Introduce iced_renderer subcrate featuring runtime renderer fallback

renderer/src/window/compositor.rs

@@ -0,0 +1,96 @@
+use crate::{Backend, Color, Error, Renderer, Settings, Viewport};
+
+use raw_window_handle::{HasRawDisplayHandle, HasRawWindowHandle};
+
+pub use iced_graphics::window::compositor::{Information, SurfaceError};
+
+pub enum Compositor<Theme> {
+    Wgpu(iced_wgpu::window::Compositor<Theme>),
+}
+
+pub enum Surface {
+    Wgpu(iced_wgpu::window::Surface),
+}
+
+impl<Theme> iced_graphics::window::Compositor for Compositor<Theme> {
+    type Settings = Settings;
+    type Renderer = Renderer<Theme>;
+    type Surface = Surface;
+
+    fn new<W: HasRawWindowHandle + HasRawDisplayHandle>(
+        settings: Self::Settings,
+        compatible_window: Option<&W>,
+    ) -> Result<(Self, Self::Renderer), Error> {
+        let (compositor, backend) = iced_wgpu::window::compositor::new(
+            iced_wgpu::Settings {
+                default_font: settings.default_font,
+                default_text_size: settings.default_text_size,
+                antialiasing: settings.antialiasing,
+                ..iced_wgpu::Settings::from_env()
+            },
+            compatible_window,
+        )?;
+
+        Ok((
+            Self::Wgpu(compositor),
+            Renderer::new(Backend::Wgpu(backend)),
+        ))
+    }
+
+    fn create_surface<W: HasRawWindowHandle + HasRawDisplayHandle>(
+        &mut self,
+        window: &W,
+    ) -> Surface {
+        match self {
+            Self::Wgpu(compositor) => {
+                Surface::Wgpu(compositor.create_surface(window))
+            }
+        }
+    }
+
+    fn configure_surface(
+        &mut self,
+        surface: &mut Surface,
+        width: u32,
+        height: u32,
+    ) {
+        match (self, surface) {
+            (Self::Wgpu(compositor), Surface::Wgpu(surface)) => {
+                compositor.configure_surface(surface, width, height);
+            }
+        }
+    }
+
+    fn fetch_information(&self) -> Information {
+        match self {
+            Self::Wgpu(compositor) => compositor.fetch_information(),
+        }
+    }
+
+    fn present<T: AsRef<str>>(
+        &mut self,
+        renderer: &mut Self::Renderer,
+        surface: &mut Self::Surface,
+        viewport: &Viewport,
+        background_color: Color,
+        overlay: &[T],
+    ) -> Result<(), SurfaceError> {
+        renderer.with_primitives(|backend, primitives| {
+            match (self, backend, surface) {
+                (
+                    Self::Wgpu(compositor),
+                    Backend::Wgpu(backend),
+                    Surface::Wgpu(surface),
+                ) => iced_wgpu::window::compositor::present(
+                    compositor,
+                    backend,
+                    surface,
+                    primitives,
+                    viewport,
+                    background_color,
+                    overlay,
+                ),
+            }
+        })
+    }
+}