Add 8px transparent border around ui tests to visualize widgets paint…

…ing outside of the aspected area

crates/egui_demo_lib/src/rendering_test.rs

@@ -690,7 +690,7 @@ mod tests {
             let mut color_test = ColorTest::default();
             let mut harness = egui_kittest::Harness::builder()
                 .with_size(vec2(2000.0, 2000.0))
-                .with_dpi(dpi)
+                .with_pixels_per_point(dpi)
                 .build_ui(|ui| {
                     color_test.ui(ui);
                 });

crates/egui_kittest/src/app_kind.rs

@@ -55,17 +55,19 @@ impl<'a> AppKind<'a> {
 
     fn run_ui(f: &mut AppKindUi<'a>, ctx: &egui::Context, sizing_pass: bool) -> egui::Response {
         egui::CentralPanel::default()
-            .frame(
-                Frame::central_panel(&ctx.style())
-                    .inner_margin(0.0)
-                    .outer_margin(0.0),
-            )
+            .frame(Frame::none())
             .show(ctx, |ui| {
                 let mut builder = egui::UiBuilder::new();
                 if sizing_pass {
                     builder.sizing_pass = true;
                 }
-                ui.scope_builder(builder, f).response
+                ui.scope_builder(builder, |ui| {
+                    Frame::central_panel(ui.style())
+                        .outer_margin(8.0)
+                        .inner_margin(0.0)
+                        .show(ui, |ui| f(ui));
+                })
+                .response
             })
             .inner
     }

crates/egui_kittest/src/wgpu.rs

@@ -128,7 +128,7 @@ impl TestRenderer {
                         view: &texture_view,
                         resolve_target: None,
                         ops: wgpu::Operations {
-                            load: wgpu::LoadOp::Clear(wgpu::Color::BLACK),
+                            load: wgpu::LoadOp::Clear(wgpu::Color::TRANSPARENT),
                             store: StoreOp::Store,
                         },
                     })],