redo custom error for Compositor::draw()

4 files changed, 63 insertions, 56 deletions

diff --git a/graphics/src/window.rs b/graphics/src/window.rs
index 6813643d..365ddfbc 100644
--- a/graphics/src/window.rs
+++ b/graphics/src/window.rs
@@ -4,7 +4,7 @@ mod compositor;
 #[cfg(feature = "opengl")]
 mod gl_compositor;
 
-pub use compositor::{Compositor, CompositorDrawError};
+pub use compositor::{Compositor, SwapChainError};
 
 #[cfg(feature = "opengl")]
 pub use gl_compositor::GLCompositor;
diff --git a/graphics/src/window/compositor.rs b/graphics/src/window/compositor.rs
index 9f7cb43f..9811d95d 100644
--- a/graphics/src/window/compositor.rs
+++ b/graphics/src/window/compositor.rs
@@ -52,33 +52,32 @@ pub trait Compositor: Sized {
         background_color: Color,
         output: &<Self::Renderer as iced_native::Renderer>::Output,
         overlay: &[T],
-    ) -> Result<mouse::Interaction, CompositorDrawError>;
+    ) -> Result<mouse::Interaction, SwapChainError>;
 }
 
 /// Result of an unsuccessful call to [`Compositor::draw`].
-#[derive(Debug)]
-pub enum CompositorDrawError {
-    /// The swapchain is outdated. Try rendering again next frame.
-    SwapchainOutdated(Box<dyn std::error::Error>),
-    /// A fatal swapchain error occured. Rendering cannot continue.
-    FatalSwapchainError(Box<dyn std::error::Error>),
+/// Result of an unsuccessful call to [`SwapChain::get_current_frame`].
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum SwapChainError {
+    /// A timeout was encountered while trying to acquire the next frame.
+    Timeout,
+    /// The underlying surface has changed, and therefore the swap chain must be updated.
+    Outdated,
+    /// The swap chain has been lost and needs to be recreated.
+    Lost,
+    /// There is no more memory left to allocate a new frame.
+    OutOfMemory,
 }
 
-impl std::error::Error for CompositorDrawError {}
+impl std::error::Error for SwapChainError {}
 
-impl std::fmt::Display for CompositorDrawError {
+impl std::fmt::Display for SwapChainError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            CompositorDrawError::SwapchainOutdated(e) => write!(
-                f,
-                "Swapchain is outdated: {}. Try rendering next frame.",
-                e
-            ),
-            CompositorDrawError::FatalSwapchainError(e) => write!(
-                f,
-                "Fatal swapchain error: {}. Rendering cannot continue.",
-                e
-            ),
-        }
+        write!(f, "{}", match self {
+            Self::Timeout => "A timeout was encountered while trying to acquire the next frame",
+            Self::Outdated => "The underlying surface has changed, and therefore the swap chain must be updated",
+            Self::Lost =>  "The swap chain has been lost and needs to be recreated",
+            Self::OutOfMemory => "There is no more memory left to allocate a new frame",
+        })
     }
 }
diff --git a/wgpu/src/window/compositor.rs b/wgpu/src/window/compositor.rs
index fd8fec6e..fb25fca4 100644
--- a/wgpu/src/window/compositor.rs
+++ b/wgpu/src/window/compositor.rs
@@ -135,8 +135,7 @@ impl iced_graphics::window::Compositor for Compositor {
         background_color: Color,
         output: &<Self::Renderer as iced_native::Renderer>::Output,
         overlay: &[T],
-    ) -> Result<mouse::Interaction, iced_graphics::window::CompositorDrawError>
-    {
+    ) -> Result<mouse::Interaction, iced_graphics::window::SwapChainError> {
         match swap_chain.get_current_frame() {
             Ok(frame) => {
                 let mut encoder = self.device.create_command_encoder(
@@ -145,27 +144,31 @@ impl iced_graphics::window::Compositor for Compositor {
                     },
                 );
 
-                let _ = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
-                    label: Some("iced_wgpu::window::Compositor render pass"),
-                    color_attachments: &[wgpu::RenderPassColorAttachment {
-                        view: &frame.output.view,
-                        resolve_target: None,
-                        ops: wgpu::Operations {
-                            load: wgpu::LoadOp::Clear({
-                                let [r, g, b, a] = background_color.into_linear();
-
-                                wgpu::Color {
-                                    r: f64::from(r),
-                                    g: f64::from(g),
-                                    b: f64::from(b),
-                                    a: f64::from(a),
-                                }
-                            }),
-                            store: true,
-                        },
-                    }],
-                    depth_stencil_attachment: None,
-                });
+                let _ =
+                    encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+                        label: Some(
+                            "iced_wgpu::window::Compositor render pass",
+                        ),
+                        color_attachments: &[wgpu::RenderPassColorAttachment {
+                            view: &frame.output.view,
+                            resolve_target: None,
+                            ops: wgpu::Operations {
+                                load: wgpu::LoadOp::Clear({
+                                    let [r, g, b, a] =
+                                        background_color.into_linear();
+
+                                    wgpu::Color {
+                                        r: f64::from(r),
+                                        g: f64::from(g),
+                                        b: f64::from(b),
+                                        a: f64::from(a),
+                                    }
+                                }),
+                                store: true,
+                            },
+                        }],
+                        depth_stencil_attachment: None,
+                    });
 
                 let mouse_interaction = renderer.backend_mut().draw(
                     &mut self.device,
@@ -192,12 +195,17 @@ impl iced_graphics::window::Compositor for Compositor {
                 Ok(mouse_interaction)
             }
             Err(error) => match error {
-                wgpu::SwapChainError::OutOfMemory => {
-                    Err(iced_graphics::window::CompositorDrawError::FatalSwapchainError(Box::new(error)))
+                wgpu::SwapChainError::Timeout => {
+                    Err(iced_graphics::window::SwapChainError::Timeout)
+                }
+                wgpu::SwapChainError::Outdated => {
+                    Err(iced_graphics::window::SwapChainError::Outdated)
                 }
-                _ => {
-                    // Try again next frame.
-                    Err(iced_graphics::window::CompositorDrawError::SwapchainOutdated(Box::new(error)))
+                wgpu::SwapChainError::Lost => {
+                    Err(iced_graphics::window::SwapChainError::Lost)
+                }
+                wgpu::SwapChainError::OutOfMemory => {
+                    Err(iced_graphics::window::SwapChainError::OutOfMemory)
                 }
             },
         }
diff --git a/winit/src/application.rs b/winit/src/application.rs
index b04fc609..1d32a5f3 100644
--- a/winit/src/application.rs
+++ b/winit/src/application.rs
@@ -391,16 +391,16 @@ async fn run_instance<A, E, C>(
                         // Maybe we can use `ControlFlow::WaitUntil` for this.
                     }
                     Err(error) => match error {
-                        window::CompositorDrawError::SwapchainOutdated(_) => {
+                        // This is an unrecoverable error.
+                        window::SwapChainError::OutOfMemory => {
+                            panic!("{}", error);
+                        }
+                        _ => {
                             debug.render_finished();
 
-                            // Swapchain is outdated. Try rendering again next frame.
+                            // Try rendering again next frame.
                             window.request_redraw();
                         }
-                        window::CompositorDrawError::FatalSwapchainError(e) => {
-                            // Fatal swapchain error. Rendering cannot continue.
-                            panic!("{}", e);
-                        }
                     },
                 }
             }