Carry advances between runs in HarfBuzzShaper.cpp

Source/platform/fonts/harfbuzz/HarfBuzzShaper.cpp

 /*
  * Copyright (c) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 BlackBerry Limited. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 930 matching lines @@
         glyphBounds.move(glyphOrigin.x(), glyphOrigin.y());
         m_glyphBoundingBox.unite(glyphBounds);
         glyphOrigin += FloatSize(advance + offsetX, offsetY);
 
         totalAdvance += advance;
     }
     currentRun->setWidth(totalAdvance > 0.0 ? totalAdvance : 0.0);
     m_totalWidth += currentRun->width();
 }
 
-void HarfBuzzShaper::fillGlyphBufferFromHarfBuzzRun(GlyphBufferWithOffsets* glyphBuffer, HarfBuzzRun* currentRun)
+void HarfBuzzShaper::fillGlyphBufferFromHarfBuzzRun(GlyphBufferWithOffsets* glyphBuffer, HarfBuzzRun* currentRun, float& carryAdvance)
 {
     FloatSize* offsets = currentRun->offsets();
     uint16_t* glyphs = currentRun->glyphs();
     float* advances = currentRun->advances();
     unsigned numGlyphs = currentRun->numGlyphs();
     uint16_t* glyphToCharacterIndexes = currentRun->glyphToCharacterIndexes();
-    float advanceSoFar = 0;
+    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)
-                advanceSoFar += advances[i];
-            else if (currentCharacterIndex >= m_fromIndex)
-                glyphBuffer->add(glyphs[i], currentRun->fontData(), offsets[i] + FloatSize(advanceSoFar, 0), advances[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)
-                advanceSoFar += advances[i];
-            else if (currentCharacterIndex < m_toIndex)
-                glyphBuffer->add(glyphs[i], currentRun->fontData(), offsets[i] + FloatSize(advanceSoFar, 0), advances[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;
+            }
         }
     }
 }
 
 void HarfBuzzShaper::fillGlyphBufferForTextEmphasis(GlyphBuffer* glyphBuffer, HarfBuzzRun* currentRun)
 {
     // FIXME: Instead of generating a synthetic GlyphBuffer here which is then used by the
     // drawEmphasisMarks method of FontFastPath, we should roll our own emphasis mark drawing function.
 
     float* advances = currentRun->advances();
@@ skipping 41 matching lines @@
             }
             clusterStart = clusterEnd;
             clusterAdvance = 0;
         }
     }
 }
 
 bool HarfBuzzShaper::fillGlyphBuffer(GlyphBuffer* glyphBuffer)
 {
     unsigned numRuns = m_harfBuzzRuns.size();
+    float carryAdvance = 0;
     if (m_run.rtl()) {
         for (int runIndex = numRuns - 1; runIndex >= 0; --runIndex) {
             HarfBuzzRun* currentRun = m_harfBuzzRuns[runIndex].get();
             if (!currentRun->hasGlyphToCharacterIndexes()) {
                 // FIXME: bug 337886, 359664
                 continue;
             }
             if (m_forTextEmphasis == ForTextEmphasis) {
                 ASSERT(!glyphBuffer->hasOffsets());
                 fillGlyphBufferForTextEmphasis(glyphBuffer, currentRun);
             } else {
                 ASSERT(glyphBuffer->hasOffsets());
                 fillGlyphBufferFromHarfBuzzRun(
-                    static_cast<GlyphBufferWithOffsets*>(glyphBuffer), currentRun);
+                    static_cast<GlyphBufferWithOffsets*>(glyphBuffer), currentRun, carryAdvance);
             }
         }
     } else {
         for (unsigned runIndex = 0; runIndex < numRuns; ++runIndex) {
             HarfBuzzRun* currentRun = m_harfBuzzRuns[runIndex].get();
             if (!currentRun->hasGlyphToCharacterIndexes()) {
                 // FIXME: bug 337886, 359664
                 continue;
             }
             if (m_forTextEmphasis == ForTextEmphasis) {
                 ASSERT(!glyphBuffer->hasOffsets());
                 fillGlyphBufferForTextEmphasis(glyphBuffer, currentRun);
             } else {
                 ASSERT(glyphBuffer->hasOffsets());
                 fillGlyphBufferFromHarfBuzzRun(
-                    static_cast<GlyphBufferWithOffsets*>(glyphBuffer), currentRun);
+                    static_cast<GlyphBufferWithOffsets*>(glyphBuffer), currentRun, carryAdvance);
             }
         }
     }
     return glyphBuffer->size();
 }
 
 int HarfBuzzShaper::offsetForPosition(float targetX)
 {
     int charactersSoFar = 0;
     float currentX = 0;
@@ skipping 70 matching lines @@
             point.x() + fromX, point.x() + toX,
             point.y(), height);
     }
 
     return Font::pixelSnappedSelectionRect(
         point.x() + toX, point.x() + fromX,
         point.y(), height);
 }
 
 } // namespace blink