Merge pull request #387 from hatoo/add-comment

Add a comment of how to clear the display to `integration` example

examples/integration/src/main.rs

@@ -154,15 +154,20 @@ pub fn main() {
                     &wgpu::CommandEncoderDescriptor { label: None },
                 );
 
-                // We draw the scene first
                 let program = state.program();
 
-                scene.draw(
+                {
-                    &mut encoder,
+                    // We clear the frame
+                    let mut render_pass = scene.clear(
                         &frame.view,
+                        &mut encoder,
                         program.background_color(),
                     );
 
+                    // Draw the scene
+                    scene.draw(&mut render_pass);
+                }
+
                 // And then iced on top
                 let mouse_interaction = renderer.backend_mut().draw(
                     &mut device,

examples/integration/src/scene.rs

@@ -16,16 +16,14 @@ impl Scene {
         }
     }
 
-    pub fn draw(
+    pub fn clear<'a>(
         &self,
-        encoder: &mut wgpu::CommandEncoder,
+        target: &'a wgpu::TextureView,
-        target: &wgpu::TextureView,
+        encoder: &'a mut wgpu::CommandEncoder,
         background_color: Color,
-    ) {
+    ) -> wgpu::RenderPass<'a> {
-        let mut rpass =
         encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
-                color_attachments: &[
+            color_attachments: &[wgpu::RenderPassColorAttachmentDescriptor {
-                    wgpu::RenderPassColorAttachmentDescriptor {
                 attachment: target,
                 resolve_target: None,
                 load_op: wgpu::LoadOp::Clear,
@@ -40,14 +38,15 @@ impl Scene {
                         a: a as f64,
                     }
                 },
-                    },
+            }],
-                ],
             depth_stencil_attachment: None,
-            });
+        })
+    }
 
-        rpass.set_pipeline(&self.pipeline);
+    pub fn draw<'a>(&'a self, render_pass: &mut wgpu::RenderPass<'a>) {
-        rpass.set_bind_group(0, &self.bind_group, &[]);
+        render_pass.set_pipeline(&self.pipeline);
-        rpass.draw(0..3, 0..1);
+        render_pass.set_bind_group(0, &self.bind_group, &[]);
+        render_pass.draw(0..3, 0..1);
     }
 }