e14743d1 |
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 */ |