refactor: extract surface dimensions and scaling mode

src/windowing/mod.rs

@@ -4,6 +4,7 @@ mod globals;
 mod macros;
 mod state;
 mod surface;
+mod surface_dimensions;
 mod system;
 
 pub use system::WindowingSystem;

src/windowing/state/mod.rs

@@ -9,10 +9,18 @@ use wayland_protocols::wp::fractional_scale::v1::client::wp_fractional_scale_v1:
 use wayland_protocols::wp::viewporter::client::wp_viewport::WpViewport;
 use crate::rendering::femtovg_window::FemtoVGWindow;
 use crate::errors::{LayerShikaError, Result};
+use crate::windowing::surface_dimensions::SurfaceDimensions;
 
 pub mod builder;
 pub mod dispatches;
 
+#[derive(Debug)]
+enum ScalingMode {
+    FractionalWithViewport,
+    FractionalOnly,
+    Integer,
+}
+
 pub struct WindowState {
     component_instance: ComponentInstance,
     surface: Rc<WlSurface>,
@@ -77,78 +85,93 @@ impl WindowState {
         })
     }
 
+    const fn determine_scaling_mode(&self) -> ScalingMode {
+        if self.fractional_scale.is_some() && self.viewport.is_some() {
+            ScalingMode::FractionalWithViewport
+        } else if self.fractional_scale.is_some() {
+            ScalingMode::FractionalOnly
+        } else {
+            ScalingMode::Integer
+        }
+    }
+
     #[allow(clippy::cast_precision_loss)]
+    fn configure_slint_window(&self, dimensions: &SurfaceDimensions, mode: &ScalingMode) {
+        match mode {
+            ScalingMode::FractionalWithViewport => {
+                self.window
+                    .set_size(slint::WindowSize::Logical(slint::LogicalSize::new(
+                        dimensions.logical_width as f32,
+                        dimensions.logical_height as f32,
+                    )));
+                self.window.set_scale_factor(self.scale_factor);
+            }
+            ScalingMode::FractionalOnly => {
+                self.window
+                    .set_size(slint::WindowSize::Logical(slint::LogicalSize::new(
+                        dimensions.logical_width as f32,
+                        dimensions.logical_height as f32,
+                    )));
+                self.window.set_scale_factor(dimensions.buffer_scale as f32);
+            }
+            ScalingMode::Integer => {
+                self.window
+                    .set_size(slint::WindowSize::Physical(dimensions.physical_size()));
+                self.window.set_scale_factor(self.scale_factor);
+            }
+        }
+    }
+
     #[allow(clippy::cast_possible_wrap)]
+    fn configure_wayland_surface(&self, dimensions: &SurfaceDimensions, mode: &ScalingMode) {
+        match mode {
+            ScalingMode::FractionalWithViewport => {
+                self.surface.set_buffer_scale(1);
+                if let Some(viewport) = &self.viewport {
+                    viewport.set_destination(
+                        dimensions.logical_width as i32,
+                        dimensions.logical_height as i32,
+                    );
+                }
+            }
+            ScalingMode::FractionalOnly | ScalingMode::Integer => {
+                self.surface.set_buffer_scale(dimensions.buffer_scale);
+            }
+        }
+
+        self.layer_surface
+            .set_size(dimensions.logical_width, dimensions.logical_height);
+        self.layer_surface.set_exclusive_zone(self.exclusive_zone);
+        self.surface.commit();
+    }
+
     pub fn update_size(&mut self, width: u32, height: u32) {
         if width == 0 || height == 0 {
             info!("Skipping update_size with zero dimension: {width}x{height}");
             return;
         }
 
-        #[allow(clippy::cast_possible_truncation)]
+        let dimensions = SurfaceDimensions::calculate(width, height, self.scale_factor);
-        #[allow(clippy::cast_sign_loss)]
+        let scaling_mode = self.determine_scaling_mode();
-        #[allow(clippy::cast_precision_loss)]
-        let physical_width = (width as f32 * self.scale_factor).round() as u32;
-        #[allow(clippy::cast_possible_truncation)]
-        #[allow(clippy::cast_sign_loss)]
-        #[allow(clippy::cast_precision_loss)]
-        let physical_height = (height as f32 * self.scale_factor).round() as u32;
-
-        let new_physical_size = PhysicalSize::new(physical_width, physical_height);
-        let new_logical_size = PhysicalSize::new(width, height);
 
         info!(
-            "Updating window size: buffer {}x{}, physical {}x{}, scale {}, has_viewport: {}",
+            "Updating window size: logical {}x{}, physical {}x{}, scale {}, buffer_scale {}, mode {:?}",
-            width,
+            dimensions.logical_width,
-            height,
+            dimensions.logical_height,
-            physical_width,
+            dimensions.physical_width,
-            physical_height,
+            dimensions.physical_height,
             self.scale_factor,
-            self.viewport.is_some()
+            dimensions.buffer_scale,
+            scaling_mode
         );
 
-        if self.fractional_scale.is_some() && self.viewport.is_some() {
+        self.configure_slint_window(&dimensions, &scaling_mode);
-            self.surface.set_buffer_scale(1);
+        self.configure_wayland_surface(&dimensions, &scaling_mode);
-            self.window
-                .set_size(slint::WindowSize::Logical(slint::LogicalSize::new(
-                    width as f32,
-                    height as f32,
-                )));
-            self.window.set_scale_factor(self.scale_factor);
-
-            if let Some(viewport) = &self.viewport {
-                viewport.set_destination(width as i32, height as i32);
-            }
-        } else if self.fractional_scale.is_some() {
-            #[allow(clippy::cast_possible_truncation)]
-            let buffer_scale = self.scale_factor.round() as i32;
-            self.surface.set_buffer_scale(buffer_scale);
-
-            self.window
-                .set_size(slint::WindowSize::Logical(slint::LogicalSize::new(
-                    width as f32,
-                    height as f32,
-                )));
-            #[allow(clippy::cast_precision_loss)]
-            self.window.set_scale_factor(buffer_scale as f32);
-        } else {
-            #[allow(clippy::cast_possible_truncation)]
-            let buffer_scale = self.scale_factor.round() as i32;
-            self.surface.set_buffer_scale(buffer_scale);
-
-            self.window
-                .set_size(slint::WindowSize::Physical(new_physical_size));
-            self.window.set_scale_factor(self.scale_factor);
-        }
 
         info!("Window physical size: {:?}", self.window.size());
 
-        self.layer_surface.set_size(width, height);
+        self.size = dimensions.physical_size();
-        self.layer_surface.set_exclusive_zone(self.exclusive_zone);
+        self.logical_size = dimensions.logical_size();
-        self.surface.commit();
-
-        self.size = new_physical_size;
-        self.logical_size = new_logical_size;
         self.window.request_redraw();
     }
 
@@ -159,8 +182,8 @@ impl WindowState {
         } else {
             let scale_factor = self.scale_factor;
             LogicalPosition::new(
-                physical_x as f32 / scale_factor,
+                (physical_x / f64::from(scale_factor)) as f32,
-                physical_y as f32 / scale_factor,
+                (physical_y / f64::from(scale_factor)) as f32,
             )
         };
         self.current_pointer_position = logical_position;
@@ -202,8 +225,8 @@ impl WindowState {
         &self.component_instance
     }
 
-    pub fn update_scale_factor(&mut self, scale_120ths: u32) {
     #[allow(clippy::cast_precision_loss)]
+    pub fn update_scale_factor(&mut self, scale_120ths: u32) {
         let new_scale_factor = scale_120ths as f32 / 120.0;
         info!(
             "Updating scale factor from {} to {} ({}x)",

src/windowing/surface_dimensions.rs

@@ -0,0 +1,39 @@
+use slint::PhysicalSize;
+
+#[derive(Debug, Clone, Copy)]
+pub struct SurfaceDimensions {
+    pub logical_width: u32,
+    pub logical_height: u32,
+    pub physical_width: u32,
+    pub physical_height: u32,
+    pub buffer_scale: i32,
+}
+
+impl SurfaceDimensions {
+    #[allow(
+        clippy::cast_possible_truncation,
+        clippy::cast_sign_loss,
+        clippy::cast_precision_loss
+    )]
+    pub fn calculate(logical_width: u32, logical_height: u32, scale_factor: f32) -> Self {
+        let physical_width = (logical_width as f32 * scale_factor).round() as u32;
+        let physical_height = (logical_height as f32 * scale_factor).round() as u32;
+        let buffer_scale = scale_factor.round() as i32;
+
+        Self {
+            logical_width,
+            logical_height,
+            physical_width,
+            physical_height,
+            buffer_scale,
+        }
+    }
+
+    pub const fn logical_size(&self) -> PhysicalSize {
+        PhysicalSize::new(self.logical_width, self.logical_height)
+    }
+
+    pub const fn physical_size(&self) -> PhysicalSize {
+        PhysicalSize::new(self.physical_width, self.physical_height)
+    }
+}