wgpu: Fix buffer bug detection

render/wgpu/src/backend.rs

@@ -5,7 +5,6 @@ use crate::surface::Surface;
 use crate::target::RenderTargetFrame;
 use crate::target::TextureTarget;
 use crate::uniform_buffer::BufferStorage;
-use crate::utils::detect_buffer_bug;
 use crate::{
     as_texture, format_list, get_backend_names, ColorAdjustments, Descriptors, Error,
     QueueSyncHandle, RenderTarget, SwapChainTarget, Texture, Transforms,
@@ -210,9 +209,8 @@ impl<T: RenderTarget> WgpuRenderBackend<T> {
 
         let (device, queue) = request_device(&adapter, trace_path).await?;
 
-        if cfg!(target_arch = "wasm") && device.limits().max_push_constant_size == 0 {
-            detect_buffer_bug(&device, &queue)?;
-        }
+        #[cfg(target_family = "wasm")]
+        crate::utils::detect_buffer_bug(&device, &queue)?;
 
         Ok(Descriptors::new(adapter, device, queue))
     }

render/wgpu/src/utils.rs

@@ -161,10 +161,11 @@ pub fn buffer_to_image(
 #[allow(dead_code)]
 // https://github.com/gfx-rs/wgpu/issues/3371
 pub fn detect_buffer_bug(device: &wgpu::Device, queue: &wgpu::Queue) -> Result<(), Error> {
-    let expected_color: [f32; 4] = [1.0, 0.5, 0.25, 1.0];
+    let expected_rgba = image::Rgba([50, 100, 200, 255]);
+    let expected_color: [f32; 4] = expected_rgba.0.map(|c| (c as f32) / 255.0);
     let size = wgpu::Extent3d {
-        width: 32,
-        height: 32,
+        width: 8,
+        height: 8,
         depth_or_array_layers: 1,
     };
     let format = wgpu::TextureFormat::Rgba8Unorm;
@@ -210,6 +211,7 @@ pub fn detect_buffer_bug(device: &wgpu::Device, queue: &wgpu::Queue) -> Result<(
         }),
         multiview: None,
     });
+    for i in 0..size.width {
         let texture = device.create_texture(&wgpu::TextureDescriptor {
             label: None,
             size,
@@ -272,13 +274,15 @@ pub fn detect_buffer_bug(device: &wgpu::Device, queue: &wgpu::Queue) -> Result<(
         );
         let index = queue.submit(Some(encoder.finish()));
         let image = buffer_to_image(device, &result, &buffer_dimensions, Some(index), size, true);
-    let expected_rgba = image::Rgba(expected_color.map(|c| (c * 256.0) as u8));
-    if image.get_pixel(0, 0) != &expected_rgba {
+        if image.get_pixel(i, i) != &expected_rgba {
             tracing::error!(
-            "Buffer test failed, expected {expected_rgba:?} but found {:?}",
-            image.get_pixel(0, 0)
+                "Buffer test failed on pass {i}, expected {expected_rgba:?} but found {:?}",
+                image.get_pixel(i, i)
             );
             return Err("Buffer test failed".to_string().into());
+        } else {
+            tracing::info!("Buffer test success on pass {i}");
+        }
     }
     Ok(())
 }