Merge pull request #41 from RustAudio/x11-frame-timer

X11 frame timer

Cargo.toml

@@ -18,6 +18,7 @@ raw-window-handle = "0.3.3"
 xcb = { version = "0.9", features = ["thread", "xlib_xcb", "dri2"] }
 x11 = { version = "2.18", features = ["xlib"] }
 libc = "0.2"
+nix = "0.18"
 
 [target.'cfg(target_os="windows")'.dependencies]
 winapi = { version = "0.3.8", features = ["libloaderapi", "winuser", "windef", "minwindef", "guiddef", "combaseapi", "wingdi", "errhandlingapi"] }

examples/open_window.rs

@@ -20,7 +20,7 @@ impl WindowHandler for MyProgram {
         Self {}
     }
 
-    fn draw(&mut self, window: &mut Window) {}
+    fn draw(&mut self, _window: &mut Window) {}
 
     fn on_event(&mut self, window: &mut Window, event: Event) {
         match event {

src/x11/window.rs

@@ -1,28 +1,30 @@
-use std::ffi::CStr;
 use std::os::raw::{c_ulong, c_void};
+use std::time::*;
+
+use raw_window_handle::{unix::XlibHandle, HasRawWindowHandle, RawWindowHandle};
 
 use super::XcbConnection;
 use crate::{Event, MouseButtonID, MouseScroll, Parent, WindowHandler, WindowOpenOptions};
 
-use raw_window_handle::{unix::XlibHandle, HasRawWindowHandle, RawWindowHandle};
 
 pub struct Window {
     xcb_connection: XcbConnection,
     window_id: u32,
     scaling: f64,
+
+    frame_interval: Duration,
+    event_loop_running: bool
 }
 
+// FIXME: move to outer crate context
+pub struct WindowHandle;
+
+
 impl Window {
     pub fn open<H: WindowHandler>(options: WindowOpenOptions) -> WindowHandle {
-        // Convert the parent to a X11 window ID if we're given one
-        let parent = match options.parent {
-            Parent::None => None,
-            Parent::AsIfParented => None, // TODO: ???
-            Parent::WithParent(p) => Some(p as u32),
-        };
-
         // Connect to the X server
-        let xcb_connection = XcbConnection::new();
+        // FIXME: baseview error type instead of unwrap()
+        let xcb_connection = XcbConnection::new().unwrap();
 
         // Get screen information (?)
         let setup = xcb_connection.conn.get_setup();
@@ -34,10 +36,9 @@ impl Window {
         let foreground = xcb_connection.conn.generate_id();
 
         // Convert parent into something that X understands
-        let parent_id = if let Some(p) = parent {
+        let parent_id = match options.parent {
-            p
+            Parent::WithParent(p) => p as u32,
-        } else {
+            Parent::None | Parent::AsIfParented => screen.root(),
-            screen.root()
         };
 
         xcb::create_gc(
@@ -73,6 +74,7 @@ impl Window {
                     | xcb::EVENT_MASK_KEY_RELEASE,
             )],
         );
+
         xcb::map_window(&xcb_connection.conn, window_id);
 
         // Change window title
@@ -89,41 +91,79 @@ impl Window {
 
         xcb_connection.conn.flush();
 
-        let scaling = get_scaling_xft(&xcb_connection)
+        let scaling = xcb_connection.get_scaling().unwrap_or(1.0);
-            .or(get_scaling_screen_dimensions(&xcb_connection))
-            .unwrap_or(1.0);
 
         let mut window = Self {
             xcb_connection,
             window_id,
             scaling,
+
+            frame_interval: Duration::from_millis(15),
+            event_loop_running: false
         };
 
         let mut handler = H::build(&mut window);
 
-        run_event_loop(&mut window, &mut handler);
+        window.run_event_loop(&mut handler);
 
         WindowHandle
     }
-}
 
-unsafe impl HasRawWindowHandle for Window {
+    #[inline]
-    fn raw_window_handle(&self) -> RawWindowHandle {
+    fn drain_xcb_events<H: WindowHandler>(&mut self, handler: &mut H) {
-        RawWindowHandle::Xlib(XlibHandle {
+        while let Some(event) = self.xcb_connection.conn.poll_for_event() {
-            window: self.window_id as c_ulong,
+            self.handle_xcb_event(handler, event);
-            display: self.xcb_connection.conn.get_raw_dpy() as *mut c_void,
+        }
-            ..raw_window_handle::unix::XlibHandle::empty()
-        })
     }
-}
 
-pub struct WindowHandle;
+    // Event loop
+    // FIXME: poll() acts fine on linux, sometimes funky on *BSD. XCB upstream uses a define to
+    // switch between poll() and select() (the latter of which is fine on *BSD), and we should do
+    // the same.
+    fn run_event_loop<H: WindowHandler>(&mut self, handler: &mut H) {
+        use nix::poll::*;
 
-// Event loop
+        let xcb_fd = unsafe {
-fn run_event_loop<H: WindowHandler>(window: &mut Window, handler: &mut H) {
+            let raw_conn = self.xcb_connection.conn.get_raw_conn();
-    loop {
+            xcb::ffi::xcb_get_file_descriptor(raw_conn)
-        let ev = window.xcb_connection.conn.wait_for_event();
+        };
-        if let Some(event) = ev {
+
+        let mut next_frame = Instant::now() + self.frame_interval;
+        self.event_loop_running = true;
+
+        while self.event_loop_running {
+            let now = Instant::now();
+            let until_next_frame =
+                if now > next_frame {
+                    handler.draw(self);
+
+                    next_frame = now + self.frame_interval;
+                    self.frame_interval
+                } else {
+                    next_frame - now
+                };
+
+            let mut fds = [
+                PollFd::new(xcb_fd, PollFlags::POLLIN)
+            ];
+
+            // FIXME: handle errors
+            poll(&mut fds, until_next_frame.subsec_millis() as i32)
+                .unwrap();
+
+            if let Some(revents) = fds[0].revents() {
+                if revents.contains(PollFlags::POLLERR) {
+                    panic!("xcb connection poll error");
+                }
+
+                if revents.contains(PollFlags::POLLIN) {
+                    self.drain_xcb_events(handler);
+                }
+            }
+        }
+    }
+
+    fn handle_xcb_event<H: WindowHandler>(&mut self, handler: &mut H, event: xcb::GenericEvent) {
         let event_type = event.response_type() & !0x80;
 
         // For all of the keyboard and mouse events, you can fetch
@@ -148,7 +188,7 @@ fn run_event_loop<H: WindowHandler>(window: &mut Window, handler: &mut H) {
 
         match event_type {
             xcb::EXPOSE => {
-                    handler.draw(window);
+                handler.draw(self);
             }
             xcb::MOTION_NOTIFY => {
                 let event = unsafe { xcb::cast_event::<xcb::MotionNotifyEvent>(&event) };
@@ -156,7 +196,7 @@ fn run_event_loop<H: WindowHandler>(window: &mut Window, handler: &mut H) {
 
                 if detail != 4 && detail != 5 {
                     handler.on_event(
-                            window,
+                        self,
                         Event::CursorMotion(event.event_x() as i32, event.event_y() as i32),
                     );
                 }
@@ -168,7 +208,7 @@ fn run_event_loop<H: WindowHandler>(window: &mut Window, handler: &mut H) {
                 match detail {
                     4 => {
                         handler.on_event(
-                                window,
+                            self,
                             Event::MouseScroll(MouseScroll {
                                 x_delta: 0.0,
                                 y_delta: 1.0,
@@ -177,7 +217,7 @@ fn run_event_loop<H: WindowHandler>(window: &mut Window, handler: &mut H) {
                     }
                     5 => {
                         handler.on_event(
-                                window,
+                            self,
                             Event::MouseScroll(MouseScroll {
                                 x_delta: 0.0,
                                 y_delta: -1.0,
@@ -186,7 +226,7 @@ fn run_event_loop<H: WindowHandler>(window: &mut Window, handler: &mut H) {
                     }
                     detail => {
                         let button_id = mouse_id(detail);
-                            handler.on_event(window, Event::MouseDown(button_id));
+                        handler.on_event(self, Event::MouseDown(button_id));
                     }
                 }
             }
@@ -196,108 +236,36 @@ fn run_event_loop<H: WindowHandler>(window: &mut Window, handler: &mut H) {
 
                 if detail != 4 && detail != 5 {
                     let button_id = mouse_id(detail);
-                        handler.on_event(window, Event::MouseUp(button_id));
+                    handler.on_event(self, Event::MouseUp(button_id));
                 }
             }
             xcb::KEY_PRESS => {
                 let event = unsafe { xcb::cast_event::<xcb::KeyPressEvent>(&event) };
                 let detail = event.detail();
 
-                    handler.on_event(window, Event::KeyDown(detail));
+                handler.on_event(self, Event::KeyDown(detail));
             }
             xcb::KEY_RELEASE => {
                 let event = unsafe { xcb::cast_event::<xcb::KeyReleaseEvent>(&event) };
                 let detail = event.detail();
 
-                    handler.on_event(window, Event::KeyUp(detail));
+                handler.on_event(self, Event::KeyUp(detail));
             }
             _ => {
                 println!("Unhandled event type: {:?}", event_type);
             }
         }
     }
-    }
 }
 
-// Try to get the scaling with this function first.
+unsafe impl HasRawWindowHandle for Window {
-// If this gives you `None`, fall back to `get_scaling_screen_dimensions`.
+    fn raw_window_handle(&self) -> RawWindowHandle {
-// If neither work, I guess just assume 96.0 and don't do any scaling.
+        RawWindowHandle::Xlib(XlibHandle {
-fn get_scaling_xft(xcb_connection: &XcbConnection) -> Option<f64> {
+            window: self.window_id as c_ulong,
-    use std::ffi::CString;
+            display: self.xcb_connection.conn.get_raw_dpy() as *mut c_void,
-    use x11::xlib::{
+            ..raw_window_handle::unix::XlibHandle::empty()
-        XResourceManagerString, XrmDestroyDatabase, XrmGetResource, XrmGetStringDatabase, XrmValue,
+        })
-    };
-
-    let display = xcb_connection.conn.get_raw_dpy();
-    unsafe {
-        let rms = XResourceManagerString(display);
-        if !rms.is_null() {
-            let db = XrmGetStringDatabase(rms);
-            if !db.is_null() {
-                let mut value = XrmValue {
-                    size: 0,
-                    addr: std::ptr::null_mut(),
-                };
-
-                let mut value_type: *mut libc::c_char = std::ptr::null_mut();
-                let name_c_str = CString::new("Xft.dpi").unwrap();
-                let c_str = CString::new("Xft.Dpi").unwrap();
-
-                let dpi = if XrmGetResource(
-                    db,
-                    name_c_str.as_ptr(),
-                    c_str.as_ptr(),
-                    &mut value_type,
-                    &mut value,
-                ) != 0
-                    && !value.addr.is_null()
-                {
-                    let value_addr: &CStr = CStr::from_ptr(value.addr);
-                    value_addr.to_str().ok();
-                    let value_str = value_addr.to_str().ok()?;
-                    let value_f64: f64 = value_str.parse().ok()?;
-                    let dpi_to_scale = value_f64 / 96.0;
-                    Some(dpi_to_scale)
-                } else {
-                    None
-                };
-                XrmDestroyDatabase(db);
-
-                return dpi;
     }
-        }
-    }
-    None
-}
-
-// Try to get the scaling with `get_scaling_xft` first.
-// Only use this function as a fallback.
-// If neither work, I guess just assume 96.0 and don't do any scaling.
-fn get_scaling_screen_dimensions(xcb_connection: &XcbConnection) -> Option<f64> {
-    // Figure out screen information
-    let setup = xcb_connection.conn.get_setup();
-    let screen = setup
-        .roots()
-        .nth(xcb_connection.xlib_display as usize)
-        .unwrap();
-
-    // Get the DPI from the screen struct
-    //
-    // there are 2.54 centimeters to an inch; so there are 25.4 millimeters.
-    // dpi = N pixels / (M millimeters / (25.4 millimeters / 1 inch))
-    //     = N pixels / (M inch / 25.4)
-    //     = N * 25.4 pixels / M inch
-    let width_px = screen.width_in_pixels() as f64;
-    let width_mm = screen.width_in_millimeters() as f64;
-    let height_px = screen.height_in_pixels() as f64;
-    let height_mm = screen.height_in_millimeters() as f64;
-    let _xres = width_px * 25.4 / width_mm;
-    let yres = height_px * 25.4 / height_mm;
-
-    let yscale = yres / 96.0;
-
-    // TODO: choose between `xres` and `yres`? (probably both are the same?)
-    Some(yscale)
 }
 
 fn mouse_id(id: u8) -> MouseButtonID {

src/x11/xcb_connection.rs

@@ -2,14 +2,109 @@
 ///
 /// Keeps track of the xcb connection itself and the xlib display ID that was used to connect.
 
+use std::ffi::{
+    CString,
+    CStr
+};
+
 pub struct XcbConnection {
     pub conn: xcb::Connection,
     pub xlib_display: i32,
 }
 
 impl XcbConnection {
-    pub fn new() -> Self {
+    pub fn new() -> Result<Self, xcb::base::ConnError> {
-        let (conn, xlib_display) = xcb::Connection::connect_with_xlib_display().unwrap();
+        xcb::Connection::connect_with_xlib_display()
-        Self { conn, xlib_display }
+            .map(|(conn, xlib_display)|
+                Self {
+                    conn,
+                    xlib_display
+                })
+    }
+
+    // Try to get the scaling with this function first.
+    // If this gives you `None`, fall back to `get_scaling_screen_dimensions`.
+    // If neither work, I guess just assume 96.0 and don't do any scaling.
+    fn get_scaling_xft(&self) -> Option<f64> {
+        use x11::xlib::{
+            XResourceManagerString, XrmDestroyDatabase, XrmGetResource, XrmGetStringDatabase, XrmValue,
+        };
+
+        let display = self.conn.get_raw_dpy();
+        unsafe {
+            let rms = XResourceManagerString(display);
+            if !rms.is_null() {
+                let db = XrmGetStringDatabase(rms);
+                if !db.is_null() {
+                    let mut value = XrmValue {
+                        size: 0,
+                        addr: std::ptr::null_mut(),
+                    };
+
+                    let mut value_type: *mut libc::c_char = std::ptr::null_mut();
+                    let name_c_str = CString::new("Xft.dpi").unwrap();
+                    let c_str = CString::new("Xft.Dpi").unwrap();
+
+                    let dpi = if XrmGetResource(
+                        db,
+                        name_c_str.as_ptr(),
+                        c_str.as_ptr(),
+                        &mut value_type,
+                        &mut value,
+                    ) != 0
+                        && !value.addr.is_null()
+                    {
+                        let value_addr: &CStr = CStr::from_ptr(value.addr);
+                        value_addr.to_str().ok();
+                        let value_str = value_addr.to_str().ok()?;
+                        let value_f64: f64 = value_str.parse().ok()?;
+                        let dpi_to_scale = value_f64 / 96.0;
+                        Some(dpi_to_scale)
+                    } else {
+                        None
+                    };
+                    XrmDestroyDatabase(db);
+
+                    return dpi;
+                }
+            }
+        }
+        None
+    }
+
+    // Try to get the scaling with `get_scaling_xft` first.
+    // Only use this function as a fallback.
+    // If neither work, I guess just assume 96.0 and don't do any scaling.
+    fn get_scaling_screen_dimensions(&self) -> Option<f64> {
+        // Figure out screen information
+        let setup = self.conn.get_setup();
+        let screen = setup
+            .roots()
+            .nth(self.xlib_display as usize)
+            .unwrap();
+
+        // Get the DPI from the screen struct
+        //
+        // there are 2.54 centimeters to an inch; so there are 25.4 millimeters.
+        // dpi = N pixels / (M millimeters / (25.4 millimeters / 1 inch))
+        //     = N pixels / (M inch / 25.4)
+        //     = N * 25.4 pixels / M inch
+        let width_px = screen.width_in_pixels() as f64;
+        let width_mm = screen.width_in_millimeters() as f64;
+        let height_px = screen.height_in_pixels() as f64;
+        let height_mm = screen.height_in_millimeters() as f64;
+        let _xres = width_px * 25.4 / width_mm;
+        let yres = height_px * 25.4 / height_mm;
+
+        let yscale = yres / 96.0;
+
+        // TODO: choose between `xres` and `yres`? (probably both are the same?)
+        Some(yscale)
+    }
+
+    #[inline]
+    pub fn get_scaling(&self) -> Option<f64> {
+        self.get_scaling_xft()
+            .or(self.get_scaling_screen_dimensions())
     }
 }