bindings-GLFW-3.1: glfw/src/linux_joystick.c
//========================================================================
// GLFW 3.1 Linux - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2010 Camilla Berglund <elmindreda@elmindreda.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would
// be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
// be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
// distribution.
//
//========================================================================
#include "internal.h"
#if defined(__linux__)
#include <linux/joystick.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/inotify.h>
#include <fcntl.h>
#include <errno.h>
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#endif // __linux__
// Attempt to open the specified joystick device
//
static void openJoystickDevice(const char* path)
{
#if defined(__linux__)
char axisCount, buttonCount;
char name[256];
int joy, fd, version;
for (joy = GLFW_JOYSTICK_1; joy <= GLFW_JOYSTICK_LAST; joy++)
{
if (!_glfw.linux_js.js[joy].present)
continue;
if (strcmp(_glfw.linux_js.js[joy].path, path) == 0)
return;
}
for (joy = GLFW_JOYSTICK_1; joy <= GLFW_JOYSTICK_LAST; joy++)
{
if (!_glfw.linux_js.js[joy].present)
break;
}
if (joy > GLFW_JOYSTICK_LAST)
return;
fd = open(path, O_RDONLY | O_NONBLOCK);
if (fd == -1)
return;
_glfw.linux_js.js[joy].fd = fd;
// Verify that the joystick driver version is at least 1.0
ioctl(fd, JSIOCGVERSION, &version);
if (version < 0x010000)
{
// It's an old 0.x interface (we don't support it)
close(fd);
return;
}
if (ioctl(fd, JSIOCGNAME(sizeof(name)), name) < 0)
strncpy(name, "Unknown", sizeof(name));
_glfw.linux_js.js[joy].name = strdup(name);
_glfw.linux_js.js[joy].path = strdup(path);
ioctl(fd, JSIOCGAXES, &axisCount);
_glfw.linux_js.js[joy].axisCount = (int) axisCount;
ioctl(fd, JSIOCGBUTTONS, &buttonCount);
_glfw.linux_js.js[joy].buttonCount = (int) buttonCount;
_glfw.linux_js.js[joy].axes = calloc(axisCount, sizeof(float));
_glfw.linux_js.js[joy].buttons = calloc(buttonCount, 1);
_glfw.linux_js.js[joy].present = GL_TRUE;
#endif // __linux__
}
// Polls for and processes events for all present joysticks
//
static void pollJoystickEvents(void)
{
#if defined(__linux__)
int i;
struct js_event e;
ssize_t offset = 0;
char buffer[16384];
const ssize_t size = read(_glfw.linux_js.inotify, buffer, sizeof(buffer));
while (size > offset)
{
regmatch_t match;
const struct inotify_event* e = (struct inotify_event*) (buffer + offset);
if (regexec(&_glfw.linux_js.regex, e->name, 1, &match, 0) == 0)
{
char path[20];
snprintf(path, sizeof(path), "/dev/input/%s", e->name);
openJoystickDevice(path);
}
offset += sizeof(struct inotify_event) + e->len;
}
for (i = 0; i <= GLFW_JOYSTICK_LAST; i++)
{
if (!_glfw.linux_js.js[i].present)
continue;
// Read all queued events (non-blocking)
for (;;)
{
errno = 0;
if (read(_glfw.linux_js.js[i].fd, &e, sizeof(e)) < 0)
{
if (errno == ENODEV)
{
// The joystick was disconnected
free(_glfw.linux_js.js[i].axes);
free(_glfw.linux_js.js[i].buttons);
free(_glfw.linux_js.js[i].name);
free(_glfw.linux_js.js[i].path);
memset(&_glfw.linux_js.js[i], 0, sizeof(_glfw.linux_js.js[i]));
}
break;
}
// We don't care if it's an init event or not
e.type &= ~JS_EVENT_INIT;
switch (e.type)
{
case JS_EVENT_AXIS:
_glfw.linux_js.js[i].axes[e.number] =
(float) e.value / 32767.0f;
break;
case JS_EVENT_BUTTON:
_glfw.linux_js.js[i].buttons[e.number] =
e.value ? GLFW_PRESS : GLFW_RELEASE;
break;
default:
break;
}
}
}
#endif // __linux__
}
//////////////////////////////////////////////////////////////////////////
////// GLFW internal API //////
//////////////////////////////////////////////////////////////////////////
// Initialize joystick interface
//
int _glfwInitJoysticks(void)
{
#if defined(__linux__)
const char* dirname = "/dev/input";
DIR* dir;
_glfw.linux_js.inotify = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
if (_glfw.linux_js.inotify == -1)
{
_glfwInputError(GLFW_PLATFORM_ERROR,
"Linux: Failed to initialize inotify: %s",
strerror(errno));
return GL_FALSE;
}
// HACK: Register for IN_ATTRIB as well to get notified when udev is done
// This works well in practice but the true way is libudev
_glfw.linux_js.watch = inotify_add_watch(_glfw.linux_js.inotify,
dirname,
IN_CREATE | IN_ATTRIB);
if (_glfw.linux_js.watch == -1)
{
_glfwInputError(GLFW_PLATFORM_ERROR,
"Linux: Failed to watch for joystick connections in %s: %s",
dirname,
strerror(errno));
// Continue without device connection notifications
}
if (regcomp(&_glfw.linux_js.regex, "^js[0-9]\\+$", 0) != 0)
{
_glfwInputError(GLFW_PLATFORM_ERROR, "Linux: Failed to compile regex");
return GL_FALSE;
}
dir = opendir(dirname);
if (dir)
{
struct dirent* entry;
while ((entry = readdir(dir)))
{
char path[20];
regmatch_t match;
if (regexec(&_glfw.linux_js.regex, entry->d_name, 1, &match, 0) != 0)
continue;
snprintf(path, sizeof(path), "%s/%s", dirname, entry->d_name);
openJoystickDevice(path);
}
closedir(dir);
}
else
{
_glfwInputError(GLFW_PLATFORM_ERROR,
"Linux: Failed to open joystick device directory %s: %s",
dirname,
strerror(errno));
// Continue with no joysticks detected
}
#endif // __linux__
return GL_TRUE;
}
// Close all opened joystick handles
//
void _glfwTerminateJoysticks(void)
{
#if defined(__linux__)
int i;
for (i = 0; i <= GLFW_JOYSTICK_LAST; i++)
{
if (_glfw.linux_js.js[i].present)
{
close(_glfw.linux_js.js[i].fd);
free(_glfw.linux_js.js[i].axes);
free(_glfw.linux_js.js[i].buttons);
free(_glfw.linux_js.js[i].name);
free(_glfw.linux_js.js[i].path);
}
}
regfree(&_glfw.linux_js.regex);
if (_glfw.linux_js.watch > 0)
close(_glfw.linux_js.watch);
if (_glfw.linux_js.inotify > 0)
close(_glfw.linux_js.inotify);
#endif // __linux__
}
//////////////////////////////////////////////////////////////////////////
////// GLFW platform API //////
//////////////////////////////////////////////////////////////////////////
int _glfwPlatformJoystickPresent(int joy)
{
pollJoystickEvents();
return _glfw.linux_js.js[joy].present;
}
const float* _glfwPlatformGetJoystickAxes(int joy, int* count)
{
pollJoystickEvents();
*count = _glfw.linux_js.js[joy].axisCount;
return _glfw.linux_js.js[joy].axes;
}
const unsigned char* _glfwPlatformGetJoystickButtons(int joy, int* count)
{
pollJoystickEvents();
*count = _glfw.linux_js.js[joy].buttonCount;
return _glfw.linux_js.js[joy].buttons;
}
const char* _glfwPlatformGetJoystickName(int joy)
{
pollJoystickEvents();
return _glfw.linux_js.js[joy].name;
}