joystick: Add HIDAPI driver for NVIDIA SHIELD 2017 controller

Basic input already works using the OS HID driver, but this enables
force feedback and battery state reporting.

Makefile.os2

@@ -89,7 +89,7 @@ SRCS+= SDL_systimer.c
 SRCS+= SDL_sysloadso.c
 SRCS+= SDL_sysfilesystem.c
 SRCS+= SDL_os2joystick.c SDL_syshaptic.c SDL_sysjoystick.c SDL_virtualjoystick.c
-SRCS+= SDL_hidapijoystick.c SDL_hidapi_rumble.c SDL_hidapi_gamecube.c SDL_hidapi_luna.c SDL_hidapi_ps4.c SDL_hidapi_ps5.c SDL_hidapi_stadia.c SDL_hidapi_switch.c SDL_hidapi_xbox360.c SDL_hidapi_xbox360w.c SDL_hidapi_xboxone.c SDL_hidapi_steam.c
+SRCS+= SDL_hidapijoystick.c SDL_hidapi_rumble.c SDL_hidapi_gamecube.c SDL_hidapi_luna.c SDL_hidapi_ps4.c SDL_hidapi_ps5.c SDL_hidapi_shield.c SDL_hidapi_stadia.c SDL_hidapi_switch.c SDL_hidapi_xbox360.c SDL_hidapi_xbox360w.c SDL_hidapi_xboxone.c SDL_hidapi_steam.c
 SRCS+= SDL_dummyaudio.c SDL_diskaudio.c
 SRCS+= SDL_nullvideo.c SDL_nullframebuffer.c SDL_nullevents.c
 SRCS+= SDL_dummysensor.c

Makefile.w32

@@ -65,7 +65,7 @@ SRCS+= SDL_systimer.c
 SRCS+= SDL_sysloadso.c
 SRCS+= SDL_sysfilesystem.c
 SRCS+= SDL_syshaptic.c SDL_sysjoystick.c SDL_virtualjoystick.c
-SRCS+= SDL_hidapijoystick.c SDL_hidapi_rumble.c SDL_hidapi_gamecube.c SDL_hidapi_luna.c SDL_hidapi_ps4.c SDL_hidapi_ps5.c SDL_hidapi_stadia.c SDL_hidapi_switch.c SDL_hidapi_xbox360.c SDL_hidapi_xbox360w.c SDL_hidapi_xboxone.c SDL_hidapi_steam.c
+SRCS+= SDL_hidapijoystick.c SDL_hidapi_rumble.c SDL_hidapi_gamecube.c SDL_hidapi_luna.c SDL_hidapi_ps4.c SDL_hidapi_ps5.c SDL_hidapi_shield.c SDL_hidapi_stadia.c SDL_hidapi_switch.c SDL_hidapi_xbox360.c SDL_hidapi_xbox360w.c SDL_hidapi_xboxone.c SDL_hidapi_steam.c
 SRCS+= SDL_dummyaudio.c SDL_diskaudio.c
 SRCS+= SDL_nullvideo.c SDL_nullframebuffer.c SDL_nullevents.c
 SRCS+= SDL_dummysensor.c

VisualC-GDK/SDL/SDL.vcxproj

@@ -595,6 +595,7 @@
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_ps4.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_ps5.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_rumble.c" />
+    <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_shield.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_stadia.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_switch.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_xbox360.c" />

VisualC-GDK/SDL/SDL.vcxproj.filters

@@ -1065,6 +1065,9 @@
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_rumble.c">
       <Filter>joystick\hidapi</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_shield.c">
+      <Filter>joystick\hidapi</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_stadia.c">
       <Filter>joystick\hidapi</Filter>
     </ClCompile>

VisualC/SDL/SDL.vcxproj

@@ -486,6 +486,7 @@
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_ps4.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_ps5.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_rumble.c" />
+    <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_shield.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_stadia.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_switch.c" />
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_xbox360.c" />

VisualC/SDL/SDL.vcxproj.filters

@@ -1058,6 +1058,9 @@
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_rumble.c">
       <Filter>joystick\hidapi</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_shield.c">
+      <Filter>joystick\hidapi</Filter>
+    </ClCompile>
     <ClCompile Include="..\..\src\joystick\hidapi\SDL_hidapi_stadia.c">
       <Filter>joystick\hidapi</Filter>
     </ClCompile>

Xcode/SDL/SDL.xcodeproj/project.pbxproj

@@ -93,6 +93,15 @@
 		75E09169241EA924004729E1 /* SDL_virtualjoystick_c.h in Headers */ = {isa = PBXBuildFile; fileRef = 75E09159241EA924004729E1 /* SDL_virtualjoystick_c.h */; };
 		75E0916A241EA924004729E1 /* SDL_virtualjoystick_c.h in Headers */ = {isa = PBXBuildFile; fileRef = 75E09159241EA924004729E1 /* SDL_virtualjoystick_c.h */; };
 		75E0916B241EA924004729E1 /* SDL_virtualjoystick_c.h in Headers */ = {isa = PBXBuildFile; fileRef = 75E09159241EA924004729E1 /* SDL_virtualjoystick_c.h */; };
+		9846B07C287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
+		9846B07D287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
+		9846B07E287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
+		9846B07F287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
+		9846B080287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
+		9846B081287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
+		9846B082287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
+		9846B083287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
+		9846B084287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */ = {isa = PBXBuildFile; fileRef = 9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */; };
 		A1626A3E2617006A003F1973 /* SDL_triangle.c in Sources */ = {isa = PBXBuildFile; fileRef = A1626A3D2617006A003F1973 /* SDL_triangle.c */; };
 		A1626A3F2617006A003F1973 /* SDL_triangle.c in Sources */ = {isa = PBXBuildFile; fileRef = A1626A3D2617006A003F1973 /* SDL_triangle.c */; };
 		A1626A402617006A003F1973 /* SDL_triangle.c in Sources */ = {isa = PBXBuildFile; fileRef = A1626A3D2617006A003F1973 /* SDL_triangle.c */; };
@@ -3629,6 +3638,7 @@
 		5C2EF7001FC9EF0F003F5197 /* SDL_egl.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDL_egl.h; sourceTree = "<group>"; };
 		75E09158241EA924004729E1 /* SDL_virtualjoystick.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = SDL_virtualjoystick.c; sourceTree = "<group>"; };
 		75E09159241EA924004729E1 /* SDL_virtualjoystick_c.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDL_virtualjoystick_c.h; sourceTree = "<group>"; };
+		9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = SDL_hidapi_shield.c; sourceTree = "<group>"; };
 		A1626A3D2617006A003F1973 /* SDL_triangle.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = SDL_triangle.c; sourceTree = "<group>"; };
 		A1626A512617008C003F1973 /* SDL_triangle.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SDL_triangle.h; sourceTree = "<group>"; };
 		A1BB8B6127F6CF320057CFA8 /* SDL_list.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = SDL_list.c; sourceTree = "<group>"; };
@@ -4902,6 +4912,7 @@
 		A7D8A7BE23E2513E00DCD162 /* hidapi */ = {
 			isa = PBXGroup;
 			children = (
+				9846B07B287A9020000C35C8 /* SDL_hidapi_shield.c */,
 				A7D8A7C923E2513E00DCD162 /* SDL_hidapi_gamecube.c */,
 				F3F07D59269640160074468B /* SDL_hidapi_luna.c */,
 				A7D8A7C323E2513E00DCD162 /* SDL_hidapi_ps4.c */,
@@ -7631,6 +7642,7 @@
 				A75FCE3B23E25AB700529352 /* SDL_wave.c in Sources */,
 				A75FCE3C23E25AB700529352 /* s_tan.c in Sources */,
 				A75FCE3D23E25AB700529352 /* SDL_hints.c in Sources */,
+				9846B083287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A75FCE3E23E25AB700529352 /* SDL_hidapi_ps4.c in Sources */,
 				A75FCE3F23E25AB700529352 /* SDL_pixels.c in Sources */,
 				A75FCE4123E25AB700529352 /* SDL_sysloadso.c in Sources */,
@@ -7823,6 +7835,7 @@
 				A75FCFF423E25AC700529352 /* SDL_wave.c in Sources */,
 				A75FCFF523E25AC700529352 /* s_tan.c in Sources */,
 				A75FCFF623E25AC700529352 /* SDL_hints.c in Sources */,
+				9846B084287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A75FCFF723E25AC700529352 /* SDL_hidapi_ps4.c in Sources */,
 				A75FCFF823E25AC700529352 /* SDL_pixels.c in Sources */,
 				A75FCFFA23E25AC700529352 /* SDL_sysloadso.c in Sources */,
@@ -8001,6 +8014,7 @@
 				A769B1BE23E259AE00872273 /* SDL_error.c in Sources */,
 				A769B1BF23E259AE00872273 /* SDL_blit.c in Sources */,
 				A769B1C023E259AE00872273 /* SDL_rwops.c in Sources */,
+				9846B081287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A769B1C123E259AE00872273 /* SDL_uikitviewcontroller.m in Sources */,
 				A769B1C223E259AE00872273 /* s_cos.c in Sources */,
 				A769B1C323E259AE00872273 /* SDL_steamcontroller.c in Sources */,
@@ -8208,6 +8222,7 @@
 				A7D8B54023E2514300DCD162 /* SDL_hidapi_ps4.c in Sources */,
 				A7D8AD6F23E2514100DCD162 /* SDL_pixels.c in Sources */,
 				5616CA52252BB35A005D5928 /* SDL_url.c in Sources */,
+				9846B07D287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A7D8B75F23E2514300DCD162 /* SDL_sysloadso.c in Sources */,
 				A7D8B5F423E2514300DCD162 /* SDL_syspower.c in Sources */,
 				A7D8B95123E2514400DCD162 /* SDL_iconv.c in Sources */,
@@ -8400,6 +8415,7 @@
 				A7D8B54123E2514300DCD162 /* SDL_hidapi_ps4.c in Sources */,
 				A7D8AD7023E2514100DCD162 /* SDL_pixels.c in Sources */,
 				5616CA55252BB35B005D5928 /* SDL_url.c in Sources */,
+				9846B07E287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A7D8B76023E2514300DCD162 /* SDL_sysloadso.c in Sources */,
 				A7D8B5F523E2514300DCD162 /* SDL_syspower.c in Sources */,
 				A7D8B95223E2514400DCD162 /* SDL_iconv.c in Sources */,
@@ -8578,6 +8594,7 @@
 				A7D8B8E823E2514400DCD162 /* SDL_error.c in Sources */,
 				A7D8AD6C23E2514100DCD162 /* SDL_blit.c in Sources */,
 				A7D8B5C123E2514300DCD162 /* SDL_rwops.c in Sources */,
+				9846B080287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A7D8ACD323E2514100DCD162 /* SDL_uikitviewcontroller.m in Sources */,
 				A7D8BA9523E2514400DCD162 /* s_cos.c in Sources */,
 				A7D8B4D423E2514300DCD162 /* SDL_steamcontroller.c in Sources */,
@@ -8699,6 +8716,7 @@
 				A7D8B62F23E2514300DCD162 /* SDL_sysfilesystem.m in Sources */,
 				A7D8BAC723E2514500DCD162 /* e_pow.c in Sources */,
 				A7D8B41C23E2514300DCD162 /* SDL_systls.c in Sources */,
+				9846B07C287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A7D8BBD923E2574800DCD162 /* SDL_uikitmessagebox.m in Sources */,
 				A7D8AD2923E2514100DCD162 /* SDL_vulkan_utils.c in Sources */,
 				A7D8A95123E2514000DCD162 /* SDL_spinlock.c in Sources */,
@@ -8889,6 +8907,7 @@
 				A7D8AE7F23E2514100DCD162 /* SDL_yuv.c in Sources */,
 				A7D8B63223E2514300DCD162 /* SDL_sysfilesystem.m in Sources */,
 				A7D8BACA23E2514500DCD162 /* e_pow.c in Sources */,
+				9846B07F287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A7D8B41F23E2514300DCD162 /* SDL_systls.c in Sources */,
 				A7D8AD2C23E2514100DCD162 /* SDL_vulkan_utils.c in Sources */,
 				A7D8A95423E2514000DCD162 /* SDL_spinlock.c in Sources */,
@@ -9079,6 +9098,7 @@
 				A7D8B63423E2514300DCD162 /* SDL_sysfilesystem.m in Sources */,
 				A7D8BACC23E2514500DCD162 /* e_pow.c in Sources */,
 				A7D8B42123E2514300DCD162 /* SDL_systls.c in Sources */,
+				9846B082287A9020000C35C8 /* SDL_hidapi_shield.c in Sources */,
 				A7D8AD2E23E2514100DCD162 /* SDL_vulkan_utils.c in Sources */,
 				A7D8A95623E2514000DCD162 /* SDL_spinlock.c in Sources */,
 				A7D8BAB423E2514400DCD162 /* s_atan.c in Sources */,

include/SDL_gamecontroller.h

@@ -69,7 +69,8 @@ typedef enum
     SDL_CONTROLLER_TYPE_VIRTUAL,
     SDL_CONTROLLER_TYPE_PS5,
     SDL_CONTROLLER_TYPE_AMAZON_LUNA,
-    SDL_CONTROLLER_TYPE_GOOGLE_STADIA
+    SDL_CONTROLLER_TYPE_GOOGLE_STADIA,
+    SDL_CONTROLLER_TYPE_NVIDIA_SHIELD
 } SDL_GameControllerType;
 
 typedef enum

include/SDL_hints.h

@@ -674,6 +674,17 @@ extern "C" {
   */
 #define SDL_HINT_JOYSTICK_HIDAPI_LUNA "SDL_JOYSTICK_HIDAPI_LUNA"
 
+/**
+  *  \brief  A variable controlling whether the HIDAPI driver for NVIDIA SHIELD controllers should be used.
+  *
+  *  This variable can be set to the following values:
+  *    "0"       - HIDAPI driver is not used
+  *    "1"       - HIDAPI driver is used
+  *
+  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
+  */
+#define SDL_HINT_JOYSTICK_HIDAPI_SHIELD "SDL_JOYSTICK_HIDAPI_SHIELD"
+
 /**
  *  \brief  A variable controlling whether the HIDAPI driver for PS4 controllers should be used.
  *

src/joystick/SDL_gamecontroller.c

@@ -634,6 +634,10 @@ static ControllerMapping_t *SDL_CreateMappingForHIDAPIController(SDL_JoystickGUI
                 /* The Google Stadia controller has a share button and a Google Assistant button */
                 SDL_strlcat(mapping_string, "misc1:b15,", sizeof(mapping_string));
                 break;
+            case SDL_CONTROLLER_TYPE_NVIDIA_SHIELD:
+                /* The NVIDIA SHIELD controller has a home button between back and start buttons */
+                SDL_strlcat(mapping_string, "misc1:b15,", sizeof(mapping_string));
+                break;
             default:
                 if (vendor == 0 && product == 0) {
                     /* This is a Bluetooth Nintendo Switch Pro controller */

src/joystick/SDL_joystick.c

@@ -1957,6 +1957,9 @@ SDL_GetJoystickGameControllerTypeFromVIDPID(Uint16 vendor, Uint16 product, const
     } else if (vendor == USB_VENDOR_GOOGLE && product == USB_PRODUCT_GOOGLE_STADIA_CONTROLLER) {
         type = SDL_CONTROLLER_TYPE_GOOGLE_STADIA;
 
+    } else if (vendor == USB_VENDOR_NVIDIA && product == USB_PRODUCT_NVIDIA_SHIELD_CONTROLLER) {
+        type = SDL_CONTROLLER_TYPE_NVIDIA_SHIELD;
+
     } else if (vendor == USB_VENDOR_NINTENDO && product == USB_PRODUCT_NINTENDO_SWITCH_JOY_CON_GRIP) {
             type = SDL_GetHintBoolean(SDL_HINT_JOYSTICK_HIDAPI_JOY_CONS, SDL_FALSE) ? SDL_CONTROLLER_TYPE_NINTENDO_SWITCH_PRO : SDL_CONTROLLER_TYPE_UNKNOWN;
 

src/joystick/hidapi/SDL_hidapi_shield.c

@@ -0,0 +1,443 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.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 "../../SDL_internal.h"
+
+#ifdef SDL_JOYSTICK_HIDAPI
+
+#include "SDL_hints.h"
+#include "SDL_events.h"
+#include "SDL_timer.h"
+#include "SDL_joystick.h"
+#include "SDL_gamecontroller.h"
+#include "../SDL_sysjoystick.h"
+#include "SDL_hidapijoystick_c.h"
+#include "SDL_hidapi_rumble.h"
+
+
+#ifdef SDL_JOYSTICK_HIDAPI_SHIELD
+
+/* Define this if you want to log all packets from the controller */
+/*#define DEBUG_SHIELD_PROTOCOL*/
+
+#define CMD_BATTERY_STATE 0x07
+#define CMD_RUMBLE 0x39
+#define CMD_CHARGE_STATE 0x3A
+
+/* Milliseconds between polls of battery state */
+#define BATTERY_POLL_INTERVAL_MS 60000
+
+/* Milliseconds between retransmission of rumble to keep motors running */
+#define RUMBLE_REFRESH_INTERVAL_MS 500
+
+/* Reports that are too small are dropped over Bluetooth */
+#define HID_REPORT_SIZE 33
+
+enum
+{
+    SDL_CONTROLLER_BUTTON_SHIELD_HOME = 15,
+    SDL_CONTROLLER_NUM_SHIELD_BUTTONS,
+};
+
+typedef struct {
+    Uint8 seq_num;
+
+    SDL_JoystickPowerLevel battery_level;
+    SDL_bool charging;
+    Uint32 last_battery_query_time;
+
+    SDL_bool rumble_report_pending;
+    SDL_bool rumble_update_pending;
+    Uint8 left_motor_amplitude;
+    Uint8 right_motor_amplitude;
+    Uint32 last_rumble_time;
+
+    Uint8 last_state[USB_PACKET_LENGTH];
+} SDL_DriverShield_Context;
+
+
+static SDL_bool
+HIDAPI_DriverShield_IsSupportedDevice(const char *name, SDL_GameControllerType type, Uint16 vendor_id, Uint16 product_id, Uint16 version, int interface_number, int interface_class, int interface_subclass, int interface_protocol)
+{
+    return (type == SDL_CONTROLLER_TYPE_NVIDIA_SHIELD) ? SDL_TRUE : SDL_FALSE;
+}
+
+static const char *
+HIDAPI_DriverShield_GetDeviceName(const char *name, Uint16 vendor_id, Uint16 product_id)
+{
+    return "NVIDIA SHIELD Controller";
+}
+
+static SDL_bool
+HIDAPI_DriverShield_InitDevice(SDL_HIDAPI_Device *device)
+{
+    return HIDAPI_JoystickConnected(device, NULL);
+}
+
+static int
+HIDAPI_DriverShield_GetDevicePlayerIndex(SDL_HIDAPI_Device *device, SDL_JoystickID instance_id)
+{
+    return -1;
+}
+
+static void
+HIDAPI_DriverShield_SetDevicePlayerIndex(SDL_HIDAPI_Device *device, SDL_JoystickID instance_id, int player_index)
+{
+}
+
+static int
+HIDAPI_DriverShield_SendCommand(SDL_HIDAPI_Device *device, Uint8 cmd, Uint8* data, int size)
+{
+    SDL_DriverShield_Context *ctx = device->context;
+    Uint8 cmd_pkt[HID_REPORT_SIZE];
+
+    if (size >= sizeof(cmd_pkt) - 3) {
+        return SDL_SetError("Invalid command data");
+    }
+
+    if (SDL_HIDAPI_LockRumble() < 0) {
+        return -1;
+    }
+
+    cmd_pkt[0] = 0x04;
+    cmd_pkt[1] = cmd;
+    cmd_pkt[2] = ctx->seq_num++;
+    if (data) {
+        SDL_memcpy(&cmd_pkt[3], data, size);
+    }
+
+    if (SDL_HIDAPI_SendRumbleAndUnlock(device, cmd_pkt, sizeof(cmd_pkt)) != sizeof(cmd_pkt)) {
+        return SDL_SetError("Couldn't send command packet");
+    }
+
+    return 0;
+}
+
+static SDL_bool
+HIDAPI_DriverShield_OpenJoystick(SDL_HIDAPI_Device *device, SDL_Joystick *joystick)
+{
+    SDL_DriverShield_Context *ctx;
+
+    ctx = (SDL_DriverShield_Context *)SDL_calloc(1, sizeof(*ctx));
+    if (!ctx) {
+        SDL_OutOfMemory();
+        return SDL_FALSE;
+    }
+
+    device->dev = SDL_hid_open_path(device->path, 0);
+    if (!device->dev) {
+        SDL_SetError("Couldn't open %s", device->path);
+        SDL_free(ctx);
+        return SDL_FALSE;
+    }
+    device->context = ctx;
+
+    /* Initialize the joystick capabilities */
+    joystick->nbuttons = SDL_CONTROLLER_NUM_SHIELD_BUTTONS;
+    joystick->naxes = SDL_CONTROLLER_AXIS_MAX;
+    joystick->epowerlevel = SDL_JOYSTICK_POWER_UNKNOWN;
+
+    /* Request battery and charging info */
+    ctx->last_battery_query_time = SDL_GetTicks();
+    HIDAPI_DriverShield_SendCommand(device, CMD_CHARGE_STATE, NULL, 0);
+    HIDAPI_DriverShield_SendCommand(device, CMD_BATTERY_STATE, NULL, 0);
+
+    return SDL_TRUE;
+}
+
+static int
+HIDAPI_DriverShield_SendNextRumble(SDL_HIDAPI_Device *device)
+{
+    SDL_DriverShield_Context *ctx = device->context;
+    Uint8 rumble_data[3];
+
+    if (!ctx->rumble_update_pending) {
+        return 0;
+    }
+
+    rumble_data[0] = 0x01; /* enable */
+    rumble_data[1] = ctx->left_motor_amplitude;
+    rumble_data[2] = ctx->right_motor_amplitude;
+
+    ctx->rumble_update_pending = SDL_FALSE;
+    ctx->last_rumble_time = SDL_GetTicks();
+
+    return HIDAPI_DriverShield_SendCommand(device, CMD_RUMBLE, rumble_data, sizeof(rumble_data));
+}
+
+static int
+HIDAPI_DriverShield_RumbleJoystick(SDL_HIDAPI_Device *device, SDL_Joystick *joystick, Uint16 low_frequency_rumble, Uint16 high_frequency_rumble)
+{
+    SDL_DriverShield_Context *ctx = device->context;
+
+    /* The rumble motors are quite intense, so tone down the intensity like the official driver does */
+    ctx->left_motor_amplitude = low_frequency_rumble >> 11;
+    ctx->right_motor_amplitude = high_frequency_rumble >> 11;
+    ctx->rumble_update_pending = SDL_TRUE;
+
+    if (ctx->rumble_report_pending) {
+        /* We will service this after the hardware acknowledges the previous request */
+        return 0;
+    }
+
+    return HIDAPI_DriverShield_SendNextRumble(device);
+}
+
+static int
+HIDAPI_DriverShield_RumbleJoystickTriggers(SDL_HIDAPI_Device *device, SDL_Joystick *joystick, Uint16 left_rumble, Uint16 right_rumble)
+{
+    return SDL_Unsupported();
+}
+
+static Uint32
+HIDAPI_DriverShield_GetJoystickCapabilities(SDL_HIDAPI_Device *device, SDL_Joystick *joystick)
+{
+    return SDL_JOYCAP_RUMBLE;
+}
+
+static int
+HIDAPI_DriverShield_SetJoystickLED(SDL_HIDAPI_Device *device, SDL_Joystick *joystick, Uint8 red, Uint8 green, Uint8 blue)
+{
+    return SDL_Unsupported();
+}
+
+static int
+HIDAPI_DriverShield_SendJoystickEffect(SDL_HIDAPI_Device *device, SDL_Joystick *joystick, const void *data, int size)
+{
+    return SDL_Unsupported();
+}
+
+static int
+HIDAPI_DriverShield_SetJoystickSensorsEnabled(SDL_HIDAPI_Device *device, SDL_Joystick *joystick, SDL_bool enabled)
+{
+    return SDL_Unsupported();
+}
+
+static void
+HIDAPI_DriverShield_HandleStatePacket(SDL_Joystick *joystick, SDL_DriverShield_Context *ctx, Uint8 *data, int size)
+{
+    if (size < 23) {
+        return;
+    }
+
+    if (ctx->last_state[2] != data[2]) {
+        SDL_bool dpad_up = SDL_FALSE;
+        SDL_bool dpad_down = SDL_FALSE;
+        SDL_bool dpad_left = SDL_FALSE;
+        SDL_bool dpad_right = SDL_FALSE;
+
+        switch (data[2]) {
+        case 0:
+            dpad_up = SDL_TRUE;
+            break;
+        case 1:
+            dpad_up = SDL_TRUE;
+            dpad_right = SDL_TRUE;
+            break;
+        case 2:
+            dpad_right = SDL_TRUE;
+            break;
+        case 3:
+            dpad_right = SDL_TRUE;
+            dpad_down = SDL_TRUE;
+            break;
+        case 4:
+            dpad_down = SDL_TRUE;
+            break;
+        case 5:
+            dpad_left = SDL_TRUE;
+            dpad_down = SDL_TRUE;
+            break;
+        case 6:
+            dpad_left = SDL_TRUE;
+            break;
+        case 7:
+            dpad_up = SDL_TRUE;
+            dpad_left = SDL_TRUE;
+            break;
+        default:
+            break;
+        }
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_DPAD_DOWN, dpad_down);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_DPAD_UP, dpad_up);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_DPAD_RIGHT, dpad_right);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_DPAD_LEFT, dpad_left);
+    }
+
+    if (ctx->last_state[3] != data[3]) {
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_A, (data[3] & 0x01) ? SDL_PRESSED : SDL_RELEASED);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_B, (data[3] & 0x02) ? SDL_PRESSED : SDL_RELEASED);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_X, (data[3] & 0x04) ? SDL_PRESSED : SDL_RELEASED);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_Y, (data[3] & 0x08) ? SDL_PRESSED : SDL_RELEASED);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_LEFTSHOULDER, (data[3] & 0x10) ? SDL_PRESSED : SDL_RELEASED);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_RIGHTSHOULDER, (data[3] & 0x20) ? SDL_PRESSED : SDL_RELEASED);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_LEFTSTICK, (data[3] & 0x40) ? SDL_PRESSED : SDL_RELEASED);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_RIGHTSTICK, (data[3] & 0x80) ? SDL_PRESSED : SDL_RELEASED);
+    }
+
+    if (ctx->last_state[4] != data[4]) {
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_START, (data[4] & 0x01) ? SDL_PRESSED : SDL_RELEASED);
+    }
+
+    SDL_PrivateJoystickAxis(joystick, SDL_CONTROLLER_AXIS_LEFTX, SDL_SwapLE16(*(Sint16*)&data[9]) - 0x8000);
+    SDL_PrivateJoystickAxis(joystick, SDL_CONTROLLER_AXIS_LEFTY, SDL_SwapLE16(*(Sint16*)&data[11]) - 0x8000);
+
+    SDL_PrivateJoystickAxis(joystick, SDL_CONTROLLER_AXIS_RIGHTX, SDL_SwapLE16(*(Sint16*)&data[13]) - 0x8000);
+    SDL_PrivateJoystickAxis(joystick, SDL_CONTROLLER_AXIS_RIGHTY, SDL_SwapLE16(*(Sint16*)&data[15]) - 0x8000);
+
+    SDL_PrivateJoystickAxis(joystick, SDL_CONTROLLER_AXIS_TRIGGERLEFT, SDL_SwapLE16(*(Sint16*)&data[19]) - 0x8000);
+    SDL_PrivateJoystickAxis(joystick, SDL_CONTROLLER_AXIS_TRIGGERRIGHT, SDL_SwapLE16(*(Sint16*)&data[21]) - 0x8000);
+
+    if (ctx->last_state[17] != data[17]) {
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_SHIELD_HOME, (data[17] & 0x01) ? SDL_PRESSED : SDL_RELEASED);
+        SDL_PrivateJoystickButton(joystick, SDL_CONTROLLER_BUTTON_BACK, (data[17] & 0x02) ? SDL_PRESSED : SDL_RELEASED);
+    }
+
+    SDL_memcpy(ctx->last_state, data, SDL_min(size, sizeof(ctx->last_state)));
+}
+
+static SDL_bool
+HIDAPI_DriverShield_UpdateDevice(SDL_HIDAPI_Device *device)
+{
+    SDL_DriverShield_Context *ctx = (SDL_DriverShield_Context *)device->context;
+    SDL_Joystick *joystick = NULL;
+    Uint8 data[USB_PACKET_LENGTH];
+    int size = 0;
+
+    if (device->num_joysticks > 0) {
+        joystick = SDL_JoystickFromInstanceID(device->joysticks[0]);
+    }
+    if (!joystick) {
+        return SDL_FALSE;
+    }
+
+    while ((size = SDL_hid_read_timeout(device->dev, data, sizeof(data), 0)) > 0) {
+#ifdef DEBUG_SHIELD_PROTOCOL
+        HIDAPI_DumpPacket("NVIDIA SHIELD packet: size = %d", data, size);
+#endif
+        switch (data[0]) {
+            case 0x01:
+                HIDAPI_DriverShield_HandleStatePacket(joystick, ctx, data, size);
+                break;
+            case 0x03:
+                switch (data[1]) {
+                    case CMD_RUMBLE:
+                        ctx->rumble_report_pending = SDL_FALSE;
+                        HIDAPI_DriverShield_SendNextRumble(device);
+                        break;
+                    case CMD_CHARGE_STATE:
+                        ctx->charging = data[2] != 0;
+                        SDL_PrivateJoystickBatteryLevel(joystick, ctx->charging ? SDL_JOYSTICK_POWER_WIRED : ctx->battery_level);
+                        break;
+                    case CMD_BATTERY_STATE:
+                        switch (data[5]) {
+                            case 0:
+                                ctx->battery_level = SDL_JOYSTICK_POWER_EMPTY;
+                                break;
+                            case 1:
+                                ctx->battery_level = SDL_JOYSTICK_POWER_LOW;
+                                break;
+                            case 2: /* 40% */
+                            case 3: /* 60% */
+                            case 4: /* 80% */
+                                ctx->battery_level = SDL_JOYSTICK_POWER_MEDIUM;
+                                break;
+                            case 5:
+                                ctx->battery_level = SDL_JOYSTICK_POWER_FULL;
+                                break;
+                            default:
+                                ctx->battery_level = SDL_JOYSTICK_POWER_UNKNOWN;
+                                break;
+                        }
+                        SDL_PrivateJoystickBatteryLevel(joystick, ctx->charging ? SDL_JOYSTICK_POWER_WIRED : ctx->battery_level);
+                        break;
+                }
+                break;
+        }
+    }
+
+    /* Ask for battery state again if we're due for an update */
+    if (SDL_TICKS_PASSED(SDL_GetTicks(), ctx->last_battery_query_time + BATTERY_POLL_INTERVAL_MS)) {
+        ctx->last_battery_query_time = SDL_GetTicks();
+        HIDAPI_DriverShield_SendCommand(device, CMD_BATTERY_STATE, NULL, 0);
+    }
+
+    /* Retransmit rumble packets if they've lasted longer than the hardware supports */
+    if ((ctx->left_motor_amplitude != 0 || ctx->right_motor_amplitude != 0) &&
+        SDL_TICKS_PASSED(SDL_GetTicks(), ctx->last_rumble_time + RUMBLE_REFRESH_INTERVAL_MS)) {
+        ctx->rumble_update_pending = SDL_TRUE;
+        HIDAPI_DriverShield_SendNextRumble(device);
+    }
+
+    if (size < 0) {
+        /* Read error, device is disconnected */
+        HIDAPI_JoystickDisconnected(device, joystick->instance_id);
+    }
+    return (size >= 0);
+}
+
+static void
+HIDAPI_DriverShield_CloseJoystick(SDL_HIDAPI_Device *device, SDL_Joystick *joystick)
+{
+    SDL_LockMutex(device->dev_lock);
+    {
+        if (device->dev) {
+            SDL_hid_close(device->dev);
+            device->dev = NULL;
+        }
+
+        SDL_free(device->context);
+        device->context = NULL;
+    }
+    SDL_UnlockMutex(device->dev_lock);
+}
+
+static void
+HIDAPI_DriverShield_FreeDevice(SDL_HIDAPI_Device *device)
+{
+}
+
+SDL_HIDAPI_DeviceDriver SDL_HIDAPI_DriverShield =
+{
+    SDL_HINT_JOYSTICK_HIDAPI_SHIELD,
+    SDL_TRUE,
+    SDL_TRUE,
+    HIDAPI_DriverShield_IsSupportedDevice,
+    HIDAPI_DriverShield_GetDeviceName,
+    HIDAPI_DriverShield_InitDevice,
+    HIDAPI_DriverShield_GetDevicePlayerIndex,
+    HIDAPI_DriverShield_SetDevicePlayerIndex,
+    HIDAPI_DriverShield_UpdateDevice,
+    HIDAPI_DriverShield_OpenJoystick,
+    HIDAPI_DriverShield_RumbleJoystick,
+    HIDAPI_DriverShield_RumbleJoystickTriggers,
+    HIDAPI_DriverShield_GetJoystickCapabilities,
+    HIDAPI_DriverShield_SetJoystickLED,
+    HIDAPI_DriverShield_SendJoystickEffect,
+    HIDAPI_DriverShield_SetJoystickSensorsEnabled,
+    HIDAPI_DriverShield_CloseJoystick,
+    HIDAPI_DriverShield_FreeDevice,
+};
+
+#endif /* SDL_JOYSTICK_HIDAPI_SHIELD */
+
+#endif /* SDL_JOYSTICK_HIDAPI */
+
+/* vi: set ts=4 sw=4 expandtab: */

src/joystick/hidapi/SDL_hidapijoystick.c

@@ -49,6 +49,9 @@ static SDL_HIDAPI_DeviceDriver *SDL_HIDAPI_drivers[] = {
 #ifdef SDL_JOYSTICK_HIDAPI_LUNA
     &SDL_HIDAPI_DriverLuna,
 #endif
+#ifdef SDL_JOYSTICK_HIDAPI_SHIELD
+    &SDL_HIDAPI_DriverShield,
+#endif
 #ifdef SDL_JOYSTICK_HIDAPI_PS4
     &SDL_HIDAPI_DriverPS4,
 #endif

src/joystick/hidapi/SDL_hidapijoystick_c.h

@@ -39,6 +39,7 @@
 #define SDL_JOYSTICK_HIDAPI_SWITCH
 #define SDL_JOYSTICK_HIDAPI_XBOX360
 #define SDL_JOYSTICK_HIDAPI_XBOXONE
+#define SDL_JOYSTICK_HIDAPI_SHIELD
 
 #if defined(__IPHONEOS__) || defined(__TVOS__) || defined(__ANDROID__)
 /* Very basic Steam Controller support on mobile devices */
@@ -111,6 +112,7 @@ typedef struct _SDL_HIDAPI_DeviceDriver
 /* HIDAPI device support */
 extern SDL_HIDAPI_DeviceDriver SDL_HIDAPI_DriverGameCube;
 extern SDL_HIDAPI_DeviceDriver SDL_HIDAPI_DriverLuna;
+extern SDL_HIDAPI_DeviceDriver SDL_HIDAPI_DriverShield;
 extern SDL_HIDAPI_DeviceDriver SDL_HIDAPI_DriverPS4;
 extern SDL_HIDAPI_DeviceDriver SDL_HIDAPI_DriverPS5;
 extern SDL_HIDAPI_DeviceDriver SDL_HIDAPI_DriverStadia;

src/joystick/usb_ids.h

@@ -39,6 +39,7 @@
 #define USB_VENDOR_SONY         0x054c
 #define USB_VENDOR_VALVE        0x28de
 
+#define USB_PRODUCT_NVIDIA_SHIELD_CONTROLLER                0x7214
 #define USB_PRODUCT_AMAZON_LUNA_CONTROLLER                  0x0419
 #define USB_PRODUCT_GOOGLE_STADIA_CONTROLLER                0x9400
 #define USB_PRODUCT_EVORETRO_GAMECUBE_ADAPTER               0x1846