wgpu: Use the preferred texture format of the surface

Signed-off-by: Tilmann Meyer <me@atiltedtree.dev>

wgpu/src/backend.rs

@@ -30,23 +30,24 @@ pub struct Backend {
 
 impl Backend {
     /// Creates a new [`Backend`].
-    pub fn new(device: &wgpu::Device, settings: Settings) -> Self {
+    pub fn new(
+        device: &wgpu::Device,
+        settings: Settings,
+        format: wgpu::TextureFormat,
+    ) -> Self {
         let text_pipeline = text::Pipeline::new(
             device,
-            settings.format,
+            format,
             settings.default_font,
             settings.text_multithreading,
         );
 
-        let quad_pipeline = quad::Pipeline::new(device, settings.format);
-        let triangle_pipeline = triangle::Pipeline::new(
-            device,
-            settings.format,
-            settings.antialiasing,
-        );
+        let quad_pipeline = quad::Pipeline::new(device, format);
+        let triangle_pipeline =
+            triangle::Pipeline::new(device, format, settings.antialiasing);
 
         #[cfg(any(feature = "image_rs", feature = "svg"))]
-        let image_pipeline = image::Pipeline::new(device, settings.format);
+        let image_pipeline = image::Pipeline::new(device, format);
 
         Self {
             quad_pipeline,

wgpu/src/settings.rs

@@ -6,11 +6,6 @@ pub use crate::Antialiasing;
 /// [`Backend`]: crate::Backend
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct Settings {
-    /// The output format of the [`Backend`].
-    ///
-    /// [`Backend`]: crate::Backend
-    pub format: wgpu::TextureFormat,
-
     /// The present mode of the [`Backend`].
     ///
     /// [`Backend`]: crate::Backend
@@ -68,7 +63,6 @@ impl Settings {
 impl Default for Settings {
     fn default() -> Settings {
         Settings {
-            format: wgpu::TextureFormat::Bgra8UnormSrgb,
             present_mode: wgpu::PresentMode::Mailbox,
             internal_backend: wgpu::BackendBit::PRIMARY,
             default_font: None,

wgpu/src/window/compositor.rs

@@ -13,6 +13,7 @@ pub struct Compositor {
     queue: wgpu::Queue,
     staging_belt: wgpu::util::StagingBelt,
     local_pool: futures::executor::LocalPool,
+    format: wgpu::TextureFormat,
 }
 
 impl Compositor {
@@ -42,6 +43,10 @@ impl Compositor {
             })
             .await?;
 
+        let format = compatible_surface
+            .as_ref()
+            .and_then(|surf| adapter.get_swap_chain_preferred_format(surf))?;
+
         let (device, queue) = adapter
             .request_device(
                 &wgpu::DeviceDescriptor {
@@ -69,12 +74,13 @@ impl Compositor {
             queue,
             staging_belt,
             local_pool,
+            format,
         })
     }
 
     /// Creates a new rendering [`Backend`] for this [`Compositor`].
     pub fn create_backend(&self) -> Backend {
-        Backend::new(&self.device, self.settings)
+        Backend::new(&self.device, self.settings, self.format)
     }
 }
 
@@ -119,7 +125,7 @@ impl iced_graphics::window::Compositor for Compositor {
             surface,
             &wgpu::SwapChainDescriptor {
                 usage: wgpu::TextureUsage::RENDER_ATTACHMENT,
-                format: self.settings.format,
+                format: self.format,
                 present_mode: self.settings.present_mode,
                 width,
                 height,