C++ SVGTextFragment类代码示例

static inline void calculateGlyphBoundaries(const QueryData* queryData, const SVGTextFragment& fragment, int startPosition, FloatRect& extent)
{
    float scalingFactor = queryData->textLineLayout.scalingFactor();
    ASSERT(scalingFactor);

    FloatPoint glyphPosition = calculateGlyphPositionWithoutTransform(queryData, fragment, startPosition);
    glyphPosition.move(0, -queryData->textLineLayout.scaledFont().fontMetrics().floatAscent() / scalingFactor);
    extent.setLocation(glyphPosition);

    // Use the SVGTextMetrics computed by SVGTextMetricsBuilder (which spends
    // time attempting to compute more correct glyph bounds already, handling
    // cursive scripts to some degree.)
    const Vector<SVGTextMetrics>& textMetricsValues = queryData->textLineLayout.layoutAttributes()->textMetricsValues();
    const SVGTextMetrics& metrics = findMetricsForCharacter(textMetricsValues, fragment, startPosition);

    // TODO(fs): Negative glyph extents seems kind of weird to have, but
    // presently it can occur in some cases (like Arabic.)
    FloatSize glyphSize(std::max<float>(metrics.width(), 0), std::max<float>(metrics.height(), 0));
    extent.setSize(glyphSize);

    // If RTL, adjust the starting point to align with the LHS of the glyph bounding box.
    if (!queryData->textBox->isLeftToRightDirection()) {
        if (queryData->isVerticalText)
            extent.move(0, -glyphSize.height());
        else
            extent.move(-glyphSize.width(), 0);
    }

    if (fragment.isTransformed()) {
        AffineTransform fragmentTransform = fragment.buildFragmentTransform(SVGTextFragment::TransformIgnoringTextLength);
        extent = fragmentTransform.mapRect(extent);
    }
}

int SVGInlineTextBox::offsetForPositionInFragment(
    const SVGTextFragment& fragment,
    LayoutUnit position,
    bool includePartialGlyphs) const {
  LineLayoutSVGInlineText lineLayoutItem =
      LineLayoutSVGInlineText(this->getLineLayoutItem());

  float scalingFactor = lineLayoutItem.scalingFactor();
  ASSERT(scalingFactor);

  const ComputedStyle& style = lineLayoutItem.styleRef();

  TextRun textRun = constructTextRun(style, fragment);

  // Eventually handle lengthAdjust="spacingAndGlyphs".
  // FIXME: Handle vertical text.
  if (fragment.isTransformed()) {
    AffineTransform fragmentTransform = fragment.buildFragmentTransform();
    textRun.setHorizontalGlyphStretch(
        clampTo<float>(fragmentTransform.xScale()));
  }

  return fragment.characterOffset - start() +
         lineLayoutItem.scaledFont().offsetForPosition(
             textRun, position * scalingFactor, includePartialGlyphs);
}

static FloatPoint calculateGlyphPosition(const QueryData* queryData, const SVGTextFragment& fragment, int offsetInFragment)
{
    FloatPoint glyphPosition = calculateGlyphPositionWithoutTransform(queryData, fragment, offsetInFragment);
    if (fragment.isTransformed()) {
        AffineTransform fragmentTransform = fragment.buildFragmentTransform(SVGTextFragment::TransformIgnoringTextLength);
        glyphPosition = fragmentTransform.mapPoint(glyphPosition);
    }
    return glyphPosition;
}

static inline void calculateGlyphBoundaries(SVGTextQuery::Data* queryData, const SVGTextFragment& fragment, int startPosition, FloatRect& extent)
{
    float scalingFactor = queryData->textRenderer->scalingFactor();
    ASSERT(scalingFactor);

    extent.setLocation(FloatPoint(fragment.x, fragment.y - queryData->textRenderer->scaledFont().fontMetrics().floatAscent() / scalingFactor));

    if (startPosition) {
        SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(queryData->textRenderer, fragment.characterOffset, startPosition);
        if (queryData->isVerticalText)
            extent.move(0, metrics.height());
        else
            extent.move(metrics.width(), 0);
    }

    SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(queryData->textRenderer, fragment.characterOffset + startPosition, 1);
    extent.setSize(FloatSize(metrics.width(), metrics.height()));

    AffineTransform fragmentTransform;
    fragment.buildFragmentTransform(fragmentTransform, SVGTextFragment::TransformIgnoringTextLength);
    if (fragmentTransform.isIdentity())
        return;

    extent = fragmentTransform.mapRect(extent);
}

bool SVGTextQuery::endPositionOfCharacterCallback(Data* queryData, const SVGTextFragment& fragment) const
{
    EndPositionOfCharacterData* data = static_cast<EndPositionOfCharacterData*>(queryData);

    int startPosition = data->position;
    int endPosition = startPosition + 1;
    if (!mapStartEndPositionsIntoFragmentCoordinates(queryData, fragment, startPosition, endPosition))
        return false;

    data->endPosition = FloatPoint(fragment.x, fragment.y);

    SVGTextMetrics metrics = SVGTextMetrics::measureCharacterRange(queryData->textRenderer, fragment.characterOffset, startPosition + 1);
    if (queryData->isVerticalText)
        data->endPosition.move(0, metrics.height());
    else
        data->endPosition.move(metrics.width(), 0);

    AffineTransform fragmentTransform;
    fragment.buildFragmentTransform(fragmentTransform, SVGTextFragment::TransformIgnoringTextLength);
    if (fragmentTransform.isIdentity())
        return true;

    data->endPosition = fragmentTransform.mapPoint(data->endPosition);
    return true;
}

static inline FloatRect calculateFragmentBoundaries(LineLayoutSVGInlineText textLineLayout, const SVGTextFragment& fragment)
{
    float scalingFactor = textLineLayout.scalingFactor();
    ASSERT(scalingFactor);
    float baseline = textLineLayout.scaledFont().fontMetrics().floatAscent() / scalingFactor;
    return fragment.boundingBox(baseline);
}

static bool rotationOfCharacterCallback(QueryData* queryData, const SVGTextFragment& fragment)
{
    RotationOfCharacterData* data = static_cast<RotationOfCharacterData*>(queryData);

    int startPosition = data->position;
    int endPosition = startPosition + 1;
    if (!mapStartEndPositionsIntoFragmentCoordinates(queryData, fragment, startPosition, endPosition))
        return false;

    if (!fragment.isTransformed()) {
        data->rotation = 0;
    } else {
        AffineTransform fragmentTransform = fragment.buildFragmentTransform(SVGTextFragment::TransformIgnoringTextLength);
        fragmentTransform.scale(1 / fragmentTransform.xScale(), 1 / fragmentTransform.yScale());
        data->rotation = narrowPrecisionToFloat(rad2deg(atan2(fragmentTransform.b(), fragmentTransform.a())));
    }
    return true;
}

static inline FloatRect calculateFragmentBoundaries(const LayoutSVGInlineText& textLayoutObject, const SVGTextFragment& fragment)
{
    float scalingFactor = textLayoutObject.scalingFactor();
    ASSERT(scalingFactor);
    float baseline = textLayoutObject.scaledFont().fontMetrics().floatAscent() / scalingFactor;

    AffineTransform fragmentTransform;
    FloatRect fragmentRect(fragment.x, fragment.y - baseline, fragment.width, fragment.height);
    fragment.buildFragmentTransform(fragmentTransform);
    return fragmentTransform.mapRect(fragmentRect);
}

int SVGInlineTextBox::offsetForPositionInFragment(const SVGTextFragment& fragment, float position, bool includePartialGlyphs) const
{
   float scalingFactor = renderer().scalingFactor();
    ASSERT(scalingFactor);

    TextRun textRun = constructTextRun(&renderer().style(), fragment);

    // Eventually handle lengthAdjust="spacingAndGlyphs".
    // FIXME: Handle vertical text.
    AffineTransform fragmentTransform;
    fragment.buildFragmentTransform(fragmentTransform);
    if (!fragmentTransform.isIdentity())
        textRun.setHorizontalGlyphStretch(narrowPrecisionToFloat(fragmentTransform.xScale()));

    return fragment.characterOffset - start() + renderer().scaledFont().offsetForPosition(textRun, position * scalingFactor, includePartialGlyphs);
}

bool SVGTextQuery::rotationOfCharacterCallback(Data* queryData, const SVGTextFragment& fragment) const
{
    RotationOfCharacterData* data = static_cast<RotationOfCharacterData*>(queryData);

    unsigned startPosition = data->position;
    unsigned endPosition = startPosition + 1;
    if (!mapStartEndPositionsIntoFragmentCoordinates(queryData, fragment, startPosition, endPosition))
        return false;

    AffineTransform fragmentTransform;
    fragment.buildFragmentTransform(fragmentTransform, SVGTextFragment::TransformIgnoringTextLength);
    if (fragmentTransform.isIdentity())
        data->rotation = 0;
    else {
        fragmentTransform.scale(1 / fragmentTransform.xScale(), 1 / fragmentTransform.yScale());
        data->rotation = narrowPrecisionToFloat(rad2deg(atan2(fragmentTransform.b(), fragmentTransform.a())));
    }

    return true;
}

int SVGInlineTextBox::offsetForPositionInFragment(const SVGTextFragment& fragment, FloatWillBeLayoutUnit position, bool includePartialGlyphs) const
{
    LayoutSVGInlineText& textLayoutObject = toLayoutSVGInlineText(this->layoutObject());

    float scalingFactor = textLayoutObject.scalingFactor();
    ASSERT(scalingFactor);

    const ComputedStyle& style = textLayoutObject.styleRef();

    TextRun textRun = constructTextRun(style, fragment);

    // Eventually handle lengthAdjust="spacingAndGlyphs".
    // FIXME: Handle vertical text.
    AffineTransform fragmentTransform;
    fragment.buildFragmentTransform(fragmentTransform);
    if (!fragmentTransform.isIdentity())
        textRun.setHorizontalGlyphStretch(narrowPrecisionToFloat(fragmentTransform.xScale()));

    return fragment.characterOffset - start() + textLayoutObject.scaledFont().offsetForPosition(textRun, position * scalingFactor, includePartialGlyphs);
}