Refactor Viewport and Compositor

core/src/rectangle.rs

@@ -125,17 +125,29 @@ impl Rectangle<f32> {
             None
         }
     }
+
+    /// Rounds the [`Rectangle`] to __unsigned__ integer coordinates.
+    ///
+    /// [`Rectangle`]: struct.Rectangle.html
+    pub fn round(self) -> Rectangle<u32> {
+        Rectangle {
+            x: self.x as u32,
+            y: self.y as u32,
+            width: (self.width + 0.5).round() as u32,
+            height: (self.height + 0.5).round() as u32,
+        }
+    }
 }
 
-impl std::ops::Mul<f32> for Rectangle<u32> {
+impl std::ops::Mul<f32> for Rectangle<f32> {
     type Output = Self;
 
     fn mul(self, scale: f32) -> Self {
         Self {
-            x: (self.x as f32 * scale).round() as u32,
-            y: (self.y as f32 * scale).round() as u32,
-            width: (self.width as f32 * scale).round() as u32,
-            height: (self.height as f32 * scale).round() as u32,
+            x: self.x as f32 * scale,
+            y: self.y as f32 * scale,
+            width: self.width * scale,
+            height: self.height * scale,
         }
     }
 }
@@ -151,17 +163,6 @@ impl From<Rectangle<u32>> for Rectangle<f32> {
     }
 }
 
-impl From<Rectangle<f32>> for Rectangle<u32> {
-    fn from(rectangle: Rectangle<f32>) -> Rectangle<u32> {
-        Rectangle {
-            x: rectangle.x as u32,
-            y: rectangle.y as u32,
-            width: (rectangle.width + 0.5).round() as u32,
-            height: (rectangle.height + 0.5).round() as u32,
-        }
-    }
-}
-
 impl<T> std::ops::Add<Vector<T>> for Rectangle<T>
 where
     T: std::ops::Add<Output = T>,

core/src/size.rs

@@ -2,11 +2,20 @@ use std::f32;
 
 /// An amount of space in 2 dimensions.
 #[derive(Debug, Clone, Copy, PartialEq)]
-pub struct Size {
+pub struct Size<T = f32> {
     /// The width.
-    pub width: f32,
+    pub width: T,
     /// The height.
-    pub height: f32,
+    pub height: T,
+}
+
+impl<T> Size<T> {
+    /// Creates a new  [`Size`] with the given width and height.
+    ///
+    /// [`Size`]: struct.Size.html
+    pub const fn new(width: T, height: T) -> Self {
+        Size { width, height }
+    }
 }
 
 impl Size {
@@ -25,13 +34,6 @@ impl Size {
     /// [`Size`]: struct.Size.html
     pub const INFINITY: Size = Size::new(f32::INFINITY, f32::INFINITY);
 
-    /// Creates a new  [`Size`] with the given width and height.
-    ///
-    /// [`Size`]: struct.Size.html
-    pub const fn new(width: f32, height: f32) -> Self {
-        Size { width, height }
-    }
-
     /// Increments the [`Size`] to account for the given padding.
     ///
     /// [`Size`]: struct.Size.html