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comparison src/joystick/riscos/SDL_sysjoystick.c @ 630:550bccdf04bd

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Added initial support for RISC OS (thanks Peter Naulls!)
author Sam Lantinga <slouken@libsdl.org>
date Thu, 29 May 2003 04:44:13 +0000
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children b8d311d90021
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629:3fa401bb4bb5 630:550bccdf04bd
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 */
22
23 /*
24 RISCOS - Joystick support by Alan Buckley (alan_baa@hotmail.com) - 10 April 2003
25
26 Note: Currently assumes joystick is present if joystick module is loaded
27 and that there is one joystick with four buttons.
28 */
29
30 #ifdef SAVE_RCSID
31 static char rcsid =
32 "@(#) $Id$";
33 #endif
34
35 /* This is the system specific header for the SDL joystick API */
36
37 #include <stdio.h> /* For the definition of NULL */
38 #include <stdlib.h>
39
40 #include "SDL_error.h"
41 #include "SDL_joystick.h"
42 #include "SDL_sysjoystick.h"
43 #include "SDL_joystick_c.h"
44
45 #include "kernel.h"
46
47 #define JOYSTICK_READ 0x43F40
48
49 struct joystick_hwdata
50 {
51 int joystate;
52 };
53
54
55 /* Function to scan the system for joysticks.
56 * This function should set SDL_numjoysticks to the number of available
57 * joysticks. Joystick 0 should be the system default joystick.
58 * It should return number of joysticks, or -1 on an unrecoverable fatal error.
59 */
60 int SDL_SYS_JoystickInit(void)
61 {
62 _kernel_swi_regs regs;
63
64 /* Try to read joystick 0 */
65 regs.r[0] = 0;
66 if (_kernel_swi(JOYSTICK_READ, &regs, &regs) == NULL)
67 {
68 /* Switch works so assume we've got a joystick */
69 return 1;
70 }
71 /* Switch fails so it looks like there's no joystick here */
72
73 return(0);
74 }
75
76 /* Function to get the device-dependent name of a joystick */
77 const char *SDL_SYS_JoystickName(int index)
78 {
79 if (index == 0)
80 {
81 return "RISCOS Joystick 0";
82 }
83
84 SDL_SetError("No joystick available with that index");
85 return(NULL);
86 }
87
88 /* Function to open a joystick for use.
89 The joystick to open is specified by the index field of the joystick.
90 This should fill the nbuttons and naxes fields of the joystick structure.
91 It returns 0, or -1 if there is an error.
92 */
93 int SDL_SYS_JoystickOpen(SDL_Joystick *joystick)
94 {
95 _kernel_swi_regs regs;
96
97 if(!(joystick->hwdata=malloc(sizeof(struct joystick_hwdata))))
98 return -1;
99
100 regs.r[0] = joystick->index;
101
102 /* Don't know how to get exact count of buttons so assume max of 4 for now */
103 joystick->nbuttons=4;
104
105 joystick->nhats=0;
106 joystick->nballs=0;
107 joystick->naxes=2;
108 joystick->hwdata->joystate=0;
109
110 return 0;
111
112 }
113
114 /* Function to update the state of a joystick - called as a device poll.
115 * This function shouldn't update the joystick structure directly,
116 * but instead should call SDL_PrivateJoystick*() to deliver events
117 * and update joystick device state.
118 */
119 void SDL_SYS_JoystickUpdate(SDL_Joystick *joystick)
120 {
121 _kernel_swi_regs regs;
122 regs.r[0] = joystick->index;
123
124 if (_kernel_swi(JOYSTICK_READ, &regs, &regs) == NULL)
125 {
126 int newstate = regs.r[0];
127 int oldstate = joystick->hwdata->joystate;
128 if (newstate != oldstate)
129 {
130 if ((newstate & 0xFF) != (oldstate & 0xFF))
131 {
132 int y = regs.r[0] & 0xFF;
133 /* Convert to signed values */
134 if (y >= 128) y -= 256;
135 SDL_PrivateJoystickAxis(joystick,1,-y * 256); /* Up and down opposite to result in SDL */
136 }
137 if ((newstate & 0xFF00) != (oldstate & 0xFF00))
138 {
139 int x = (regs.r[0] & 0xFF00) >> 8;
140 if (x >= 128) x -= 256;
141 SDL_PrivateJoystickAxis(joystick,0,x * 256);
142 }
143
144 if ((newstate & 0xFF0000) != (oldstate & 0xFF0000))
145 {
146 int buttons = (regs.r[0] & 0xFF0000) >> 16;
147 int oldbuttons = (oldstate & 0xFF0000) >> 16;
148 int i;
149 for (i = 0; i < joystick->nbuttons; i++)
150 {
151 if ((buttons & (1<<i)) != (oldbuttons & (1<<i)))
152 {
153 if (buttons & (1<<i)) SDL_PrivateJoystickButton(joystick,i,SDL_PRESSED);
154 else SDL_PrivateJoystickButton(joystick,i,SDL_RELEASED);
155 }
156 }
157 }
158 joystick->hwdata->joystate = newstate;
159 }
160 }
161
162 return;
163 }
164
165 /* Function to close a joystick after use */
166 void SDL_SYS_JoystickClose(SDL_Joystick *joystick)
167 {
168 if(joystick->hwdata)
169 free(joystick->hwdata);
170 return;
171 }
172
173 /* Function to perform any system-specific joystick related cleanup */
174 void SDL_SYS_JoystickQuit(void)
175 {
176 SDL_numjoysticks=0;
177
178 return;
179 }
180