From 3fb2b008a208cfdef4faf60e7ab3a16ee5923b42 Mon Sep 17 00:00:00 2001
From: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
Date: Wed, 18 Oct 2023 16:27:46 +0200
Subject: [PATCH] LibWeb/Painting: Do not paint paths not visible in viewport

Painting optimization to do less unnecessary work
---
 .../LibWeb/Painting/RecordingPainter.cpp         | 16 ++++++++++++++++
 .../Libraries/LibWeb/Painting/RecordingPainter.h |  4 ++++
 2 files changed, 20 insertions(+)

diff --git a/Userland/Libraries/LibWeb/Painting/RecordingPainter.cpp b/Userland/Libraries/LibWeb/Painting/RecordingPainter.cpp
index 1a584cd5d1..2cc992db5d 100644
--- a/Userland/Libraries/LibWeb/Painting/RecordingPainter.cpp
+++ b/Userland/Libraries/LibWeb/Painting/RecordingPainter.cpp
@@ -87,6 +87,8 @@ CommandResult DrawTextRun::execute(CommandExecutionState& state) const
 
 CommandResult FillPathUsingColor::execute(CommandExecutionState& state) const
 {
+    if (state.would_be_fully_clipped_by_painter(bounding_rect))
+        return CommandResult::Continue;
     auto& painter = state.painter();
     Gfx::AntiAliasingPainter aa_painter(painter);
     if (aa_translation.has_value())
@@ -97,6 +99,8 @@ CommandResult FillPathUsingColor::execute(CommandExecutionState& state) const
 
 CommandResult FillPathUsingPaintStyle::execute(CommandExecutionState& state) const
 {
+    if (state.would_be_fully_clipped_by_painter(bounding_rect))
+        return CommandResult::Continue;
     auto& painter = state.painter();
     Gfx::AntiAliasingPainter aa_painter(painter);
     if (aa_translation.has_value())
@@ -107,6 +111,8 @@ CommandResult FillPathUsingPaintStyle::execute(CommandExecutionState& state) con
 
 CommandResult StrokePathUsingColor::execute(CommandExecutionState& state) const
 {
+    if (state.would_be_fully_clipped_by_painter(bounding_rect))
+        return CommandResult::Continue;
     auto& painter = state.painter();
     Gfx::AntiAliasingPainter aa_painter(painter);
     if (aa_translation.has_value())
@@ -117,6 +123,8 @@ CommandResult StrokePathUsingColor::execute(CommandExecutionState& state) const
 
 CommandResult StrokePathUsingPaintStyle::execute(CommandExecutionState& state) const
 {
+    if (state.would_be_fully_clipped_by_painter(bounding_rect))
+        return CommandResult::Continue;
     auto& painter = state.painter();
     Gfx::AntiAliasingPainter aa_painter(painter);
     if (aa_translation.has_value())
@@ -526,7 +534,9 @@ void RecordingPainter::fill_rect(Gfx::IntRect const& rect, Color color)
 
 void RecordingPainter::fill_path(FillPathUsingColorParams params)
 {
+    auto bounding_rect = params.path.bounding_box().translated(params.translation.value_or({})).to_type<int>();
     push_command(FillPathUsingColor {
+        .bounding_rect = bounding_rect,
         .path = params.path,
         .color = params.color,
         .winding_rule = params.winding_rule,
@@ -536,7 +546,9 @@ void RecordingPainter::fill_path(FillPathUsingColorParams params)
 
 void RecordingPainter::fill_path(FillPathUsingPaintStyleParams params)
 {
+    auto bounding_rect = params.path.bounding_box().translated(params.translation.value_or({})).to_type<int>();
     push_command(FillPathUsingPaintStyle {
+        .bounding_rect = bounding_rect,
         .path = params.path,
         .paint_style = params.paint_style,
         .winding_rule = params.winding_rule,
@@ -547,7 +559,9 @@ void RecordingPainter::fill_path(FillPathUsingPaintStyleParams params)
 
 void RecordingPainter::stroke_path(StrokePathUsingColorParams params)
 {
+    auto bounding_rect = params.path.bounding_box().translated(params.translation.value_or({})).to_type<int>();
     push_command(StrokePathUsingColor {
+        .bounding_rect = bounding_rect,
         .path = params.path,
         .color = params.color,
         .thickness = params.thickness,
@@ -557,7 +571,9 @@ void RecordingPainter::stroke_path(StrokePathUsingColorParams params)
 
 void RecordingPainter::stroke_path(StrokePathUsingPaintStyleParams params)
 {
+    auto bounding_rect = params.path.bounding_box().translated(params.translation.value_or({})).to_type<int>();
     push_command(StrokePathUsingPaintStyle {
+        .bounding_rect = bounding_rect,
         .path = params.path,
         .paint_style = params.paint_style,
         .thickness = params.thickness,
diff --git a/Userland/Libraries/LibWeb/Painting/RecordingPainter.h b/Userland/Libraries/LibWeb/Painting/RecordingPainter.h
index f4742c8b9b..3af89ecea3 100644
--- a/Userland/Libraries/LibWeb/Painting/RecordingPainter.h
+++ b/Userland/Libraries/LibWeb/Painting/RecordingPainter.h
@@ -194,6 +194,7 @@ struct FillRectWithRoundedCorners {
 };
 
 struct FillPathUsingColor {
+    Gfx::IntRect bounding_rect;
     Gfx::Path path;
     Color color;
     Gfx::Painter::WindingRule winding_rule;
@@ -203,6 +204,7 @@ struct FillPathUsingColor {
 };
 
 struct FillPathUsingPaintStyle {
+    Gfx::IntRect bounding_rect;
     Gfx::Path path;
     NonnullRefPtr<Gfx::PaintStyle> paint_style;
     Gfx::Painter::WindingRule winding_rule;
@@ -213,6 +215,7 @@ struct FillPathUsingPaintStyle {
 };
 
 struct StrokePathUsingColor {
+    Gfx::IntRect bounding_rect;
     Gfx::Path path;
     Color color;
     float thickness;
@@ -222,6 +225,7 @@ struct StrokePathUsingColor {
 };
 
 struct StrokePathUsingPaintStyle {
+    Gfx::IntRect bounding_rect;
     Gfx::Path path;
     NonnullRefPtr<Gfx::PaintStyle> paint_style;
     float thickness;