C++ SVGFontElement类代码示例

SVGFontElement* CachedFont::getSVGFontById(const String& fontName) const
{
    ASSERT(m_isSVGFont);
    RefPtr<NodeList> list = m_externalSVGDocument->getElementsByTagNameNS(SVGNames::fontTag.namespaceURI(), SVGNames::fontTag.localName());
    if (!list)
        return 0;

    unsigned listLength = list->length();
    if (!listLength)
        return 0;

#ifndef NDEBUG
    for (unsigned i = 0; i < listLength; ++i) {
        ASSERT(list->item(i));
        ASSERT(list->item(i)->hasTagName(SVGNames::fontTag));
    }
#endif

    if (fontName.isEmpty())
        return static_cast<SVGFontElement*>(list->item(0));

    for (unsigned i = 0; i < listLength; ++i) {
        SVGFontElement* element = static_cast<SVGFontElement*>(list->item(i));
        if (element->getIdAttribute() == fontName)
            return element;
    }

    return 0;
}

SVGFontElement* FontResource::getSVGFontById(const String& fontName) const
{
    RefPtr<HTMLCollection> collection = m_externalSVGDocument->getElementsByTagNameNS(SVGNames::fontTag.namespaceURI(), SVGNames::fontTag.localName());
    if (!collection)
        return 0;

    unsigned collectionLength = collection->length();
    if (!collectionLength)
        return 0;

#ifndef NDEBUG
    for (unsigned i = 0; i < collectionLength; ++i) {
        ASSERT(collection->item(i));
        ASSERT(isSVGFontElement(collection->item(i)));
    }
#endif

    if (fontName.isEmpty())
        return toSVGFontElement(collection->item(0));

    for (unsigned i = 0; i < collectionLength; ++i) {
        SVGFontElement* element = toSVGFontElement(collection->item(i));
        if (element->getIdAttribute() == fontName)
            return element;
    }

    return 0;
}

SimpleFontData::SimpleFontData(const FontPlatformData& f, bool customFont, bool loading, SVGFontData* svgFontData)
    : m_maxCharWidth(-1)
    , m_avgCharWidth(-1)
    , m_unitsPerEm(defaultUnitsPerEm)
    , m_platformData(f)
    , m_treatAsFixedPitch(false)
#if ENABLE(SVG_FONTS)
    , m_svgFontData(svgFontData)
#endif
    , m_isCustomFont(customFont)
    , m_isLoading(loading)
    , m_smallCapsFontData(0)
#if (PLATFORM(WKC))
    , m_lineSpacing(0)
#endif
{
#if !ENABLE(SVG_FONTS)
    UNUSED_PARAM(svgFontData);
#else
    if (SVGFontFaceElement* svgFontFaceElement = svgFontData ? svgFontData->svgFontFaceElement() : 0) {
        m_unitsPerEm = svgFontFaceElement->unitsPerEm();

        double scale = f.size();
        if (m_unitsPerEm)
            scale /= m_unitsPerEm;

        m_ascent = static_cast<int>(svgFontFaceElement->ascent() * scale);
        m_descent = static_cast<int>(svgFontFaceElement->descent() * scale);
        m_xHeight = static_cast<int>(svgFontFaceElement->xHeight() * scale);
        m_lineGap = 0.1f * f.size();
        m_lineSpacing = m_ascent + m_descent + m_lineGap;

        SVGFontElement* associatedFontElement = svgFontFaceElement->associatedFontElement();

        Vector<SVGGlyphIdentifier> spaceGlyphs;
        associatedFontElement->getGlyphIdentifiersForString(String(" ", 1), spaceGlyphs);
        m_spaceWidth = spaceGlyphs.isEmpty() ? m_xHeight : static_cast<float>(spaceGlyphs.first().horizontalAdvanceX * scale);

        Vector<SVGGlyphIdentifier> numeralZeroGlyphs;
        associatedFontElement->getGlyphIdentifiersForString(String("0", 1), numeralZeroGlyphs);
        m_avgCharWidth = numeralZeroGlyphs.isEmpty() ? m_spaceWidth : static_cast<float>(numeralZeroGlyphs.first().horizontalAdvanceX * scale);

        Vector<SVGGlyphIdentifier> letterWGlyphs;
        associatedFontElement->getGlyphIdentifiersForString(String("W", 1), letterWGlyphs);
        m_maxCharWidth = letterWGlyphs.isEmpty() ? m_ascent : static_cast<float>(letterWGlyphs.first().horizontalAdvanceX * scale);

        // FIXME: is there a way we can get the space glyph from the SVGGlyphIdentifier above?
        m_spaceGlyph = 0;
        determinePitch();
        m_adjustedSpaceWidth = roundf(m_spaceWidth);
        m_missingGlyphData.fontData = this;
        m_missingGlyphData.glyph = 0;
        return;
    }
#endif

    platformInit();
    platformGlyphInit();
    platformCharWidthInit();
}

float SVGTextLayoutEngineSpacing::calculateSVGKerning(bool isVerticalText, const SVGTextMetrics::Glyph& currentGlyph)
{
#if ENABLE(SVG_FONTS)
    if (!m_font.isSVGFont()) {
        m_lastGlyph.isValid = false;
        return 0;
    }

    SVGFontElement* svgFont = m_font.svgFont();
    ASSERT(svgFont);

    float kerning = 0;
    if (m_lastGlyph.isValid) {
        if (isVerticalText)
            kerning = svgFont->verticalKerningForPairOfStringsAndGlyphs(m_lastGlyph.unicodeString, m_lastGlyph.name, currentGlyph.unicodeString, currentGlyph.name);
        else
            kerning = svgFont->horizontalKerningForPairOfStringsAndGlyphs(m_lastGlyph.unicodeString, m_lastGlyph.name, currentGlyph.unicodeString, currentGlyph.name);
    }

    m_lastGlyph = currentGlyph;
    m_lastGlyph.isValid = true;
    kerning *= m_font.size() / m_font.primaryFont()->unitsPerEm();
    return kerning;
#else
    UNUSED_PARAM(isVerticalText);
    UNUSED_PARAM(currentGlyph);
    return false;
#endif
}

SimpleFontData::SimpleFontData(PassOwnPtr<SVGFontData> svgFontData, int size, bool syntheticBold, bool syntheticItalic)
    : m_platformData(FontPlatformData(size, syntheticBold, syntheticItalic))
    , m_treatAsFixedPitch(false)
    , m_svgFontData(svgFontData)
    , m_isCustomFont(true)
    , m_isLoading(false)
    , m_isTextOrientationFallback(false)
    , m_isBrokenIdeographFallback(false)
    , m_hasVerticalGlyphs(false)
{
    SVGFontFaceElement* svgFontFaceElement = m_svgFontData->svgFontFaceElement();
    unsigned unitsPerEm = svgFontFaceElement->unitsPerEm();

    float scale = size;
    if (unitsPerEm)
        scale /= unitsPerEm;

    float xHeight = svgFontFaceElement->xHeight() * scale;
    float ascent = svgFontFaceElement->ascent() * scale;
    float descent = svgFontFaceElement->descent() * scale;
    float lineGap = 0.1f * size;

    SVGFontElement* associatedFontElement = svgFontFaceElement->associatedFontElement();
    if (!xHeight) {    
        // Fallback if x_heightAttr is not specified for the font element.
        Vector<SVGGlyphIdentifier> letterXGlyphs;
        associatedFontElement->getGlyphIdentifiersForString(String("x", 1), letterXGlyphs);
        xHeight = letterXGlyphs.isEmpty() ? 2 * ascent / 3 : letterXGlyphs.first().horizontalAdvanceX * scale;
    }

    m_fontMetrics.setUnitsPerEm(unitsPerEm);
    m_fontMetrics.setAscent(ascent);
    m_fontMetrics.setDescent(descent);
    m_fontMetrics.setLineGap(lineGap);
    m_fontMetrics.setLineSpacing(roundf(ascent) + roundf(descent) + roundf(lineGap));
    m_fontMetrics.setXHeight(xHeight);

    Vector<SVGGlyphIdentifier> spaceGlyphs;
    associatedFontElement->getGlyphIdentifiersForString(String(" ", 1), spaceGlyphs);
    m_spaceWidth = spaceGlyphs.isEmpty() ? xHeight : spaceGlyphs.first().horizontalAdvanceX * scale;

    Vector<SVGGlyphIdentifier> numeralZeroGlyphs;
    associatedFontElement->getGlyphIdentifiersForString(String("0", 1), numeralZeroGlyphs);
    m_avgCharWidth = numeralZeroGlyphs.isEmpty() ? m_spaceWidth : numeralZeroGlyphs.first().horizontalAdvanceX * scale;

    Vector<SVGGlyphIdentifier> letterWGlyphs;
    associatedFontElement->getGlyphIdentifiersForString(String("W", 1), letterWGlyphs);
    m_maxCharWidth = letterWGlyphs.isEmpty() ? ascent : letterWGlyphs.first().horizontalAdvanceX * scale;

    // FIXME: is there a way we can get the space glyph from the SVGGlyphIdentifier above?
    m_spaceGlyph = 0;
    m_zeroWidthSpaceGlyph = 0;
    determinePitch();
    m_missingGlyphData.fontData = this;
    m_missingGlyphData.glyph = 0;
}

float SVGFontData::widthForSVGGlyph(Glyph glyph, float fontSize) const
{
    SVGFontFaceElement* svgFontFaceElement = this->svgFontFaceElement();
    ASSERT(svgFontFaceElement);

    SVGFontElement* associatedFontElement = svgFontFaceElement->associatedFontElement();
    ASSERT(associatedFontElement);

    SVGGlyph svgGlyph = associatedFontElement->svgGlyphForGlyph(glyph);
    SVGGlyphElement::inheritUnspecifiedAttributes(svgGlyph, this);
    return svgGlyph.horizontalAdvanceX * scaleEmToUnits(fontSize, svgFontFaceElement->unitsPerEm());
}

SimpleFontData::SimpleFontData(PassOwnPtr<SVGFontData> svgFontData, int size, bool syntheticBold, bool syntheticItalic)
    : m_orientation(Horizontal)
    , m_platformData(FontPlatformData(size, syntheticBold, syntheticItalic))
    , m_treatAsFixedPitch(false)
    , m_svgFontData(svgFontData)
    , m_isCustomFont(true)
    , m_isLoading(false)
    , m_isBrokenIdeographFont(false)
{
    SVGFontFaceElement* svgFontFaceElement = m_svgFontData->svgFontFaceElement();
    m_unitsPerEm = svgFontFaceElement->unitsPerEm();

    double scale = size;
    if (m_unitsPerEm)
        scale /= m_unitsPerEm;

    m_ascent = static_cast<int>(svgFontFaceElement->ascent() * scale);
    m_descent = static_cast<int>(svgFontFaceElement->descent() * scale);
    m_xHeight = static_cast<int>(svgFontFaceElement->xHeight() * scale);
    m_lineGap = 0.1f * size;
    m_lineSpacing = m_ascent + m_descent + m_lineGap;

    SVGFontElement* associatedFontElement = svgFontFaceElement->associatedFontElement();

    Vector<SVGGlyphIdentifier> spaceGlyphs;
    associatedFontElement->getGlyphIdentifiersForString(String(" ", 1), spaceGlyphs);
    m_spaceWidth = spaceGlyphs.isEmpty() ? m_xHeight : static_cast<float>(spaceGlyphs.first().horizontalAdvanceX * scale);

    Vector<SVGGlyphIdentifier> numeralZeroGlyphs;
    associatedFontElement->getGlyphIdentifiersForString(String("0", 1), numeralZeroGlyphs);
    m_avgCharWidth = numeralZeroGlyphs.isEmpty() ? m_spaceWidth : static_cast<float>(numeralZeroGlyphs.first().horizontalAdvanceX * scale);

    Vector<SVGGlyphIdentifier> letterWGlyphs;
    associatedFontElement->getGlyphIdentifiersForString(String("W", 1), letterWGlyphs);
    m_maxCharWidth = letterWGlyphs.isEmpty() ? m_ascent : static_cast<float>(letterWGlyphs.first().horizontalAdvanceX * scale);

    // FIXME: is there a way we can get the space glyph from the SVGGlyphIdentifier above?
    m_spaceGlyph = 0;
    m_zeroWidthSpaceGlyph = 0;
    determinePitch();
    m_adjustedSpaceWidth = roundf(m_spaceWidth);
    m_missingGlyphData.fontData = this;
    m_missingGlyphData.glyph = 0;
}

bool SVGTextRunRenderingContext::applySVGKerning(const SimpleFontData* fontData, WidthIterator& iterator, GlyphBuffer* glyphBuffer, int from) const
{
    ASSERT(glyphBuffer);
    ASSERT(glyphBuffer->size() > 1);
    SVGFontElement* fontElement = 0;
    SVGFontFaceElement* fontFaceElement = 0;

    svgFontAndFontFaceElementForFontData(fontData, fontFaceElement, fontElement);
    if (!fontElement || !fontFaceElement)
        return false;

    if (fontElement->horizontalKerningMapIsEmpty())
        return true;

    float scale = scaleEmToUnits(fontData->platformData().size(), fontFaceElement->unitsPerEm());

    String lastGlyphName;
    String lastUnicodeString;
    int characterOffset = iterator.m_currentCharacter;
    String text = iterator.run().string();
    const int glyphCount = glyphBuffer->size() - from;
    GlyphBufferAdvance* advances = glyphBuffer->advances(from);

    for (int i = 0; i < glyphCount; ++i) {
        Glyph glyph = glyphBuffer->glyphAt(from + i);
        if (!glyph)
            continue;
        float kerning = 0;
        SVGGlyph svgGlyph = fontElement->svgGlyphForGlyph(glyph);
        String unicodeString = text.substring(characterOffset, svgGlyph.unicodeStringLength);
        if (i >= 1) {
            // FIXME: Support vertical text.
            kerning = fontElement->horizontalKerningForPairOfStringsAndGlyphs(lastUnicodeString, lastGlyphName, unicodeString, svgGlyph.glyphName);
            advances[i - 1].setWidth(advances[i - 1].width() - kerning * scale);
        }
        lastGlyphName = svgGlyph.glyphName;
        lastUnicodeString = unicodeString;
        characterOffset += svgGlyph.unicodeStringLength;
    }

    return true;
}

float SVGTextLayoutEngineSpacing::calculateSVGKerning(bool isVerticalText, const SVGTextMetrics::Glyph& currentGlyph)
{
#if ENABLE(SVG_FONTS)
    const SimpleFontData* fontData = m_font.primaryFont();
    if (!fontData->isSVGFont()) {
        m_lastGlyph.isValid = false;
        return 0;
    }

    ASSERT(fontData->isCustomFont());
    ASSERT(fontData->isSVGFont());

    const SVGFontData* svgFontData = static_cast<const SVGFontData*>(fontData->fontData());
    SVGFontFaceElement* svgFontFace = svgFontData->svgFontFaceElement();
    ASSERT(svgFontFace);

    SVGFontElement* svgFont = svgFontFace->associatedFontElement();
    if (!svgFont) {
        m_lastGlyph.isValid = false;
        return 0;
    }

    float kerning = 0;
    if (m_lastGlyph.isValid) {
        if (isVerticalText)
            kerning = svgFont->verticalKerningForPairOfStringsAndGlyphs(m_lastGlyph.unicodeString, m_lastGlyph.name, currentGlyph.unicodeString, currentGlyph.name);
        else
            kerning = svgFont->horizontalKerningForPairOfStringsAndGlyphs(m_lastGlyph.unicodeString, m_lastGlyph.name, currentGlyph.unicodeString, currentGlyph.name);
    }

    m_lastGlyph = currentGlyph;
    m_lastGlyph.isValid = true;
    kerning *= m_font.size() / m_font.fontMetrics().unitsPerEm();
    return kerning;
#else
    UNUSED_PARAM(isVerticalText);
    UNUSED_PARAM(currentGlyph);
    return false;
#endif
}

void SVGTextRunRenderingContext::drawSVGGlyphs(GraphicsContext* context, const TextRun& run, const SimpleFontData* fontData, const GlyphBuffer& glyphBuffer, int from, int numGlyphs, const FloatPoint& point) const
{
    SVGFontElement* fontElement = 0;
    SVGFontFaceElement* fontFaceElement = 0;

    const SVGFontData* svgFontData = svgFontAndFontFaceElementForFontData(fontData, fontFaceElement, fontElement);
    if (!fontElement || !fontFaceElement)
        return;

    // We can only paint SVGFonts if a context is available.
    RenderSVGResource* activePaintingResource = activePaintingResourceFromRun(run);
    RenderObject* renderObject = renderObjectFromRun(run);
    RenderObject* parentRenderObject = firstParentRendererForNonTextNode(renderObject);
    RenderStyle* parentRenderObjectStyle = 0;

    ASSERT(renderObject);
    if (!activePaintingResource) {
        // TODO: We're only supporting simple filled HTML text so far.
        RenderSVGResourceSolidColor* solidPaintingResource = RenderSVGResource::sharedSolidPaintingResource();
        solidPaintingResource->setColor(context->fillColor());
        activePaintingResource = solidPaintingResource;
    }
 
    bool isVerticalText = false;
    if (parentRenderObject) {
        parentRenderObjectStyle = parentRenderObject->style();
        ASSERT(parentRenderObjectStyle);
        isVerticalText = parentRenderObjectStyle->svgStyle()->isVerticalWritingMode();
    }

    float scale = scaleEmToUnits(fontData->platformData().size(), fontFaceElement->unitsPerEm());
    ASSERT(activePaintingResource);

    FloatPoint glyphOrigin;
    glyphOrigin.setX(svgFontData->horizontalOriginX() * scale);
    glyphOrigin.setY(svgFontData->horizontalOriginY() * scale);

    FloatPoint currentPoint = point;
    RenderSVGResourceMode resourceMode = context->textDrawingMode() == TextModeStroke ? ApplyToStrokeMode : ApplyToFillMode;
    for (int i = 0; i < numGlyphs; ++i) {
        Glyph glyph = glyphBuffer.glyphAt(from + i);
        if (!glyph)
            continue;

        float advance = glyphBuffer.advanceAt(from + i);
        SVGGlyph svgGlyph = fontElement->svgGlyphForGlyph(glyph);
        ASSERT(!svgGlyph.isPartOfLigature);
        ASSERT(svgGlyph.tableEntry == glyph);

        SVGGlyphElement::inheritUnspecifiedAttributes(svgGlyph, svgFontData);

        // FIXME: Support arbitary SVG content as glyph (currently limited to <glyph d="..."> situations).
        if (svgGlyph.pathData.isEmpty()) {
            if (isVerticalText)
                currentPoint.move(0, advance);
            else
                currentPoint.move(advance, 0);
            continue;
         }

        context->save();

        if (isVerticalText) {
            glyphOrigin.setX(svgGlyph.verticalOriginX * scale);
            glyphOrigin.setY(svgGlyph.verticalOriginY * scale);
         }

        AffineTransform glyphPathTransform;
        glyphPathTransform.translate(currentPoint.x() + glyphOrigin.x(), currentPoint.y() + glyphOrigin.y());
        glyphPathTransform.scale(scale, -scale);

        Path glyphPath = svgGlyph.pathData;
        glyphPath.transform(glyphPathTransform);

        if (activePaintingResource->applyResource(parentRenderObject, parentRenderObjectStyle, context, resourceMode)) {
            if (renderObject && renderObject->isSVGInlineText()) {
                const RenderSVGInlineText* textRenderer = toRenderSVGInlineText(renderObject);
                context->setStrokeThickness(context->strokeThickness() * textRenderer->scalingFactor());
            }
            activePaintingResource->postApplyResource(parentRenderObject, context, resourceMode, &glyphPath, 0);
         }
 
        context->restore();

        if (isVerticalText)
            currentPoint.move(0, advance);
        else
            currentPoint.move(advance, 0);
    }
}

void SVGTextRunRenderingContext::drawSVGGlyphs(GraphicsContext* context, const TextRun& run, const SimpleFontData* fontData, const GlyphBuffer& glyphBuffer, int from, int numGlyphs, const FloatPoint& point) const
{
    SVGFontElement* fontElement = 0;
    SVGFontFaceElement* fontFaceElement = 0;

    const SVGFontData* svgFontData = svgFontAndFontFaceElementForFontData(fontData, fontFaceElement, fontElement);
    if (!fontElement || !fontFaceElement)
        return;

    // We can only paint SVGFonts if a context is available.
    RenderObject* renderObject = renderObjectFromRun(run);
    ASSERT(renderObject);

    bool isVerticalText = false;
    if (RenderObject* parentRenderObject = firstParentRendererForNonTextNode(renderObject)) {
        RenderStyle* parentRenderObjectStyle = parentRenderObject->style();
        ASSERT(parentRenderObjectStyle);
        isVerticalText = parentRenderObjectStyle->svgStyle().isVerticalWritingMode();
    }

    float scale = scaleEmToUnits(fontData->platformData().size(), fontFaceElement->unitsPerEm());

    FloatPoint glyphOrigin;
    glyphOrigin.setX(svgFontData->horizontalOriginX() * scale);
    glyphOrigin.setY(svgFontData->horizontalOriginY() * scale);

    unsigned short resourceMode = context->textDrawingMode() == TextModeStroke ? ApplyToStrokeMode : ApplyToFillMode;

    FloatPoint currentPoint = point;
    for (int i = 0; i < numGlyphs; ++i) {
        Glyph glyph = glyphBuffer.glyphAt(from + i);
        if (!glyph)
            continue;

        float advance = glyphBuffer.advanceAt(from + i);
        SVGGlyph svgGlyph = fontElement->svgGlyphForGlyph(glyph);
        ASSERT(!svgGlyph.isPartOfLigature);
        ASSERT(svgGlyph.tableEntry == glyph);

        SVGGlyphElement::inheritUnspecifiedAttributes(svgGlyph, svgFontData);

        // FIXME: Support arbitary SVG content as glyph (currently limited to <glyph d="..."> situations).
        if (svgGlyph.pathData.isEmpty()) {
            if (isVerticalText)
                currentPoint.move(0, advance);
            else
                currentPoint.move(advance, 0);
            continue;
         }

        if (isVerticalText) {
            glyphOrigin.setX(svgGlyph.verticalOriginX * scale);
            glyphOrigin.setY(svgGlyph.verticalOriginY * scale);
         }

        AffineTransform glyphPathTransform;
        glyphPathTransform.translate(currentPoint.x() + glyphOrigin.x(), currentPoint.y() + glyphOrigin.y());
        glyphPathTransform.scale(scale, -scale);

        Path glyphPath = svgGlyph.pathData;
        glyphPath.transform(glyphPathTransform);

        SVGRenderSupport::fillOrStrokePath(context, resourceMode, glyphPath);

        if (isVerticalText)
            currentPoint.move(0, advance);
        else
            currentPoint.move(advance, 0);
    }
}