Merge pull request #304 from drgnchan/fix/ch9329-macos-drag

fix(hid): add macOS drag compatibility for OTG and CH9329

docs/macos-drag-compatibility.md

@@ -0,0 +1,24 @@
+# macOS 拖拽兼容模式（实验性）
+
+适用于 OTG 和 CH9329 后端的绝对鼠标输入。遇到目标 Mac 上拖拽只能移动一小段便停止时，可在设置页的 HID 配置中开启「macOS 拖拽兼容模式」。默认关闭。
+
+配置字段为 `hid.mouse_macos_drag`，旧 PR 的 `ch9329_macos_drag` 字段仍可作为读取别名。OTG 必须同时启用相对鼠标和绝对鼠标接口，否则配置保存会被拒绝。CH9329 同时启用 Linux 兼容开关时，此模式优先。
+
+## 报告行为
+
+- 未按键时仍使用绝对坐标定位。
+- 从绝对输入开始的拖拽：按下使用绝对报告，移动和滚轮使用相对报告，释放时先更新相对按钮状态，再发送绝对按钮释放。
+- 按键报告的通道保持到所有按钮释放，不随拖拽期间的输入模式切换而改变。
+- 从相对输入开始的点击、拖拽继续使用相对按钮报告；此选项不修复原生相对模式的点击兼容问题。
+- 位移从原始 15 位输入坐标换算，累计小数余量，大位移按单包范围分包并保留总量及方向。
+- 运行时使用当前视频采集尺寸，并在 HID 重载后恢复尺寸；视频尚未提供尺寸时使用配置尺寸。
+
+## 验证范围与限制
+
+本次 OTG 扩展及位移换算修改没有 macOS 实机验证。原 PR 作者对旧 CH9329 实现的实机反馈不能视为本版本已经验证。
+
+本地自动化覆盖位移累计/分包、1080p/4K 换算、往返移动、滚轮、输入模式切换、复位、CH9329 命令队列、OTG 临时文件模拟端点及配置校验。临时文件测试仅验证写出的字节，不验证 USB 枚举或目标系统的事件解释。
+
+相对位移受 macOS 鼠标速度、加速、显示缩放及多屏布局影响，无法保证与绝对定位逐像素一致。松手报告携带最后的客户端绝对坐标，仍可能出现落点偏移或光标跳位；大位移分包也可能增加低波特率串口延迟。
+
+后续实机验证应分别覆盖两个后端：窗口/文件/文本拖拽，快速及慢速移动，滚轮和多按钮组合，1080p/4K 与缩放显示，输入模式切换、断开重连、精确落点。异常时关闭此选项恢复默认行为。

src/config/schema/hid.rs

@@ -231,6 +231,9 @@ pub struct HidConfig {
     #[serde(default)]
     pub ch9329_hybrid_mouse: bool,
     #[serde(default)]
+    #[serde(alias = "ch9329_macos_drag")]
+    pub mouse_macos_drag: bool,
+    #[serde(default)]
     pub ch9329_descriptor: Ch9329DescriptorConfig,
     pub mouse_absolute: bool,
 }
@@ -248,6 +251,7 @@ impl Default for HidConfig {
             ch9329_port: "/dev/ttyUSB0".to_string(),
             ch9329_baudrate: 9600,
             ch9329_hybrid_mouse: false,
+            mouse_macos_drag: false,
             ch9329_descriptor: Ch9329DescriptorConfig::default(),
             mouse_absolute: true,
         }
@@ -273,6 +277,11 @@ impl HidConfig {
         }
 
         let functions = self.effective_otg_functions();
+        if self.mouse_macos_drag && (!functions.mouse_relative || !functions.mouse_absolute) {
+            return Err(crate::error::AppError::BadRequest(
+                "macOS drag compatibility requires both OTG mouse interfaces".to_string(),
+            ));
+        }
         if functions.is_empty() {
             return Err(crate::error::AppError::BadRequest(
                 "OTG HID functions cannot be empty".to_string(),
@@ -308,6 +317,22 @@ impl HidConfig {
 mod bluetooth_tests {
     use super::*;
     #[test]
+    fn mouse_compatibility_defaults_alias_and_otg_validation() {
+        let defaults: HidConfig = serde_json::from_str(r#"{"backend":"otg"}"#).unwrap();
+        assert!(!defaults.mouse_macos_drag);
+        let mut config: HidConfig =
+            serde_json::from_str(r#"{"backend":"otg","ch9329_macos_drag":true}"#).unwrap();
+        assert!(config.mouse_macos_drag);
+        assert!(config.validate_otg_functions().is_ok());
+        config.otg_profile = OtgHidProfile::LegacyMouseRelative;
+        assert!(config.validate_otg_functions().is_err());
+        config.backend = HidBackend::Ch9329;
+        assert!(config.validate_otg_functions().is_ok());
+        let saved = serde_json::to_value(&config).unwrap();
+        assert_eq!(saved["mouse_macos_drag"], true);
+        assert!(saved.get("ch9329_macos_drag").is_none());
+    }
+    #[test]
     fn old_configs_keep_bluetooth_disabled_and_get_defaults() {
         let config: HidConfig = serde_json::from_str(r#"{"backend":"otg"}"#).unwrap();
         assert_eq!(config.backend, HidBackend::Otg);

src/hid/backend.rs

@@ -17,7 +17,10 @@ fn default_ch9329_baud_rate() -> u32 {
 #[serde(tag = "type", rename_all = "lowercase")]
 #[derive(Default)]
 pub enum HidBackendType {
-    Otg,
+    Otg {
+        #[serde(default)]
+        macos_drag: bool,
+    },
     Bluetooth {
         config: crate::config::BluetoothHidConfig,
     },
@@ -27,6 +30,8 @@ pub enum HidBackendType {
         baud_rate: u32,
         #[serde(default)]
         hybrid_mouse: bool,
+        #[serde(default)]
+        macos_drag: bool,
     },
     #[default]
     None,
@@ -35,7 +40,7 @@ pub enum HidBackendType {
 impl HidBackendType {
     pub fn name_str(&self) -> &str {
         match self {
-            Self::Otg => "otg",
+            Self::Otg { .. } => "otg",
             Self::Bluetooth { .. } => "bluetooth",
             Self::Ch9329 { .. } => "ch9329",
             Self::None => "none",

src/hid/ch9329.rs

@@ -238,6 +238,8 @@ pub struct Ch9329Backend {
     last_abs_y: Arc<AtomicU16>,
     relative_mouse_active: Arc<AtomicBool>,
     hybrid_mouse: bool,
+    macos_drag: bool,
+    macos_drag_state: Mutex<super::macos_drag::MacosDrag>,
     runtime: Arc<Ch9329RuntimeState>,
 }
 
@@ -251,6 +253,15 @@ impl Ch9329Backend {
     }
 
     pub fn with_options(port_path: &str, baud_rate: u32, hybrid_mouse: bool) -> Result<Self> {
+        Self::with_compatibility_options(port_path, baud_rate, hybrid_mouse, false)
+    }
+
+    pub fn with_compatibility_options(
+        port_path: &str,
+        baud_rate: u32,
+        hybrid_mouse: bool,
+        macos_drag: bool,
+    ) -> Result<Self> {
         Ok(Self {
             port_path: port_path.to_string(),
             baud_rate,
@@ -266,6 +277,8 @@ impl Ch9329Backend {
             last_abs_y: Arc::new(AtomicU16::new(0)),
             relative_mouse_active: Arc::new(AtomicBool::new(false)),
             hybrid_mouse,
+            macos_drag,
+            macos_drag_state: Mutex::new(super::macos_drag::MacosDrag::default()),
             runtime: Arc::new(Ch9329RuntimeState::new()),
         })
     }
@@ -978,11 +991,12 @@ impl Ch9329Backend {
     }
 
     fn should_send_button_wheel_relative(&self) -> bool {
-        self.hybrid_mouse || self.relative_mouse_active.load(Ordering::Relaxed)
+        (self.hybrid_mouse && !self.macos_drag)
+            || self.relative_mouse_active.load(Ordering::Relaxed)
     }
 
     fn absolute_move_buttons(&self, buttons: u8) -> u8 {
-        if self.hybrid_mouse {
+        if self.hybrid_mouse && !self.macos_drag {
             0
         } else {
             buttons
@@ -1272,6 +1286,31 @@ impl HidBackend for Ch9329Backend {
     async fn send_mouse(&self, event: MouseEvent) -> Result<()> {
         let buttons = self.mouse_buttons.load(Ordering::Relaxed);
 
+        if self.macos_drag {
+            use super::macos_drag::MouseReport;
+            let mut state = self.macos_drag_state.lock();
+            let (buttons, reports) = state.plan(event, buttons, *self.screen_resolution.read());
+            self.mouse_buttons.store(buttons, Ordering::Relaxed);
+            for report in reports {
+                match report {
+                    MouseReport::Absolute { buttons, x, y } => {
+                        let x = (u32::from(x) * CH9329_MOUSE_RESOLUTION / 32768) as u16;
+                        let y = (u32::from(y) * CH9329_MOUSE_RESOLUTION / 32768) as u16;
+                        self.send_mouse_absolute(buttons, x, y, 0)?;
+                    }
+                    MouseReport::Relative {
+                        buttons,
+                        dx,
+                        dy,
+                        wheel,
+                    } => {
+                        self.send_mouse_relative(buttons, dx, dy, wheel)?;
+                    }
+                }
+            }
+            return Ok(());
+        }
+
         match event.event_type {
             MouseEventType::Move => {
                 self.relative_mouse_active.store(true, Ordering::Relaxed);
@@ -1361,6 +1400,7 @@ impl HidBackend for Ch9329Backend {
         }
 
         self.mouse_buttons.store(0, Ordering::Relaxed);
+        self.macos_drag_state.lock().reset();
         self.last_abs_x.store(0, Ordering::Relaxed);
         self.last_abs_y.store(0, Ordering::Relaxed);
         self.relative_mouse_active.store(false, Ordering::Relaxed);
@@ -1666,13 +1706,67 @@ mod tests {
     }
 
     #[test]
-    fn test_hybrid_mouse_routes_buttons_and_wheel_to_relative_reports() {
+    fn test_hybrid_mouse_preserves_linux_compatibility_routing() {
         let backend = Ch9329Backend::with_options("/dev/null", DEFAULT_BAUD_RATE, true).unwrap();
 
         assert!(backend.should_send_button_wheel_relative());
         assert_eq!(backend.absolute_move_buttons(0x07), 0);
     }
 
+    #[tokio::test]
+    async fn test_macos_drag_uses_absolute_edges_and_relative_motion() {
+        let backend =
+            Ch9329Backend::with_compatibility_options("/dev/null", DEFAULT_BAUD_RATE, false, true)
+                .unwrap();
+        let (worker_tx, worker_rx) = mpsc::channel();
+        *backend.worker_tx.lock() = Some(worker_tx);
+        backend.set_screen_resolution(1920, 1080);
+
+        backend
+            .send_mouse(MouseEvent::move_abs(8000, 8000))
+            .await
+            .unwrap();
+        backend
+            .send_mouse(MouseEvent::button_down(crate::hid::MouseButton::Left))
+            .await
+            .unwrap();
+        backend
+            .send_mouse(MouseEvent::move_abs(8064, 8064))
+            .await
+            .unwrap();
+        backend
+            .send_mouse(MouseEvent::button_up(crate::hid::MouseButton::Left))
+            .await
+            .unwrap();
+
+        let packets: Vec<_> = worker_rx
+            .try_iter()
+            .filter_map(|command| match command {
+                WorkerCommand::Packet { cmd, data } => Some((cmd, data)),
+                _ => None,
+            })
+            .collect();
+        assert_eq!(
+            packets,
+            vec![
+                (
+                    cmd::SEND_MS_ABS_DATA,
+                    vec![0x02, 0x00, 0xE8, 0x03, 0xE8, 0x03, 0x00],
+                ),
+                (
+                    cmd::SEND_MS_ABS_DATA,
+                    vec![0x02, 0x01, 0xE8, 0x03, 0xE8, 0x03, 0x00],
+                ),
+                (cmd::SEND_MS_REL_DATA, vec![0x01, 0x01, 0x03, 0x02, 0x00]),
+                (cmd::SEND_MS_REL_DATA, vec![0x01, 0x00, 0x00, 0x00, 0x00]),
+                (
+                    cmd::SEND_MS_ABS_DATA,
+                    vec![0x02, 0x00, 0xF0, 0x03, 0xF0, 0x03, 0x00],
+                ),
+            ]
+        );
+    }
+
     #[test]
     fn test_default_mouse_mode_preserves_absolute_report_buttons() {
         let backend = Ch9329Backend::with_baud_rate("/dev/null", DEFAULT_BAUD_RATE).unwrap();

src/hid/factory.rs

@@ -44,21 +44,27 @@ impl HidBackendFactory {
 
     async fn create(&self, backend_type: &HidBackendType) -> Result<Option<Arc<dyn HidBackend>>> {
         match backend_type {
-            HidBackendType::Otg => self.create_otg_backend().await.map(Some),
+            HidBackendType::Otg { macos_drag } => {
+                self.create_otg_backend(*macos_drag).await.map(Some)
+            }
             HidBackendType::Ch9329 {
                 port,
                 baud_rate,
                 hybrid_mouse,
+                macos_drag,
             } => {
                 info!(
-                    "Initializing CH9329 HID backend on {} @ {} baud, hybrid_mouse={}",
+                    "Initializing CH9329 HID backend on {} @ {} baud, hybrid_mouse={}, macos_drag={}",
-                    port, baud_rate, hybrid_mouse
+                    port, baud_rate, hybrid_mouse, macos_drag
                 );
-                Ok(Some(Arc::new(ch9329::Ch9329Backend::with_options(
+                Ok(Some(Arc::new(
+                    ch9329::Ch9329Backend::with_compatibility_options(
                         port,
                         *baud_rate,
                         *hybrid_mouse,
-                )?)))
+                        *macos_drag,
+                    )?,
+                )))
             }
             HidBackendType::Bluetooth { config } => {
                 #[cfg(target_os = "linux")]
@@ -84,7 +90,7 @@ impl HidBackendFactory {
     }
 
     #[cfg(unix)]
-    async fn create_otg_backend(&self) -> Result<Arc<dyn HidBackend>> {
+    async fn create_otg_backend(&self, macos_drag: bool) -> Result<Arc<dyn HidBackend>> {
         let otg_service = self
             .otg_service
             .as_ref()
@@ -96,11 +102,13 @@ impl HidBackendFactory {
             .ok_or_else(|| AppError::Config("OTG HID paths are not available".to_string()))?;
 
         info!("Creating OTG HID backend from device paths");
-        Ok(Arc::new(super::otg::OtgBackend::from_handles(handles)?))
+        Ok(Arc::new(super::otg::OtgBackend::with_macos_drag(
+            handles, macos_drag,
+        )?))
     }
 
     #[cfg(not(unix))]
-    async fn create_otg_backend(&self) -> Result<Arc<dyn HidBackend>> {
+    async fn create_otg_backend(&self, _macos_drag: bool) -> Result<Arc<dyn HidBackend>> {
         Err(AppError::Config(
             "OTG HID is only available on Linux".to_string(),
         ))

src/hid/macos_drag.rs

@@ -0,0 +1,256 @@
+//! Experimental absolute-button / relative-drag routing shared by USB backends.
+//! Relative counts are subject to host acceleration; they are not screen pixels.
+
+use super::{MouseEvent, MouseEventType};
+
+#[derive(Debug, PartialEq)]
+pub(super) enum MouseReport {
+    Absolute {
+        buttons: u8,
+        x: u16,
+        y: u16,
+    },
+    Relative {
+        buttons: u8,
+        dx: i8,
+        dy: i8,
+        wheel: i8,
+    },
+}
+
+#[derive(Default)]
+pub(super) struct MacosDrag {
+    position: (u16, u16),
+    remainder: (i64, i64),
+    extent: (u32, u32),
+    relative_input: bool,
+    absolute_drag: bool,
+}
+
+impl MacosDrag {
+    pub fn reset(&mut self) {
+        *self = Self::default();
+    }
+
+    pub fn plan(
+        &mut self,
+        event: MouseEvent,
+        buttons: u8,
+        extent: (u32, u32),
+    ) -> (u8, Vec<MouseReport>) {
+        let mut reports = Vec::new();
+        let mut next_buttons = buttons;
+        if extent != self.extent || buttons == 0 {
+            self.remainder = (0, 0);
+            self.extent = extent;
+        }
+        match event.event_type {
+            MouseEventType::MoveAbs => {
+                let position = (
+                    event.x.clamp(0, 32767) as u16,
+                    event.y.clamp(0, 32767) as u16,
+                );
+                self.relative_input = false;
+                if buttons != 0 {
+                    let dx =
+                        Self::delta(position.0, self.position.0, extent.0, &mut self.remainder.0);
+                    let dy =
+                        Self::delta(position.1, self.position.1, extent.1, &mut self.remainder.1);
+                    Self::motion(&mut reports, buttons, dx, dy);
+                } else {
+                    reports.push(MouseReport::Absolute {
+                        buttons: 0,
+                        x: position.0,
+                        y: position.1,
+                    });
+                }
+                self.position = position;
+            }
+            MouseEventType::Move => {
+                self.relative_input = true;
+                Self::motion(
+                    &mut reports,
+                    buttons,
+                    i64::from(event.x.clamp(-127, 127)),
+                    i64::from(event.y.clamp(-127, 127)),
+                );
+            }
+            MouseEventType::Down | MouseEventType::Up => {
+                if let Some(button) = event.button {
+                    let down = event.event_type == MouseEventType::Down;
+                    next_buttons = if down {
+                        buttons | button.to_hid_bit()
+                    } else {
+                        buttons & !button.to_hid_bit()
+                    };
+                    if down && buttons == 0 {
+                        self.absolute_drag = !self.relative_input;
+                    }
+                    // Latch the button route until all buttons are released, even
+                    // if the client changes pointer mode during the drag.
+                    if self.absolute_drag {
+                        if !down {
+                            // Relative drag reports also carry buttons. Clear their
+                            // state before releasing the absolute collection.
+                            reports.push(MouseReport::Relative {
+                                buttons: next_buttons,
+                                dx: 0,
+                                dy: 0,
+                                wheel: 0,
+                            });
+                        }
+                        reports.push(MouseReport::Absolute {
+                            buttons: next_buttons,
+                            x: self.position.0,
+                            y: self.position.1,
+                        });
+                    } else {
+                        reports.push(MouseReport::Relative {
+                            buttons: next_buttons,
+                            dx: 0,
+                            dy: 0,
+                            wheel: 0,
+                        });
+                    }
+                    if next_buttons == 0 {
+                        self.absolute_drag = false;
+                        self.remainder = (0, 0);
+                    }
+                }
+            }
+            MouseEventType::Scroll => {
+                reports.push(MouseReport::Relative {
+                    buttons,
+                    dx: 0,
+                    dy: 0,
+                    wheel: event.scroll,
+                });
+            }
+        }
+        (next_buttons, reports)
+    }
+
+    fn delta(current: u16, previous: u16, extent: u32, remainder: &mut i64) -> i64 {
+        // Keep the original 15-bit input precision and carry fractional counts.
+        let scaled =
+            (i64::from(current) - i64::from(previous)) * i64::from(extent.max(1)) + *remainder;
+        *remainder = scaled % 32768;
+        scaled / 32768
+    }
+
+    fn motion(reports: &mut Vec<MouseReport>, buttons: u8, dx: i64, dy: i64) {
+        // Distribute both axes over the same packets to preserve diagonal paths.
+        let count = (dx.abs().max(dy.abs()) + 126) / 127;
+        let mut previous = (0, 0);
+        for index in 1..=count {
+            let position = (dx * index / count, dy * index / count);
+            reports.push(MouseReport::Relative {
+                buttons,
+                dx: (position.0 - previous.0) as i8,
+                dy: (position.1 - previous.1) as i8,
+                wheel: 0,
+            });
+            previous = position;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::hid::MouseButton;
+
+    fn drag(steps: &[i32], extent: (u32, u32)) -> (i64, i64) {
+        let mut state = MacosDrag::default();
+        state.plan(MouseEvent::move_abs(8000, 8000), 0, extent);
+        state.plan(MouseEvent::button_down(MouseButton::Left), 0, extent);
+        let mut total = (0, 0);
+        for &x in steps {
+            for report in state.plan(MouseEvent::move_abs(x, x), 1, extent).1 {
+                if let MouseReport::Relative { dx, dy, .. } = report {
+                    total.0 += i64::from(dx);
+                    total.1 += i64::from(dy);
+                } else {
+                    panic!("absolute movement during drag");
+                }
+            }
+        }
+        total
+    }
+
+    #[test]
+    fn preserves_total_across_event_splitting_and_large_moves() {
+        let steps: Vec<_> = (8001..=16000).collect();
+        assert_eq!(drag(&[16000], (1920, 1080)), (468, 263));
+        assert_eq!(drag(&steps, (1920, 1080)), (468, 263));
+        assert_eq!(drag(&[16000, 8000], (1920, 1080)), (0, 0));
+        assert_eq!(drag(&[16000], (3840, 2160)), (937, 527));
+    }
+
+    #[test]
+    fn scroll_and_mode_switch_keep_absolute_drag_release() {
+        let mut state = MacosDrag::default();
+        let extent = (1920, 1080);
+        state.plan(MouseEvent::move_abs(8000, 8000), 0, extent);
+        state.plan(MouseEvent::button_down(MouseButton::Left), 0, extent);
+        let mut wheel = MouseEvent::move_abs(0, 0);
+        wheel.event_type = MouseEventType::Scroll;
+        wheel.scroll = 1;
+        assert_eq!(
+            state.plan(wheel, 1, extent).1,
+            vec![MouseReport::Relative {
+                buttons: 1,
+                dx: 0,
+                dy: 0,
+                wheel: 1
+            }]
+        );
+        state.plan(MouseEvent::move_rel(10, 0), 1, extent);
+        assert_eq!(
+            state
+                .plan(MouseEvent::button_up(MouseButton::Left), 1, extent)
+                .1,
+            vec![
+                MouseReport::Relative {
+                    buttons: 0,
+                    dx: 0,
+                    dy: 0,
+                    wheel: 0
+                },
+                MouseReport::Absolute {
+                    buttons: 0,
+                    x: 8000,
+                    y: 8000
+                },
+            ]
+        );
+    }
+
+    #[test]
+    fn native_relative_clicks_and_reset() {
+        let mut state = MacosDrag::default();
+        state.plan(MouseEvent::move_rel(1, 1), 0, (1920, 1080));
+        assert_eq!(
+            state
+                .plan(MouseEvent::button_down(MouseButton::Left), 0, (1920, 1080))
+                .1,
+            vec![MouseReport::Relative {
+                buttons: 1,
+                dx: 0,
+                dy: 0,
+                wheel: 0
+            }]
+        );
+        state.reset();
+        assert_eq!(
+            state
+                .plan(MouseEvent::button_down(MouseButton::Left), 0, (1920, 1080))
+                .1,
+            vec![MouseReport::Absolute {
+                buttons: 1,
+                x: 0,
+                y: 0
+            }]
+        );
+    }
+}

src/hid/mod.rs

@@ -9,6 +9,7 @@ pub mod consumer;
 pub mod datachannel;
 mod factory;
 pub mod keyboard;
+mod macos_drag;
 #[cfg(unix)]
 pub mod otg;
 #[cfg(unix)]
@@ -135,6 +136,7 @@ pub struct HidController {
     runtime_worker: Mutex<Option<JoinHandle<()>>>,
     backend_available: Arc<AtomicBool>,
     reset_requested: Arc<AtomicBool>,
+    screen_resolution: parking_lot::RwLock<(u32, u32)>,
 }
 
 impl HidController {
@@ -157,6 +159,7 @@ impl HidController {
             runtime_worker: Mutex::new(None),
             backend_available: Arc::new(AtomicBool::new(false)),
             reset_requested: Arc::new(AtomicBool::new(false)),
+            screen_resolution: parking_lot::RwLock::new((1920, 1080)),
         }
     }
 
@@ -179,6 +182,7 @@ impl HidController {
             runtime_worker: Mutex::new(None),
             backend_available: Arc::new(AtomicBool::new(false)),
             reset_requested: Arc::new(AtomicBool::new(false)),
+            screen_resolution: parking_lot::RwLock::new((1920, 1080)),
         }
     }
 
@@ -210,7 +214,12 @@ impl HidController {
             }
         };
 
-        *self.backend.write().await = Some(backend);
+        {
+            let mut slot = self.backend.write().await;
+            let (width, height) = *self.screen_resolution.read();
+            backend.set_screen_resolution(width, height);
+            *slot = Some(backend);
+        }
         self.sync_runtime_state_from_backend().await;
 
         self.start_event_worker().await;
@@ -245,7 +254,8 @@ impl HidController {
     }
 
     pub async fn prepare_otg_rebuild(&self) -> Result<()> {
-        if !matches!(*self.backend_type.read().await, HidBackendType::Otg) {
+        let backend_type = self.backend_type.read().await.clone();
+        if !matches!(backend_type, HidBackendType::Otg { .. }) {
             return Ok(());
         }
 
@@ -259,7 +269,7 @@ impl HidController {
 
         let current = self.runtime_state.read().await.clone();
         let rebuilding_state = HidRuntimeState::with_error(
-            &HidBackendType::Otg,
+            &backend_type,
             &current,
             "OTG gadget is rebuilding",
             "rebuilding",
@@ -337,6 +347,24 @@ impl HidController {
         self.backend_type.read().await.clone()
     }
 
+    /// Keep the active capture dimensions across HID reloads and USB rebuilds.
+    pub async fn set_screen_resolution(&self, width: u32, height: u32) {
+        if width == 0 || height == 0 || width > 65535 || height > 65535 {
+            return;
+        }
+        {
+            let mut resolution = self.screen_resolution.write();
+            if *resolution == (width, height) {
+                return;
+            }
+            *resolution = (width, height);
+        }
+        if let Some(backend) = self.backend.read().await.as_ref() {
+            let (width, height) = *self.screen_resolution.read();
+            backend.set_screen_resolution(width, height);
+        }
+    }
+
     pub async fn snapshot(&self) -> HidRuntimeState {
         self.runtime_state.read().await.clone()
     }
@@ -403,7 +431,14 @@ impl HidController {
             }
         };
 
-        *self.backend.write().await = new_backend;
+        {
+            let mut slot = self.backend.write().await;
+            if let Some(backend) = new_backend.as_ref() {
+                let (width, height) = *self.screen_resolution.read();
+                backend.set_screen_resolution(width, height);
+            }
+            *slot = new_backend;
+        }
 
         if matches!(new_backend_type, HidBackendType::None) {
             *self.backend_type.write().await = HidBackendType::None;
@@ -687,6 +722,27 @@ fn merge_pending_move(pending: &mut Option<MouseEvent>, event: MouseEvent) {
 #[cfg(test)]
 mod queue_tests {
     use super::*;
+    #[tokio::test]
+    async fn screen_resolution_updates_backend_and_retains_valid_dimensions() {
+        #[cfg(unix)]
+        let controller = HidController::new(HidBackendType::None, None);
+        #[cfg(not(unix))]
+        let controller = HidController::new(HidBackendType::None);
+        let backend = Arc::new(ch9329::Ch9329Backend::new("/dev/null").unwrap());
+        *controller.backend.write().await = Some(backend.clone());
+        controller.set_screen_resolution(3840, 2160).await;
+        assert_eq!(
+            backend.runtime_snapshot().screen_resolution,
+            Some((3840, 2160))
+        );
+        controller.set_screen_resolution(0, 0).await;
+        assert_eq!(*controller.screen_resolution.read(), (3840, 2160));
+        controller.set_screen_resolution(1280, 720).await;
+        assert_eq!(
+            backend.runtime_snapshot().screen_resolution,
+            Some((1280, 720))
+        );
+    }
     struct TestBackend {
         pressed: Arc<AtomicBool>,
         reset_done: Arc<tokio::sync::Notify>,

src/hid/otg.rs

@@ -80,6 +80,8 @@ pub struct OtgBackend {
     keyboard_leds_enabled: bool,
     keyboard_state: Mutex<KeyboardReport>,
     mouse_buttons: AtomicU8,
+    macos_drag: bool,
+    macos_drag_state: Mutex<super::macos_drag::MacosDrag>,
     led_state: Arc<parking_lot::RwLock<LedState>>,
     screen_resolution: parking_lot::RwLock<Option<(u32, u32)>>,
     udc_name: Arc<parking_lot::RwLock<Option<String>>>,
@@ -99,6 +101,15 @@ const OTG_RUNTIME_POLL_INTERVAL: Duration = Duration::from_millis(500);
 impl OtgBackend {
     /// Gadget must already exist; paths come from `OtgService`.
     pub fn from_handles(paths: HidDevicePaths) -> Result<Self> {
+        Self::with_macos_drag(paths, false)
+    }
+
+    pub fn with_macos_drag(paths: HidDevicePaths, macos_drag: bool) -> Result<Self> {
+        if macos_drag && (paths.mouse_relative.is_none() || paths.mouse_absolute.is_none()) {
+            return Err(AppError::Config(
+                "macOS drag compatibility requires both OTG mouse interfaces".into(),
+            ));
+        }
         let (runtime_notify_tx, _runtime_notify_rx) = watch::channel(());
         Ok(Self {
             keyboard_path: paths.keyboard,
@@ -112,6 +123,8 @@ impl OtgBackend {
             keyboard_leds_enabled: paths.keyboard_leds_enabled,
             keyboard_state: Mutex::new(KeyboardReport::default()),
             mouse_buttons: AtomicU8::new(0),
+            macos_drag,
+            macos_drag_state: Mutex::new(super::macos_drag::MacosDrag::default()),
             led_state: Arc::new(parking_lot::RwLock::new(LedState::default())),
             screen_resolution: parking_lot::RwLock::new(Some((1920, 1080))),
             udc_name: Arc::new(parking_lot::RwLock::new(paths.udc)),
@@ -852,6 +865,28 @@ impl HidBackend for OtgBackend {
     async fn send_mouse(&self, event: MouseEvent) -> Result<()> {
         let buttons = self.mouse_buttons.load(Ordering::Relaxed);
 
+        if self.macos_drag {
+            use super::macos_drag::MouseReport;
+            let mut state = self.macos_drag_state.lock();
+            let extent = self.screen_resolution.read().unwrap_or((1920, 1080));
+            let (buttons, reports) = state.plan(event, buttons, extent);
+            self.mouse_buttons.store(buttons, Ordering::Relaxed);
+            for report in reports {
+                match report {
+                    MouseReport::Absolute { buttons, x, y } => {
+                        self.send_mouse_report_absolute(buttons, x, y, 0)?
+                    }
+                    MouseReport::Relative {
+                        buttons,
+                        dx,
+                        dy,
+                        wheel,
+                    } => self.send_mouse_report_relative(buttons, dx, dy, wheel)?,
+                }
+            }
+            return Ok(());
+        }
+
         match event.event_type {
             MouseEventType::Move => {
                 let dx = event.x.clamp(-127, 127) as i8;
@@ -896,6 +931,7 @@ impl HidBackend for OtgBackend {
         }
 
         self.mouse_buttons.store(0, Ordering::Relaxed);
+        self.macos_drag_state.lock().reset();
         self.send_mouse_report_relative(0, 0, 0, 0)?;
         self.send_mouse_report_absolute(0, 0, 0, 0)?;
 
@@ -988,6 +1024,51 @@ mod tests {
         assert_eq!(kb_report.to_bytes().len(), 8);
     }
 
+    #[tokio::test]
+    async fn mouse_compatibility_writes_both_endpoints_and_preserves_default() {
+        use crate::hid::MouseButton;
+        for enabled in [false, true] {
+            let relative = tempfile::NamedTempFile::new().unwrap();
+            let absolute = tempfile::NamedTempFile::new().unwrap();
+            let backend = OtgBackend::with_macos_drag(
+                HidDevicePaths {
+                    mouse_relative: Some(relative.path().to_path_buf()),
+                    mouse_absolute: Some(absolute.path().to_path_buf()),
+                    ..Default::default()
+                },
+                enabled,
+            )
+            .unwrap();
+            for event in [
+                MouseEvent::move_abs(8000, 8000),
+                MouseEvent::button_down(MouseButton::Left),
+                MouseEvent::move_abs(16000, 16000),
+                MouseEvent::button_up(MouseButton::Left),
+            ] {
+                backend.send_mouse(event).await.unwrap();
+            }
+            let abs = fs::read(absolute.path()).unwrap();
+            let rel = fs::read(relative.path()).unwrap();
+            let buttons: Vec<_> = abs.chunks_exact(6).map(|packet| packet[0]).collect();
+            assert_eq!(buttons, if enabled { vec![0, 1, 0] } else { vec![0, 0] });
+            let dx: i32 = rel
+                .chunks_exact(4)
+                .map(|packet| i32::from(packet[1] as i8))
+                .sum();
+            let dy: i32 = rel
+                .chunks_exact(4)
+                .map(|packet| i32::from(packet[2] as i8))
+                .sum();
+            assert_eq!((dx, dy), if enabled { (468, 263) } else { (0, 0) });
+            assert_eq!(&rel[rel.len() - 4..], &[0, 0, 0, 0]);
+        }
+    }
+
+    #[test]
+    fn compatibility_requires_both_mouse_endpoints() {
+        assert!(OtgBackend::with_macos_drag(HidDevicePaths::default(), true).is_err());
+    }
+
     #[tokio::test]
     async fn prepare_rebuild_closes_devices_without_writing_reset_reports() {
         let mut file = tempfile::tempfile().unwrap();

src/runtime/builder.rs

@@ -107,6 +107,8 @@ impl RuntimeBuilder {
         #[cfg(target_os = "linux")]
         hid.set_bond_store(config_store.hid_bonds());
         hid.set_event_bus(events.clone()).await;
+        hid.set_screen_resolution(video_resolution.width, video_resolution.height)
+            .await;
         if let Err(error) = hid.init().await {
             tracing::warn!("Failed to initialize HID backend: {}", error);
         }
@@ -407,11 +409,14 @@ async fn build_otg(config: &AppConfig) -> Arc<OtgService> {
 
 fn hid_backend_type(config: &AppConfig) -> HidBackendType {
     match config.hid.backend {
-        config::HidBackend::Otg => HidBackendType::Otg,
+        config::HidBackend::Otg => HidBackendType::Otg {
+            macos_drag: config.hid.mouse_macos_drag,
+        },
         config::HidBackend::Ch9329 => HidBackendType::Ch9329 {
             port: config.hid.ch9329_port.clone(),
             baud_rate: config.hid.ch9329_baudrate,
             hybrid_mouse: config.hid.ch9329_hybrid_mouse,
+            macos_drag: config.hid.mouse_macos_drag,
         },
         config::HidBackend::None => HidBackendType::None,
         config::HidBackend::Bluetooth => HidBackendType::Bluetooth {

src/runtime/usb.rs

@@ -175,14 +175,15 @@ impl UsbCoordinator {
             old_config.constrained_otg_functions() != new_config.constrained_otg_functions();
         let keyboard_leds_changed =
             old_config.effective_otg_keyboard_leds() != new_config.effective_otg_keyboard_leds();
-        let ch9329_runtime_changed =
+        let mouse_compatibility_changed = old_config.ch9329_hybrid_mouse
-            old_config.ch9329_hybrid_mouse != new_config.ch9329_hybrid_mouse;
+            != new_config.ch9329_hybrid_mouse
+            || old_config.mouse_macos_drag != new_config.mouse_macos_drag;
 
         if old_config.backend == new_config.backend
             && old_config.ch9329_port == new_config.ch9329_port
             && old_config.ch9329_baudrate == new_config.ch9329_baudrate
             && old_config.bluetooth == new_config.bluetooth
-            && !ch9329_runtime_changed
+            && !mouse_compatibility_changed
             && old_config.otg_udc == new_config.otg_udc
             && !descriptor_changed
             && !hid_functions_changed
@@ -299,7 +300,7 @@ impl UsbCoordinator {
 
         if hid_config.backend == HidBackend::Otg && (options.force || old_enabled != new_enabled) {
             self.hid
-                .reload(HidBackendType::Otg)
+                .reload(hid_backend_type(hid_config))
                 .await
                 .map_err(|error| AppError::Config(format!("OTG HID reload failed: {error}")))?;
         }
@@ -309,11 +310,14 @@ impl UsbCoordinator {
 
 fn hid_backend_type(config: &HidConfig) -> HidBackendType {
     match config.backend {
-        HidBackend::Otg => HidBackendType::Otg,
+        HidBackend::Otg => HidBackendType::Otg {
+            macos_drag: config.mouse_macos_drag,
+        },
         HidBackend::Ch9329 => HidBackendType::Ch9329 {
             port: config.ch9329_port.clone(),
             baud_rate: config.ch9329_baudrate,
             hybrid_mouse: config.ch9329_hybrid_mouse,
+            macos_drag: config.mouse_macos_drag,
         },
         HidBackend::None => HidBackendType::None,
         HidBackend::Bluetooth => HidBackendType::Bluetooth {

src/state.rs

@@ -218,6 +218,11 @@ impl AppState {
 
     pub async fn publish_device_info(&self) {
         let device_info = self.get_device_info().await;
+        if let SystemEvent::DeviceInfo { video, .. } = &device_info {
+            if let Some((width, height)) = video.resolution {
+                self.hid.set_screen_resolution(width, height).await;
+            }
+        }
         let _ = self.device_info_tx.send(Some(device_info));
     }
 

src/web/handlers/config/types.rs

@@ -409,6 +409,8 @@ pub struct HidConfigUpdate {
     pub ch9329_port: Option<String>,
     pub ch9329_baudrate: Option<u32>,
     pub ch9329_hybrid_mouse: Option<bool>,
+    #[serde(alias = "ch9329_macos_drag")]
+    pub mouse_macos_drag: Option<bool>,
     pub ch9329_descriptor: Option<Ch9329DescriptorConfigUpdate>,
     pub otg_udc: Option<String>,
     pub otg_descriptor: Option<OtgDescriptorConfigUpdate>,
@@ -465,6 +467,9 @@ impl HidConfigUpdate {
         if let Some(enabled) = self.ch9329_hybrid_mouse {
             config.ch9329_hybrid_mouse = enabled;
         }
+        if let Some(enabled) = self.mouse_macos_drag {
+            config.mouse_macos_drag = enabled;
+        }
         if let Some(ref desc) = self.ch9329_descriptor {
             desc.apply_to(&mut config.ch9329_descriptor);
         }

src/web/handlers/config/usb_update.rs

@@ -284,6 +284,7 @@ mod tests {
             ch9329_port: None,
             ch9329_baudrate: None,
             ch9329_hybrid_mouse: None,
+            mouse_macos_drag: None,
             ch9329_descriptor: None,
             otg_udc: None,
             otg_descriptor: None,

src/web/handlers/msd_api.rs

@@ -270,10 +270,8 @@ pub async fn msd_disk_mode_put(
         }));
     }
 
-    let hid_is_otg = matches!(
+    let hid_backend_type = state.hid.backend_type().await;
-        state.hid.backend_type().await,
+    let hid_is_otg = matches!(hid_backend_type, crate::hid::HidBackendType::Otg { .. });
-        crate::hid::HidBackendType::Otg
-    );
 
     if hid_is_otg {
         state
@@ -294,7 +292,7 @@ pub async fn msd_disk_mode_put(
     let hid_reload_result = if hid_is_otg {
         state
             .hid
-            .reload(crate::hid::HidBackendType::Otg)
+            .reload(hid_backend_type)
             .await
             .map_err(|e| AppError::Config(format!("OTG HID reload failed: {e}")))
     } else {

web/src/i18n/en-US.ts

@@ -818,6 +818,9 @@ export default {
     ch9329OptionsDesc: 'Configure runtime compatibility for the CH9329 serial HID chip',
     ch9329HybridMouse: 'Linux Absolute Mouse Compatibility',
     ch9329HybridMouseDesc: 'Keep absolute movement on absolute packets, but send buttons and wheel through relative packets',
+    mouseMacosDrag: 'macOS Drag Compatibility',
+    mouseMacosDragRequiresBoth: 'Enable both relative and absolute mouse interfaces before saving.',
+    mouseMacosDragDesc: 'Experimental workaround for interrupted drags in absolute mouse mode (OTG / CH9329). OTG requires both mouse interfaces. Tracking speed and drop position may vary with macOS settings; this version has not been tested on a Mac.',
     ch9329Descriptor: 'CH9329 USB Device Descriptor',
     ch9329DescriptorDesc: 'Read USB identification fields from the CH9329 chip before editing',
     ch9329DescriptorLoading: 'Reading CH9329 descriptor...',

web/src/i18n/zh-CN.ts

@@ -817,6 +817,9 @@ export default {
     ch9329OptionsDesc: '配置 CH9329 串口 HID 芯片的运行兼容性',
     ch9329HybridMouse: 'Linux 绝对鼠标兼容模式',
     ch9329HybridMouseDesc: '绝对移动仍使用绝对鼠标包，点击和滚轮改用相对鼠标包发送',
+    mouseMacosDrag: 'macOS 拖拽兼容模式',
+    mouseMacosDragRequiresBoth: '请同时启用相对鼠标和绝对鼠标接口后保存。',
+    mouseMacosDragDesc: '实验性缓解绝对鼠标模式下的拖拽中断，适用于 OTG / CH9329。OTG 需同时启用两种鼠标接口。移动速度和落点可能受 macOS 设置影响；本版本尚未进行 Mac 实机验证。',
     ch9329Descriptor: 'CH9329 USB 设备描述符',
     ch9329DescriptorDesc: '先从 CH9329 芯片读取 USB 标识信息，读取成功后再修改',
     ch9329DescriptorLoading: '正在读取 CH9329 描述符...',

web/src/types/generated.ts

@@ -71,6 +71,7 @@ export interface HidConfig {
 	ch9329_port: string;
 	ch9329_baudrate: number;
 	ch9329_hybrid_mouse?: boolean;
+	mouse_macos_drag?: boolean;
 	ch9329_descriptor?: Ch9329DescriptorConfig;
 	mouse_absolute: boolean;
 }
@@ -570,6 +571,7 @@ export interface HidConfigUpdate {
 	ch9329_port?: string;
 	ch9329_baudrate?: number;
 	ch9329_hybrid_mouse?: boolean;
+	mouse_macos_drag?: boolean;
 	ch9329_descriptor?: Ch9329DescriptorConfigUpdate;
 	otg_udc?: string;
 	otg_descriptor?: OtgDescriptorConfigUpdate;

web/src/views/SettingsView.vue

@@ -692,6 +692,7 @@ const config = ref({
   } as OtgHidFunctions,
   hid_otg_keyboard_leds: false,
   hid_ch9329_hybrid_mouse: false,
+  hid_mouse_macos_drag: false,
   msd_enabled: false,
   msd_dir: '',
   msd_flash_inquiry_string: 'One-KVM Virtual Flash',
@@ -1176,6 +1177,8 @@ const isCh9329DescriptorDirty = computed(() => {
 
 const isHidSettingsValid = computed(() =>
   isHidFunctionSelectionValid.value
+  && !(config.value.hid_backend === 'otg' && config.value.hid_mouse_macos_drag
+    && (!effectiveOtgFunctions.value.mouse_relative || !effectiveOtgFunctions.value.mouse_absolute))
   && isCh9329DescriptorValid.value
   && areMsdInquiryStringsValid.value
 )
@@ -1454,7 +1457,12 @@ async function saveConfig() {
         return
       }
       const hidUpdate: HidConfigUpdate = configStore.hid?.backend === 'ch9329'
-        ? { ch9329_hybrid_mouse: config.value.hid_ch9329_hybrid_mouse } : {}
+        ? {
+            ch9329_hybrid_mouse: config.value.hid_ch9329_hybrid_mouse,
+          } : {}
+      if (['otg', 'ch9329'].includes(config.value.hid_backend)) {
+        hidUpdate.mouse_macos_drag = config.value.hid_mouse_macos_drag
+      }
       if (config.value.hid_backend === 'ch9329' && isCh9329DescriptorDirty.value) {
         hidUpdate.ch9329_descriptor = {
           vendor_id: parseInt(ch9329VendorIdHex.value, 16) || 0x1a86,
@@ -1524,7 +1532,7 @@ async function saveConfig() {
 const hidFeatureBaseline = ref('')
 function hidFeatureSnapshot() {
   return JSON.stringify({
-    fields: Object.fromEntries(Object.entries(config.value).filter(([key]) => key.startsWith('msd_') || key.startsWith('otg_network_') || key.startsWith('uac_') || ['hid_otg_functions', 'hid_otg_keyboard_leds', 'hid_ch9329_hybrid_mouse'].includes(key))),
+    fields: Object.fromEntries(Object.entries(config.value).filter(([key]) => key.startsWith('msd_') || key.startsWith('otg_network_') || key.startsWith('uac_') || ['hid_otg_functions', 'hid_otg_keyboard_leds', 'hid_ch9329_hybrid_mouse', 'hid_mouse_macos_drag'].includes(key))),
     descriptor: [otgVendorIdHex.value, otgProductIdHex.value, otgManufacturer.value, otgProduct.value, otgSerialNumber.value],
   })
 }
@@ -1566,6 +1574,7 @@ async function loadConfig() {
       } as OtgHidFunctions,
       hid_otg_keyboard_leds: hid.otg_keyboard_leds ?? false,
       hid_ch9329_hybrid_mouse: hid.ch9329_hybrid_mouse ?? false,
+      hid_mouse_macos_drag: hid.mouse_macos_drag ?? false,
       msd_enabled: msd.enabled || false,
       msd_dir: msd.msd_dir || '',
       msd_flash_inquiry_string: msd.flash_inquiry_string || 'One-KVM Virtual Flash',
@@ -3225,6 +3234,14 @@ watch(isWindows, () => {
                 </template>
 
                 <!-- OTG Descriptor Settings -->
+                <div v-if="['otg', 'ch9329'].includes(config.hid_backend)" class="flex items-center justify-between gap-4 rounded-md border border-border/60 p-3">
+                  <div>
+                    <Label>{{ t('settings.mouseMacosDrag') }}</Label>
+                    <p class="text-xs text-muted-foreground">{{ t('settings.mouseMacosDragDesc') }}</p>
+                    <p v-if="config.hid_backend === 'otg' && config.hid_mouse_macos_drag && (!effectiveOtgFunctions.mouse_relative || !effectiveOtgFunctions.mouse_absolute)" class="text-xs text-warning">{{ t('settings.mouseMacosDragRequiresBoth') }}</p>
+                  </div>
+                  <Switch v-model="config.hid_mouse_macos_drag" />
+                </div>
                 <template v-if="config.hid_backend === 'otg'">
                   <Separator class="my-4" />
                   <div class="space-y-4">