From 5aeb8ebebc15f46a38cbe9e1f281cd8350eef70f Mon Sep 17 00:00:00 2001
From: Andreas Kling <andreas@ladybird.org>
Date: Thu, 15 Aug 2024 07:19:25 +0200
Subject: [PATCH] LibWeb: Clip underlying Painter in CRC2D::clip()

---
 Userland/Libraries/LibGfx/Painter.h                 |  2 ++
 Userland/Libraries/LibGfx/PainterSkia.cpp           |  7 +++++++
 Userland/Libraries/LibGfx/PainterSkia.h             |  1 +
 Userland/Libraries/LibWeb/HTML/Canvas/CanvasState.h |  6 ------
 .../LibWeb/HTML/CanvasRenderingContext2D.cpp        | 13 +++++--------
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/Userland/Libraries/LibGfx/Painter.h b/Userland/Libraries/LibGfx/Painter.h
index 510099ab3b3..3710ecf9c73 100644
--- a/Userland/Libraries/LibGfx/Painter.h
+++ b/Userland/Libraries/LibGfx/Painter.h
@@ -35,6 +35,8 @@ public:
 
     virtual void save() = 0;
     virtual void restore() = 0;
+
+    virtual void clip(Gfx::Path const&, Gfx::WindingRule) = 0;
 };
 
 }
diff --git a/Userland/Libraries/LibGfx/PainterSkia.cpp b/Userland/Libraries/LibGfx/PainterSkia.cpp
index f9889920a63..2dd2723da2b 100644
--- a/Userland/Libraries/LibGfx/PainterSkia.cpp
+++ b/Userland/Libraries/LibGfx/PainterSkia.cpp
@@ -275,4 +275,11 @@ void PainterSkia::restore()
     impl().canvas()->restore();
 }
 
+void PainterSkia::clip(Gfx::Path const& path, Gfx::WindingRule winding_rule)
+{
+    auto sk_path = to_skia_path(path);
+    sk_path.setFillType(to_skia_path_fill_type(winding_rule));
+    impl().canvas()->clipPath(sk_path, SkClipOp::kIntersect, true);
+}
+
 }
diff --git a/Userland/Libraries/LibGfx/PainterSkia.h b/Userland/Libraries/LibGfx/PainterSkia.h
index bbb7319be67..b0440f39d66 100644
--- a/Userland/Libraries/LibGfx/PainterSkia.h
+++ b/Userland/Libraries/LibGfx/PainterSkia.h
@@ -27,6 +27,7 @@ public:
     virtual void set_transform(Gfx::AffineTransform const&) override;
     virtual void save() override;
     virtual void restore() override;
+    virtual void clip(Gfx::Path const&, Gfx::WindingRule) override;
 
 private:
     struct Impl;
diff --git a/Userland/Libraries/LibWeb/HTML/Canvas/CanvasState.h b/Userland/Libraries/LibWeb/HTML/Canvas/CanvasState.h
index 8eb4274b122..db3e6cae7c4 100644
--- a/Userland/Libraries/LibWeb/HTML/Canvas/CanvasState.h
+++ b/Userland/Libraries/LibWeb/HTML/Canvas/CanvasState.h
@@ -24,11 +24,6 @@ namespace Web::HTML {
 // https://html.spec.whatwg.org/multipage/canvas.html#canvasstate
 class CanvasState {
 public:
-    struct ClipPath {
-        Gfx::Path path;
-        Gfx::WindingRule winding_rule;
-    };
-
     virtual ~CanvasState() = default;
 
     void save();
@@ -87,7 +82,6 @@ public:
         bool image_smoothing_enabled { true };
         Bindings::ImageSmoothingQuality image_smoothing_quality { Bindings::ImageSmoothingQuality::Low };
         float global_alpha = { 1 };
-        Optional<ClipPath> clip;
         RefPtr<CSS::CSSStyleValue> font_style_value { nullptr };
         RefPtr<Gfx::Font const> current_font { nullptr };
         Bindings::CanvasTextAlign text_align { Bindings::CanvasTextAlign::Start };
diff --git a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
index 300163600aa..af4a83c6808 100644
--- a/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
+++ b/Userland/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
@@ -543,15 +543,12 @@ CanvasRenderingContext2D::PreparedText CanvasRenderingContext2D::prepare_text(By
 
 void CanvasRenderingContext2D::clip_internal(Gfx::Path& path, Gfx::WindingRule winding_rule)
 {
-    // FIXME: This should calculate the new clip path by intersecting the given path with the current one.
-    // See: https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-clip-dev
-    path.close_all_subpaths();
-    if (drawing_state().clip.has_value()) {
-        auto& current_clip = drawing_state().clip->path;
-        current_clip.intersect(path);
+    auto* painter = this->painter();
+    if (!painter)
         return;
-    }
-    drawing_state().clip = CanvasState::ClipPath { path, winding_rule };
+
+    path.close_all_subpaths();
+    painter->clip(path, winding_rule);
 }
 
 void CanvasRenderingContext2D::clip(StringView fill_rule)