Enable joystick support on FreeBSD using the Linux driver.

This is arguably incomplete; it supports joysticks via webcamd (which uses Linux
drivers running in userspace), but not via uhidd (which is FreeBSD's own thing).

Nevertheless a strict improvement.

Tested using a gamepad I have that is supported by the "xpad" Linux driver.

Note: adds build dependency on devel/evdev-proto and devel/libinotify.
To actually use it, need to install multimedia/webcamd at runtime (if not
installed or not running, no joysticks will be detected).

Fixes #1892.

README.md

@@ -88,6 +88,10 @@ in the documentation for more information.
 GLFW itself needs only CMake 3.1 or later and the headers and libraries for your
 OS and window system.
 
+As an exception, on FreeBSD, the `devel/evdev-proto` and `devel/libinotify`
+ports need to be installed; furthermore, to actually use gamepads/joysticks,
+`multimedia/webcamd` needs to be installed and configured.
+
 The examples and test programs depend on a number of tiny libraries.  These are
 located in the `deps/` directory.
 

src/CMakeLists.txt

@@ -49,6 +49,12 @@ endif()
 if (_GLFW_X11 OR _GLFW_WAYLAND)
     if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
         target_sources(glfw PRIVATE linux_joystick.h linux_joystick.c)
+    elseif (CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
+        target_sources(glfw PRIVATE linux_joystick.h linux_joystick.c)
+        pkg_check_modules(LIBINOTIFY REQUIRED libinotify)
+        target_link_libraries(glfw PRIVATE ${LIBINOTIFY_LINK_LIBRARIES})
+        target_include_directories(glfw PRIVATE ${LIBINOTIFY_INCLUDE_DIRS})
+        target_compile_options(glfw PRIVATE ${LIBINOTIFY_CFLAGS_OTHER})
     else()
         target_sources(glfw PRIVATE null_joystick.h null_joystick.c)
     endif()

src/linux_joystick.c

@@ -324,7 +324,7 @@ GLFWbool _glfwPlatformInitJoysticks(void)
 
     // Continue without device connection notifications if inotify fails
 
-    if (regcomp(&_glfw.linjs.regex, "^event[0-9]\\+$", 0) != 0)
+    if (regcomp(&_glfw.linjs.regex, "^event[0-9][0-9]*$", 0) != 0)
     {
         _glfwInputError(GLFW_PLATFORM_ERROR, "Linux: Failed to compile regex");
         return GLFW_FALSE;

src/linux_joystick.h

@@ -25,7 +25,11 @@
 //========================================================================
 
 #include <linux/input.h>
+#ifdef __linux__
 #include <linux/limits.h>
+#else
+#include <limits.h>
+#endif
 #include <regex.h>
 
 #define _GLFW_PLATFORM_JOYSTICK_STATE         _GLFWjoystickLinux linjs

src/wl_platform.h

@@ -47,7 +47,7 @@ typedef VkBool32 (APIENTRY *PFN_vkGetPhysicalDeviceWaylandPresentationSupportKHR
 
 #include "posix_thread.h"
 #include "posix_time.h"
-#ifdef __linux__
+#if defined(__linux__) || defined(__FreeBSD__)
 #include "linux_joystick.h"
 #else
 #include "null_joystick.h"

src/x11_init.c

@@ -1487,7 +1487,7 @@ const char* _glfwPlatformGetVersionString(void)
 #if defined(_POSIX_MONOTONIC_CLOCK)
         " monotonic"
 #endif
-#if defined(__linux__)
+#if defined(__linux__) || defined(__FreeBSD__)
         " evdev"
 #endif
 #if defined(_GLFW_BUILD_DLL)

src/x11_platform.h

@@ -378,7 +378,7 @@ typedef VkBool32 (APIENTRY *PFN_vkGetPhysicalDeviceXcbPresentationSupportKHR)(Vk
 #include "posix_time.h"
 #include "xkb_unicode.h"
 #include "glx_context.h"
-#if defined(__linux__)
+#if defined(__linux__) || defined(__FreeBSD__)
 #include "linux_joystick.h"
 #else
 #include "null_joystick.h"

src/x11_window.c

@@ -67,7 +67,7 @@ static GLFWbool waitForEvent(double* timeout)
     const int fd = ConnectionNumber(_glfw.x11.display);
     int count = fd + 1;
 
-#if defined(__linux__)
+#if defined(__linux__) || defined(__FreeBSD__)
     if (_glfw.linjs.inotify > fd)
         count = _glfw.linjs.inotify + 1;
 #endif
@@ -75,7 +75,7 @@ static GLFWbool waitForEvent(double* timeout)
     {
         FD_ZERO(&fds);
         FD_SET(fd, &fds);
-#if defined(__linux__)
+#if defined(__linux__) || defined(__FreeBSD__)
         if (_glfw.linjs.inotify > 0)
             FD_SET(_glfw.linjs.inotify, &fds);
 #endif
@@ -2779,7 +2779,7 @@ void _glfwPlatformPollEvents(void)
 {
     _GLFWwindow* window;
 
-#if defined(__linux__)
+#if defined(__linux__) || defined(__FreeBSD__)
     if (_glfw.joysticksInitialized)
         _glfwDetectJoystickConnectionLinux();
 #endif