Add UHID gamepad rumble WIP

There was a registration mechanism to listen to HID outputs with a
specific HID id.

However, the UHID gamepad processor handles several ids, so it will not
work. We could complexify the registration mechanism, but instead,
directly dispatch to the expected processor based on the UHID id.

Concretely, instead of passing a sc_uhid_devices instance to construct a
sc_keyboard_uhid, so that it can register itself, construct the
sc_uhid_devices with all the UHID instances (currently only
sc_keyboard_uhid) so that it can dispatch HID outputs directly.

app/data/bash-completion/scrcpy

@@ -26,6 +26,8 @@ _scrcpy() {
         -e --select-tcpip
         -f --fullscreen
         --force-adb-forward
+        -G
+        --gamepad=
         -h --help
         -K
         --keyboard=
@@ -127,6 +129,10 @@ _scrcpy() {
             COMPREPLY=($(compgen -W 'disabled sdk uhid aoa' -- "$cur"))
             return
             ;;
+        --gamepad)
+            COMPREPLY=($(compgen -W 'disabled uhid aoa' -- "$cur"))
+            return
+            ;;
         --orientation|--display-orientation)
             COMPREPLY=($(compgen -W '0 90 180 270 flip0 flip90 flip180 flip270' -- "$cur"))
             return

app/data/zsh-completion/_scrcpy

@@ -33,8 +33,10 @@ arguments=(
     {-e,--select-tcpip}'[Use TCP/IP device]'
     {-f,--fullscreen}'[Start in fullscreen]'
     '--force-adb-forward[Do not attempt to use \"adb reverse\" to connect to the device]'
+    '-G[Use UHID/AOA gamepad (same as --gamepad=uhid or --gamepad=aoa, depending on OTG mode)]'
+    '--gamepad=[Set the gamepad input mode]:mode:(disabled uhid aoa)'
     {-h,--help}'[Print the help]'
-    '-K[Use UHID keyboard (same as --keyboard=uhid)]'
+    '-K[Use UHID/AOA keyboard (same as --keyboard=uhid or --keyboard=aoa, depending on OTG mode)]'
     '--keyboard=[Set the keyboard input mode]:mode:(disabled sdk uhid aoa)'
     '--kill-adb-on-close[Kill adb when scrcpy terminates]'
     '--legacy-paste[Inject computer clipboard text as a sequence of key events on Ctrl+v]'
@@ -44,7 +46,7 @@ arguments=(
     '--list-encoders[List video and audio encoders available on the device]'
     '--lock-video-orientation=[Lock video orientation]:orientation:(unlocked initial 0 90 180 270)'
     {-m,--max-size=}'[Limit both the width and height of the video to value]'
-    '-M[Use UHID mouse (same as --mouse=uhid)]'
+    '-M[Use UHID/AOA mouse (same as --mouse=uhid or --mouse=aoa, depending on OTG mode)]'
     '--max-fps=[Limit the frame rate of screen capture]'
     '--mouse=[Set the mouse input mode]:mode:(disabled sdk uhid aoa)'
     '--mouse-bind=[Configure bindings of secondary clicks]'

app/src/cli.c

@@ -2812,7 +2812,7 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             }
         } else if (opts->mouse_input_mode == SC_MOUSE_INPUT_MODE_UHID_OR_AOA) {
             opts->mouse_input_mode = otg ? SC_MOUSE_INPUT_MODE_AOA
-                                         : SC_MOUSE_INPUT_MODE_SDK;
+                                         : SC_MOUSE_INPUT_MODE_UHID;
         } else if (opts->mouse_input_mode == SC_MOUSE_INPUT_MODE_SDK
                     && !opts->video_playback) {
             LOGE("SDK mouse mode requires video playback. Try --mouse=uhid.");
@@ -2885,9 +2885,16 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             return false;
         }
 
+        enum sc_gamepad_input_mode gmode = opts->gamepad_input_mode;
+        if (gmode != SC_GAMEPAD_INPUT_MODE_AOA
+                && gmode != SC_GAMEPAD_INPUT_MODE_DISABLED) {
+            LOGE("In OTG mode, --gamepad only supports aoa or disabled.");
+        }
+
         if (kmode == SC_KEYBOARD_INPUT_MODE_DISABLED
-                && mmode == SC_MOUSE_INPUT_MODE_DISABLED) {
-            LOGE("Could not disable both keyboard and mouse in OTG mode.");
+                && mmode == SC_MOUSE_INPUT_MODE_DISABLED
+                && gmode == SC_GAMEPAD_INPUT_MODE_DISABLED) {
+            LOGE("Cannot not disable all inputs in OTG mode.");
             return false;
         }
     }
@@ -2928,18 +2935,18 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
         }
 
         if (opts->camera_id && opts->camera_facing != SC_CAMERA_FACING_ANY) {
-            LOGE("Could not specify both --camera-id and --camera-facing");
+            LOGE("Cannot specify both --camera-id and --camera-facing");
             return false;
         }
 
         if (opts->camera_size) {
             if (opts->max_size) {
-                LOGE("Could not specify both --camera-size and -m/--max-size");
+                LOGE("Cannot specify both --camera-size and -m/--max-size");
                 return false;
             }
 
             if (opts->camera_ar) {
-                LOGE("Could not specify both --camera-size and --camera-ar");
+                LOGE("Cannot specify both --camera-size and --camera-ar");
                 return false;
             }
         }
@@ -3080,19 +3087,19 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
 
     if (!opts->control) {
         if (opts->turn_screen_off) {
-            LOGE("Could not request to turn screen off if control is disabled");
+            LOGE("Cannot request to turn screen off if control is disabled");
             return false;
         }
         if (opts->stay_awake) {
-            LOGE("Could not request to stay awake if control is disabled");
+            LOGE("Cannot request to stay awake if control is disabled");
             return false;
         }
         if (opts->show_touches) {
-            LOGE("Could not request to show touches if control is disabled");
+            LOGE("Cannot request to show touches if control is disabled");
             return false;
         }
         if (opts->power_off_on_close) {
-            LOGE("Could not request power off on close if control is disabled");
+            LOGE("Cannot request power off on close if control is disabled");
             return false;
         }
     }
@@ -3117,7 +3124,7 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
         // OTG mode is compatible with only very few options.
         // Only report obvious errors.
         if (opts->record_filename) {
-            LOGE("OTG mode: could not record");
+            LOGE("OTG mode: cannot record");
             return false;
         }
         if (opts->turn_screen_off) {

app/src/control_msg.c

@@ -83,15 +83,34 @@ write_position(uint8_t *buf, const struct sc_position *position) {
     sc_write16be(&buf[10], position->screen_size.height);
 }
 
-// write length (4 bytes) + string (non null-terminated)
+// Write truncated string, and return the size
 static size_t
-write_string(const char *utf8, size_t max_len, uint8_t *buf) {
+write_string_payload(uint8_t *payload, const char *utf8, size_t max_len) {
+    if (!utf8) {
+        return 0;
+    }
     size_t len = sc_str_utf8_truncation_index(utf8, max_len);
+    memcpy(payload, utf8, len);
+    return len;
+}
+
+// Write length (4 bytes) + string (non null-terminated)
+static size_t
+write_string(uint8_t *buf, const char *utf8, size_t max_len) {
+    size_t len = write_string_payload(buf + 4, utf8, max_len);
     sc_write32be(buf, len);
-    memcpy(&buf[4], utf8, len);
     return 4 + len;
 }
 
+// Write length (1 byte) + string (non null-terminated)
+static size_t
+write_string_tiny(uint8_t *buf, const char *utf8, size_t max_len) {
+    assert(max_len <= 0xFF);
+    size_t len = write_string_payload(buf + 1, utf8, max_len);
+    buf[0] = len;
+    return 1 + len;
+}
+
 size_t
 sc_control_msg_serialize(const struct sc_control_msg *msg, uint8_t *buf) {
     buf[0] = msg->type;
@@ -103,9 +122,8 @@ sc_control_msg_serialize(const struct sc_control_msg *msg, uint8_t *buf) {
             sc_write32be(&buf[10], msg->inject_keycode.metastate);
             return 14;
         case SC_CONTROL_MSG_TYPE_INJECT_TEXT: {
-            size_t len =
-                write_string(msg->inject_text.text,
-                             SC_CONTROL_MSG_INJECT_TEXT_MAX_LENGTH, &buf[1]);
+            size_t len = write_string(&buf[1], msg->inject_text.text,
+                                      SC_CONTROL_MSG_INJECT_TEXT_MAX_LENGTH);
             return 1 + len;
         }
         case SC_CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT:
@@ -137,19 +155,26 @@ sc_control_msg_serialize(const struct sc_control_msg *msg, uint8_t *buf) {
         case SC_CONTROL_MSG_TYPE_SET_CLIPBOARD:
             sc_write64be(&buf[1], msg->set_clipboard.sequence);
             buf[9] = !!msg->set_clipboard.paste;
-            size_t len = write_string(msg->set_clipboard.text,
-                                      SC_CONTROL_MSG_CLIPBOARD_TEXT_MAX_LENGTH,
-                                      &buf[10]);
+            size_t len = write_string(&buf[10], msg->set_clipboard.text,
+                                      SC_CONTROL_MSG_CLIPBOARD_TEXT_MAX_LENGTH);
             return 10 + len;
         case SC_CONTROL_MSG_TYPE_SET_SCREEN_POWER_MODE:
             buf[1] = msg->set_screen_power_mode.mode;
             return 2;
         case SC_CONTROL_MSG_TYPE_UHID_CREATE:
             sc_write16be(&buf[1], msg->uhid_create.id);
-            sc_write16be(&buf[3], msg->uhid_create.report_desc_size);
-            memcpy(&buf[5], msg->uhid_create.report_desc,
-                            msg->uhid_create.report_desc_size);
-            return 5 + msg->uhid_create.report_desc_size;
+
+            size_t index = 3;
+            index += write_string_tiny(&buf[index], msg->uhid_create.name, 127);
+
+            sc_write16be(&buf[index], msg->uhid_create.report_desc_size);
+            index += 2;
+
+            memcpy(&buf[index], msg->uhid_create.report_desc,
+                                msg->uhid_create.report_desc_size);
+            index += msg->uhid_create.report_desc_size;
+
+            return index;
         case SC_CONTROL_MSG_TYPE_UHID_INPUT:
             sc_write16be(&buf[1], msg->uhid_input.id);
             sc_write16be(&buf[3], msg->uhid_input.size);
@@ -255,10 +280,15 @@ sc_control_msg_log(const struct sc_control_msg *msg) {
         case SC_CONTROL_MSG_TYPE_ROTATE_DEVICE:
             LOG_CMSG("rotate device");
             break;
-        case SC_CONTROL_MSG_TYPE_UHID_CREATE:
-            LOG_CMSG("UHID create [%" PRIu16 "] report_desc_size=%" PRIu16,
-                     msg->uhid_create.id, msg->uhid_create.report_desc_size);
+        case SC_CONTROL_MSG_TYPE_UHID_CREATE: {
+            // Quote only if name is not null
+            const char *name = msg->uhid_create.name;
+            const char *quote = name ? "\"" : "";
+            LOG_CMSG("UHID create [%" PRIu16 "] name=%s%s%s "
+                     "report_desc_size=%" PRIu16, msg->uhid_create.id,
+                     quote, name, quote, msg->uhid_create.report_desc_size);
             break;
+        }
         case SC_CONTROL_MSG_TYPE_UHID_INPUT: {
             char *hex = sc_str_to_hex_string(msg->uhid_input.data,
                                              msg->uhid_input.size);

app/src/control_msg.h

@@ -98,6 +98,7 @@ struct sc_control_msg {
         } set_screen_power_mode;
         struct {
             uint16_t id;
+            const char *name; // pointer to static data
             uint16_t report_desc_size;
             const uint8_t *report_desc; // pointer to static data
         } uhid_create;

app/src/hid/hid_event.h

@@ -15,6 +15,7 @@ struct sc_hid_input {
 
 struct sc_hid_open {
     uint16_t hid_id;
+    const char *name; // pointer to static memory
     const uint8_t *report_desc; // pointer to static memory
     size_t report_desc_size;
 };

app/src/hid/hid_gamepad.c

@@ -90,7 +90,7 @@ static const uint8_t SC_HID_GAMEPAD_REPORT_DESC[] = {
     // Usage Minimum (1)
     0x19, 0x01,
     // Usage Maximum (16)
-    0x29, 0x0F,
+    0x29, 0x10,
     // Logical Minimum (0)
     0x15, 0x00,
     // Logical Maximum (1)
@@ -244,8 +244,14 @@ sc_hid_gamepad_generate_open(struct sc_hid_gamepad *hid,
 
     sc_hid_gamepad_slot_init(&hid->slots[slot_idx], gamepad_id);
 
+    SDL_GameController* game_controller =
+        SDL_GameControllerFromInstanceID(gamepad_id);
+    assert(game_controller);
+    const char *name = SDL_GameControllerName(game_controller);
+
     uint16_t hid_id = sc_hid_gamepad_slot_get_id(slot_idx);
     hid_open->hid_id = hid_id;
+    hid_open->name = name;
     hid_open->report_desc = SC_HID_GAMEPAD_REPORT_DESC;
     hid_open->report_desc_size = sizeof(SC_HID_GAMEPAD_REPORT_DESC);
 

app/src/hid/hid_gamepad.h

@@ -9,7 +9,7 @@
 #include "input_events.h"
 
 #define SC_MAX_GAMEPADS 8
-#define SC_HID_ID_GAMEPAD_FIRST 2
+#define SC_HID_ID_GAMEPAD_FIRST 3
 #define SC_HID_ID_GAMEPAD_LAST (SC_HID_ID_GAMEPAD_FIRST + SC_MAX_GAMEPADS - 1)
 
 struct sc_hid_gamepad_slot {

app/src/hid/hid_keyboard.c

@@ -335,6 +335,7 @@ sc_hid_keyboard_generate_input_from_mods(struct sc_hid_input *hid_input,
 
 void sc_hid_keyboard_generate_open(struct sc_hid_open *hid_open) {
     hid_open->hid_id = SC_HID_ID_KEYBOARD;
+    hid_open->name = "Keyboard";
     hid_open->report_desc = SC_HID_KEYBOARD_REPORT_DESC;
     hid_open->report_desc_size = sizeof(SC_HID_KEYBOARD_REPORT_DESC);
 }

app/src/hid/hid_mouse.c

@@ -190,6 +190,7 @@ sc_hid_mouse_generate_input_from_scroll(struct sc_hid_input *hid_input,
 
 void sc_hid_mouse_generate_open(struct sc_hid_open *hid_open) {
     hid_open->hid_id = SC_HID_ID_MOUSE;
+    hid_open->name = "Mouse";
     hid_open->report_desc = SC_HID_MOUSE_REPORT_DESC;
     hid_open->report_desc_size = sizeof(SC_HID_MOUSE_REPORT_DESC);
 }

app/src/scrcpy.c

@@ -756,6 +756,7 @@ aoa_complete:
         if (options->gamepad_input_mode == SC_GAMEPAD_INPUT_MODE_UHID) {
             sc_gamepad_uhid_init(&s->gamepad_uhid, &s->controller);
             gp = &s->gamepad_uhid.gamepad_processor;
+            uhid_gamepad = &s->gamepad_uhid;
         }
 
         struct sc_uhid_devices *uhid_devices = NULL;

app/src/uhid/gamepad_uhid.c

@@ -31,6 +31,7 @@ sc_gamepad_uhid_send_open(struct sc_gamepad_uhid *gamepad,
     struct sc_control_msg msg;
     msg.type = SC_CONTROL_MSG_TYPE_UHID_CREATE;
     msg.uhid_create.id = hid_open->hid_id;
+    msg.uhid_create.name = hid_open->name;
     msg.uhid_create.report_desc = hid_open->report_desc;
     msg.uhid_create.report_desc_size = hid_open->report_desc_size;
 

app/src/uhid/keyboard_uhid.c

@@ -141,6 +141,7 @@ sc_keyboard_uhid_init(struct sc_keyboard_uhid *kb,
     struct sc_control_msg msg;
     msg.type = SC_CONTROL_MSG_TYPE_UHID_CREATE;
     msg.uhid_create.id = SC_HID_ID_KEYBOARD;
+    msg.uhid_create.name = hid_open.name;
     msg.uhid_create.report_desc = hid_open.report_desc;
     msg.uhid_create.report_desc_size = hid_open.report_desc_size;
     if (!sc_controller_push_msg(controller, &msg)) {

app/src/uhid/mouse_uhid.c

@@ -81,6 +81,7 @@ sc_mouse_uhid_init(struct sc_mouse_uhid *mouse,
     struct sc_control_msg msg;
     msg.type = SC_CONTROL_MSG_TYPE_UHID_CREATE;
     msg.uhid_create.id = SC_HID_ID_MOUSE;
+    msg.uhid_create.name = hid_open.name;
     msg.uhid_create.report_desc = hid_open.report_desc;
     msg.uhid_create.report_desc_size = hid_open.report_desc_size;
     if (!sc_controller_push_msg(controller, &msg)) {

app/tests/test_control_msg_serialize.c

@@ -329,6 +329,7 @@ static void test_serialize_uhid_create(void) {
         .type = SC_CONTROL_MSG_TYPE_UHID_CREATE,
         .uhid_create = {
             .id = 42,
+            .name = "ABC",
             .report_desc_size = sizeof(report_desc),
             .report_desc = report_desc,
         },
@@ -336,12 +337,14 @@ static void test_serialize_uhid_create(void) {
 
     uint8_t buf[SC_CONTROL_MSG_MAX_SIZE];
     size_t size = sc_control_msg_serialize(&msg, buf);
-    assert(size == 16);
+    assert(size == 20);
 
     const uint8_t expected[] = {
         SC_CONTROL_MSG_TYPE_UHID_CREATE,
         0, 42, // id
-        0, 11, // size
+        3, // name size
+        65, 66, 67, // "ABC"
+        0, 11, // report desc size
         1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
     };
     assert(!memcmp(buf, expected, sizeof(expected)));

server/src/main/java/com/genymobile/scrcpy/control/ControlMessage.java

@@ -131,10 +131,11 @@ public final class ControlMessage {
         return msg;
     }
 
-    public static ControlMessage createUhidCreate(int id, byte[] reportDesc) {
+    public static ControlMessage createUhidCreate(int id, String name, byte[] reportDesc) {
         ControlMessage msg = new ControlMessage();
         msg.type = TYPE_UHID_CREATE;
         msg.id = id;
+        msg.text = name;
         msg.data = reportDesc;
         return msg;
     }

server/src/main/java/com/genymobile/scrcpy/control/ControlMessageReader.java

@@ -75,6 +75,12 @@ public class ControlMessageReader {
         return value;
     }
 
+    private String parseString(int sizeBytes) throws IOException {
+        assert sizeBytes > 0 && sizeBytes <= 4;
+        byte[] data = parseByteArray(sizeBytes);
+        return new String(data, StandardCharsets.UTF_8);
+    }
+
     private String parseString() throws IOException {
         byte[] data = parseByteArray(4);
         return new String(data, StandardCharsets.UTF_8);
@@ -134,8 +140,9 @@ public class ControlMessageReader {
 
     private ControlMessage parseUhidCreate() throws IOException {
         int id = dis.readUnsignedShort();
+        String name = parseString(1);
         byte[] data = parseByteArray(2);
-        return ControlMessage.createUhidCreate(id, data);
+        return ControlMessage.createUhidCreate(id, name, data);
     }
 
     private ControlMessage parseUhidInput() throws IOException {

server/src/main/java/com/genymobile/scrcpy/control/Controller.java

@@ -210,7 +210,7 @@ public class Controller implements AsyncProcessor {
                 device.rotateDevice();
                 break;
             case ControlMessage.TYPE_UHID_CREATE:
-                getUhidManager().open(msg.getId(), msg.getData());
+                getUhidManager().open(msg.getId(), msg.getText(), msg.getData());
                 break;
             case ControlMessage.TYPE_UHID_INPUT:
                 getUhidManager().writeInput(msg.getId(), msg.getData());

server/src/main/java/com/genymobile/scrcpy/control/UhidManager.java

@@ -1,6 +1,7 @@
 package com.genymobile.scrcpy.control;
 
 import com.genymobile.scrcpy.util.Ln;
+import com.genymobile.scrcpy.util.StringUtils;
 
 import android.os.Build;
 import android.os.HandlerThread;
@@ -46,7 +47,7 @@ public final class UhidManager {
         }
     }
 
-    public void open(int id, byte[] reportDesc) throws IOException {
+    public void open(int id, String name, byte[] reportDesc) throws IOException {
         try {
             FileDescriptor fd = Os.open("/dev/uhid", OsConstants.O_RDWR, 0);
             try {
@@ -56,7 +57,7 @@ public final class UhidManager {
                     close(old);
                 }
 
-                byte[] req = buildUhidCreate2Req(reportDesc);
+                byte[] req = buildUhidCreate2Req(name, reportDesc);
                 Os.write(fd, req, 0, req.length);
 
                 registerUhidListener(id, fd);
@@ -146,7 +147,7 @@ public final class UhidManager {
         }
     }
 
-    private static byte[] buildUhidCreate2Req(byte[] reportDesc) {
+    private static byte[] buildUhidCreate2Req(String name, byte[] reportDesc) {
         /*
          * struct uhid_event {
          *     uint32_t type;
@@ -171,8 +172,19 @@ public final class UhidManager {
         byte[] empty = new byte[256];
         ByteBuffer buf = ByteBuffer.allocate(280 + reportDesc.length).order(ByteOrder.nativeOrder());
         buf.putInt(UHID_CREATE2);
-        buf.put("scrcpy".getBytes(StandardCharsets.US_ASCII));
-        buf.put(empty, 0, 256 - "scrcpy".length());
+
+        final String prefix = "scrcpy: ";
+        if (name.isEmpty()) {
+            name = "(no name)";
+        }
+        byte[] utf8Name = name.getBytes(StandardCharsets.UTF_8);
+        int len = StringUtils.getUtf8TruncationIndex(utf8Name, 127 - prefix.length());
+        int nameLen = prefix.length() + len;
+        assert nameLen <= 127;
+        buf.put(prefix.getBytes(StandardCharsets.US_ASCII));
+        buf.put(utf8Name, 0, len);
+        buf.put(empty, 0, 256 - nameLen);
+
         buf.putShort((short) reportDesc.length);
         buf.putShort(BUS_VIRTUAL);
         buf.putInt(0); // vendor id

server/src/test/java/com/genymobile/scrcpy/control/ControlMessageReaderTest.java

@@ -324,8 +324,10 @@ public class ControlMessageReaderTest {
         DataOutputStream dos = new DataOutputStream(bos);
         dos.writeByte(ControlMessage.TYPE_UHID_CREATE);
         dos.writeShort(42); // id
+        dos.writeByte(3); // name size
+        dos.write("ABC".getBytes(StandardCharsets.US_ASCII));
         byte[] data = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
-        dos.writeShort(data.length); // size
+        dos.writeShort(data.length); // report desc size
         dos.write(data);
         byte[] packet = bos.toByteArray();
 
@@ -335,6 +337,7 @@ public class ControlMessageReaderTest {
         ControlMessage event = reader.read();
         Assert.assertEquals(ControlMessage.TYPE_UHID_CREATE, event.getType());
         Assert.assertEquals(42, event.getId());
+        Assert.assertEquals("ABC", event.getText());
         Assert.assertArrayEquals(data, event.getData());
 
         Assert.assertEquals(-1, bis.read()); // EOS