From e2d6d2df77e934726045ecd4d8b3245c60ce3712 Mon Sep 17 00:00:00 2001
From: nlevy <nicolaspierrelevy@gmail.com>
Date: Mon, 6 Dec 2021 14:34:47 +0100
Subject: [PATCH] Check window size before redrawing

---
 examples/integration_wgpu/src/main.rs | 56 +++++++++++++++++++--------
 1 file changed, 40 insertions(+), 16 deletions(-)

diff --git a/examples/integration_wgpu/src/main.rs b/examples/integration_wgpu/src/main.rs
index 35a69a7d72..79a9d02d4b 100644
--- a/examples/integration_wgpu/src/main.rs
+++ b/examples/integration_wgpu/src/main.rs
@@ -5,13 +5,18 @@ use controls::Controls;
 use scene::Scene;
 
 use iced_wgpu::{wgpu, Backend, Renderer, Settings, Viewport};
-use iced_winit::{conversion, futures, program, winit, Clipboard, Debug, Size};
+use iced_winit::{
+    conversion, futures, program,
+    winit::{self, dpi::PhysicalSize},
+    Clipboard, Debug, Size,
+};
 
 use futures::task::SpawnExt;
 use winit::{
     dpi::PhysicalPosition,
     event::{Event, ModifiersState, WindowEvent},
     event_loop::{ControlFlow, EventLoop},
+    window::Window,
 };
 
 pub fn main() {
@@ -19,7 +24,7 @@ pub fn main() {
 
     // Initialize winit
     let event_loop = EventLoop::new();
-    let window = winit::window::Window::new(&event_loop).unwrap();
+    let window = Window::new(&event_loop).unwrap();
 
     let physical_size = window.inner_size();
     let mut viewport = Viewport::with_physical_size(
@@ -77,6 +82,7 @@ pub fn main() {
         )
     };
     let mut resized = false;
+    let mut last_processed_size = window.inner_size();
 
     // Initialize staging belt and local pool
     let mut staging_belt = wgpu::util::StagingBelt::new(5 * 1024);
@@ -112,11 +118,8 @@ pub fn main() {
                     WindowEvent::ModifiersChanged(new_modifiers) => {
                         modifiers = new_modifiers;
                     }
-                    WindowEvent::Resized(new_size) => {
-                        viewport = Viewport::with_physical_size(
-                            Size::new(new_size.width, new_size.height),
-                            window.scale_factor(),
-                        );
+                    WindowEvent::Resized(_) => {
+                        process_resize(&mut viewport, &mut last_processed_size, &window);
 
                         resized = true;
                     }
@@ -156,15 +159,21 @@ pub fn main() {
             }
             Event::RedrawRequested(_) => {
                 if resized {
-                    let size = window.inner_size();
-
+                    if last_processed_size != window.inner_size() {
+                        // This can happen when resizing the window quickly, we enter this branch
+                        // with the wrong window size, wich could cause validations errors
+                        process_resize(&mut viewport, &mut last_processed_size, &window);
+                        resized = true;
+                        window.request_redraw();
+                        return;
+                    }
                     surface.configure(
                         &device,
                         &wgpu::SurfaceConfiguration {
                             usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
                             format: format,
-                            width: size.width,
-                            height: size.height,
+                            width: last_processed_size.width,
+                            height: last_processed_size.height,
                             present_mode: wgpu::PresentMode::Mailbox,
                         },
                     );
@@ -190,6 +199,7 @@ pub fn main() {
                                 program.background_color(),
                             );
 
+
                             // Draw the scene
                             scene.draw(&mut render_pass);
                         }
@@ -213,11 +223,11 @@ pub fn main() {
                         frame.present();
 
                         // Update the mouse cursor
-                         window.set_cursor_icon(
-                             iced_winit::conversion::mouse_interaction(
-                                 state.mouse_interaction(),
-                             ),
-                         );
+                        window.set_cursor_icon(
+                            iced_winit::conversion::mouse_interaction(
+                                state.mouse_interaction(),
+                            ),
+                        );
 
                         // And recall staging buffers
                         local_pool
@@ -237,8 +247,22 @@ pub fn main() {
                         }
                     },
                 }
+                window.set_min_inner_size(Some(last_processed_size).filter(|_| false)); // using the filter to infer the type of None
             }
             _ => {}
         }
     })
 }
+
+fn process_resize(
+    viewport: &mut Viewport,
+    last_processed_size: &mut PhysicalSize<u32>,
+    window: &Window,
+) {
+    let new_size = window.inner_size();
+    *last_processed_size = window.inner_size();
+    *viewport = Viewport::with_physical_size(
+        Size::new(new_size.width, new_size.height),
+        window.scale_factor(),
+    );
+}