Simplify LayoutText line box collection

This uses the same mechanism used in
https://chromium-review.googlesource.com/c/chromium/src/+/1612358
for LayoutInline.

The new code favors LayoutNG for performance, to avoid back-and-forth
flipping in some cases for LayoutNG and allow that for Legacy.

Also fix an issue of unnecessary flipping for SVG text.

Change-Id: I70dc61807d2284a3cdda1fd4733b7ab2bfdd00e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1615680
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Aleks Totic <atotic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660998}

third_party/blink/renderer/core/layout/layout_text.h

@@ -120,11 +120,8 @@ class CORE_EXPORT LayoutText : public LayoutObject {
   FloatRect LocalBoundingBoxRectForAccessibility() const final;
 
   enum ClippingOption { kNoClipping, kClipToEllipsis };
-  enum LocalOrAbsoluteOption { kLocalQuads, kAbsoluteQuads };
-  void Quads(Vector<FloatQuad>&,
-             ClippingOption = kNoClipping,
-             LocalOrAbsoluteOption = kAbsoluteQuads,
-             MapCoordinatesFlags mode = 0) const;
+  void LocalQuadsInFlippedBlocksDirection(Vector<FloatQuad>&,
+                                          ClippingOption = kNoClipping) const;
 
   PositionWithAffinity PositionForPoint(const LayoutPoint&) const override;
 
@@ -346,11 +343,11 @@ class CORE_EXPORT LayoutText : public LayoutObject {
  private:
   InlineTextBoxList& MutableTextBoxes();
 
-  void AccumlateQuads(Vector<FloatQuad>&,
-                      const IntRect& ellipsis_rect,
-                      LocalOrAbsoluteOption,
-                      MapCoordinatesFlags mode,
-                      const LayoutRect&) const;
+  // PhysicalRectCollector should be like a function:
+  // void (const PhysicalRect&).
+  template <typename PhysicalRectCollector>
+  void CollectLineBoxRects(const PhysicalRectCollector&,
+                           ClippingOption option = kNoClipping) const;
 
   void ComputePreferredLogicalWidths(float lead_width);
   void ComputePreferredLogicalWidths(
@@ -395,6 +392,22 @@ class CORE_EXPORT LayoutText : public LayoutObject {
   bool CanOptimizeSetText() const;
   void SetFirstTextBoxLogicalLeft(float text_width) const;
 
+  bool NeedsFlipForWritingMode() const {
+    return HasFlippedBlocksWritingMode() && !IsSVG();
+  }
+  // These functions flip the input rect in ContainingBlock() if
+  // NeedsFlipForWritingMode() is true. If |block_for_flipping| is not null,
+  // it should be ContainingBlock(), otherwise the function will call
+  // ContainingBlock() by themselves. The caller should prepare
+  // |block_for_flipping| if it will loop through many rects to flip to avoid
+  // the cost of repeated ContainingBlock() calls.
+  ALWAYS_INLINE WARN_UNUSED_RESULT LayoutRect
+  FlipForWritingMode(const PhysicalRect& r,
+                     const LayoutBlock* block_for_flipping = nullptr) const;
+  ALWAYS_INLINE WARN_UNUSED_RESULT PhysicalRect
+  FlipForWritingMode(const LayoutRect& r,
+                     const LayoutBlock* block_for_flipping = nullptr) const;
+
  private:
   ContentCaptureManager* GetContentCaptureManager();
   NodeHolder node_holder_;

third_party/blink/renderer/core/layout/layout_text_test.cc

@@ -662,21 +662,6 @@ TEST_P(ParameterizedLayoutTextTest, PhysicalLinesBoundingBoxVerticalRL) {
                 ->PhysicalLinesBoundingBox());
 }
 
-TEST_P(ParameterizedLayoutTextTest, QuadsBasic) {
-  GetDocument().SetCompatibilityMode(Document::kQuirksMode);
-  LoadAhem();
-  SetBasicBody(
-      "<style>p {font: 13px/17px Ahem;}</style>"
-      "<p id=one>one</p>");
-  const Element& one = *GetDocument().getElementById("one");
-  Vector<FloatQuad> actual_quads;
-  ToLayoutText(one.firstChild()->GetLayoutObject())->Quads(actual_quads);
-  EXPECT_EQ(
-      Vector<FloatQuad>({FloatQuad(FloatPoint(8, 10), FloatPoint(47, 10),
-                                   FloatPoint(47, 23), FloatPoint(8, 23))}),
-      actual_quads);
-}
-
 TEST_P(ParameterizedLayoutTextTest, WordBreakElement) {
   SetBasicBody("foo <wbr> bar");
 
@@ -807,4 +792,51 @@ TEST_P(ParameterizedLayoutTextTest, LocalSelectionRectLineHeightVertical) {
                                 "foo bar b^a|z</div>"));
 }
 
+TEST_P(ParameterizedLayoutTextTest, VisualRectInDocumentSVGTspan) {
+  LoadAhem();
+  SetBodyInnerHTML(R"HTML(
+    <style>
+      body {
+        margin:0px;
+        font: 20px/20px Ahem;
+      }
+    </style>
+    <svg>
+      <text x="10" y="50" width="100">
+        <tspan id="target" dx="15" dy="25">tspan</tspan>
+      </text>
+    </svg>
+  )HTML");
+
+  LayoutText* target =
+      ToLayoutText(GetLayoutObjectByElementId("target")->SlowFirstChild());
+  const int ascent = 16;
+  PhysicalRect expected(10 + 15, 50 + 25 - ascent, 20 * 5, 20);
+  EXPECT_EQ(expected, target->VisualRectInDocument());
+  EXPECT_EQ(expected, target->VisualRectInDocument(kUseGeometryMapper));
+}
+
+TEST_P(ParameterizedLayoutTextTest, VisualRectInDocumentSVGTspanTB) {
+  LoadAhem();
+  SetBodyInnerHTML(R"HTML(
+    <style>
+      body {
+        margin:0px;
+        font: 20px/20px Ahem;
+      }
+    </style>
+    <svg>
+      <text x="50" y="10" width="100" writing-mode="tb">
+        <tspan id="target" dx="15" dy="25">tspan</tspan>
+      </text>
+    </svg>
+  )HTML");
+
+  LayoutText* target =
+      ToLayoutText(GetLayoutObjectByElementId("target")->SlowFirstChild());
+  PhysicalRect expected(50 + 15 - 20 / 2, 10 + 25, 20, 20 * 5);
+  EXPECT_EQ(expected, target->VisualRectInDocument());
+  EXPECT_EQ(expected, target->VisualRectInDocument(kUseGeometryMapper));
+}
+
 }  // namespace blink