C++ DashArray类代码示例

DashArray SVGLayoutSupport::resolveSVGDashArray(const SVGDashArray& svgDashArray, const ComputedStyle& style, const SVGLengthContext& lengthContext)
{
    DashArray dashArray;
    for (const Length& dashLength : svgDashArray.vector())
        dashArray.append(lengthContext.valueForLength(dashLength, style));
    return dashArray;
}

void SVGRenderSupport::applyStrokeStyleToStrokeData(StrokeData* strokeData, const RenderStyle* style, const RenderObject* object)
{
    ASSERT(strokeData);
    ASSERT(style);
    ASSERT(object);
    ASSERT(object->node());
    ASSERT(object->node()->isSVGElement());

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

    SVGLengthContext lengthContext(toSVGElement(object->node()));
    strokeData->setThickness(svgStyle->strokeWidth()->value(lengthContext));
    strokeData->setLineCap(svgStyle->capStyle());
    strokeData->setLineJoin(svgStyle->joinStyle());
    strokeData->setMiterLimit(svgStyle->strokeMiterLimit());

    RefPtr<SVGLengthList> dashes = svgStyle->strokeDashArray();
    if (dashes->isEmpty())
        return;

    DashArray dashArray;
    size_t length = dashes->length();
    for (size_t i = 0; i < length; ++i)
        dashArray.append(dashes->at(i)->value(lengthContext));

    strokeData->setLineDash(dashArray, svgStyle->strokeDashOffset()->value(lengthContext));
}

void GraphicsContext::drawLinesForText(const FloatPoint& point, const DashArray& widths, bool printing, bool doubleUnderlines)
{
    if (paintingDisabled())
        return;

    if (widths.size() <= 0)
        return;

    Color localStrokeColor(strokeColor());

    bool shouldAntialiasLine;
    FloatRect bounds = computeLineBoundsAndAntialiasingModeForText(point, widths.last(), printing, shouldAntialiasLine, localStrokeColor);

    Vector<FloatRect, 4> dashBounds;
    ASSERT(!(widths.size() % 2));
    dashBounds.reserveInitialCapacity(dashBounds.size() / 2);
    for (size_t i = 0; i < widths.size(); i += 2)
        dashBounds.append(FloatRect(FloatPoint(bounds.x() + widths[i], bounds.y()), FloatSize(widths[i+1] - widths[i], bounds.height())));

    if (doubleUnderlines) {
        // The space between double underlines is equal to the height of the underline
        for (size_t i = 0; i < widths.size(); i += 2)
            dashBounds.append(FloatRect(FloatPoint(bounds.x() + widths[i], bounds.y() + 2 * bounds.height()), FloatSize(widths[i+1] - widths[i], bounds.height())));
    }

    cairo_t* cr = platformContext()->cr();
    cairo_save(cr);

    for (auto& dash : dashBounds)
        fillRectWithColor(cr, dash, localStrokeColor);

    cairo_restore(cr);
}

void SVGRenderSupport::applyStrokeStyleToContext(GraphicsContext* context, const RenderStyle& style, const RenderElement& renderer)
{
    ASSERT(context);
    ASSERT(renderer.element());
    ASSERT(renderer.element()->isSVGElement());

    const SVGRenderStyle& svgStyle = style.svgStyle();

    SVGLengthContext lengthContext(toSVGElement(renderer.element()));
    context->setStrokeThickness(svgStyle.strokeWidth().value(lengthContext));
    context->setLineCap(svgStyle.capStyle());
    context->setLineJoin(svgStyle.joinStyle());
    if (svgStyle.joinStyle() == MiterJoin)
        context->setMiterLimit(svgStyle.strokeMiterLimit());

    const Vector<SVGLength>& dashes = svgStyle.strokeDashArray();
    if (dashes.isEmpty())
        context->setStrokeStyle(SolidStroke);
    else {
        DashArray dashArray;
        dashArray.reserveInitialCapacity(dashes.size());
        for (unsigned i = 0, size = dashes.size(); i < size; ++i)
            dashArray.uncheckedAppend(dashes[i].value(lengthContext));

        context->setLineDash(dashArray, svgStyle.strokeDashOffset().value(lengthContext));
    }
}

void GraphicsContext::setLineDash(const DashArray& dashes, float dashOffset)
{
    if (paintingDisabled())
        return;

    platformContext()->setLineDash(dashes.data(), dashes.size(), dashOffset);
}

    void applyStrokeStyle()
    {
        if (strokeStyle == DottedStroke) {
            VGfloat vgFloatArray[2] = { 1.0, 1.0 };
            vgSetfv(VG_STROKE_DASH_PATTERN, 2, vgFloatArray);
            vgSetf(VG_STROKE_DASH_PHASE, 0.0);
        } else if (strokeStyle == DashedStroke) {
            if (!strokeDashArray.size()) {
                VGfloat vgFloatArray[2] = { 4.0, 3.0 };
                vgSetfv(VG_STROKE_DASH_PATTERN, 2, vgFloatArray);
            } else {
                Vector<VGfloat> vgFloatArray(strokeDashArray.size());
                for (int i = 0; i < strokeDashArray.size(); ++i)
                    vgFloatArray[i] = strokeDashArray[i];

                vgSetfv(VG_STROKE_DASH_PATTERN, vgFloatArray.size(), vgFloatArray.data());
            }
            vgSetf(VG_STROKE_DASH_PHASE, strokeDashOffset);
        } else {
            vgSetfv(VG_STROKE_DASH_PATTERN, 0, 0);
            vgSetf(VG_STROKE_DASH_PHASE, 0.0);
        }

        ASSERT_VG_NO_ERROR();
    }

void SVGRenderSupport::applyStrokeStyleToStrokeData(StrokeData* strokeData, const RenderStyle* style, const RenderObject* object)
{
    ASSERT(strokeData);
    ASSERT(style);
    ASSERT(object);
    ASSERT(object->node());
    ASSERT(object->node()->isSVGElement());

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

    SVGLengthContext lengthContext(toSVGElement(object->node()));
    strokeData->setThickness(svgStyle->strokeWidth().value(lengthContext));
    strokeData->setLineCap(svgStyle->capStyle());
    strokeData->setLineJoin(svgStyle->joinStyle());
    strokeData->setMiterLimit(svgStyle->strokeMiterLimit());

    const Vector<SVGLength>& dashes = svgStyle->strokeDashArray();
    if (dashes.isEmpty())
        return;

    DashArray dashArray;
    const Vector<SVGLength>::const_iterator end = dashes.end();
    for (Vector<SVGLength>::const_iterator it = dashes.begin(); it != end; ++it)
        dashArray.append((*it).value(lengthContext));

    strokeData->setLineDash(dashArray, svgStyle->strokeDashOffset().value(lengthContext));
}

void GraphicsContext::drawLineForText(const FloatPoint& origin, float width, bool printing, bool doubleUnderlines)
{
    DashArray widths;
    widths.append(width);
    widths.append(0);
    drawLinesForText(origin, widths, printing, doubleUnderlines);
}

static void writeStyle(TextStream& ts, const RenderObject& object)
{
    const RenderStyle* style = object.style();
    const SVGRenderStyle* svgStyle = style->svgStyle();

    if (!object.localTransform().isIdentity())
        writeNameValuePair(ts, "transform", object.localTransform());
    writeIfNotDefault(ts, "image rendering", style->imageRendering(), RenderStyle::initialImageRendering());
    writeIfNotDefault(ts, "opacity", style->opacity(), RenderStyle::initialOpacity());
    if (object.isSVGShape()) {
        const RenderSVGShape& shape = static_cast<const RenderSVGShape&>(object);
        ASSERT(shape.node());
        ASSERT(shape.node()->isSVGElement());

        Color fallbackColor;
        if (RenderSVGResource* strokePaintingResource = RenderSVGResource::strokePaintingResource(const_cast<RenderSVGShape*>(&shape), shape.style(), fallbackColor)) {
            TextStreamSeparator s(" ");
            ts << " [stroke={" << s;
            writeSVGPaintingResource(ts, strokePaintingResource);

            SVGLengthContext lengthContext(toSVGElement(shape.node()));
            double dashOffset = svgStyle->strokeDashOffset().value(lengthContext);
            double strokeWidth = svgStyle->strokeWidth().value(lengthContext);
            const Vector<SVGLength>& dashes = svgStyle->strokeDashArray();

            DashArray dashArray;
            const Vector<SVGLength>::const_iterator end = dashes.end();
            for (Vector<SVGLength>::const_iterator it = dashes.begin(); it != end; ++it)
                dashArray.append((*it).value(lengthContext));

            writeIfNotDefault(ts, "opacity", svgStyle->strokeOpacity(), 1.0f);
            writeIfNotDefault(ts, "stroke width", strokeWidth, 1.0);
            writeIfNotDefault(ts, "miter limit", svgStyle->strokeMiterLimit(), 4.0f);
            writeIfNotDefault(ts, "line cap", svgStyle->capStyle(), ButtCap);
            writeIfNotDefault(ts, "line join", svgStyle->joinStyle(), MiterJoin);
            writeIfNotDefault(ts, "dash offset", dashOffset, 0.0);
            if (!dashArray.isEmpty())
                writeNameValuePair(ts, "dash array", dashArray);

            ts << "}]";
        }

        if (RenderSVGResource* fillPaintingResource = RenderSVGResource::fillPaintingResource(const_cast<RenderSVGShape*>(&shape), shape.style(), fallbackColor)) {
            TextStreamSeparator s(" ");
            ts << " [fill={" << s;
            writeSVGPaintingResource(ts, fillPaintingResource);

            writeIfNotDefault(ts, "opacity", svgStyle->fillOpacity(), 1.0f);
            writeIfNotDefault(ts, "fill rule", svgStyle->fillRule(), RULE_NONZERO);
            ts << "}]";
        }
        writeIfNotDefault(ts, "clip rule", svgStyle->clipRule(), RULE_NONZERO);
    }

    writeIfNotEmpty(ts, "start marker", svgStyle->markerStartResource());
    writeIfNotEmpty(ts, "middle marker", svgStyle->markerMidResource());
    writeIfNotEmpty(ts, "end marker", svgStyle->markerEndResource());
}

static void drawSkipInkUnderline(GraphicsContext& context, const FontCascade& font, const TextRun& textRun, const FloatPoint& textOrigin, const FloatPoint& localOrigin,
    float underlineOffset, float width, bool isPrinting, bool doubleLines, StrokeStyle strokeStyle)
{
    FloatPoint adjustedLocalOrigin = localOrigin;
    adjustedLocalOrigin.move(0, underlineOffset);
    FloatRect underlineBoundingBox = context.computeUnderlineBoundsForText(adjustedLocalOrigin, width, isPrinting);
    DashArray intersections = font.dashesForIntersectionsWithRect(textRun, textOrigin, underlineBoundingBox);
    DashArray a = translateIntersectionPointsToSkipInkBoundaries(intersections, underlineBoundingBox.height(), width);
    ASSERT(!(a.size() % 2));
    context.drawLinesForText(adjustedLocalOrigin, a, isPrinting, doubleLines, strokeStyle);
}

DashArray FontCascade::dashesForIntersectionsWithRect(const TextRun& run, const FloatPoint& textOrigin, const FloatRect& lineExtents) const
{
    if (isLoadingCustomFonts())
        return DashArray();

    GlyphBuffer glyphBuffer;
    glyphBuffer.saveOffsetsInString();
    float deltaX;
    if (codePath(run) != FontCascade::Complex)
        deltaX = getGlyphsAndAdvancesForSimpleText(run, 0, run.length(), glyphBuffer);
    else
        deltaX = getGlyphsAndAdvancesForComplexText(run, 0, run.length(), glyphBuffer);

    if (!glyphBuffer.size())
        return DashArray();

    // FIXME: Handle SVG + non-SVG interleaved runs. https://bugs.webkit.org/show_bug.cgi?id=133778
    FloatPoint origin = FloatPoint(textOrigin.x() + deltaX, textOrigin.y());
    std::unique_ptr<GlyphToPathTranslator> translator = std::make_unique<CairoGlyphToPathTranslator>(run, glyphBuffer, origin);
    DashArray result;
    for (int index = 0; translator->containsMorePaths(); ++index, translator->advance()) {
        float centerOfLine = lineExtents.y() + (lineExtents.height() / 2);
        GlyphIterationState info = GlyphIterationState(FloatPoint(), FloatPoint(), centerOfLine, lineExtents.x() + lineExtents.width(), lineExtents.x());
        const Font* localFontData = glyphBuffer.fontAt(index);
        if (!localFontData) {
            // The advances will get all messed up if we do anything other than bail here.
            result.clear();
            break;
        }
        switch (translator->underlineType()) {
        case GlyphToPathTranslator::GlyphUnderlineType::SkipDescenders: {
            Path path = translator->path();
            path.apply([&info](const PathElement& pathElement) {
                findPathIntersections(info, pathElement);
            });
            if (info.minX < info.maxX) {
                result.append(info.minX - lineExtents.x());
                result.append(info.maxX - lineExtents.x());
            }
            break;
        }
        case GlyphToPathTranslator::GlyphUnderlineType::SkipGlyph: {
            std::pair<float, float> extents = translator->extents();
            result.append(extents.first - lineExtents.x());
            result.append(extents.second - lineExtents.x());
            break;
        }
        case GlyphToPathTranslator::GlyphUnderlineType::DrawOverGlyph:
            // Nothing to do
            break;
        }
    }
    return result;
}

static void writeStyle(TextStream& ts, const LayoutObject& object)
{
    const ComputedStyle& style = object.styleRef();
    const SVGComputedStyle& svgStyle = style.svgStyle();

    if (!object.localTransform().isIdentity())
        writeNameValuePair(ts, "transform", object.localTransform());
    writeIfNotDefault(ts, "image rendering", style.imageRendering(), ComputedStyle::initialImageRendering());
    writeIfNotDefault(ts, "opacity", style.opacity(), ComputedStyle::initialOpacity());
    if (object.isSVGShape()) {
        const LayoutSVGShape& shape = static_cast<const LayoutSVGShape&>(object);
        ASSERT(shape.element());

        SVGPaintDescription strokePaintDescription = LayoutSVGResourcePaintServer::requestPaintDescription(shape, shape.styleRef(), ApplyToStrokeMode);
        if (strokePaintDescription.isValid) {
            TextStreamSeparator s(" ");
            ts << " [stroke={" << s;
            writeSVGPaintingResource(ts, strokePaintDescription);

            SVGLengthContext lengthContext(shape.element());
            double dashOffset = lengthContext.valueForLength(svgStyle.strokeDashOffset(), style);
            double strokeWidth = lengthContext.valueForLength(svgStyle.strokeWidth());
            DashArray dashArray = SVGLayoutSupport::resolveSVGDashArray(*svgStyle.strokeDashArray(), style, lengthContext);

            writeIfNotDefault(ts, "opacity", svgStyle.strokeOpacity(), 1.0f);
            writeIfNotDefault(ts, "stroke width", strokeWidth, 1.0);
            writeIfNotDefault(ts, "miter limit", svgStyle.strokeMiterLimit(), 4.0f);
            writeIfNotDefault(ts, "line cap", svgStyle.capStyle(), ButtCap);
            writeIfNotDefault(ts, "line join", svgStyle.joinStyle(), MiterJoin);
            writeIfNotDefault(ts, "dash offset", dashOffset, 0.0);
            if (!dashArray.isEmpty())
                writeNameValuePair(ts, "dash array", dashArray);

            ts << "}]";
        }

        SVGPaintDescription fillPaintDescription = LayoutSVGResourcePaintServer::requestPaintDescription(shape, shape.styleRef(), ApplyToFillMode);
        if (fillPaintDescription.isValid) {
            TextStreamSeparator s(" ");
            ts << " [fill={" << s;
            writeSVGPaintingResource(ts, fillPaintDescription);

            writeIfNotDefault(ts, "opacity", svgStyle.fillOpacity(), 1.0f);
            writeIfNotDefault(ts, "fill rule", svgStyle.fillRule(), RULE_NONZERO);
            ts << "}]";
        }
        writeIfNotDefault(ts, "clip rule", svgStyle.clipRule(), RULE_NONZERO);
    }

    writeIfNotEmpty(ts, "start marker", svgStyle.markerStartResource());
    writeIfNotEmpty(ts, "middle marker", svgStyle.markerMidResource());
    writeIfNotEmpty(ts, "end marker", svgStyle.markerEndResource());
}

void GraphicsContext::setLineDash(const DashArray& dashes, float dashOffset)
{
    if (paintingDisabled())
        return;

    // FIXME: This is lifted directly off SkiaSupport, lines 49-74
    // so it is not guaranteed to work correctly.
    size_t dashLength = dashes.size();
    if (!dashLength) {
        // If no dash is set, revert to solid stroke
        // FIXME: do we need to set NoStroke in some cases?
        platformContext()->setStrokeStyle(SolidStroke);
        platformContext()->setDashPathEffect(0);
        return;
    }

    size_t count = !(dashLength % 2) ? dashLength : dashLength * 2;
    SkScalar* intervals = new SkScalar[count];

    for (unsigned int i = 0; i < count; i++)
        intervals[i] = dashes[i % dashLength];

    platformContext()->setDashPathEffect(new SkDashPathEffect(intervals, count, dashOffset));

    delete[] intervals;
}

DashArray dashArrayFromRenderingStyle(const RenderStyle* style, RenderStyle* rootStyle)
{
    DashArray array;
    
    CSSValueList* dashes = style->svgStyle()->strokeDashArray();
    if (dashes) {
        CSSPrimitiveValue* dash = 0;
        unsigned long len = dashes->length();
        for (unsigned long i = 0; i < len; i++) {
            dash = static_cast<CSSPrimitiveValue*>(dashes->itemWithoutBoundsCheck(i));
            if (!dash)
                continue;

            array.append((float) dash->computeLengthFloat(const_cast<RenderStyle*>(style), rootStyle));
        }
    }

    return array;
}

static DashArray translateIntersectionPointsToSkipInkBoundaries(const DashArray& intersections, float dilationAmount, float totalWidth)
{
    ASSERT(!(intersections.size() % 2));
    
    // Step 1: Make pairs so we can sort based on range starting-point. We dilate the ranges in this step as well.
    Vector<std::pair<float, float>> tuples;
    for (auto i = intersections.begin(); i != intersections.end(); i++, i++)
        tuples.append(std::make_pair(*i - dilationAmount, *(i + 1) + dilationAmount));
    std::sort(tuples.begin(), tuples.end(), &compareTuples);

    // Step 2: Deal with intersecting ranges.
    Vector<std::pair<float, float>> intermediateTuples;
    if (tuples.size() >= 2) {
        intermediateTuples.append(*tuples.begin());
        for (auto i = tuples.begin() + 1; i != tuples.end(); i++) {
            float& firstEnd = intermediateTuples.last().second;
            float secondStart = i->first;
            float secondEnd = i->second;
            if (secondStart <= firstEnd && secondEnd <= firstEnd) {
                // Ignore this range completely
            } else if (secondStart <= firstEnd)
                firstEnd = secondEnd;
            else
                intermediateTuples.append(*i);
        }
    } else
        intermediateTuples = tuples;

    // Step 3: Output the space between the ranges, but only if the space warrants an underline.
    float previous = 0;
    DashArray result;
    for (const auto& tuple : intermediateTuples) {
        if (tuple.first - previous > dilationAmount) {
            result.append(previous);
            result.append(tuple.first);
        }
        previous = tuple.second;
    }
    if (totalWidth - previous > dilationAmount) {
        result.append(previous);
        result.append(totalWidth);
    }
    
    return result;
}