RetroArch/input/linuxraw_joypad.c
2013-01-01 01:41:15 +01:00

151 lines
3.5 KiB
C

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2013 - Hans-Kristian Arntzen
*
* RetroArch is free software: you can redistribute it and/or modify it under the terms
* of the GNU General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with RetroArch.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include "input_common.h"
#include "../general.h"
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <linux/joystick.h>
#define NUM_BUTTONS 32
#define NUM_AXES 32
struct linuxraw_joypad
{
int fd;
bool buttons[NUM_BUTTONS];
int16_t axes[NUM_AXES];
};
static struct linuxraw_joypad g_pads[MAX_PLAYERS];
static void poll_pad(struct linuxraw_joypad *pad)
{
struct js_event event;
while (read(pad->fd, &event, sizeof(event)) == (ssize_t)sizeof(event))
{
unsigned type = event.type & ~JS_EVENT_INIT;
switch (type)
{
case JS_EVENT_BUTTON:
if (event.number < NUM_BUTTONS)
pad->buttons[event.number] = event.value;
break;
case JS_EVENT_AXIS:
if (event.number < NUM_AXES)
pad->axes[event.number] = event.value;
break;
}
}
}
static void linuxraw_joypad_poll(void)
{
for (unsigned i = 0; i < MAX_PLAYERS; i++)
{
struct linuxraw_joypad *pad = &g_pads[i];
if (pad->fd < 0)
continue;
poll_pad(pad);
}
}
static bool linuxraw_joypad_init(void)
{
bool has_pad = false;
for (unsigned i = 0; i < MAX_PLAYERS; i++)
{
struct linuxraw_joypad *pad = &g_pads[i];
char path[PATH_MAX];
snprintf(path, sizeof(path), "/dev/input/js%u", i);
pad->fd = open(path, O_RDONLY | O_NONBLOCK);
has_pad |= pad->fd >= 0;
}
// Get initial state.
if (has_pad)
linuxraw_joypad_poll();
return has_pad;
}
static void linuxraw_joypad_destroy(void)
{
for (unsigned i = 0; i < MAX_PLAYERS; i++)
{
if (g_pads[i].fd >= 0)
close(g_pads[i].fd);
}
memset(g_pads, 0, sizeof(g_pads));
for (unsigned i = 0; i < MAX_PLAYERS; i++)
g_pads[i].fd = -1;
}
static bool linuxraw_joypad_button(unsigned port, uint16_t joykey)
{
const struct linuxraw_joypad *pad = &g_pads[port];
return joykey < NUM_BUTTONS && pad->buttons[joykey];
}
static int16_t linuxraw_joypad_axis(unsigned port, uint32_t joyaxis)
{
if (joyaxis == AXIS_NONE)
return 0;
const struct linuxraw_joypad *pad = &g_pads[port];
int16_t val = 0;
if (AXIS_NEG_GET(joyaxis) < NUM_AXES)
{
val = pad->axes[AXIS_NEG_GET(joyaxis)];
if (val > 0)
val = 0;
// Kernel returns values in range [-0x7fff, 0x7fff].
}
else if (AXIS_POS_GET(joyaxis) < NUM_AXES)
{
val = pad->axes[AXIS_POS_GET(joyaxis)];
if (val < 0)
val = 0;
}
return val;
}
static bool linuxraw_joypad_query_pad(unsigned pad)
{
return pad < MAX_PLAYERS && g_pads[pad].fd >= 0;
}
const rarch_joypad_driver_t linuxraw_joypad = {
linuxraw_joypad_init,
linuxraw_joypad_query_pad,
linuxraw_joypad_destroy,
linuxraw_joypad_button,
linuxraw_joypad_axis,
linuxraw_joypad_poll,
"linuxraw",
};