Build display lists from SkParagraph output using the ParagraphPainter interface

display_list/display_list_builder.cc

@@ -1071,6 +1071,13 @@ void DisplayListBuilder::drawTextBlob(const sk_sp<SkTextBlob> blob,
   Push<DrawTextBlobOp>(0, 1, blob, x, y);
   CheckLayerOpacityCompatibility();
 }
+void DisplayListBuilder::drawTextBlob(const sk_sp<SkTextBlob>& blob,
+                                      SkScalar x,
+                                      SkScalar y,
+                                      const DlPaint& paint) {
+  setAttributesFromDlPaint(paint, DisplayListOpFlags::kDrawTextBlobFlags);
+  drawTextBlob(blob, x, y);
+}
 void DisplayListBuilder::drawShadow(const SkPath& path,
                                     const DlColor color,
                                     const SkScalar elevation,

display_list/display_list_builder.h

@@ -334,6 +334,10 @@ class DisplayListBuilder final : public virtual Dispatcher,
   void drawTextBlob(const sk_sp<SkTextBlob> blob,
                     SkScalar x,
                     SkScalar y) override;
+  void drawTextBlob(const sk_sp<SkTextBlob>& blob,
+                    SkScalar x,
+                    SkScalar y,
+                    const DlPaint& paint);
   void drawShadow(const SkPath& path,
                   const DlColor color,
                   const SkScalar elevation,
@@ -503,7 +507,6 @@ class DisplayListBuilder final : public virtual Dispatcher,
   void onSetColorFilter(const DlColorFilter* filter);
   void onSetPathEffect(const DlPathEffect* effect);
   void onSetMaskFilter(const DlMaskFilter* filter);
-  void onSetMaskBlurFilter(SkBlurStyle style, SkScalar sigma);
 
   DlPaint current_;
   // If |current_blender_| is set then ignore |current_.getBlendMode()|

display_list/display_list_mask_filter.h

@@ -58,12 +58,13 @@ class DlMaskFilter
 // filter is then used to combine those colors.
 class DlBlurMaskFilter final : public DlMaskFilter {
  public:
-  DlBlurMaskFilter(SkBlurStyle style, SkScalar sigma)
-      : style_(style), sigma_(sigma) {}
+  DlBlurMaskFilter(SkBlurStyle style, SkScalar sigma, bool respect_ctm = true)
+      : style_(style), sigma_(sigma), respect_ctm_(respect_ctm) {}
   DlBlurMaskFilter(const DlBlurMaskFilter& filter)
-      : DlBlurMaskFilter(filter.style_, filter.sigma_) {}
+      : DlBlurMaskFilter(filter.style_, filter.sigma_, filter.respect_ctm_) {}
   DlBlurMaskFilter(const DlBlurMaskFilter* filter)
-      : DlBlurMaskFilter(filter->style_, filter->sigma_) {}
+      : DlBlurMaskFilter(filter->style_, filter->sigma_, filter->respect_ctm_) {
+  }
 
   DlMaskFilterType type() const override { return DlMaskFilterType::kBlur; }
   size_t size() const override { return sizeof(*this); }
@@ -73,24 +74,29 @@ class DlBlurMaskFilter final : public DlMaskFilter {
   }
 
   sk_sp<SkMaskFilter> skia_object() const override {
-    return SkMaskFilter::MakeBlur(style_, sigma_);
+    return SkMaskFilter::MakeBlur(style_, sigma_, respect_ctm_);
   }
 
   const DlBlurMaskFilter* asBlur() const override { return this; }
 
   SkBlurStyle style() const { return style_; }
   SkScalar sigma() const { return sigma_; }
+  bool respectCTM() const { return respect_ctm_; }
 
  protected:
   bool equals_(DlMaskFilter const& other) const override {
     FML_DCHECK(other.type() == DlMaskFilterType::kBlur);
     auto that = static_cast<DlBlurMaskFilter const*>(&other);
-    return style_ == that->style_ && sigma_ == that->sigma_;
+    return style_ == that->style_ && sigma_ == that->sigma_ &&
+           respect_ctm_ == that->respect_ctm_;
   }
 
  private:
   SkBlurStyle style_;
   SkScalar sigma_;
+  // Added for backward compatibility with Flutter text shadow rendering which
+  // uses Skia blur filters with this flag set to false.
+  bool respect_ctm_;
 };
 
 // A wrapper class for a Skia MaskFilter of unknown type. The above 4 types

display_list/display_list_test_utils.cc

@@ -284,15 +284,15 @@ std::vector<DisplayListInvocationGroup> CreateAllAttributesOps() {
        }},
       {"SetMaskFilter",
        {
-           {0, 24, 0, 0,
+           {0, 32, 0, 0,
             [](DisplayListBuilder& b) { b.setMaskFilter(&kTestMaskFilter1); }},
-           {0, 24, 0, 0,
+           {0, 32, 0, 0,
             [](DisplayListBuilder& b) { b.setMaskFilter(&kTestMaskFilter2); }},
-           {0, 24, 0, 0,
+           {0, 32, 0, 0,
             [](DisplayListBuilder& b) { b.setMaskFilter(&kTestMaskFilter3); }},
-           {0, 24, 0, 0,
+           {0, 32, 0, 0,
             [](DisplayListBuilder& b) { b.setMaskFilter(&kTestMaskFilter4); }},
-           {0, 24, 0, 0,
+           {0, 32, 0, 0,
             [](DisplayListBuilder& b) { b.setMaskFilter(&kTestMaskFilter5); }},
            {0, 0, 0, 0,
             [](DisplayListBuilder& b) { b.setMaskFilter(nullptr); }},

lib/ui/painting/canvas.h

@@ -190,6 +190,11 @@ class Canvas : public RefCountedDartWrappable<Canvas>, DisplayListOpFlags {
   SkCanvas* canvas() const { return canvas_; }
   void Invalidate();
 
+  DisplayListBuilder* builder() {
+    return display_list_recorder_ ? display_list_recorder_->builder().get()
+                                  : nullptr;
+  }
+
  private:
   explicit Canvas(SkCanvas* canvas);
 
@@ -205,9 +210,6 @@ class Canvas : public RefCountedDartWrappable<Canvas>, DisplayListOpFlags {
   // paint attributes from an SkPaint and an operation type as well as access
   // to the raw DisplayListBuilder for emitting custom rendering operations.
   sk_sp<DisplayListCanvasRecorder> display_list_recorder_;
-  DisplayListBuilder* builder() {
-    return display_list_recorder_->builder().get();
-  }
 };
 
 }  // namespace flutter

lib/ui/text/paragraph.cc

@@ -64,11 +64,15 @@ void Paragraph::paint(Canvas* canvas, double x, double y) {
     return;
   }
 
-  SkCanvas* sk_canvas = canvas->canvas();
-  if (!sk_canvas) {
+  DisplayListBuilder* builder = canvas->builder();
+  if (builder && m_paragraph->Paint(builder, x, y)) {
     return;
   }
-  m_paragraph->Paint(sk_canvas, x, y);
+  // Fall back to SkCanvas if painting to DisplayListBuilder is not supported.
+  SkCanvas* sk_canvas = canvas->canvas();
+  if (sk_canvas) {
+    m_paragraph->Paint(sk_canvas, x, y);
+  }
 }
 
 static tonic::Float32List EncodeTextBoxes(

lib/ui/text/paragraph_builder.cc

@@ -472,6 +472,9 @@ void ParagraphBuilder::pushStyle(const tonic::Int32List& encoded,
       SkPaint sk_paint;
       style.has_background = true;
       style.background = *background.paint(sk_paint);
+      DlPaint dl_paint;
+      background.toDlPaint(dl_paint);
+      style.background_dl = dl_paint;
     }
   }
 
@@ -481,6 +484,9 @@ void ParagraphBuilder::pushStyle(const tonic::Int32List& encoded,
       SkPaint sk_paint;
       style.has_foreground = true;
       style.foreground = *foreground.paint(sk_paint);
+      DlPaint dl_paint;
+      foreground.toDlPaint(dl_paint);
+      style.foreground_dl = dl_paint;
     }
   }
 

third_party/txt/BUILD.gn

@@ -143,6 +143,7 @@ source_set("txt") {
   configs += [ ":define_skshaper" ]
 
   public_deps = [
+    "//flutter/display_list",
     "//flutter/fml",
     "//third_party/harfbuzz",
     "//third_party/icu",

third_party/txt/src/skia/paragraph_builder_skia.cc

@@ -42,10 +42,68 @@ SkFontStyle MakeSkFontStyle(txt::FontWeight font_weight,
                                            : SkFontStyle::Slant::kItalic_Slant);
 }
 
-skt::ParagraphStyle TxtToSkia(const ParagraphStyle& txt) {
+}  // anonymous namespace
+
+ParagraphBuilderSkia::ParagraphBuilderSkia(
+    const ParagraphStyle& style,
+    std::shared_ptr<FontCollection> font_collection)
+    : base_style_(style.GetTextStyle()) {
+  builder_ = skt::ParagraphBuilder::make(
+      TxtToSkia(style), font_collection->CreateSktFontCollection());
+}
+
+ParagraphBuilderSkia::~ParagraphBuilderSkia() = default;
+
+void ParagraphBuilderSkia::PushStyle(const TextStyle& style) {
+  builder_->pushStyle(TxtToSkia(style));
+  txt_style_stack_.push(style);
+}
+
+void ParagraphBuilderSkia::Pop() {
+  builder_->pop();
+  txt_style_stack_.pop();
+}
+
+const TextStyle& ParagraphBuilderSkia::PeekStyle() {
+  return txt_style_stack_.empty() ? base_style_ : txt_style_stack_.top();
+}
+
+void ParagraphBuilderSkia::AddText(const std::u16string& text) {
+  builder_->addText(text);
+}
+
+void ParagraphBuilderSkia::AddPlaceholder(PlaceholderRun& span) {
+  skt::PlaceholderStyle placeholder_style;
+  placeholder_style.fHeight = span.height;
+  placeholder_style.fWidth = span.width;
+  placeholder_style.fBaseline = static_cast<skt::TextBaseline>(span.baseline);
+  placeholder_style.fBaselineOffset = span.baseline_offset;
+  placeholder_style.fAlignment =
+      static_cast<skt::PlaceholderAlignment>(span.alignment);
+
+  builder_->addPlaceholder(placeholder_style);
+}
+
+std::unique_ptr<Paragraph> ParagraphBuilderSkia::Build() {
+  return std::make_unique<ParagraphSkia>(builder_->Build(),
+                                         std::move(dl_paints_));
+}
+
+skt::ParagraphPainter::PaintID ParagraphBuilderSkia::CreatePaintID(
+    const flutter::DlPaint& dl_paint) {
+  dl_paints_.push_back(dl_paint);
+  return dl_paints_.size() - 1;
+}
+
+skt::ParagraphStyle ParagraphBuilderSkia::TxtToSkia(const ParagraphStyle& txt) {
   skt::ParagraphStyle skia;
   skt::TextStyle text_style;
 
+  // Convert the default color of an SkParagraph text style into a DlPaint.
+  flutter::DlPaint dl_paint;
+  dl_paint.setColor(text_style.getColor());
+  text_style.setForegroundPaintID(CreatePaintID(dl_paint));
+
   text_style.setFontStyle(MakeSkFontStyle(txt.font_weight, txt.font_style));
   text_style.setFontSize(SkDoubleToScalar(txt.font_size));
   text_style.setHeight(SkDoubleToScalar(txt.height));
@@ -84,7 +142,7 @@ skt::ParagraphStyle TxtToSkia(const ParagraphStyle& txt) {
   return skia;
 }
 
-skt::TextStyle TxtToSkia(const TextStyle& txt) {
+skt::TextStyle ParagraphBuilderSkia::TxtToSkia(const TextStyle& txt) {
   skt::TextStyle skia;
 
   skia.setColor(txt.color);
@@ -112,10 +170,14 @@ skt::TextStyle TxtToSkia(const TextStyle& txt) {
 
   skia.setLocale(SkString(txt.locale.c_str()));
   if (txt.has_background) {
-    skia.setBackgroundColor(txt.background);
+    skia.setBackgroundPaintID(CreatePaintID(txt.background_dl));
   }
   if (txt.has_foreground) {
-    skia.setForegroundColor(txt.foreground);
+    skia.setForegroundPaintID(CreatePaintID(txt.foreground_dl));
+  } else {
+    flutter::DlPaint dl_paint;
+    dl_paint.setColor(txt.color);
+    skia.setForegroundPaintID(CreatePaintID(dl_paint));
   }
 
   skia.resetFontFeatures();
@@ -153,50 +215,4 @@ skt::TextStyle TxtToSkia(const TextStyle& txt) {
   return skia;
 }
 
-}  // anonymous namespace
-
-ParagraphBuilderSkia::ParagraphBuilderSkia(
-    const ParagraphStyle& style,
-    std::shared_ptr<FontCollection> font_collection)
-    : builder_(skt::ParagraphBuilder::make(
-          TxtToSkia(style),
-          font_collection->CreateSktFontCollection())),
-      base_style_(style.GetTextStyle()) {}
-
-ParagraphBuilderSkia::~ParagraphBuilderSkia() = default;
-
-void ParagraphBuilderSkia::PushStyle(const TextStyle& style) {
-  builder_->pushStyle(TxtToSkia(style));
-  txt_style_stack_.push(style);
-}
-
-void ParagraphBuilderSkia::Pop() {
-  builder_->pop();
-  txt_style_stack_.pop();
-}
-
-const TextStyle& ParagraphBuilderSkia::PeekStyle() {
-  return txt_style_stack_.empty() ? base_style_ : txt_style_stack_.top();
-}
-
-void ParagraphBuilderSkia::AddText(const std::u16string& text) {
-  builder_->addText(text);
-}
-
-void ParagraphBuilderSkia::AddPlaceholder(PlaceholderRun& span) {
-  skt::PlaceholderStyle placeholder_style;
-  placeholder_style.fHeight = span.height;
-  placeholder_style.fWidth = span.width;
-  placeholder_style.fBaseline = static_cast<skt::TextBaseline>(span.baseline);
-  placeholder_style.fBaselineOffset = span.baseline_offset;
-  placeholder_style.fAlignment =
-      static_cast<skt::PlaceholderAlignment>(span.alignment);
-
-  builder_->addPlaceholder(placeholder_style);
-}
-
-std::unique_ptr<Paragraph> ParagraphBuilderSkia::Build() {
-  return std::make_unique<ParagraphSkia>(builder_->Build());
-}
-
 }  // namespace txt

third_party/txt/src/skia/paragraph_builder_skia.h

@@ -19,6 +19,7 @@
 
 #include "txt/paragraph_builder.h"
 
+#include "flutter/display_list/display_list_paint.h"
 #include "third_party/skia/modules/skparagraph/include/ParagraphBuilder.h"
 
 namespace txt {
@@ -39,9 +40,15 @@ class ParagraphBuilderSkia : public ParagraphBuilder {
   virtual std::unique_ptr<Paragraph> Build() override;
 
  private:
+  skia::textlayout::ParagraphPainter::PaintID CreatePaintID(
+      const flutter::DlPaint& dl_paint);
+  skia::textlayout::ParagraphStyle TxtToSkia(const ParagraphStyle& txt);
+  skia::textlayout::TextStyle TxtToSkia(const TextStyle& txt);
+
   std::shared_ptr<skia::textlayout::ParagraphBuilder> builder_;
   TextStyle base_style_;
   std::stack<TextStyle> txt_style_stack_;
+  std::vector<flutter::DlPaint> dl_paints_;
 };
 
 }  // namespace txt