joystick.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

#include "joystick.h"

static int joystick_fd = -1;

/* These are sensible on Logitech Dual Action Rumble and xbox360 controller. */
static int joystick_x_axis = 0;
static int joystick_y_axis = 1;

int open_joystick(char *joystick_device)
{
	if (joystick_device == NULL)
		joystick_device = JOYSTICK_DEVNAME;
	joystick_fd = open(joystick_device, O_RDWR | O_NONBLOCK); /* read write for force feedback? */
	if (joystick_fd < 0)
		return joystick_fd;

	/* maybe ioctls to interrogate features here? */

	return joystick_fd;
}

int read_joystick_event(struct js_event *jse)
{
	int bytes;

	bytes = read(joystick_fd, jse, sizeof(*jse)); 

	if (bytes == -1)
		return 0;

	if (bytes > 0)
		return 1;

	printf("Unexpected bytes from joystick:%d\n", bytes);

	return -1;
}

void close_joystick()
{
	close(joystick_fd);
}

int get_joystick_status(struct wwvi_js_event *wjse)
{
	int rc;
	struct js_event jse;
	if (joystick_fd < 0)
		return -1;

	// memset(wjse, 0, sizeof(*wjse));
	while ((rc = read_joystick_event(&jse) == 1)) {
		jse.type &= ~JS_EVENT_INIT; /* ignore synthetic events */
		if (jse.type == JS_EVENT_AXIS) {
			if (jse.number == joystick_x_axis)
				wjse->stick_x = jse.value;
			if (jse.number == joystick_y_axis)
				wjse->stick_y = jse.value;
		} else if (jse.type == JS_EVENT_BUTTON) {
			if (jse.number < 11) {
				switch (jse.value) {
				case 0:
				case 1: wjse->button[jse.number] = jse.value;
					break;
				default:
					break;
				}
			}
		}
	}
	// printf("%d\n", wjse->stick1_y);
	return 0;
}

void set_joystick_y_axis(int axis)
{
	joystick_y_axis = axis;
}

void set_joystick_x_axis(int axis)
{
	joystick_x_axis = axis;
}


#if 0
/* a little test program */
int main(int argc, char *argv[])
{
	int fd, rc;
	int done = 0;

	struct js_event jse;

	if (argc == 2) {
		fd = open_joystick(argv[1]);
	} else {
		fd = open_joystick(NULL);
	}
	if (fd < 0) {
		printf("open failed.\n");
		exit(1);
	}

	while (!done) {
		rc = read_joystick_event(&jse);
		usleep(1);
		if (rc == 1) {
			printf("Event: time %8u, value %8hd, type: %3u, axis/button: %u\n", 
				jse.time, jse.value, jse.type, jse.number);
		} else {
		}
	}
}
#endif