Bug 1777671 - Account for glyph orientations when returning rotation of character r=jfkthame

Differential Revision: https://phabricator.services.mozilla.com/D150858

gfx/thebes/gfxTextRun.h

@@ -513,6 +513,16 @@ class gfxTextRun : public gfxShapedText {
       }
       return false;
     }
+
+    bool IsSidewaysLeft() const {
+      return (mOrientation & mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_MASK) ==
+             mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_VERTICAL_SIDEWAYS_LEFT;
+    }
+
+    bool IsSidewaysRight() const {
+      return (mOrientation & mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_MASK) ==
+             mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_VERTICAL_SIDEWAYS_RIGHT;
+    }
   };
 
   // Script run codes that we will mark as CJK to suppress skip-ink behavior.

layout/svg/SVGTextFrame.cpp

@@ -2034,6 +2034,11 @@ class CharIterator {
    */
   bool IsClusterAndLigatureGroupStart() const;
 
+  /**
+   * Returns the glyph run for the current character.
+   */
+  const gfxTextRun::GlyphRun& GlyphRun() const;
+
   /**
    * Returns whether the current character is trimmed away when painting,
    * due to it being leading/trailing white space.
@@ -2281,6 +2286,15 @@ bool CharIterator::IsClusterAndLigatureGroupStart() const {
          mTextRun->IsClusterStart(mSkipCharsIterator.GetSkippedOffset());
 }
 
+const gfxTextRun::GlyphRun& CharIterator::GlyphRun() const {
+  uint32_t numRuns;
+  const gfxTextRun::GlyphRun* glyphRuns = mTextRun->GetGlyphRuns(&numRuns);
+  uint32_t runIndex = mTextRun->FindFirstGlyphRunContaining(
+      mSkipCharsIterator.GetSkippedOffset());
+  MOZ_ASSERT(runIndex < numRuns);
+  return glyphRuns[runIndex];
+}
+
 bool CharIterator::IsOriginalCharTrimmed() const {
   if (mFrameForTrimCheck != TextFrame()) {
     // Since we do a lot of trim checking, we cache the trimmed offsets and
@@ -4025,7 +4039,13 @@ float SVGTextFrame::GetRotationOfChar(nsIContent* aContent, uint32_t aCharNum,
     return 0;
   }
 
-  return mPositions[it.TextElementCharIndex()].mAngle * 180.0 / M_PI;
+  // we need to account for the glyph's underlying orientation
+  const gfxTextRun::GlyphRun& glyphRun = it.GlyphRun();
+  int32_t glyphOrientation =
+      90 * (glyphRun.IsSidewaysRight() - glyphRun.IsSidewaysLeft());
+
+  return mPositions[it.TextElementCharIndex()].mAngle * 180.0 / M_PI +
+         glyphOrientation;
 }
 
 //----------------------------------------------------------------------

testing/web-platform/meta/svg/text/scripted/getrotationofchar.html.ini

@@ -1,13 +0,0 @@
-[getrotationofchar.html]
-  ['text-orientation: mixed' - vertical-rl]
-    expected: FAIL
-
-  ['text-orientation: sideways' - vertical-rl]
-    expected: FAIL
-
-  [Rotation attribute - vertical-rl]
-    expected: FAIL
-
-  [<textPath> - vertical-rl]
-    expected: FAIL
-

testing/web-platform/tests/svg/text/scripted/getrotationofchar.html

@@ -29,38 +29,41 @@ function normalizedRotation(element, index) {
 }
 
 const container = document.querySelector('#container');
-['horizontal-tb', 'vertical-rl'].forEach(mode => {
+['horizontal-tb', 'vertical-rl', 'vertical-lr', 'sideways-rl', 'sideways-lr'].forEach(mode => {
   const isHorizontal = mode == 'horizontal-tb';
+  const isVertical = mode == 'vertical-rl' || mode == 'vertical-lr';
+  const sidewaysDelta = 90 * ((mode == 'sideways-rl') - (mode == 'sideways-lr'));
   container.style.writingMode = mode;
 
   test(() => {
     container.style.textOrientation = 'mixed';
-    const element = container.appendChild(createSVGElement('text', {}, 'M月'));
-    assert_equals(element.getRotationOfChar(0), isHorizontal ? 0 : 90, 'M');
-    assert_equals(element.getRotationOfChar(1), 0, '月');
+    const element = container.appendChild(createSVGElement('text', {}, '  M月X'));
+    assert_equals(element.getRotationOfChar(0), isVertical ? 90 : sidewaysDelta, 'M');
+    assert_equals(element.getRotationOfChar(1), sidewaysDelta, '月');
+    assert_equals(element.getRotationOfChar(2), isVertical ? 90 : sidewaysDelta, 'X');
   }, `'text-orientation: mixed' - ${mode}`);
 
   test(() => {
     container.style.textOrientation = 'upright';
     const element = container.appendChild(createSVGElement('text', {}, 'T火'));
-    assert_equals(element.getRotationOfChar(0), 0, 'T');
-    assert_equals(element.getRotationOfChar(1), 0, '火');
+    assert_equals(element.getRotationOfChar(0), sidewaysDelta, 'T');
+    assert_equals(element.getRotationOfChar(1), sidewaysDelta, '火');
   }, `'text-orientation: upright' - ${mode}`);
 
   test(() => {
     container.style.textOrientation = 'sideways';
     const element = container.appendChild(createSVGElement('text', {}, 'W水'));
-    assert_equals(element.getRotationOfChar(0), isHorizontal ? 0 : 90, 'W');
-    assert_equals(element.getRotationOfChar(1), isHorizontal ? 0 : 90, '水');
+    assert_equals(element.getRotationOfChar(0), isVertical ? 90 : sidewaysDelta, 'W');
+    assert_equals(element.getRotationOfChar(1), isVertical ? 90 : sidewaysDelta, '水');
   }, `'text-orientation: sideways' - ${mode}`);
 
   test(() => {
     container.style.textOrientation = 'mixed';
     const element = container.appendChild(
         createSVGElement('text', {rotate: '0 180.5 360 365 -10'}, 't木cde'));
-    const shift = isHorizontal ? 0 : 90;
+    const shift = isHorizontal ? 0 : 90 * (mode == 'sideways-rl' || isVertical) + 270 * (mode == 'sideways-lr');
     assert_equals(normalizedRotation(element, 0), 0 + shift, 't');
-    assert_equals(normalizedRotation(element, 1), 180.5, '木');
+    assert_equals(normalizedRotation(element, 1), 180.5 + sidewaysDelta, '木');
     assert_equals(normalizedRotation(element, 2), 0 + shift, 'c');
     assert_equals(normalizedRotation(element, 3), 5 + shift, 'd');
     assert_equals(normalizedRotation(element, 4), normalize(350 + shift), 'e');
@@ -72,9 +75,10 @@ const container = document.querySelector('#container');
     const element = container.appendChild(
         createSVGElement('text', {rotate: '0 0 25'},
             createSVGElement('textPath', {href: '#path1'}, 'F金r')));
-    assert_equals(normalizedRotation(element, 0), 45, 'F');
-    assert_equals(normalizedRotation(element, 1), isHorizontal ? 45 : 315, '金');
-    assert_equals(normalizedRotation(element, 2), 45 + 25, 'r');
+    const shift = (mode == 'sideways-lr') ? 180 : 0;
+    assert_equals(normalizedRotation(element, 0), 45 + shift, 'F');
+    assert_equals(normalizedRotation(element, 1), isVertical ? 315 : 45 + shift, '金');
+    assert_equals(normalizedRotation(element, 2), 45 + 25 + shift, 'r');
   }, `<textPath> - ${mode}`);
 });
 </script>