//========================================================================

// GLFW 3.3 Linux - www.glfw.org

//------------------------------------------------------------------------

// Copyright (c) 2002-2006 Marcus Geelnard

// Copyright (c) 2006-2016 Camilla Löwy <elmindreda@glfw.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"

#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>

#ifndef SYN_DROPPED // < v2.6.39 kernel headers

// Workaround for CentOS-6, which is supported till 2020-11-30, but still on v2.6.32

#define SYN_DROPPED 3

#endif

// Apply an EV_KEY event to the specified joystick

//

static void handleKeyEvent(_GLFWjoystick* js, int code, int value)

{

_glfwInputJoystickButton(js,

js->linjs.keyMap[code - BTN_MISC],

value ? GLFW_PRESS : GLFW_RELEASE);

}

// Apply an EV_ABS event to the specified joystick

//

static void handleAbsEvent(_GLFWjoystick* js, int code, int value)

{

const int index = js->linjs.absMap[code];

if (code >= ABS_HAT0X && code <= ABS_HAT3Y)

{

static const char stateMap[3][3] =

{

{ GLFW_HAT_CENTERED, GLFW_HAT_UP, GLFW_HAT_DOWN },

{ GLFW_HAT_LEFT, GLFW_HAT_LEFT_UP, GLFW_HAT_LEFT_DOWN },

{ GLFW_HAT_RIGHT, GLFW_HAT_RIGHT_UP, GLFW_HAT_RIGHT_DOWN },

};

const int hat = (code - ABS_HAT0X) / 2;

const int axis = (code - ABS_HAT0X) % 2;

int* state = js->linjs.hats[hat];

// NOTE: Looking at several input drivers, it seems all hat events use

// -1 for left / up, 0 for centered and 1 for right / down

if (value == 0)

state[axis] = 0;

else if (value < 0)

state[axis] = 1;

else if (value > 0)

state[axis] = 2;

_glfwInputJoystickHat(js, index, stateMap[state[0]][state[1]]);

}

else

{

const struct input_absinfo* info = &js->linjs.absInfo[code];

float normalized = value;

const int range = info->maximum - info->minimum;

if (range)

{

// Normalize to 0.0 -> 1.0

normalized = (normalized - info->minimum) / range;

// Normalize to -1.0 -> 1.0

normalized = normalized * 2.0f - 1.0f;

}

_glfwInputJoystickAxis(js, index, normalized);

}

}

// Poll state of absolute axes

//

static void pollAbsState(_GLFWjoystick* js)

{

int code;

for (code = 0; code < ABS_CNT; code++)

{

if (js->linjs.absMap[code] < 0)

continue;

struct input_absinfo* info = &js->linjs.absInfo[code];

if (ioctl(js->linjs.fd, EVIOCGABS(code), info) < 0)

continue;

handleAbsEvent(js, code, info->value);

}

}

#define isBitSet(bit, arr) (arr[(bit) / 8] & (1 << ((bit) % 8)))

// Attempt to open the specified joystick device

//

static GLFWbool openJoystickDevice(const char* path)

{

int jid, code;

char name[256] = "";

char guid[33] = "";

char evBits[(EV_CNT + 7) / 8] = {0};

char keyBits[(KEY_CNT + 7) / 8] = {0};

char absBits[(ABS_CNT + 7) / 8] = {0};

int axisCount = 0, buttonCount = 0, hatCount = 0;

struct input_id id;

_GLFWjoystickLinux linjs = {0};

_GLFWjoystick* js = NULL;

for (jid = 0; jid <= GLFW_JOYSTICK_LAST; jid++)

{

if (!_glfw.joysticks[jid].present)

continue;

if (strcmp(_glfw.joysticks[jid].linjs.path, path) == 0)

return GLFW_FALSE;

}

linjs.fd = open(path, O_RDONLY | O_NONBLOCK);

if (linjs.fd == -1)

return GLFW_FALSE;

if (ioctl(linjs.fd, EVIOCGBIT(0, sizeof(evBits)), evBits) < 0 ||

ioctl(linjs.fd, EVIOCGBIT(EV_KEY, sizeof(keyBits)), keyBits) < 0 ||

ioctl(linjs.fd, EVIOCGBIT(EV_ABS, sizeof(absBits)), absBits) < 0 ||

ioctl(linjs.fd, EVIOCGID, &id) < 0)

{

_glfwInputError(GLFW_PLATFORM_ERROR,

"Linux: Failed to query input device: %s",

strerror(errno));

close(linjs.fd);

return GLFW_FALSE;

}

// Ensure this device supports the events expected of a joystick

if (!isBitSet(EV_KEY, evBits) || !isBitSet(EV_ABS, evBits))

{

close(linjs.fd);

return GLFW_FALSE;

}

if (ioctl(linjs.fd, EVIOCGNAME(sizeof(name)), name) < 0)

strncpy(name, "Unknown", sizeof(name));

// Generate a joystick GUID that matches the SDL 2.0.5+ one

if (id.vendor && id.product && id.version)

{

sprintf(guid, "%02x%02x0000%02x%02x0000%02x%02x0000%02x%02x0000",

id.bustype & 0xff, id.bustype >> 8,

id.vendor & 0xff, id.vendor >> 8,

id.product & 0xff, id.product >> 8,

id.version & 0xff, id.version >> 8);

}

else

{

sprintf(guid, "%02x%02x0000%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x00",

id.bustype & 0xff, id.bustype >> 8,

name[0], name[1], name[2], name[3],

name[4], name[5], name[6], name[7],

name[8], name[9], name[10]);

}

for (code = BTN_MISC; code < KEY_CNT; code++)

{

if (!isBitSet(code, keyBits))

continue;

linjs.keyMap[code - BTN_MISC] = buttonCount;

buttonCount++;

}

for (code = 0; code < ABS_CNT; code++)

{

linjs.absMap[code] = -1;

if (!isBitSet(code, absBits))

continue;

if (code >= ABS_HAT0X && code <= ABS_HAT3Y)

{

linjs.absMap[code] = hatCount;

hatCount++;

// Skip the Y axis

code++;

}

else

{

if (ioctl(linjs.fd, EVIOCGABS(code), &linjs.absInfo[code]) < 0)

continue;

linjs.absMap[code] = axisCount;

axisCount++;

}

}

js = _glfwAllocJoystick(name, guid, axisCount, buttonCount, hatCount);

if (!js)

{

close(linjs.fd);

return GLFW_FALSE;

}

strncpy(linjs.path, path, sizeof(linjs.path) - 1);

memcpy(&js->linjs, &linjs, sizeof(linjs));

pollAbsState(js);

_glfwInputJoystick(js, GLFW_CONNECTED);

return GLFW_TRUE;

}

#undef isBitSet

// Frees all resources associated with the specified joystick

//

static void closeJoystick(_GLFWjoystick* js)

{

close(js->linjs.fd);

_glfwFreeJoystick(js);

_glfwInputJoystick(js, GLFW_DISCONNECTED);

}

// Lexically compare joysticks by name; used by qsort

//

static int compareJoysticks(const void* fp, const void* sp)

{

const _GLFWjoystick* fj = fp;

const _GLFWjoystick* sj = sp;

return strcmp(fj->linjs.path, sj->linjs.path);

}

//////////////////////////////////////////////////////////////////////////

////// GLFW internal API //////

//////////////////////////////////////////////////////////////////////////

// Initialize joystick interface

//

GLFWbool _glfwInitJoysticksLinux(void)

{

DIR* dir;

int count = 0;

const char* dirname = "/dev/input";

_glfw.linjs.inotify = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);

if (_glfw.linjs.inotify > 0)

{

// HACK: Register for IN_ATTRIB to get notified when udev is done

// This works well in practice but the true way is libudev

_glfw.linjs.watch = inotify_add_watch(_glfw.linjs.inotify,

dirname,

IN_CREATE | IN_ATTRIB | IN_DELETE);

}

// Continue without device connection notifications if inotify fails

if (regcomp(&_glfw.linjs.regex, "^event[0-9]\\+$", 0) != 0)

{

_glfwInputError(GLFW_PLATFORM_ERROR, "Linux: Failed to compile regex");

return GLFW_FALSE;

}

dir = opendir(dirname);

if (dir)

{

struct dirent* entry;

while ((entry = readdir(dir)))

{

regmatch_t match;

if (regexec(&_glfw.linjs.regex, entry->d_name, 1, &match, 0) != 0)

continue;

char path[PATH_MAX];

snprintf(path, sizeof(path), "%s/%s", dirname, entry->d_name);

if (openJoystickDevice(path))

count++;

}

closedir(dir);

}

// Continue with no joysticks if enumeration fails

qsort(_glfw.joysticks, count, sizeof(_GLFWjoystick), compareJoysticks);

return GLFW_TRUE;

}

// Close all opened joystick handles

//

void _glfwTerminateJoysticksLinux(void)

{

int jid;

for (jid = 0; jid <= GLFW_JOYSTICK_LAST; jid++)

{

_GLFWjoystick* js = _glfw.joysticks + jid;

if (js->present)

closeJoystick(js);

}

regfree(&_glfw.linjs.regex);

if (_glfw.linjs.inotify > 0)

{

if (_glfw.linjs.watch > 0)

inotify_rm_watch(_glfw.linjs.inotify, _glfw.linjs.watch);

close(_glfw.linjs.inotify);

}

}

void _glfwDetectJoystickConnectionLinux(void)

{

ssize_t offset = 0;

char buffer[16384];

if (_glfw.linjs.inotify <= 0)

return;

const ssize_t size = read(_glfw.linjs.inotify, buffer, sizeof(buffer));

while (size > offset)

{

regmatch_t match;

const struct inotify_event* e = (struct inotify_event*) (buffer + offset);

offset += sizeof(struct inotify_event) + e->len;

if (regexec(&_glfw.linjs.regex, e->name, 1, &match, 0) != 0)

continue;

char path[PATH_MAX];

snprintf(path, sizeof(path), "/dev/input/%s", e->name);

if (e->mask & (IN_CREATE | IN_ATTRIB))

openJoystickDevice(path);

else if (e->mask & IN_DELETE)

{

int jid;

for (jid = 0; jid <= GLFW_JOYSTICK_LAST; jid++)

{

if (strcmp(_glfw.joysticks[jid].linjs.path, path) == 0)

{

closeJoystick(_glfw.joysticks + jid);

break;

}

}

}

}

}

//////////////////////////////////////////////////////////////////////////

////// GLFW platform API //////

//////////////////////////////////////////////////////////////////////////

int _glfwPlatformPollJoystick(_GLFWjoystick* js, int mode)

{

// Read all queued events (non-blocking)

for (;;)

{

struct input_event e;

errno = 0;

if (read(js->linjs.fd, &e, sizeof(e)) < 0)

{

// Reset the joystick slot if the device was disconnected

if (errno == ENODEV)

closeJoystick(js);

break;

}

if (e.type == EV_SYN)

{

if (e.code == SYN_DROPPED)

_glfw.linjs.dropped = GLFW_TRUE;

else if (e.code == SYN_REPORT)

{

_glfw.linjs.dropped = GLFW_FALSE;

pollAbsState(js);

}

}

if (_glfw.linjs.dropped)

continue;

if (e.type == EV_KEY)

handleKeyEvent(js, e.code, e.value);

else if (e.type == EV_ABS)

handleAbsEvent(js, e.code, e.value);

}

return js->present;

}

void _glfwPlatformUpdateGamepadGUID(char* guid)

{

}