root/Source/core/rendering/svg/SVGTextLayoutEngine.cpp

DEFINITIONS

1. m_textPathScaling
2. updateCharacerPositionIfNeeded
3. updateCurrentTextPosition
4. updateRelativePositionAdjustmentsIfNeeded
5. recordTextFragment
6. parentDefinesTextLength
7. beginTextPathLayout
8. endTextPathLayout
9. layoutInlineTextBox
10. dumpTextBoxes
11. finalizeTransformMatrices
12. finishLayout
13. currentLogicalCharacterAttributes
14. currentLogicalCharacterMetrics
15. currentVisualCharacterMetrics
16. advanceToNextLogicalCharacter
17. advanceToNextVisualCharacter
18. layoutTextOnLineOrPath

/*
 * Copyright (C) Research In Motion Limited 2010-2012. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"

#include "core/rendering/svg/SVGTextLayoutEngine.h"

#include "core/rendering/svg/RenderSVGInlineText.h"
#include "core/rendering/svg/RenderSVGTextPath.h"
#include "core/rendering/svg/SVGInlineTextBox.h"
#include "core/rendering/svg/SVGTextLayoutEngineBaseline.h"
#include "core/rendering/svg/SVGTextLayoutEngineSpacing.h"
#include "core/svg/SVGElement.h"
#include "core/svg/SVGLengthContext.h"

// Set to a value > 0 to dump the text fragments
#define DUMP_TEXT_FRAGMENTS 0

namespace WebCore {

SVGTextLayoutEngine::SVGTextLayoutEngine(Vector<SVGTextLayoutAttributes*>& layoutAttributes)
    : m_layoutAttributes(layoutAttributes)
    , m_layoutAttributesPosition(0)
    , m_logicalCharacterOffset(0)
    , m_logicalMetricsListOffset(0)
    , m_visualCharacterOffset(0)
    , m_visualMetricsListOffset(0)
    , m_x(0)
    , m_y(0)
    , m_dx(0)
    , m_dy(0)
    , m_isVerticalText(false)
    , m_inPathLayout(false)
    , m_textPathCalculator(0)
    , m_textPathLength(0)
    , m_textPathCurrentOffset(0)
    , m_textPathSpacing(0)
    , m_textPathScaling(1)
{
    ASSERT(!m_layoutAttributes.isEmpty());
}

void SVGTextLayoutEngine::updateCharacerPositionIfNeeded(float& x, float& y)
{
    if (m_inPathLayout)
        return;

    // Replace characters x/y position, with the current text position plus any
    // relative adjustments, if it doesn't specify an absolute position itself.
    if (x == SVGTextLayoutAttributes::emptyValue())
        x = m_x + m_dx;

    if (y == SVGTextLayoutAttributes::emptyValue())
        y = m_y + m_dy;

    m_dx = 0;
    m_dy = 0;
}

void SVGTextLayoutEngine::updateCurrentTextPosition(float x, float y, float glyphAdvance)
{
    // Update current text position after processing the character.
    if (m_isVerticalText) {
        m_x = x;
        m_y = y + glyphAdvance;
    } else {
        m_x = x + glyphAdvance;
        m_y = y;
    }
}

void SVGTextLayoutEngine::updateRelativePositionAdjustmentsIfNeeded(float dx, float dy)
{
    // Update relative positioning information.
    if (dx == SVGTextLayoutAttributes::emptyValue() && dy == SVGTextLayoutAttributes::emptyValue())
        return;

    if (dx == SVGTextLayoutAttributes::emptyValue())
        dx = 0;
    if (dy == SVGTextLayoutAttributes::emptyValue())
        dy = 0;

    if (m_inPathLayout) {
        if (m_isVerticalText) {
            m_dx += dx;
            m_dy = dy;
        } else {
            m_dx = dx;
            m_dy += dy;
        }

        return;
    }

    m_dx = dx;
    m_dy = dy;
}

void SVGTextLayoutEngine::recordTextFragment(SVGInlineTextBox* textBox, Vector<SVGTextMetrics>& textMetricsValues)
{
    ASSERT(!m_currentTextFragment.length);
    ASSERT(m_visualMetricsListOffset > 0);

    // Figure out length of fragment.
    m_currentTextFragment.length = m_visualCharacterOffset - m_currentTextFragment.characterOffset;

    // Figure out fragment metrics.
    SVGTextMetrics& lastCharacterMetrics = textMetricsValues.at(m_visualMetricsListOffset - 1);
    m_currentTextFragment.width = lastCharacterMetrics.width();
    m_currentTextFragment.height = lastCharacterMetrics.height();

    if (m_currentTextFragment.length > 1) {
        // SVGTextLayoutAttributesBuilder assures that the length of the range is equal to the sum of the individual lengths of the glyphs.
        float length = 0;
        if (m_isVerticalText) {
            for (unsigned i = m_currentTextFragment.metricsListOffset; i < m_visualMetricsListOffset; ++i)
                length += textMetricsValues.at(i).height();
            m_currentTextFragment.height = length;
        } else {
            for (unsigned i = m_currentTextFragment.metricsListOffset; i < m_visualMetricsListOffset; ++i)
                length += textMetricsValues.at(i).width();
            m_currentTextFragment.width = length;
        }
    }

    textBox->textFragments().append(m_currentTextFragment);
    m_currentTextFragment = SVGTextFragment();
}

bool SVGTextLayoutEngine::parentDefinesTextLength(RenderObject* parent) const
{
    RenderObject* currentParent = parent;
    while (currentParent) {
        if (SVGTextContentElement* textContentElement = SVGTextContentElement::elementFromRenderer(currentParent)) {
            SVGLengthContext lengthContext(textContentElement);
            if (textContentElement->lengthAdjust()->currentValue()->enumValue() == SVGLengthAdjustSpacing && textContentElement->textLengthIsSpecifiedByUser())
                return true;
        }

        if (currentParent->isSVGText())
            return false;

        currentParent = currentParent->parent();
    }

    ASSERT_NOT_REACHED();
    return false;
}

void SVGTextLayoutEngine::beginTextPathLayout(RenderObject* object, SVGTextLayoutEngine& lineLayout)
{
    ASSERT(object);

    m_inPathLayout = true;
    RenderSVGTextPath* textPath = toRenderSVGTextPath(object);

    Path path = textPath->layoutPath();
    if (path.isEmpty())
        return;
    m_textPathCalculator = new Path::PositionCalculator(path);
    m_textPathStartOffset = textPath->startOffset();
    m_textPathLength = path.length();
    if (m_textPathStartOffset > 0 && m_textPathStartOffset <= 1)
        m_textPathStartOffset *= m_textPathLength;

    float totalLength = 0;
    unsigned totalCharacters = 0;

    lineLayout.m_chunkLayoutBuilder.buildTextChunks(lineLayout.m_lineLayoutBoxes);
    const Vector<SVGTextChunk>& textChunks = lineLayout.m_chunkLayoutBuilder.textChunks();

    unsigned size = textChunks.size();
    for (unsigned i = 0; i < size; ++i) {
        const SVGTextChunk& chunk = textChunks.at(i);

        float length = 0;
        unsigned characters = 0;
        chunk.calculateLength(length, characters);

        // Handle text-anchor as additional start offset for text paths.
        m_textPathStartOffset += chunk.calculateTextAnchorShift(length);

        totalLength += length;
        totalCharacters += characters;
    }

    m_textPathCurrentOffset = m_textPathStartOffset;

    // Eventually handle textLength adjustments.
    SVGLengthAdjustType lengthAdjust = SVGLengthAdjustUnknown;
    float desiredTextLength = 0;

    if (SVGTextContentElement* textContentElement = SVGTextContentElement::elementFromRenderer(textPath)) {
        SVGLengthContext lengthContext(textContentElement);
        lengthAdjust = textContentElement->lengthAdjust()->currentValue()->enumValue();
        if (textContentElement->textLengthIsSpecifiedByUser())
            desiredTextLength = textContentElement->textLength()->currentValue()->value(lengthContext);
        else
            desiredTextLength = 0;
    }

    if (!desiredTextLength)
        return;

    if (lengthAdjust == SVGLengthAdjustSpacing)
        m_textPathSpacing = (desiredTextLength - totalLength) / totalCharacters;
    else
        m_textPathScaling = desiredTextLength / totalLength;
}

void SVGTextLayoutEngine::endTextPathLayout()
{
    m_inPathLayout = false;
    delete m_textPathCalculator;
    m_textPathCalculator = 0;
    m_textPathLength = 0;
    m_textPathStartOffset = 0;
    m_textPathCurrentOffset = 0;
    m_textPathSpacing = 0;
    m_textPathScaling = 1;
}

void SVGTextLayoutEngine::layoutInlineTextBox(SVGInlineTextBox* textBox)
{
    ASSERT(textBox);

    RenderSVGInlineText& text = toRenderSVGInlineText(textBox->textRenderer());
    ASSERT(text.parent());
    ASSERT(text.parent()->node());
    ASSERT(text.parent()->node()->isSVGElement());

    const RenderStyle* style = text.style();
    ASSERT(style);

    textBox->clearTextFragments();
    m_isVerticalText = style->svgStyle()->isVerticalWritingMode();
    layoutTextOnLineOrPath(textBox, &text, style);

    if (m_inPathLayout) {
        m_pathLayoutBoxes.append(textBox);
        return;
    }

    m_lineLayoutBoxes.append(textBox);
}

#if DUMP_TEXT_FRAGMENTS > 0
static inline void dumpTextBoxes(Vector<SVGInlineTextBox*>& boxes)
{
    unsigned boxCount = boxes.size();
    fprintf(stderr, "Dumping all text fragments in text sub tree, %i boxes\n", boxCount);

    for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
        SVGInlineTextBox* textBox = boxes.at(boxPosition);
        Vector<SVGTextFragment>& fragments = textBox->textFragments();
        fprintf(stderr, "-> Box %i: Dumping text fragments for SVGInlineTextBox, textBox=%p, textRenderer=%p\n", boxPosition, textBox, textBox->textRenderer());
        fprintf(stderr, "        textBox properties, start=%i, len=%i, box direction=%i\n", textBox->start(), textBox->len(), textBox->direction());
        fprintf(stderr, "   textRenderer properties, textLength=%i\n", textBox->textRenderer()->textLength());

        String characters = textBox->textRenderer()->text();

        unsigned fragmentCount = fragments.size();
        for (unsigned i = 0; i < fragmentCount; ++i) {
            SVGTextFragment& fragment = fragments.at(i);
            String fragmentString = characters.substring(fragment.characterOffset, fragment.length);
            fprintf(stderr, "    -> Fragment %i, x=%lf, y=%lf, width=%lf, height=%lf, characterOffset=%i, length=%i, characters='%s'\n"
                          , i, fragment.x, fragment.y, fragment.width, fragment.height, fragment.characterOffset, fragment.length, fragmentString.utf8().data());
        }
    }
}
#endif

void SVGTextLayoutEngine::finalizeTransformMatrices(Vector<SVGInlineTextBox*>& boxes)
{
    unsigned boxCount = boxes.size();
    if (!boxCount)
        return;

    AffineTransform textBoxTransformation;
    for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
        SVGInlineTextBox* textBox = boxes.at(boxPosition);
        Vector<SVGTextFragment>& fragments = textBox->textFragments();

        unsigned fragmentCount = fragments.size();
        for (unsigned i = 0; i < fragmentCount; ++i) {
            m_chunkLayoutBuilder.transformationForTextBox(textBox, textBoxTransformation);
            if (textBoxTransformation.isIdentity())
                continue;
            ASSERT(fragments[i].lengthAdjustTransform.isIdentity());
            fragments[i].lengthAdjustTransform = textBoxTransformation;
        }
    }

    boxes.clear();
}

void SVGTextLayoutEngine::finishLayout()
{
    // After all text fragments are stored in their correpsonding SVGInlineTextBoxes, we can layout individual text chunks.
    // Chunk layouting is only performed for line layout boxes, not for path layout, where it has already been done.
    m_chunkLayoutBuilder.layoutTextChunks(m_lineLayoutBoxes);

    // Finalize transform matrices, after the chunk layout corrections have been applied, and all fragment x/y positions are finalized.
    if (!m_lineLayoutBoxes.isEmpty()) {
#if DUMP_TEXT_FRAGMENTS > 0
        fprintf(stderr, "Line layout: ");
        dumpTextBoxes(m_lineLayoutBoxes);
#endif

        finalizeTransformMatrices(m_lineLayoutBoxes);
    }

    if (!m_pathLayoutBoxes.isEmpty()) {
#if DUMP_TEXT_FRAGMENTS > 0
        fprintf(stderr, "Path layout: ");
        dumpTextBoxes(m_pathLayoutBoxes);
#endif

        finalizeTransformMatrices(m_pathLayoutBoxes);
    }
}

bool SVGTextLayoutEngine::currentLogicalCharacterAttributes(SVGTextLayoutAttributes*& logicalAttributes)
{
    if (m_layoutAttributesPosition == m_layoutAttributes.size())
        return false;

    logicalAttributes = m_layoutAttributes[m_layoutAttributesPosition];
    ASSERT(logicalAttributes);

    if (m_logicalCharacterOffset != logicalAttributes->context()->textLength())
        return true;

    ++m_layoutAttributesPosition;
    if (m_layoutAttributesPosition == m_layoutAttributes.size())
        return false;

    logicalAttributes = m_layoutAttributes[m_layoutAttributesPosition];
    m_logicalMetricsListOffset = 0;
    m_logicalCharacterOffset = 0;
    return true;
}

bool SVGTextLayoutEngine::currentLogicalCharacterMetrics(SVGTextLayoutAttributes*& logicalAttributes, SVGTextMetrics& logicalMetrics)
{
    Vector<SVGTextMetrics>* textMetricsValues = &logicalAttributes->textMetricsValues();
    unsigned textMetricsSize = textMetricsValues->size();
    while (true) {
        if (m_logicalMetricsListOffset == textMetricsSize) {
            if (!currentLogicalCharacterAttributes(logicalAttributes))
                return false;

            textMetricsValues = &logicalAttributes->textMetricsValues();
            textMetricsSize = textMetricsValues->size();
            continue;
        }

        ASSERT(textMetricsSize);
        ASSERT(m_logicalMetricsListOffset < textMetricsSize);
        logicalMetrics = textMetricsValues->at(m_logicalMetricsListOffset);
        if (logicalMetrics.isEmpty() || (!logicalMetrics.width() && !logicalMetrics.height())) {
            advanceToNextLogicalCharacter(logicalMetrics);
            continue;
        }

        // Stop if we found the next valid logical text metrics object.
        return true;
    }

    ASSERT_NOT_REACHED();
    return true;
}

bool SVGTextLayoutEngine::currentVisualCharacterMetrics(SVGInlineTextBox* textBox, Vector<SVGTextMetrics>& visualMetricsValues, SVGTextMetrics& visualMetrics)
{
    ASSERT(!visualMetricsValues.isEmpty());
    unsigned textMetricsSize = visualMetricsValues.size();
    unsigned boxStart = textBox->start();
    unsigned boxLength = textBox->len();

    while (m_visualMetricsListOffset < textMetricsSize) {
        // Advance to text box start location.
        if (m_visualCharacterOffset < boxStart) {
            advanceToNextVisualCharacter(visualMetricsValues[m_visualMetricsListOffset]);
            continue;
        }

        // Stop if we've finished processing this text box.
        if (m_visualCharacterOffset >= boxStart + boxLength)
            return false;

        visualMetrics = visualMetricsValues[m_visualMetricsListOffset];
        return true;
    }

    return false;
}

void SVGTextLayoutEngine::advanceToNextLogicalCharacter(const SVGTextMetrics& logicalMetrics)
{
    ++m_logicalMetricsListOffset;
    m_logicalCharacterOffset += logicalMetrics.length();
}

void SVGTextLayoutEngine::advanceToNextVisualCharacter(const SVGTextMetrics& visualMetrics)
{
    ++m_visualMetricsListOffset;
    m_visualCharacterOffset += visualMetrics.length();
}

void SVGTextLayoutEngine::layoutTextOnLineOrPath(SVGInlineTextBox* textBox, RenderSVGInlineText* text, const RenderStyle* style)
{
    if (m_inPathLayout && !m_textPathCalculator)
        return;

    SVGElement* lengthContext = toSVGElement(text->parent()->node());

    RenderObject* textParent = text->parent();
    bool definesTextLength = textParent ? parentDefinesTextLength(textParent) : false;

    const SVGRenderStyle* svgStyle = style->svgStyle();
    ASSERT(svgStyle);

    m_visualMetricsListOffset = 0;
    m_visualCharacterOffset = 0;

    Vector<SVGTextMetrics>& visualMetricsValues = text->layoutAttributes()->textMetricsValues();
    ASSERT(!visualMetricsValues.isEmpty());

    const Font& font = style->font();

    SVGTextLayoutEngineSpacing spacingLayout(font);
    SVGTextLayoutEngineBaseline baselineLayout(font);

    bool didStartTextFragment = false;
    bool applySpacingToNextCharacter = false;

    float lastAngle = 0;
    float baselineShift = baselineLayout.calculateBaselineShift(svgStyle, lengthContext);
    baselineShift -= baselineLayout.calculateAlignmentBaselineShift(m_isVerticalText, text);

    // Main layout algorithm.
    while (true) {
        // Find the start of the current text box in this list, respecting ligatures.
        SVGTextMetrics visualMetrics(SVGTextMetrics::SkippedSpaceMetrics);
        if (!currentVisualCharacterMetrics(textBox, visualMetricsValues, visualMetrics))
            break;

        if (visualMetrics.isEmpty()) {
            advanceToNextVisualCharacter(visualMetrics);
            continue;
        }

        SVGTextLayoutAttributes* logicalAttributes = 0;
        if (!currentLogicalCharacterAttributes(logicalAttributes))
            break;

        ASSERT(logicalAttributes);
        SVGTextMetrics logicalMetrics(SVGTextMetrics::SkippedSpaceMetrics);
        if (!currentLogicalCharacterMetrics(logicalAttributes, logicalMetrics))
            break;

        SVGCharacterDataMap& characterDataMap = logicalAttributes->characterDataMap();
        SVGCharacterData data;
        SVGCharacterDataMap::iterator it = characterDataMap.find(m_logicalCharacterOffset + 1);
        if (it != characterDataMap.end())
            data = it->value;

        float x = data.x;
        float y = data.y;

        // When we've advanced to the box start offset, determine using the original x/y values,
        // whether this character starts a new text chunk, before doing any further processing.
        if (m_visualCharacterOffset == textBox->start())
            textBox->setStartsNewTextChunk(logicalAttributes->context()->characterStartsNewTextChunk(m_logicalCharacterOffset));

        float angle = data.rotate == SVGTextLayoutAttributes::emptyValue() ? 0 : data.rotate;

        // Calculate glyph orientation angle.
        UChar currentCharacter = text->characterAt(m_visualCharacterOffset);
        float orientationAngle = baselineLayout.calculateGlyphOrientationAngle(m_isVerticalText, svgStyle, currentCharacter);

        // Calculate glyph advance & x/y orientation shifts.
        float xOrientationShift = 0;
        float yOrientationShift = 0;
        float glyphAdvance = baselineLayout.calculateGlyphAdvanceAndOrientation(m_isVerticalText, visualMetrics, orientationAngle, xOrientationShift, yOrientationShift);

        // Assign current text position to x/y values, if needed.
        updateCharacerPositionIfNeeded(x, y);

        // Apply dx/dy value adjustments to current text position, if needed.
        updateRelativePositionAdjustmentsIfNeeded(data.dx, data.dy);

        // Calculate SVG Fonts kerning, if needed.
        float kerning = spacingLayout.calculateSVGKerning(m_isVerticalText, visualMetrics.glyph());

        // Calculate CSS 'kerning', 'letter-spacing' and 'word-spacing' for next character, if needed.
        float spacing = spacingLayout.calculateCSSKerningAndSpacing(svgStyle, lengthContext, currentCharacter);

        float textPathOffset = 0;
        if (m_inPathLayout) {
            float scaledGlyphAdvance = glyphAdvance * m_textPathScaling;
            if (m_isVerticalText) {
                // If there's an absolute y position available, it marks the beginning of a new position along the path.
                if (y != SVGTextLayoutAttributes::emptyValue())
                    m_textPathCurrentOffset = y + m_textPathStartOffset;

                m_textPathCurrentOffset += m_dy - kerning;
                m_dy = 0;

                // Apply dx/dy correction and setup translations that move to the glyph midpoint.
                xOrientationShift += m_dx + baselineShift;
                yOrientationShift -= scaledGlyphAdvance / 2;
            } else {
                // If there's an absolute x position available, it marks the beginning of a new position along the path.
                if (x != SVGTextLayoutAttributes::emptyValue())
                    m_textPathCurrentOffset = x + m_textPathStartOffset;

                m_textPathCurrentOffset += m_dx - kerning;
                m_dx = 0;

                // Apply dx/dy correction and setup translations that move to the glyph midpoint.
                xOrientationShift -= scaledGlyphAdvance / 2;
                yOrientationShift += m_dy - baselineShift;
            }

            // Calculate current offset along path.
            textPathOffset = m_textPathCurrentOffset + scaledGlyphAdvance / 2;

            // Move to next character.
            m_textPathCurrentOffset += scaledGlyphAdvance + m_textPathSpacing + spacing * m_textPathScaling;

            // Skip character, if we're before the path.
            if (textPathOffset < 0) {
                advanceToNextLogicalCharacter(logicalMetrics);
                advanceToNextVisualCharacter(visualMetrics);
                continue;
            }

            // Stop processing, if the next character lies behind the path.
            if (textPathOffset > m_textPathLength)
                break;

            FloatPoint point;
            bool ok = m_textPathCalculator->pointAndNormalAtLength(textPathOffset, point, angle);
            ASSERT_UNUSED(ok, ok);
            x = point.x();
            y = point.y();

            // For vertical text on path, the actual angle has to be rotated 90 degrees anti-clockwise, not the orientation angle!
            if (m_isVerticalText)
                angle -= 90;
        } else {
            // Apply all previously calculated shift values.
            if (m_isVerticalText) {
                x += baselineShift;
                y -= kerning;
            } else {
                x -= kerning;
                y -= baselineShift;
            }

            x += m_dx;
            y += m_dy;
        }

        // Determine whether we have to start a new fragment.
        bool shouldStartNewFragment = m_dx || m_dy || m_isVerticalText || m_inPathLayout || angle || angle != lastAngle
            || orientationAngle || kerning || applySpacingToNextCharacter || definesTextLength;

        // If we already started a fragment, close it now.
        if (didStartTextFragment && shouldStartNewFragment) {
            applySpacingToNextCharacter = false;
            recordTextFragment(textBox, visualMetricsValues);
        }

        // Eventually start a new fragment, if not yet done.
        if (!didStartTextFragment || shouldStartNewFragment) {
            ASSERT(!m_currentTextFragment.characterOffset);
            ASSERT(!m_currentTextFragment.length);

            didStartTextFragment = true;
            m_currentTextFragment.characterOffset = m_visualCharacterOffset;
            m_currentTextFragment.metricsListOffset = m_visualMetricsListOffset;
            m_currentTextFragment.x = x;
            m_currentTextFragment.y = y;

            // Build fragment transformation.
            if (angle)
                m_currentTextFragment.transform.rotate(angle);

            if (xOrientationShift || yOrientationShift)
                m_currentTextFragment.transform.translate(xOrientationShift, yOrientationShift);

            if (orientationAngle)
                m_currentTextFragment.transform.rotate(orientationAngle);

            m_currentTextFragment.isTextOnPath = m_inPathLayout && m_textPathScaling != 1;
            if (m_currentTextFragment.isTextOnPath) {
                if (m_isVerticalText)
                    m_currentTextFragment.lengthAdjustTransform.scaleNonUniform(1, m_textPathScaling);
                else
                    m_currentTextFragment.lengthAdjustTransform.scaleNonUniform(m_textPathScaling, 1);
            }
        }

        // Update current text position, after processing of the current character finished.
        if (m_inPathLayout)
            updateCurrentTextPosition(x, y, glyphAdvance);
        else {
            // Apply CSS 'kerning', 'letter-spacing' and 'word-spacing' to next character, if needed.
            if (spacing)
                applySpacingToNextCharacter = true;

            float xNew = x - m_dx;
            float yNew = y - m_dy;

            if (m_isVerticalText)
                xNew -= baselineShift;
            else
                yNew += baselineShift;

            updateCurrentTextPosition(xNew, yNew, glyphAdvance + spacing);
        }

        advanceToNextLogicalCharacter(logicalMetrics);
        advanceToNextVisualCharacter(visualMetrics);
        lastAngle = angle;
    }

    if (!didStartTextFragment)
        return;

    // Close last open fragment, if needed.
    recordTextFragment(textBox, visualMetricsValues);
}

}