LibWeb: Avoid repeated layout lookups in resolve_paint_only_properties()

By caching the layout node and its computed values in locals, we can
avoid the small amount of redundant work needed to look them up every
single time.

Userland/Libraries/LibWeb/Painting/ViewportPaintable.cpp

@@ -233,21 +233,22 @@ void ViewportPaintable::resolve_paint_only_properties()
  // - Transform origins
  // - Outlines
  for_each_in_inclusive_subtree([&](Paintable& paintable) {
- auto& node = paintable.layout_node();
+ auto& layout_node = paintable.layout_node();
 
  auto const is_inline_paintable = paintable.is_inline_paintable();
  auto const is_paintable_box = paintable.is_paintable_box();
  auto const is_paintable_with_lines = paintable.is_paintable_with_lines();
+ auto const& computed_values = layout_node.computed_values();
 
  // Border radii
  if (is_inline_paintable) {
  auto& inline_paintable = static_cast<Painting::InlinePaintable&>(paintable);
  auto& fragments = inline_paintable.fragments();
 
- auto const& top_left_border_radius = inline_paintable.computed_values().border_top_left_radius();
- auto const& top_right_border_radius = inline_paintable.computed_values().border_top_right_radius();
- auto const& bottom_right_border_radius = inline_paintable.computed_values().border_bottom_right_radius();
- auto const& bottom_left_border_radius = inline_paintable.computed_values().border_bottom_left_radius();
+ auto const& top_left_border_radius = computed_values.border_top_left_radius();
+ auto const& top_right_border_radius = computed_values.border_top_right_radius();
+ auto const& bottom_right_border_radius = computed_values.border_bottom_right_radius();
+ auto const& bottom_left_border_radius = computed_values.border_bottom_left_radius();
 
  auto containing_block_position_in_absolute_coordinates = inline_paintable.containing_block()->absolute_position();
  for (size_t i = 0; i < fragments.size(); ++i) {
@@ -267,7 +268,7 @@ void ViewportPaintable::resolve_paint_only_properties()
  auto extra_end_width = inline_paintable.box_model().padding.right;
  absolute_fragment_rect.set_width(absolute_fragment_rect.width() + extra_end_width);
  }
- auto border_radii_data = normalize_border_radii_data(inline_paintable.layout_node(),
+ auto border_radii_data = normalize_border_radii_data(layout_node,
  absolute_fragment_rect, top_left_border_radius,
  top_right_border_radius,
  bottom_right_border_radius,
@@ -281,29 +282,29 @@ void ViewportPaintable::resolve_paint_only_properties()
  auto& paintable_box = static_cast<Painting::PaintableBox&>(paintable);
 
  CSSPixelRect const border_rect { 0, 0, paintable_box.border_box_width(), paintable_box.border_box_height() };
- auto const& border_top_left_radius = node.computed_values().border_top_left_radius();
- auto const& border_top_right_radius = node.computed_values().border_top_right_radius();
- auto const& border_bottom_right_radius = node.computed_values().border_bottom_right_radius();
- auto const& border_bottom_left_radius = node.computed_values().border_bottom_left_radius();
+ auto const& border_top_left_radius = computed_values.border_top_left_radius();
+ auto const& border_top_right_radius = computed_values.border_top_right_radius();
+ auto const& border_bottom_right_radius = computed_values.border_bottom_right_radius();
+ auto const& border_bottom_left_radius = computed_values.border_bottom_left_radius();
 
- auto radii_data = normalize_border_radii_data(node, border_rect, border_top_left_radius,
+ auto radii_data = normalize_border_radii_data(layout_node, border_rect, border_top_left_radius,
  border_top_right_radius, border_bottom_right_radius,
  border_bottom_left_radius);
  paintable_box.set_border_radii_data(radii_data);
  }
 
  // Box shadows
- auto const& box_shadow_data = node.computed_values().box_shadow();
+ auto const& box_shadow_data = computed_values.box_shadow();
  if (!box_shadow_data.is_empty()) {
  Vector<Painting::ShadowData> resolved_box_shadow_data;
  resolved_box_shadow_data.ensure_capacity(box_shadow_data.size());
  for (auto const& layer : box_shadow_data) {
  resolved_box_shadow_data.empend(
  layer.color,
- layer.offset_x.to_px(node),
- layer.offset_y.to_px(node),
- layer.blur_radius.to_px(node),
- layer.spread_distance.to_px(node),
+ layer.offset_x.to_px(layout_node),
+ layer.offset_y.to_px(layout_node),
+ layer.blur_radius.to_px(layout_node),
+ layer.spread_distance.to_px(layout_node),
  layer.placement == CSS::ShadowPlacement::Outer ? Painting::ShadowPlacement::Outer
  : Painting::ShadowPlacement::Inner);
  }
@@ -328,10 +329,10 @@ void ViewportPaintable::resolve_paint_only_properties()
  for (auto const& layer : text_shadow) {
  resolved_shadow_data.empend(
  layer.color,
- layer.offset_x.to_px(paintable_with_lines.layout_node()),
- layer.offset_y.to_px(paintable_with_lines.layout_node()),
- layer.blur_radius.to_px(paintable_with_lines.layout_node()),
- layer.spread_distance.to_px(paintable_with_lines.layout_node()),
+ layer.offset_x.to_px(layout_node),
+ layer.offset_y.to_px(layout_node),
+ layer.blur_radius.to_px(layout_node),
+ layer.spread_distance.to_px(layout_node),
  Painting::ShadowPlacement::Outer);
  }
  const_cast<Painting::PaintableFragment&>(fragment).set_shadows(move(resolved_shadow_data));
@@ -415,17 +416,16 @@ void ViewportPaintable::resolve_paint_only_properties()
  }
  VERIFY_NOT_REACHED();
  }();
- auto x = reference_box.left() + transform_origin.x.to_px(node, reference_box.width());
- auto y = reference_box.top() + transform_origin.y.to_px(node, reference_box.height());
+ auto x = reference_box.left() + transform_origin.x.to_px(layout_node, reference_box.width());
+ auto y = reference_box.top() + transform_origin.y.to_px(layout_node, reference_box.height());
  paintable_box.set_transform_origin({ x, y });
  paintable_box.set_transform_origin({ x, y });
  }
 
  // Outlines
- auto const& computed_values = node.computed_values();
- auto outline_width = computed_values.outline_width().to_px(node);
- auto outline_data = borders_data_for_outline(node, computed_values.outline_color(), computed_values.outline_style(), outline_width);
- auto outline_offset = computed_values.outline_offset().to_px(node);
+ auto outline_width = computed_values.outline_width().to_px(layout_node);
+ auto outline_data = borders_data_for_outline(layout_node, computed_values.outline_color(), computed_values.outline_style(), outline_width);
+ auto outline_offset = computed_values.outline_offset().to_px(layout_node);
  if (is_paintable_box) {
  auto& paintable_box = static_cast<Painting::PaintableBox&>(paintable);
  paintable_box.set_outline_data(outline_data);