Merge Blink code to cache SkTextBlob

sky/engine/platform/fonts/harfbuzz/HarfBuzzShaper.cpp

Index: sky/engine/platform/fonts/harfbuzz/HarfBuzzShaper.cpp
diff --git a/sky/engine/platform/fonts/harfbuzz/HarfBuzzShaper.cpp b/sky/engine/platform/fonts/harfbuzz/HarfBuzzShaper.cpp
index 34fc737235e5218eb7a5f5a7d550f93a25a8068e..1a3da207aef2a10fcb47a5b98a8825c5bf4523a1 100644
--- a/sky/engine/platform/fonts/harfbuzz/HarfBuzzShaper.cpp
+++ b/sky/engine/platform/fonts/harfbuzz/HarfBuzzShaper.cpp
@@ -278,7 +278,7 @@ inline void HarfBuzzShaper::HarfBuzzRun::setGlyphAndPositions(unsigned index, ui
 {
     m_glyphs[index] = glyphId;
     m_advances[index] = advance;
-    m_offsets[index] = FloatPoint(offsetX, offsetY);
+    m_offsets[index] = FloatSize(offsetX, offsetY);
 }
 
 int HarfBuzzShaper::HarfBuzzRun::characterIndexForXPosition(float targetX)
@@ -571,11 +571,6 @@ bool HarfBuzzShaper::shape(GlyphBuffer* glyphBuffer)
     return true;
 }
 
-FloatPoint HarfBuzzShaper::adjustStartPoint(const FloatPoint& point)
-{
-    return point + m_startOffset;
-}
-
 static inline int handleMultipleUChar(
     UChar32 character,
     unsigned clusterLength,
@@ -950,29 +945,35 @@ void HarfBuzzShaper::setGlyphPositionsForHarfBuzzRun(HarfBuzzRun* currentRun, hb
     m_totalWidth += currentRun->width();
 }
 
-void HarfBuzzShaper::fillGlyphBufferFromHarfBuzzRun(GlyphBuffer* glyphBuffer, HarfBuzzRun* currentRun, FloatPoint& firstOffsetOfNextRun)
+void HarfBuzzShaper::fillGlyphBufferFromHarfBuzzRun(GlyphBuffer* glyphBuffer, HarfBuzzRun* currentRun, float& carryAdvance)
 {
-    FloatPoint* offsets = currentRun->offsets();
+    FloatSize* offsets = currentRun->offsets();
     uint16_t* glyphs = currentRun->glyphs();
     float* advances = currentRun->advances();
     unsigned numGlyphs = currentRun->numGlyphs();
     uint16_t* glyphToCharacterIndexes = currentRun->glyphToCharacterIndexes();
-    for (unsigned i = 0; i < numGlyphs; ++i) {
-        uint16_t currentCharacterIndex = currentRun->startIndex() + glyphToCharacterIndexes[i];
-        FloatPoint& currentOffset = offsets[i];
-        FloatPoint& nextOffset = (i == numGlyphs - 1) ? firstOffsetOfNextRun : offsets[i + 1];
-        float glyphAdvanceX = advances[i] + nextOffset.x() - currentOffset.x();
-        float glyphAdvanceY = nextOffset.y() - currentOffset.y();
-        if (m_run.rtl()) {
-            if (currentCharacterIndex >= m_toIndex)
-                m_startOffset.move(glyphAdvanceX, glyphAdvanceY);
-            else if (currentCharacterIndex >= m_fromIndex)
-                glyphBuffer->add(glyphs[i], currentRun->fontData(), FloatSize(glyphAdvanceX, glyphAdvanceY));
-        } else {
-            if (currentCharacterIndex < m_fromIndex)
-                m_startOffset.move(glyphAdvanceX, glyphAdvanceY);
-            else if (currentCharacterIndex < m_toIndex)
-                glyphBuffer->add(glyphs[i], currentRun->fontData(), FloatSize(glyphAdvanceX, glyphAdvanceY));
+    FloatSize runStartOffset = FloatSize();
+    if (m_run.rtl()) {
+        for (unsigned i = 0; i < numGlyphs; ++i) {
+            uint16_t currentCharacterIndex = currentRun->startIndex() + glyphToCharacterIndexes[i];
+            if (currentCharacterIndex >= m_toIndex) {
+                carryAdvance += advances[i];
+            } else if (currentCharacterIndex >= m_fromIndex) {
+                runStartOffset = HB_DIRECTION_IS_HORIZONTAL(currentRun->direction()) ? FloatSize(carryAdvance, 0) : FloatSize(0, carryAdvance);
+                glyphBuffer->add(glyphs[i], currentRun->fontData(), runStartOffset + offsets[i], carryAdvance + advances[i]);
+                carryAdvance = 0;
+            }
+        }
+    } else {
+        for (unsigned i = 0; i < numGlyphs; ++i) {
+            uint16_t currentCharacterIndex = currentRun->startIndex() + glyphToCharacterIndexes[i];
+            if (currentCharacterIndex < m_fromIndex) {
+                carryAdvance += advances[i];
+            } else if (currentCharacterIndex < m_toIndex) {
+                runStartOffset = HB_DIRECTION_IS_HORIZONTAL(currentRun->direction()) ? FloatSize(carryAdvance, 0) : FloatSize(0, carryAdvance);
+                glyphBuffer->add(glyphs[i], currentRun->fontData(), runStartOffset + offsets[i], carryAdvance + advances[i]);
+                carryAdvance = 0;
+            }
         }
     }
 }
@@ -1034,33 +1035,30 @@ void HarfBuzzShaper::fillGlyphBufferForTextEmphasis(GlyphBuffer* glyphBuffer, Ha
 bool HarfBuzzShaper::fillGlyphBuffer(GlyphBuffer* glyphBuffer)
 {
     unsigned numRuns = m_harfBuzzRuns.size();
+    float carryAdvance = 0;
     if (m_run.rtl()) {
-        m_startOffset = m_harfBuzzRuns.last()->offsets()[0];
         for (int runIndex = numRuns - 1; runIndex >= 0; --runIndex) {
             HarfBuzzRun* currentRun = m_harfBuzzRuns[runIndex].get();
             if (!currentRun->hasGlyphToCharacterIndexes()) {
                 // FIXME: bug 337886, 359664
                 continue;
             }
-            FloatPoint firstOffsetOfNextRun = !runIndex ? FloatPoint() : m_harfBuzzRuns[runIndex - 1]->offsets()[0];
             if (m_forTextEmphasis == ForTextEmphasis)
                 fillGlyphBufferForTextEmphasis(glyphBuffer, currentRun);
             else
-                fillGlyphBufferFromHarfBuzzRun(glyphBuffer, currentRun, firstOffsetOfNextRun);
+                fillGlyphBufferFromHarfBuzzRun(glyphBuffer, currentRun, carryAdvance);
         }
     } else {
-        m_startOffset = m_harfBuzzRuns.first()->offsets()[0];
         for (unsigned runIndex = 0; runIndex < numRuns; ++runIndex) {
             HarfBuzzRun* currentRun = m_harfBuzzRuns[runIndex].get();
             if (!currentRun->hasGlyphToCharacterIndexes()) {
                 // FIXME: bug 337886, 359664
                 continue;
             }
-            FloatPoint firstOffsetOfNextRun = runIndex == numRuns - 1 ? FloatPoint() : m_harfBuzzRuns[runIndex + 1]->offsets()[0];
             if (m_forTextEmphasis == ForTextEmphasis)
                 fillGlyphBufferForTextEmphasis(glyphBuffer, currentRun);
             else
-                fillGlyphBufferFromHarfBuzzRun(glyphBuffer, currentRun, firstOffsetOfNextRun);
+                fillGlyphBufferFromHarfBuzzRun(glyphBuffer, currentRun, carryAdvance);
         }
     }
     return glyphBuffer->size();