Make canvas minimal render on first loop

examples/canvas_minimal/src/main.rs

@@ -82,14 +82,20 @@ fn main() {
     let mut renderer = Renderer::new(pathfinder_device, &resource_loader, mode, options);
 
     let font_context = CanvasFontContext::from_system_source();
+    let mut is_first_render = true;
     // Wait for a keypress.
     event_loop.run_forever(|event| {
+        let mut should_render = is_first_render;
         match event {
             Event::WindowEvent { event: WindowEvent::CloseRequested, .. } |
-            Event::WindowEvent { event: WindowEvent::KeyboardInput { .. }, .. } => {
+            Event::WindowEvent { event: WindowEvent::KeyboardInput { .. }, .. } => return ControlFlow::Break,
-                ControlFlow::Break
-            }
             Event::WindowEvent { event: WindowEvent::Refresh, .. } => {
+                should_render = true;
+            }
+            _ => {},
+        }
+
+        if should_render {
             // Make a canvas. We're going to draw a house.
             let mut canvas = Canvas::new(framebuffer_size.to_f32()).get_context_2d(font_context.clone());
 
@@ -120,11 +126,10 @@ fn main() {
             let mut surface = device.unbind_surface_from_context(&mut context).unwrap().unwrap();
             device.present_surface(&mut context, &mut surface).unwrap();
             device.bind_surface_to_context(&mut context, surface).unwrap();
+        }
 
+        is_first_render = false;
         ControlFlow::Continue
-            }
-            _ => ControlFlow::Continue,
-        }
     });
 
     // Clean up.