Refactor `Viewport` and `Compositor`

6 files changed, 109 insertions, 48 deletions

diff --git a/graphics/Cargo.toml b/graphics/Cargo.toml
index 61f1f6d4..12ad3f14 100644
--- a/graphics/Cargo.toml
+++ b/graphics/Cargo.toml
@@ -13,6 +13,7 @@ font-icons = []
 [dependencies]
 bytemuck = "1.2"
 glam = "0.8"
+raw-window-handle = "0.3"
 
 [dependencies.iced_native]
 version = "0.2"
diff --git a/graphics/src/layer.rs b/graphics/src/layer.rs
index ae9c6ce0..916b5c83 100644
--- a/graphics/src/layer.rs
+++ b/graphics/src/layer.rs
@@ -7,7 +7,7 @@ use crate::{
 };
 
 pub struct Layer<'a> {
-    pub bounds: Rectangle<u32>,
+    pub bounds: Rectangle,
     pub quads: Vec<Quad>,
     pub meshes: Vec<Mesh<'a>>,
     pub text: Vec<Text<'a>>,
@@ -15,7 +15,7 @@ pub struct Layer<'a> {
 }
 
 impl<'a> Layer<'a> {
-    pub fn new(bounds: Rectangle<u32>) -> Self {
+    pub fn new(bounds: Rectangle) -> Self {
         Self {
             bounds,
             quads: Vec::new(),
@@ -26,14 +26,8 @@ impl<'a> Layer<'a> {
     }
 
     pub fn overlay(lines: &'a [impl AsRef<str>], viewport: &Viewport) -> Self {
-        let (width, height) = viewport.dimensions();
-
-        let mut overlay = Layer::new(Rectangle {
-            x: 0,
-            y: 0,
-            width,
-            height,
-        });
+        let mut overlay =
+            Layer::new(Rectangle::with_size(viewport.logical_size()));
 
         for (i, line) in lines.iter().enumerate() {
             let text = Text {
@@ -61,28 +55,14 @@ impl<'a> Layer<'a> {
         overlay
     }
 
-    pub(crate) fn intersection(
-        &self,
-        rectangle: Rectangle,
-    ) -> Option<Rectangle<u32>> {
-        let layer_bounds: Rectangle<f32> = self.bounds.into();
-
-        layer_bounds.intersection(&rectangle).map(Into::into)
-    }
-
     pub fn generate(
         primitive: &'a Primitive,
         viewport: &Viewport,
     ) -> Vec<Self> {
-        let mut layers = Vec::new();
-        let (width, height) = viewport.dimensions();
+        let first_layer =
+            Layer::new(Rectangle::with_size(viewport.logical_size()));
 
-        layers.push(Layer::new(Rectangle {
-            x: 0,
-            y: 0,
-            width,
-            height,
-        }));
+        let mut layers = vec![first_layer];
 
         Self::process_primitive(&mut layers, Vector::new(0.0, 0.0), primitive);
 
@@ -156,11 +136,11 @@ impl<'a> Layer<'a> {
                 );
 
                 // Only draw visible content
-                if let Some(clip_bounds) = layer.intersection(bounds) {
+                if let Some(clip_bounds) = layer.bounds.intersection(&bounds) {
                     layer.meshes.push(Mesh {
                         origin: Point::new(translation.x, translation.y),
                         buffers,
-                        clip_bounds: clip_bounds.into(),
+                        clip_bounds,
                     });
                 }
             }
@@ -170,12 +150,13 @@ impl<'a> Layer<'a> {
                 content,
             } => {
                 let layer = layers.last_mut().unwrap();
+                let translated_bounds = *bounds + translation;
 
                 // Only draw visible content
                 if let Some(clip_bounds) =
-                    layer.intersection(*bounds + translation)
+                    layer.bounds.intersection(&translated_bounds)
                 {
-                    let clip_layer = Layer::new(clip_bounds.into());
+                    let clip_layer = Layer::new(clip_bounds);
                     let new_layer = Layer::new(layer.bounds);
 
                     layers.push(clip_layer);
@@ -236,7 +217,7 @@ pub struct Quad {
 pub struct Mesh<'a> {
     pub origin: Point,
     pub buffers: &'a triangle::Mesh2D,
-    pub clip_bounds: Rectangle<u32>,
+    pub clip_bounds: Rectangle<f32>,
 }
 
 #[derive(Debug, Clone, Copy)]
diff --git a/graphics/src/lib.rs b/graphics/src/lib.rs
index 5ab333c7..2de9d21c 100644
--- a/graphics/src/lib.rs
+++ b/graphics/src/lib.rs
@@ -10,6 +10,7 @@ pub mod backend;
 pub mod font;
 pub mod layer;
 pub mod triangle;
+pub mod window;
 
 #[doc(no_inline)]
 pub use widget::*;
diff --git a/graphics/src/viewport.rs b/graphics/src/viewport.rs
index 48e5a249..745ef339 100644
--- a/graphics/src/viewport.rs
+++ b/graphics/src/viewport.rs
@@ -1,33 +1,48 @@
-use crate::Transformation;
+use crate::{Size, Transformation};
 
 /// A viewing region for displaying computer graphics.
 #[derive(Debug)]
 pub struct Viewport {
-    width: u32,
-    height: u32,
-    transformation: Transformation,
+    physical_size: Size<u32>,
+    logical_size: Size<f32>,
+    scale_factor: f64,
+    projection: Transformation,
 }
 
 impl Viewport {
-    /// Creates a new [`Viewport`] with the given dimensions.
-    pub fn new(width: u32, height: u32) -> Viewport {
+    /// Creates a new [`Viewport`] with the given physical dimensions and scale
+    /// factor.
+    ///
+    /// [`Viewport`]: struct.Viewport.html
+    pub fn with_physical_size(size: Size<u32>, scale_factor: f64) -> Viewport {
         Viewport {
-            width,
-            height,
-            transformation: Transformation::orthographic(width, height),
+            physical_size: size,
+            logical_size: Size::new(
+                (size.width as f64 / scale_factor) as f32,
+                (size.height as f64 / scale_factor) as f32,
+            ),
+            scale_factor,
+            projection: Transformation::orthographic(size.width, size.height),
         }
     }
 
-    pub fn height(&self) -> u32 {
-        self.height
+    pub fn physical_size(&self) -> Size<u32> {
+        self.physical_size
     }
 
-    /// Returns the dimensions of the [`Viewport`].
-    pub fn dimensions(&self) -> (u32, u32) {
-        (self.width, self.height)
+    pub fn physical_height(&self) -> u32 {
+        self.physical_size.height
     }
 
-    pub fn transformation(&self) -> Transformation {
-        self.transformation
+    pub fn logical_size(&self) -> Size<f32> {
+        self.logical_size
+    }
+
+    pub fn scale_factor(&self) -> f64 {
+        self.scale_factor
+    }
+
+    pub fn projection(&self) -> Transformation {
+        self.projection
     }
 }
diff --git a/graphics/src/window.rs b/graphics/src/window.rs
new file mode 100644
index 00000000..a7c8911b
--- /dev/null
+++ b/graphics/src/window.rs
@@ -0,0 +1,3 @@
+mod compositor;
+
+pub use compositor::Compositor;
diff --git a/graphics/src/window/compositor.rs b/graphics/src/window/compositor.rs
new file mode 100644
index 00000000..82faa6e1
--- /dev/null
+++ b/graphics/src/window/compositor.rs
@@ -0,0 +1,60 @@
+use crate::Viewport;
+use iced_native::mouse;
+use raw_window_handle::HasRawWindowHandle;
+
+/// A graphics compositor that can draw to windows.
+pub trait Compositor: Sized {
+    /// The settings of the backend.
+    type Settings: Default + Clone;
+
+    /// The iced renderer of the backend.
+    type Renderer: iced_native::Renderer;
+
+    /// The surface of the backend.
+    type Surface;
+
+    /// The swap chain of the backend.
+    type SwapChain;
+
+    /// Creates a new [`Backend`].
+    ///
+    /// [`Backend`]: trait.Backend.html
+    fn new(settings: Self::Settings) -> Self;
+
+    /// Crates a new [`Surface`] for the given window.
+    ///
+    /// [`Surface`]: #associatedtype.Surface
+    fn create_surface<W: HasRawWindowHandle>(
+        &mut self,
+        window: &W,
+    ) -> Self::Surface;
+
+    /// Crates a new [`Renderer`].
+    ///
+    /// [`Renderer`]: #associatedtype.Renderer
+    fn create_renderer(&mut self, settings: Self::Settings) -> Self::Renderer;
+
+    /// Crates a new [`SwapChain`] for the given [`Surface`].
+    ///
+    /// [`SwapChain`]: #associatedtype.SwapChain
+    /// [`Surface`]: #associatedtype.Surface
+    fn create_swap_chain(
+        &mut self,
+        surface: &Self::Surface,
+        width: u32,
+        height: u32,
+    ) -> Self::SwapChain;
+
+    /// Draws the output primitives to the next frame of the given [`SwapChain`].
+    ///
+    /// [`SwapChain`]: #associatedtype.SwapChain
+    /// [`Surface`]: #associatedtype.Surface
+    fn draw<T: AsRef<str>>(
+        &mut self,
+        renderer: &mut Self::Renderer,
+        swap_chain: &mut Self::SwapChain,
+        viewport: &Viewport,
+        output: &<Self::Renderer as iced_native::Renderer>::Output,
+        overlay: &[T],
+    ) -> mouse::Interaction;
+}