LibWeb: Use shape-rendering to control anti aliasing for SVG paths

Anti-aliasing is disabled if `shape-rendering` is set to
`optimizeSpeed` or `crispEdges`.

Libraries/LibWeb/Forward.h

@@ -896,6 +896,7 @@ class VideoPaintable;
 class ViewportPaintable;
 
 enum class PaintPhase;
+enum class ShouldAntiAlias : bool;
 
 struct BorderRadiiData;
 struct BorderRadiusData;

Libraries/LibWeb/Painting/DisplayListCommand.h

@@ -30,6 +30,7 @@
 #include <LibWeb/Painting/PaintBoxShadowParams.h>
 #include <LibWeb/Painting/PaintStyle.h>
 #include <LibWeb/Painting/ScrollState.h>
+#include <LibWeb/Painting/ShouldAntiAlias.h>
 
 namespace Web::Painting {
 
@@ -217,6 +218,7 @@ struct FillPath {
     float opacity { 1.0f };
     PaintStyleOrColor paint_style_or_color;
     Gfx::WindingRule winding_rule;
+    ShouldAntiAlias should_anti_alias { ShouldAntiAlias::Yes };
 
     [[nodiscard]] Gfx::IntRect bounding_rect() const { return path_bounding_rect; }
 
@@ -239,6 +241,7 @@ struct StrokePath {
     float opacity;
     PaintStyleOrColor paint_style_or_color;
     float thickness;
+    ShouldAntiAlias should_anti_alias { ShouldAntiAlias::Yes };
 
     [[nodiscard]] Gfx::IntRect bounding_rect() const { return path_bounding_rect; }
 

Libraries/LibWeb/Painting/DisplayListPlayerSkia.cpp

@@ -654,7 +654,7 @@ void DisplayListPlayerSkia::fill_path(FillPath const& command)
         auto const& color = command.paint_style_or_color.get<Color>();
         paint.setColor(to_skia_color(color));
     }
-    paint.setAntiAlias(true);
+    paint.setAntiAlias(command.should_anti_alias == ShouldAntiAlias::Yes);
     surface().canvas().drawPath(path, paint);
 }
 
@@ -670,7 +670,7 @@ void DisplayListPlayerSkia::stroke_path(StrokePath const& command)
         auto const& color = command.paint_style_or_color.get<Color>();
         paint.setColor(to_skia_color(color));
     }
-    paint.setAntiAlias(true);
+    paint.setAntiAlias(command.should_anti_alias == ShouldAntiAlias::Yes);
     paint.setStyle(SkPaint::Style::kStroke_Style);
     paint.setStrokeWidth(command.thickness);
     paint.setStrokeCap(to_skia_cap(command.cap_style));

Libraries/LibWeb/Painting/DisplayListRecorder.cpp

@@ -78,7 +78,7 @@ void DisplayListRecorder::fill_path(FillPathParams params)
         .opacity = params.opacity,
         .paint_style_or_color = params.paint_style_or_color,
         .winding_rule = params.winding_rule,
-    });
+        .should_anti_alias = params.should_anti_alias });
 }
 
 void DisplayListRecorder::stroke_path(StrokePathParams params)
@@ -105,7 +105,7 @@ void DisplayListRecorder::stroke_path(StrokePathParams params)
         .opacity = params.opacity,
         .paint_style_or_color = params.paint_style_or_color,
         .thickness = params.thickness,
-    });
+        .should_anti_alias = params.should_anti_alias });
 }
 
 void DisplayListRecorder::draw_ellipse(Gfx::IntRect const& a_rect, Color color, int thickness)

Libraries/LibWeb/Painting/DisplayListRecorder.h

@@ -25,6 +25,7 @@
 #include <LibWeb/Painting/GradientData.h>
 #include <LibWeb/Painting/PaintBoxShadowParams.h>
 #include <LibWeb/Painting/PaintStyle.h>
+#include <LibWeb/Painting/ShouldAntiAlias.h>
 
 namespace Web::Painting {
 
@@ -45,6 +46,7 @@ public:
         float opacity = 1.0f;
         PaintStyleOrColor paint_style_or_color;
         Gfx::WindingRule winding_rule = Gfx::WindingRule::EvenOdd;
+        ShouldAntiAlias should_anti_alias { ShouldAntiAlias::Yes };
     };
     void fill_path(FillPathParams params);
 
@@ -58,6 +60,7 @@ public:
         float opacity = 1.0f;
         PaintStyleOrColor paint_style_or_color;
         float thickness;
+        ShouldAntiAlias should_anti_alias { ShouldAntiAlias::Yes };
     };
     void stroke_path(StrokePathParams);
 

Libraries/LibWeb/Painting/PaintableBox.h

@@ -18,6 +18,7 @@
 #include <LibWeb/Painting/ClipFrame.h>
 #include <LibWeb/Painting/Paintable.h>
 #include <LibWeb/Painting/PaintableFragment.h>
+#include <LibWeb/Painting/ShouldAntiAlias.h>
 
 namespace Web::Painting {
 

Libraries/LibWeb/Painting/SVGPaintable.cpp

@@ -33,4 +33,12 @@ CSSPixelRect SVGPaintable::compute_absolute_rect() const
     return PaintableBox::compute_absolute_rect();
 }
 
+ShouldAntiAlias SVGPaintable::should_anti_alias() const
+{
+    auto shape_rendering = computed_values().shape_rendering();
+    if (first_is_one_of(shape_rendering, CSS::ShapeRendering::Optimizespeed, CSS::ShapeRendering::Crispedges))
+        return ShouldAntiAlias::No;
+    return ShouldAntiAlias::Yes;
+}
+
 }

Libraries/LibWeb/Painting/SVGPaintable.h

@@ -23,6 +23,8 @@ protected:
     SVGPaintable(Layout::SVGBox const&);
 
     virtual CSSPixelRect compute_absolute_rect() const override;
+
+    ShouldAntiAlias should_anti_alias() const;
 };
 
 template<>

Libraries/LibWeb/Painting/SVGPathPaintable.cpp

@@ -98,6 +98,7 @@ void SVGPathPaintable::paint(DisplayListRecordingContext& context, PaintPhase ph
             .path = closed_path(),
             .paint_style_or_color = Gfx::Color(Color::Black),
             .winding_rule = to_gfx_winding_rule(graphics_element.clip_rule().value_or(SVG::ClipRule::Nonzero)),
+            .should_anti_alias = should_anti_alias(),
         });
         return;
     }
@@ -116,12 +117,14 @@ void SVGPathPaintable::paint(DisplayListRecordingContext& context, PaintPhase ph
             .opacity = fill_opacity,
             .paint_style_or_color = *paint_style,
             .winding_rule = winding_rule,
+            .should_anti_alias = should_anti_alias(),
         });
     } else if (auto fill_color = graphics_element.fill_color(); fill_color.has_value()) {
         context.display_list_recorder().fill_path({
             .path = closed_path(),
             .paint_style_or_color = fill_color->with_opacity(fill_opacity),
             .winding_rule = winding_rule,
+            .should_anti_alias = should_anti_alias(),
         });
     }
 
@@ -177,6 +180,7 @@ void SVGPathPaintable::paint(DisplayListRecordingContext& context, PaintPhase ph
             .opacity = stroke_opacity,
             .paint_style_or_color = *paint_style,
             .thickness = stroke_thickness,
+            .should_anti_alias = should_anti_alias(),
         });
     } else if (auto stroke_color = graphics_element.stroke_color(); stroke_color.has_value()) {
         context.display_list_recorder().stroke_path({
@@ -188,6 +192,7 @@ void SVGPathPaintable::paint(DisplayListRecordingContext& context, PaintPhase ph
             .path = path,
             .paint_style_or_color = stroke_color->with_opacity(stroke_opacity),
             .thickness = stroke_thickness,
+            .should_anti_alias = should_anti_alias(),
         });
     }
 }

Libraries/LibWeb/Painting/ShouldAntiAlias.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+namespace Web::Painting {
+
+enum class ShouldAntiAlias : bool {
+    Yes,
+    No,
+};
+
+}