Refactor Viewport and Compositor

glow/src/backend.rs

@@ -47,12 +47,10 @@ impl Backend {
         gl: &glow::Context,
         viewport: &Viewport,
         (primitive, mouse_interaction): &(Primitive, mouse::Interaction),
-        scale_factor: f64,
         overlay_text: &[T],
     ) -> mouse::Interaction {
-        let (width, height) = viewport.dimensions();
-        let scale_factor = scale_factor as f32;
-        let transformation = viewport.transformation();
+        let viewport_size = viewport.physical_size();
+        let projection = viewport.projection();
 
         let mut layers = Layer::generate(primitive, viewport);
         layers.push(Layer::overlay(overlay_text, viewport));
@@ -60,12 +58,11 @@ impl Backend {
         for layer in layers {
             self.flush(
                 gl,
-                viewport,
-                scale_factor,
-                transformation,
+                viewport.scale_factor() as f32,
+                projection,
                 &layer,
-                width,
-                height,
+                viewport_size.width,
+                viewport_size.height,
             );
         }
 
@@ -75,19 +72,18 @@ impl Backend {
     fn flush(
         &mut self,
         gl: &glow::Context,
-        viewport: &Viewport,
         scale_factor: f32,
         transformation: Transformation,
         layer: &Layer<'_>,
         target_width: u32,
         target_height: u32,
     ) {
-        let bounds = layer.bounds * scale_factor;
+        let bounds = (layer.bounds * scale_factor).round();
 
         if !layer.quads.is_empty() {
             self.quad_pipeline.draw(
                 gl,
-                viewport,
+                target_height,
                 &layer.quads,
                 transformation,
                 scale_factor,
@@ -175,8 +171,7 @@ impl Backend {
                 transformation,
                 glow_glyph::Region {
                     x: bounds.x,
-                    y: viewport.height()
-                        - (bounds.y + bounds.height).min(viewport.height()),
+                    y: target_height - (bounds.y + bounds.height),
                     width: bounds.width,
                     height: bounds.height,
                 },

glow/src/quad.rs

@@ -1,4 +1,4 @@
-use crate::{Transformation, Viewport};
+use crate::Transformation;
 use glow::HasContext;
 use iced_graphics::layer;
 use iced_native::Rectangle;
@@ -54,7 +54,7 @@ impl Pipeline {
     pub fn draw(
         &mut self,
         gl: &glow::Context,
-        viewport: &Viewport,
+        target_height: u32,
         instances: &[layer::Quad],
         transformation: Transformation,
         scale: f32,
@@ -64,9 +64,7 @@ impl Pipeline {
             gl.enable(glow::SCISSOR_TEST);
             gl.scissor(
                 bounds.x as i32,
-                (viewport.height()
-                    - (bounds.y + bounds.height).min(viewport.height()))
-                    as i32,
+                (target_height - (bounds.y + bounds.height)) as i32,
                 bounds.width as i32,
                 bounds.height as i32,
             );

glow/src/window/compositor.rs

@@ -13,11 +13,11 @@ pub struct Compositor {
     gl: Option<glow::Context>,
 }
 
-impl iced_native::window::Compositor for Compositor {
+impl iced_graphics::window::Compositor for Compositor {
     type Settings = Settings;
     type Renderer = Renderer;
     type Surface = ();
-    type SwapChain = Viewport;
+    type SwapChain = ();
 
     fn new(_settings: Self::Settings) -> Self {
         let connection = surfman::Connection::new().expect("Create connection");
@@ -133,16 +133,14 @@ impl iced_native::window::Compositor for Compositor {
             gl.enable(glow::BLEND);
             gl.blend_func(glow::SRC_ALPHA, glow::ONE_MINUS_SRC_ALPHA);
         }
-
-        Viewport::new(width, height)
     }
 
     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,
-        scale_factor: f64,
         overlay: &[T],
     ) -> mouse::Interaction {
         let gl = self.gl.as_ref().unwrap();
@@ -151,13 +149,7 @@ impl iced_native::window::Compositor for Compositor {
             gl.clear(glow::COLOR_BUFFER_BIT);
         }
 
-        let mouse = renderer.backend_mut().draw(
-            gl,
-            swap_chain,
-            output,
-            scale_factor,
-            overlay,
-        );
+        let mouse = renderer.backend_mut().draw(gl, viewport, output, overlay);
 
         {
             let mut surface = self