Add DSU joystick driver

CMakeLists.txt

@@ -1245,6 +1245,35 @@ if(SDL_JOYSTICK)
     file(GLOB JOYSTICK_VIRTUAL_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/virtual/*.c)
     list(APPEND SOURCE_FILES ${JOYSTICK_VIRTUAL_SOURCES})
   endif()
+
+  # DSU (DualShock UDP) client support
+  option(SDL_DSU_JOYSTICK "Enable DSU client joystick support" ON)
+  if(SDL_DSU_JOYSTICK)
+    set(SDL_JOYSTICK_DSU 1)
+    file(GLOB JOYSTICK_DSU_SOURCES ${SDL2_SOURCE_DIR}/src/joystick/dsu/*.c)
+    list(APPEND SOURCE_FILES ${JOYSTICK_DSU_SOURCES})
+
+    # DSU requires network libraries on Unix-like systems
+    if(UNIX AND NOT APPLE AND NOT ANDROID)
+      if(NOT WIN32)
+        # Check if we need to link against socket libraries
+        include(CheckFunctionExists)
+        check_function_exists(socket HAVE_SOCKET_IN_LIBC)
+        if(NOT HAVE_SOCKET_IN_LIBC)
+          # Try to find socket in libsocket (Solaris)
+          check_library_exists(socket socket "" HAVE_LIBSOCKET)
+          if(HAVE_LIBSOCKET)
+            list(APPEND EXTRA_LIBS socket)
+          endif()
+          # Try to find inet_addr in libnsl (Solaris)
+          check_library_exists(nsl inet_addr "" HAVE_LIBNSL)
+          if(HAVE_LIBNSL)
+            list(APPEND EXTRA_LIBS nsl)
+          endif()
+        endif()
+      endif()
+    endif()
+  endif()
 endif()
 
 if(SDL_VIDEO)
@@ -1984,6 +2013,10 @@ elseif(WINDOWS)
   # Libraries for Win32 native and MinGW
   if(NOT WINDOWS_STORE)
     list(APPEND EXTRA_LIBS kernel32 user32 gdi32 winmm imm32 ole32 oleaut32 version uuid advapi32 setupapi shell32)
+    # Add Winsock library for DSU support
+    if(SDL_DSU_JOYSTICK)
+      list(APPEND EXTRA_LIBS ws2_32)
+    endif()
   endif()
 
   if(WINDOWS_STORE)
@@ -2468,6 +2501,11 @@ elseif(HAIKU)
 
   CheckPTHREAD()
   list(APPEND EXTRA_LIBS root be media game device textencoding)
+
+  # Add network library for DSU support on Haiku
+  if(SDL_DSU_JOYSTICK)
+    list(APPEND EXTRA_LIBS network)
+  endif()
 
 elseif(RISCOS)
   if(SDL_MISC)

include/SDL_config.h.cmake

@@ -352,6 +352,7 @@
 #cmakedefine SDL_JOYSTICK_RAWINPUT @SDL_JOYSTICK_RAWINPUT@
 #cmakedefine SDL_JOYSTICK_EMSCRIPTEN @SDL_JOYSTICK_EMSCRIPTEN@
 #cmakedefine SDL_JOYSTICK_VIRTUAL @SDL_JOYSTICK_VIRTUAL@
+#cmakedefine SDL_JOYSTICK_DSU @SDL_JOYSTICK_DSU@
 #cmakedefine SDL_JOYSTICK_VITA @SDL_JOYSTICK_VITA@
 #cmakedefine SDL_JOYSTICK_PSP @SDL_JOYSTICK_PSP@
 #cmakedefine SDL_JOYSTICK_PS2 @SDL_JOYSTICK_PS2@

include/SDL_config_windows.h

@@ -261,6 +261,7 @@ typedef unsigned int uintptr_t;
 #define SDL_JOYSTICK_RAWINPUT   1
 #endif
 #define SDL_JOYSTICK_VIRTUAL    1
+#define SDL_JOYSTICK_DSU    1
 #ifdef HAVE_WINDOWS_GAMING_INPUT_H
 #define SDL_JOYSTICK_WGI    1
 #endif

include/SDL_hints.h

@@ -1234,6 +1234,40 @@ extern "C" {
  */
 #define SDL_HINT_JOYSTICK_HIDAPI_XBOX_ONE_HOME_LED "SDL_JOYSTICK_HIDAPI_XBOX_ONE_HOME_LED"
 
+/**
+ * A variable controlling whether the DSU (DualShock UDP) joystick driver should be used.
+ *
+ * This variable can be set to the following values:
+ *
+ * - "0": DSU driver is disabled
+ * - "1": DSU driver is enabled (default)
+ *
+ * The DSU driver allows SDL to connect to DSU servers (DS4Windows, BetterJoy, etc.)
+ * to receive controller data over UDP, including motion sensors and touchpad data.
+ */
+#define SDL_HINT_JOYSTICK_DSU "SDL_JOYSTICK_DSU"
+
+/**
+ * A variable controlling the DSU server address.
+ *
+ * The default value is "127.0.0.1"
+ */
+#define SDL_HINT_DSU_SERVER "SDL_DSU_SERVER"
+
+/**
+ * A variable controlling the DSU server port.
+ *
+ * The default value is "26760"
+ */
+#define SDL_HINT_DSU_SERVER_PORT "SDL_DSU_SERVER_PORT"
+
+/**
+ * A variable controlling the DSU client port.
+ *
+ * The default value is "0" (auto-select)
+ */
+#define SDL_HINT_DSU_CLIENT_PORT "SDL_DSU_CLIENT_PORT"
+
 /**
  * A variable controlling whether IOKit should be used for controller
  * handling.

src/joystick/SDL_joystick.c

@@ -51,6 +51,10 @@
 #include "./virtual/SDL_virtualjoystick_c.h"
 #endif
 
+#ifdef SDL_JOYSTICK_DSU
+#include "./dsu/SDL_dsujoystick_c.h"
+#endif
+
 static SDL_JoystickDriver *SDL_joystick_drivers[] = {
 #ifdef SDL_JOYSTICK_HIDAPI /* Before WINDOWS_ driver, as WINDOWS wants to check if this driver is handling things */
     &SDL_HIDAPI_JoystickDriver,
@@ -100,6 +104,9 @@ static SDL_JoystickDriver *SDL_joystick_drivers[] = {
 #ifdef SDL_JOYSTICK_VIRTUAL
     &SDL_VIRTUAL_JoystickDriver,
 #endif
+#ifdef SDL_JOYSTICK_DSU
+    &SDL_DSU_JoystickDriver,
+#endif
 #ifdef SDL_JOYSTICK_VITA
     &SDL_VITA_JoystickDriver,
 #endif