Extract RenderDevice from world to avoid manual drop.

examples/wgpu/wgpu_instancing/wgpu_instancing.rs

@@ -278,7 +278,7 @@ fn special_color(index: usize) -> [f32; 3] {
     }
 }
 
-fn render(app: &RenderApp, model: &Model, frame: Frame) {
+fn render(app: &RenderApp, model: &Model, mut frame: Frame) {
     let mut g = model.graphics.lock().unwrap();
 
     // If the window has changed size, recreate our depth texture to match.
@@ -342,9 +342,6 @@ fn render(app: &RenderApp, model: &Model, frame: Frame) {
         usage,
     });
 
-    // Drop the device to avoid borrowing issues
-    drop(device);
-
     let mut encoder = frame.command_encoder();
     encoder.copy_buffer_to_buffer(&new_uniform_buffer, 0, &g.uniform_buffer, 0, uniforms_size);
     let mut render_pass = wgpu::RenderPassBuilder::new()

examples/wgpu/wgpu_teapot/wgpu_teapot.rs

@@ -152,9 +152,6 @@ fn render(app: &RenderApp, model: &Model, frame: Frame) {
         usage,
     });
 
-    // Avoid borrowing issues by dropping device when finished.
-    drop(device);
-
     let mut encoder = frame.command_encoder();
     encoder.copy_buffer_to_buffer(&new_uniform_buffer, 0, &g.uniform_buffer, 0, uniforms_size);
     let mut render_pass = wgpu::RenderPassBuilder::new()

nannou/src/frame.rs

@@ -1,7 +1,7 @@
 use bevy::ecs::entity::EntityHashMap;
 use bevy::prelude::*;
 use bevy::render::render_resource::Extent3d;
-use bevy::render::renderer::RenderContext;
+use bevy::render::renderer::{RenderContext, RenderDevice};
 use bevy::render::view::{ExtractedView, ExtractedWindows, ViewTarget};
 use bevy::render::{Extract, RenderApp};
 use nannou_core::geom;
@@ -39,6 +39,7 @@ pub struct Frame<'a, 'w> {
     view_target: &'w ViewTarget,
     extracted_windows: &'w ExtractedWindows,
     extracted_view: &'w ExtractedView,
+    render_device: &'w RenderDevice,
     render_context: RefCell<&'a mut RenderContext<'w>>,
 }
 
@@ -54,10 +55,12 @@ impl<'a, 'w> Frame<'a, 'w> {
         extracted_view: &'w ExtractedView,
         render_context: &'a mut RenderContext<'w>,
     ) -> Self {
+        let render_device = world.resource::<RenderDevice>();
         Frame {
             window_id: view_target_id,
             world,
             view_target,
+            render_device,
             render_context: RefCell::new(render_context),
             extracted_windows,
             extracted_view,
@@ -115,10 +118,8 @@ impl<'a, 'w> Frame<'a, 'w> {
     ///
     /// This refers to the same **DeviceQueuePair** as held by the window associated with this
     /// frame.
-    pub fn device(&self) -> std::cell::Ref<wgpu::Device> {
-        std::cell::Ref::map(self.render_context.borrow(), |x| {
-            x.render_device().wgpu_device()
-        })
+    pub fn device(&self) -> &wgpu::Device {
+        self.render_device.wgpu_device()
     }
 
     /// The texture to which all graphics should be drawn this frame.