SDL: Added support for the Steam Virtual Gamepad on macOS Sequoia

From d7b1ba1bfca7c9bf4f57075258ccfa0e0c6b2051 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Wed, 16 Oct 2024 10:46:08 -0700
Subject: [PATCH] Added support for the Steam Virtual Gamepad on macOS Sequoia

---
 src/joystick/SDL_joystick.c                |  9 +++++++++
 src/joystick/SDL_joystick_c.h              |  3 +++
 src/joystick/apple/SDL_mfijoystick.m       |  4 ++++
 src/joystick/hidapi/SDL_hidapi_xbox360.c   | 22 +++++++++++++++++++---
 src/joystick/hidapi/SDL_hidapijoystick.c   |  7 +++++++
 src/joystick/hidapi/SDL_hidapijoystick_c.h |  1 +
 6 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/src/joystick/SDL_joystick.c b/src/joystick/SDL_joystick.c
index 43d51fe2dd5af..e595aa8a825e4 100644
--- a/src/joystick/SDL_joystick.c
+++ b/src/joystick/SDL_joystick.c
@@ -3090,6 +3090,15 @@ bool SDL_IsJoystickNVIDIASHIELDController(Uint16 vendor_id, Uint16 product_id)
              product_id == USB_PRODUCT_NVIDIA_SHIELD_CONTROLLER_V104));
 }
 
+bool SDL_IsJoystickSteamVirtualGamepad(Uint16 vendor_id, Uint16 product_id, Uint16 version)
+{
+#ifdef SDL_PLATFORM_MACOS
+    return (vendor_id == USB_VENDOR_MICROSOFT && product_id == USB_PRODUCT_XBOX360_WIRED_CONTROLLER && version == 0);
+#else
+    return (vendor_id == USB_VENDOR_VALVE && product_id == USB_PRODUCT_STEAM_VIRTUAL_GAMEPAD);
+#endif
+}
+
 bool SDL_IsJoystickSteamController(Uint16 vendor_id, Uint16 product_id)
 {
     EControllerType eType = GuessControllerType(vendor_id, product_id);
diff --git a/src/joystick/SDL_joystick_c.h b/src/joystick/SDL_joystick_c.h
index b31dcb18bd4dc..bee3814c2213d 100644
--- a/src/joystick/SDL_joystick_c.h
+++ b/src/joystick/SDL_joystick_c.h
@@ -126,6 +126,9 @@ extern bool SDL_IsJoystickGoogleStadiaController(Uint16 vendor_id, Uint16 produc
 // Function to return whether a joystick is an NVIDIA SHIELD controller
 extern bool SDL_IsJoystickNVIDIASHIELDController(Uint16 vendor_id, Uint16 product_id);
 
+// Function to return whether a joystick is a Steam Virtual Gamepad
+extern bool SDL_IsJoystickSteamVirtualGamepad(Uint16 vendor_id, Uint16 product_id, Uint16 version);
+
 // Function to return whether a joystick is a Steam Controller
 extern bool SDL_IsJoystickSteamController(Uint16 vendor_id, Uint16 product_id);
 
diff --git a/src/joystick/apple/SDL_mfijoystick.m b/src/joystick/apple/SDL_mfijoystick.m
index 6f14991d642c4..bf0b002ea4815 100644
--- a/src/joystick/apple/SDL_mfijoystick.m
+++ b/src/joystick/apple/SDL_mfijoystick.m
@@ -405,6 +405,10 @@ static bool IOS_AddMFIJoystickDevice(SDL_JoystickDeviceItem *device, GCControlle
         return false;
     }
 #endif
+    if (device->is_xbox && SDL_strncmp(name, "GamePad-", 8) == 0) {
+        // This is a Steam Virtual Gamepad, which isn't supported by GCController
+        return false;
+    }
     CheckControllerSiriRemote(controller, &device->is_siri_remote);
 
     if (device->is_siri_remote && !SDL_GetHintBoolean(SDL_HINT_TV_REMOTE_AS_JOYSTICK, true)) {
diff --git a/src/joystick/hidapi/SDL_hidapi_xbox360.c b/src/joystick/hidapi/SDL_hidapi_xbox360.c
index 6d47f0d0662f2..838ed145de02f 100644
--- a/src/joystick/hidapi/SDL_hidapi_xbox360.c
+++ b/src/joystick/hidapi/SDL_hidapi_xbox360.c
@@ -81,9 +81,14 @@ static bool HIDAPI_DriverXbox360_IsSupportedDevice(SDL_HIDAPI_Device *device, co
         return false;
     }
 #if defined(SDL_PLATFORM_MACOS) && defined(SDL_JOYSTICK_MFI)
-    // On macOS you can't write output reports to wired XBox controllers,
-    // so we'll just use the GCController support instead.
-    return false;
+    if (SDL_IsJoystickSteamVirtualGamepad(vendor_id, product_id, version)) {
+        // GCController support doesn't work with the Steam Virtual Gamepad
+        return true;
+    } else {
+        // On macOS you can't write output reports to wired XBox controllers,
+        // so we'll just use the GCController support instead.
+        return false;
+    }
 #else
     return (type == SDL_GAMEPAD_TYPE_XBOX360);
 #endif
@@ -138,6 +143,13 @@ static bool HIDAPI_DriverXbox360_InitDevice(SDL_HIDAPI_Device *device)
 
     device->type = SDL_GAMEPAD_TYPE_XBOX360;
 
+    if (SDL_IsJoystickSteamVirtualGamepad(device->vendor_id, device->product_id, device->version) &&
+        device->product_string && SDL_strncmp(device->product_string, "GamePad-", 8) == 0) {
+        int slot = 0;
+        SDL_sscanf(device->product_string, "GamePad-%d", &slot);
+        device->steam_virtual_gamepad_slot = (slot - 1);
+    }
+
     return HIDAPI_JoystickConnected(device, NULL);
 }
 
@@ -231,7 +243,11 @@ static bool HIDAPI_DriverXbox360_SetJoystickSensorsEnabled(SDL_HIDAPI_Device *de
 static void HIDAPI_DriverXbox360_HandleStatePacket(SDL_Joystick *joystick, SDL_DriverXbox360_Context *ctx, Uint8 *data, int size)
 {
     Sint16 axis;
+#ifdef SDL_PLATFORM_MACOS
+    const bool invert_y_axes = false;
+#else
     const bool invert_y_axes = true;
+#endif
     Uint64 timestamp = SDL_GetTicksNS();
 
     if (ctx->last_state[2] != data[2]) {
diff --git a/src/joystick/hidapi/SDL_hidapijoystick.c b/src/joystick/hidapi/SDL_hidapijoystick.c
index 634d91e7e103c..7399c10f6af2d 100644
--- a/src/joystick/hidapi/SDL_hidapijoystick.c
+++ b/src/joystick/hidapi/SDL_hidapijoystick.c
@@ -983,6 +983,7 @@ static SDL_HIDAPI_Device *HIDAPI_AddDevice(const struct SDL_hid_device_info *inf
     device->guid = SDL_CreateJoystickGUID(bus, device->vendor_id, device->product_id, device->version, device->manufacturer_string, device->product_string, 'h', 0);
     device->joystick_type = SDL_JOYSTICK_TYPE_GAMEPAD;
     device->type = SDL_GetJoystickGameControllerProtocol(device->name, device->vendor_id, device->product_id, device->interface_number, device->interface_class, device->interface_subclass, device->interface_protocol);
+    device->steam_virtual_gamepad_slot = -1;
 
     if (num_children > 0) {
         int i;
@@ -1440,6 +1441,12 @@ static const char *HIDAPI_JoystickGetDevicePath(int device_index)
 
 static int HIDAPI_JoystickGetDeviceSteamVirtualGamepadSlot(int device_index)
 {
+    SDL_HIDAPI_Device *device;
+
+    device = HIDAPI_GetDeviceByIndex(device_index, NULL);
+    if (device) {
+        return device->steam_virtual_gamepad_slot;
+    }
     return -1;
 }
 
diff --git a/src/joystick/hidapi/SDL_hidapijoystick_c.h b/src/joystick/hidapi/SDL_hidapijoystick_c.h
index 8b97f762aec07..5ec0a3931ec33 100644
--- a/src/joystick/hidapi/SDL_hidapijoystick_c.h
+++ b/src/joystick/hidapi/SDL_hidapijoystick_c.h
@@ -85,6 +85,7 @@ typedef struct SDL_HIDAPI_Device
     bool is_bluetooth;
     SDL_JoystickType joystick_type;
     SDL_GamepadType type;
+    int steam_virtual_gamepad_slot;
 
     struct SDL_HIDAPI_DeviceDriver *driver;
     void *context;