sideways: Support SVG

In , a text in sideways-lr works like a text in horizontal-tb.

Bug: 40501131
Change-Id: I17340abd83cbe375d7cc8d1a6a37521d7bfc8157
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5992678
Commit-Queue: Koji Ishii 
Reviewed-by: Koji Ishii 
Auto-Submit: Kent Tamura 
Cr-Commit-Position: refs/heads/main@{#1378784}

Author: tkent-google

third_party/blink/renderer/core/layout/inline/fragment_item.cc

@@ -709,12 +709,22 @@ AffineTransform FragmentItem::BuildSvgTransformForTextPath(
   // PositionOnPath()|.
   float x = svg_data.rect.x();
   float y = svg_data.rect.y();
-  if (IsHorizontal()) {
-    y += font_data->GetFontMetrics().FixedAscent(font_baseline);
-    transform.Translate(-svg_data.rect.width() / 2, svg_data.baseline_shift);
-  } else {
-    x += font_data->GetFontMetrics().FixedDescent(font_baseline);
-    transform.Translate(svg_data.baseline_shift, -svg_data.rect.height() / 2);
+  switch (GetWritingMode()) {
+    case WritingMode::kHorizontalTb:
+      y += font_data->GetFontMetrics().FixedAscent(font_baseline);
+      transform.Translate(-svg_data.rect.width() / 2, svg_data.baseline_shift);
+      break;
+    case WritingMode::kVerticalLr:
+    case WritingMode::kVerticalRl:
+    case WritingMode::kSidewaysRl:
+      x += font_data->GetFontMetrics().FixedDescent(font_baseline);
+      transform.Translate(svg_data.baseline_shift, -svg_data.rect.height() / 2);
+      break;
+    case WritingMode::kSidewaysLr:
+      x += font_data->GetFontMetrics().FixedAscent(font_baseline);
+      y = svg_data.rect.bottom();
+      transform.Translate(-svg_data.baseline_shift, svg_data.rect.height() / 2);
+      break;
   }
   transform.PreConcat(length_adjust);
   transform.SetE(transform.E() + x);

third_party/blink/renderer/core/layout/svg/svg_text_layout_algorithm.cc

@@ -667,10 +667,11 @@ void SvgTextLayoutAlgorithm::PositionOnPath(
           //      mid is x + advance / 2 + offset
           //   -> false
           //      mid is y + advance / 2 + offset
+          const float char_offset = IsHorizontal()         ? *info.x
+                                    : IsVerticalDownward() ? *info.y
+                                                           : -*info.y;
           const float mid =
-              ((horizontal_ ? *info.x : *info.y) + info.inline_size / 2) /
-                  scaling_factor +
-              offset;
+              (char_offset + info.inline_size / 2) / scaling_factor + offset;
 
           // 5.1.2.3. Let length be the length of path.
           // 5.1.2.9. If path is a closed subpath depending on the values of
@@ -698,26 +699,34 @@ void SvgTextLayoutAlgorithm::PositionOnPath(
               info.hidden = true;
             }
             point_tangent.tangent_in_degrees += info.rotate.value_or(0.0f);
-            if (!horizontal_) {
+            if (IsVerticalDownward()) {
               point_tangent.tangent_in_degrees -= 90;
+            } else if (IsVerticalUpward()) {
+              point_tangent.tangent_in_degrees += 90;
             }
             info.rotate = point_tangent.tangent_in_degrees;
             if (*info.rotate == 0.0f) {
-              if (horizontal_) {
+              if (IsHorizontal()) {
                 info.x = point_tangent.point.x() * scaling_factor -
                          info.inline_size / 2;
                 info.y = point_tangent.point.y() * scaling_factor + *info.y;
-              } else {
+              } else if (IsVerticalDownward()) {
                 info.x = point_tangent.point.x() * scaling_factor + *info.x;
                 info.y = point_tangent.point.y() * scaling_factor -
                          info.inline_size / 2;
+              } else {
+                info.x = point_tangent.point.x() * scaling_factor + *info.x;
+                info.y = point_tangent.point.y() * scaling_factor +
+                         info.inline_size / 2;
               }
             } else {
               // Unlike the specification, we just set result[index].x/y to the
               // point along the path. The character is moved by an
               // AffineTransform produced from baseline_shift and inline_size/2.
               // See |FragmentItem::BuildSVGTransformForTextPath()|.
-              info.baseline_shift = horizontal_ ? *info.y : *info.x;
+              info.baseline_shift = IsHorizontal()         ? *info.y
+                                    : IsVerticalDownward() ? *info.x
+                                                           : -*info.x;
               info.x = point_tangent.point.x() * scaling_factor;
               info.y = point_tangent.point.y() * scaling_factor;
             }
@@ -769,12 +778,15 @@ void SvgTextLayoutAlgorithm::PositionOnPath(
               reverse_result_range,
               [](const auto& info) { return !info.hidden && !info.middle; });
           if (iter != reverse_result_range.end()) {
-            if (horizontal_) {
+            if (IsHorizontal()) {
               path_end_x = *iter->x + iter->inline_size;
               path_end_y = *iter->y;
-            } else {
+            } else if (IsVerticalDownward()) {
               path_end_x = *iter->x;
               path_end_y = *iter->y + iter->inline_size;
+            } else {
+              path_end_x = *iter->x;
+              path_end_y = *iter->y - iter->inline_size;
             }
           } else {
             path_end_x = 0.0f;

third_party/blink/web_tests/external/wpt/svg/text/scripted/getrotationofchar-expected.txt

@@ -1,5 +1,5 @@
 This is a testharness.js-based test.
 [FAIL]  - sideways-lr
-  assert_equals: 金 expected 225 but got 0
+  assert_equals: F expected 225 but got 45
 Harness: the test ran to completion.