27 | RISC OS - Joystick support by Alan Buckley (alan_baa@hotmail.com) - 10 April 2003 |
| 28 | |
| 29 | Note: Currently assumes joystick is present if joystick module is loaded |
| 30 | and that there is one joystick with four buttons. |
| 31 | */ |
| 32 | |
| 33 | /* This is the system specific header for the SDL joystick API */ |
| 34 | |
| 35 | #include "SDL_events.h" |
| 36 | #include "SDL_joystick.h" |
| 37 | #include "../SDL_sysjoystick.h" |
| 38 | #include "../SDL_joystick_c.h" |
| 39 | |
| 40 | #include "kernel.h" |
| 41 | |
| 42 | #define JOYSTICK_READ 0x43F40 |
| 43 | |
| 44 | struct joystick_hwdata |
| 45 | { |
| 46 | int joystate; |
| 47 | }; |
| 48 | |
| 49 | |
| 50 | /* Function to scan the system for joysticks. |
| 51 | * This function should set SDL_numjoysticks to the number of available |
| 52 | * joysticks. Joystick 0 should be the system default joystick. |
| 53 | * It should return number of joysticks, or -1 on an unrecoverable fatal error. |
| 54 | */ |
| 55 | int SDL_SYS_JoystickInit(void) |
| 56 | { |
| 57 | _kernel_swi_regs regs; |
| 58 | |
| 59 | /* Try to read joystick 0 */ |
| 60 | regs.r[0] = 0; |
| 61 | if (_kernel_swi(JOYSTICK_READ, ®s, ®s) == NULL) |
| 62 | { |
| 63 | /* Switch works so assume we've got a joystick */ |
| 64 | return 1; |
| 65 | } |
| 66 | /* Switch fails so it looks like there's no joystick here */ |
| 67 | |
| 68 | return(0); |
| 69 | } |
| 70 | |
| 71 | /* Function to get the device-dependent name of a joystick */ |
| 72 | const char *SDL_SYS_JoystickName(int index) |
| 73 | { |
| 74 | if (index == 0) |
| 75 | { |
| 76 | return "RISC OS Joystick 0"; |
| 77 | } |
| 78 | |
| 79 | SDL_SetError("No joystick available with that index"); |
| 80 | return(NULL); |
| 81 | } |
| 82 | |
| 83 | /* Function to open a joystick for use. |
| 84 | The joystick to open is specified by the index field of the joystick. |
| 85 | This should fill the nbuttons and naxes fields of the joystick structure. |
| 86 | It returns 0, or -1 if there is an error. |
| 87 | */ |
| 88 | int SDL_SYS_JoystickOpen(SDL_Joystick *joystick) |
| 89 | { |
| 90 | _kernel_swi_regs regs; |
| 91 | |
| 92 | if(!(joystick->hwdata=SDL_malloc(sizeof(struct joystick_hwdata)))) |
| 93 | return -1; |
| 94 | |
| 95 | regs.r[0] = joystick->index; |
| 96 | |
| 97 | /* Don't know how to get exact count of buttons so assume max of 4 for now */ |
| 98 | joystick->nbuttons=4; |
| 99 | |
| 100 | joystick->nhats=0; |
| 101 | joystick->nballs=0; |
| 102 | joystick->naxes=2; |
| 103 | joystick->hwdata->joystate=0; |
| 104 | |
| 105 | return 0; |
| 106 | |
| 107 | } |
| 108 | |
| 109 | /* Function to update the state of a joystick - called as a device poll. |
| 110 | * This function shouldn't update the joystick structure directly, |
| 111 | * but instead should call SDL_PrivateJoystick*() to deliver events |
| 112 | * and update joystick device state. |
| 113 | */ |
| 114 | void SDL_SYS_JoystickUpdate(SDL_Joystick *joystick) |
| 115 | { |
| 116 | _kernel_swi_regs regs; |
| 117 | regs.r[0] = joystick->index; |
| 118 | |
| 119 | if (_kernel_swi(JOYSTICK_READ, ®s, ®s) == NULL) |
| 120 | { |
| 121 | int newstate = regs.r[0]; |
| 122 | int oldstate = joystick->hwdata->joystate; |
| 123 | if (newstate != oldstate) |
| 124 | { |
| 125 | if ((newstate & 0xFF) != (oldstate & 0xFF)) |
| 126 | { |
| 127 | int y = regs.r[0] & 0xFF; |
| 128 | /* Convert to signed values */ |
| 129 | if (y >= 128) y -= 256; |
| 130 | SDL_PrivateJoystickAxis(joystick,1,-y * 256); /* Up and down opposite to result in SDL */ |
| 131 | } |
| 132 | if ((newstate & 0xFF00) != (oldstate & 0xFF00)) |
| 133 | { |
| 134 | int x = (regs.r[0] & 0xFF00) >> 8; |
| 135 | if (x >= 128) x -= 256; |
| 136 | SDL_PrivateJoystickAxis(joystick,0,x * 256); |
| 137 | } |
| 138 | |
| 139 | if ((newstate & 0xFF0000) != (oldstate & 0xFF0000)) |
| 140 | { |
| 141 | int buttons = (regs.r[0] & 0xFF0000) >> 16; |
| 142 | int oldbuttons = (oldstate & 0xFF0000) >> 16; |
| 143 | int i; |
| 144 | for (i = 0; i < joystick->nbuttons; i++) |
| 145 | { |
| 146 | if ((buttons & (1<<i)) != (oldbuttons & (1<<i))) |
| 147 | { |
| 148 | if (buttons & (1<<i)) SDL_PrivateJoystickButton(joystick,i,SDL_PRESSED); |
| 149 | else SDL_PrivateJoystickButton(joystick,i,SDL_RELEASED); |
| 150 | } |
| 151 | } |
| 152 | } |
| 153 | joystick->hwdata->joystate = newstate; |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | return; |
| 158 | } |
| 159 | |
| 160 | /* Function to close a joystick after use */ |
| 161 | void SDL_SYS_JoystickClose(SDL_Joystick *joystick) |
| 162 | { |
| 163 | if(joystick->hwdata) |
| 164 | SDL_free(joystick->hwdata); |
| 165 | return; |
| 166 | } |
| 167 | |
| 168 | /* Function to perform any system-specific joystick related cleanup */ |
| 169 | void SDL_SYS_JoystickQuit(void) |
| 170 | { |
| 171 | SDL_numjoysticks=0; |
| 172 | |
| 173 | return; |
| 174 | } |
| 175 | |
| 176 | #endif /* SDL_JOYSTICK_RISCOS */ |