1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
/* zblast - simple shoot-em-up.
* Copyright (C) 1993-2000 Russell Marks. See zblast.c for license.
*
* joy.c - Linux joystick/joypad handler.
*/
/* I believe this requires version >=1.2.x of the driver, though
* that's not especially clear. But that dates from 1998 or earlier,
* so it's probably not that bad a requirement.
*/
/* XXX should read up on this, and check we have the right version
* (at runtime)
*/
#ifdef JOYSTICK_SUPPORT
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <linux/joystick.h>
#include "joy.h"
#define JOYSTICK_DEV "/dev/js0"
/* these are assumed to be equidistant from zero */
#define AXIS_MIN (-32767)
#define AXIS_MAX (32767)
/* there's a central `dead area' for each axis
* (just under 10% either way of centre)
*/
#define DEAD_AREA_MIN (-3000)
#define DEAD_AREA_MAX (3000)
static struct joystate_tag joystate;
static int joyfd=-1;
int joy_init(void)
{
int f;
for(f=0;f<MAX_AXES;f++)
joystate.axis[f]=joystate.digital_axis[f]=0;
for(f=0;f<MAX_BUTS;f++)
joystate.but[f]=0;
if((joyfd=open(JOYSTICK_DEV,O_RDONLY|O_NONBLOCK))<0)
return(0);
/* read joystick spec */
if(ioctl(joyfd,JSIOCGAXES,&joystate.num_axes)==-1)
perror("joystick axes ioctl failed"),joystate.num_axes=2;
if(ioctl(joyfd,JSIOCGBUTTONS,&joystate.num_buts)==-1)
perror("joystick buttons ioctl failed"),joystate.num_buts=2;
return(1);
}
struct joystate_tag *joy_update(void)
{
struct js_event ev;
int pos;
if(joyfd<0) return(NULL);
while(read(joyfd,&ev,sizeof(ev))>0)
{
switch(ev.type&~JS_EVENT_INIT)
{
case JS_EVENT_BUTTON:
joystate.but[ev.number]=ev.value;
break;
case JS_EVENT_AXIS:
joystate.axis[ev.number]=ev.value;
pos=0;
if(ev.value<DEAD_AREA_MIN) pos=-1;
if(ev.value>DEAD_AREA_MAX) pos= 1;
joystate.digital_axis[ev.number]=pos;
break;
}
}
return(&joystate);
}
void joy_close(void)
{
if(joyfd>=0) close(joyfd);
}
#endif /* JOYSTICK_SUPPORT */
|
