gfx_joystick.c

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/* joystick handling, linux */

#include "../fb_gfx.h"
#include "fb_gfx_linux.h"
#include <fcntl.h>
#include <sys/ioctl.h>

/* From linux/joystick.h */

#define JS_EVENT_BUTTON         0x01
#define JS_EVENT_AXIS           0x02
#define JS_EVENT_INIT           0x80

typedef struct _JS_EVENT {
        unsigned int time;
        short value;
        unsigned char type;
        unsigned char number;
} JS_EVENT;

#define JSIOCGVERSION           _IOR('j', 0x01, unsigned int)

typedef struct _JOYDATA {
        int fd;
        float axis[8];
        int buttons;
} JOYDATA;

static JOYDATA joydata[16];
static int inited = FALSE;

FBCALL int fb_GfxGetJoystick(int id, ssize_t *buttons, float *a1, float *a2, float *a3, float *a4, float *a5, float *a6, float *a7, float *a8)
{
        const char *device[] = { "/dev/input/js",
                                                         "/dev/js",
                                                         NULL };
        char device_name[16];
        JOYDATA *joy;
        JS_EVENT event;
        int i, j, k, count = 0;
        int version;

        if (!inited) {
                fb_hMemSet(joydata, 0, sizeof(JOYDATA) * 16);
                for (i = 0; i < 16; i++)
                        joydata[i].fd = -1;
                joy = joydata;
                for (i = 0; device[i] && (count < 16); i++) {
                        for (j = 0; (j < 16) && (count < 16); j++) {
                                sprintf(device_name, "%s%d", device[i], j);
                                joy->fd = open(device_name, O_NONBLOCK);
                                if (joy->fd >= 0) {
                                        ioctl(joy->fd, JSIOCGVERSION, &version);
                                        if (version < 0x10000) {
                                                close(joy->fd);
                                                continue;
                                        }
                                        for (k = 0; k < 8; k++)
                                                joy->axis[k] = -1000.0;
                                        joy++;
                                        count++;
                                }
                        }
                }
                inited = TRUE;
        }

        *buttons = -1;
        *a1 = *a2 = *a3 = *a4 = *a5 = *a6 = *a7 = *a8 = -1000.0;

        if ((id < 0) || (id > 15))
                return fb_ErrorSetNum(FB_RTERROR_ILLEGALFUNCTIONCALL);
        joy = &joydata[id];

        if (joy->fd < 0)
                return fb_ErrorSetNum(FB_RTERROR_ILLEGALFUNCTIONCALL);

        while (read(joy->fd, &event, sizeof(event)) > 0) {
                switch (event.type & ~JS_EVENT_INIT) {

                        case JS_EVENT_AXIS:
                                if (event.number < 8)
                                        joy->axis[event.number] = (float)event.value / 32767.0;
                                break;

                        case JS_EVENT_BUTTON:
                                if (event.number < 32) {
                                        if (event.value)
                                                joy->buttons |= (1 << event.number);
                                        else
                                                joy->buttons &= ~(1 << event.number);
                                }
                                break;
                }
        }

        *a1 = joy->axis[0];
        *a2 = joy->axis[1];
        *a3 = joy->axis[2];
        *a4 = joy->axis[3];
        *a5 = joy->axis[4];
        *a6 = joy->axis[5];
        *a7 = joy->axis[6];
        *a8 = joy->axis[7];
        *buttons = joy->buttons;

        return fb_ErrorSetNum( FB_RTERROR_OK );
}