wayland: implement scaling

This involves many subsystems:

- config:
    - allow setting the connector scale
    - allow setting the cursor size
- cursors:
    - load server cursors for all requested sizes and scales
- wl_surface:
    - track the output the surface belongs to
    - send wl_surface.enter/leave
- wl_output:
    - implement wl_output.scale
- text:
    - pre-render texts for all used scales
- renderer:
    - properly align scale textures and rectangles
- wp_fractional_scale:
    - new interface for fractional scaling

jay-config/src/_private/client.rs

@@ -359,6 +359,10 @@ impl Client {
         size
     }
 
+    pub fn set_cursor_size(&self, seat: Seat, size: i32) {
+        self.send(&ClientMessage::SetCursorSize { seat, size })
+    }
+
     pub fn set_size(&self, sized: Resizable, size: i32) {
         self.send(&ClientMessage::SetSize { sized, size })
     }
@@ -459,6 +463,16 @@ impl Client {
         connected
     }
 
+    pub fn connector_set_scale(&self, connector: Connector, scale: f64) {
+        self.send(&ClientMessage::ConnectorSetScale { connector, scale });
+    }
+
+    pub fn connector_get_scale(&self, connector: Connector) -> f64 {
+        let res = self.send_with_response(&ClientMessage::ConnectorGetScale { connector });
+        get_response!(res, 1.0, ConnectorGetScale { scale });
+        scale
+    }
+
     pub fn connector_type(&self, connector: Connector) -> ConnectorType {
         let res = self.send_with_response(&ClientMessage::ConnectorType { connector });
         get_response!(res, CON_UNKNOWN, ConnectorType { ty });
@@ -483,6 +497,12 @@ impl Client {
         }
     }
 
+    pub fn connector_size(&self, connector: Connector) -> (i32, i32) {
+        let res = self.send_with_response(&ClientMessage::ConnectorSize { connector });
+        get_response!(res, (0, 0), ConnectorSize { width, height });
+        (width, height)
+    }
+
     pub fn drm_devices(&self) -> Vec<DrmDevice> {
         let res = self.send_with_response(&ClientMessage::GetDrmDevices);
         get_response!(res, vec![], GetDrmDevices { devices });

jay-config/src/_private/ipc.rs

@@ -274,6 +274,20 @@ pub enum ClientMessage<'a> {
         device: InputDevice,
         px: f64,
     },
+    ConnectorSetScale {
+        connector: Connector,
+        scale: f64,
+    },
+    ConnectorGetScale {
+        connector: Connector,
+    },
+    ConnectorSize {
+        connector: Connector,
+    },
+    SetCursorSize {
+        seat: Seat,
+        size: i32,
+    },
 }
 
 #[derive(Encode, Decode, Debug)]
@@ -360,6 +374,13 @@ pub enum Response {
     GetFont {
         font: String,
     },
+    ConnectorGetScale {
+        scale: f64,
+    },
+    ConnectorSize {
+        width: i32,
+        height: i32,
+    },
 }
 
 #[derive(Encode, Decode, Debug)]

jay-config/src/input.rs

@@ -107,6 +107,13 @@ impl Seat {
         Self(raw)
     }
 
+    /// Sets the size of the cursor theme.
+    ///
+    /// Default: 16.
+    pub fn set_cursor_size(self, size: i32) {
+        get!().set_cursor_size(self, size)
+    }
+
     /// Creates a compositor-wide hotkey.
     ///
     /// The closure is invoked when the user presses the last key of the modified keysym.

jay-config/src/video.rs

@@ -79,6 +79,23 @@ impl Connector {
         get!(false).connector_connected(self)
     }
 
+    /// Returns the scale of the currently connected monitor.
+    pub fn scale(self) -> f64 {
+        if !self.exists() {
+            return 1.0;
+        }
+        get!(1.0).connector_get_scale(self)
+    }
+
+    /// Sets the scale to use for the currently connected monitor.
+    pub fn set_scale(self, scale: f64) {
+        if !self.exists() {
+            return;
+        }
+        log::info!("setting scale to {}", scale);
+        get!().connector_set_scale(self, scale);
+    }
+
     /// Returns the connector type.
     pub fn ty(self) -> ConnectorType {
         if !self.exists() {
@@ -95,18 +112,18 @@ impl Connector {
         get!(Mode::zeroed()).connector_mode(self)
     }
 
-    /// Returns the width of the current mode of the connector.
+    /// Returns the logical width of the connector.
     ///
-    /// This is a shortcut for `mode().width()`.
+    /// The returned value will be different from `mode().width()` if the scale is not 1.
     pub fn width(self) -> i32 {
-        self.mode().width
+        get!().connector_size(self).0
     }
 
-    /// Returns the height of the current mode of the connector.
+    /// Returns the logical height of the connector.
     ///
-    /// This is a shortcut for `mode().height()`.
+    /// The returned value will be different from `mode().height()` if the scale is not 1.
     pub fn height(self) -> i32 {
-        self.mode().height
+        get!().connector_size(self).1
     }
 
     /// Returns the refresh rate in mhz of the current mode of the connector.