C++ AffineTransform::yScale方法代码示例

void GeneratorGeneratedImage::drawPattern(GraphicsContext* destContext, const FloatRect& srcRect, const AffineTransform& patternTransform,
    const FloatPoint& phase, ColorSpace styleColorSpace, CompositeOperator compositeOp, const FloatRect& destRect, BlendMode)
{
    // Allow the generator to provide visually-equivalent tiling parameters for better performance.
    IntSize adjustedSize = m_size;
    FloatRect adjustedSrcRect = srcRect;
    m_gradient->adjustParametersForTiledDrawing(adjustedSize, adjustedSrcRect);

    // Factor in the destination context's scale to generate at the best resolution
    AffineTransform destContextCTM = destContext->getCTM(GraphicsContext::DefinitelyIncludeDeviceScale);
    double xScale = fabs(destContextCTM.xScale());
    double yScale = fabs(destContextCTM.yScale());
    AffineTransform adjustedPatternCTM = patternTransform;
    adjustedPatternCTM.scale(1.0 / xScale, 1.0 / yScale);
    adjustedSrcRect.scale(xScale, yScale);

    unsigned generatorHash = m_gradient->hash();

    if (!m_cachedImageBuffer || m_cachedGeneratorHash != generatorHash || m_cachedAdjustedSize != adjustedSize || !destContext->isCompatibleWithBuffer(m_cachedImageBuffer.get())) {
        m_cachedImageBuffer = destContext->createCompatibleBuffer(adjustedSize, m_gradient->hasAlpha());
        if (!m_cachedImageBuffer)
            return;

        // Fill with the generated image.
        m_cachedImageBuffer->context()->fillRect(FloatRect(FloatPoint(), adjustedSize), *m_gradient);

        m_cachedGeneratorHash = generatorHash;
        m_cachedAdjustedSize = adjustedSize;
    }

    m_cachedImageBuffer->setSpaceSize(spaceSize());
    // Tile the image buffer into the context.
    m_cachedImageBuffer->drawPattern(destContext, adjustedSrcRect, adjustedPatternCTM, phase, styleColorSpace, compositeOp, destRect);
}

void SVGImage::drawPatternForContainer(GraphicsContext& context, const FloatSize& containerSize, float zoom, const FloatRect& srcRect,
    const AffineTransform& patternTransform, const FloatPoint& phase, const FloatSize& spacing, CompositeOperator compositeOp, const FloatRect& dstRect, BlendMode blendMode)
{
    FloatRect zoomedContainerRect = FloatRect(FloatPoint(), containerSize);
    zoomedContainerRect.scale(zoom);

    // The ImageBuffer size needs to be scaled to match the final resolution.
    AffineTransform transform = context.getCTM();
    FloatSize imageBufferScale = FloatSize(transform.xScale(), transform.yScale());
    ASSERT(imageBufferScale.width());
    ASSERT(imageBufferScale.height());

    FloatRect imageBufferSize = zoomedContainerRect;
    imageBufferSize.scale(imageBufferScale.width(), imageBufferScale.height());

    std::unique_ptr<ImageBuffer> buffer = ImageBuffer::createCompatibleBuffer(expandedIntSize(imageBufferSize.size()), 1, ColorSpaceSRGB, context, true);
    if (!buffer) // Failed to allocate buffer.
        return;
    drawForContainer(buffer->context(), containerSize, zoom, imageBufferSize, zoomedContainerRect, CompositeSourceOver, BlendModeNormal);
    if (context.drawLuminanceMask())
        buffer->convertToLuminanceMask();

    RefPtr<Image> image = ImageBuffer::sinkIntoImage(WTFMove(buffer), Unscaled);
    if (!image)
        return;

    // Adjust the source rect and transform due to the image buffer's scaling.
    FloatRect scaledSrcRect = srcRect;
    scaledSrcRect.scale(imageBufferScale.width(), imageBufferScale.height());
    AffineTransform unscaledPatternTransform(patternTransform);
    unscaledPatternTransform.scale(1 / imageBufferScale.width(), 1 / imageBufferScale.height());

    context.setDrawLuminanceMask(false);
    image->drawPattern(context, scaledSrcRect, unscaledPatternTransform, phase, spacing, compositeOp, dstRect, blendMode);
}

void GeneratorGeneratedImage::drawPattern(GraphicsContext* destContext, const FloatRect& srcRect, const AffineTransform& patternTransform,
                                 const FloatPoint& phase, ColorSpace styleColorSpace, CompositeOperator compositeOp, const FloatRect& destRect)
{
    // Allow the generator to provide visually-equivalent tiling parameters for better performance.
    IntSize adjustedSize = m_size;
    FloatRect adjustedSrcRect = srcRect;
    m_generator->adjustParametersForTiledDrawing(adjustedSize, adjustedSrcRect);

    // Factor in the destination context's scale to generate at the best resolution
    AffineTransform destContextCTM = destContext->getCTM();
    double xScale = fabs(destContextCTM.xScale());
    double yScale = fabs(destContextCTM.yScale());
    AffineTransform adjustedPatternCTM = patternTransform;
    adjustedPatternCTM.scale(1.0 / xScale, 1.0 / yScale);
    adjustedSrcRect.scale(xScale, yScale);

    // Create a BitmapImage and call drawPattern on it.
    OwnPtr<ImageBuffer> imageBuffer = destContext->createCompatibleBuffer(adjustedSize);
    if (!imageBuffer)
        return;

    // Fill with the generated image.
    GraphicsContext* graphicsContext = imageBuffer->context();
    graphicsContext->fillRect(FloatRect(FloatPoint(), adjustedSize), *m_generator.get());

    // Tile the image buffer into the context.
    imageBuffer->drawPattern(destContext, adjustedSrcRect, adjustedPatternCTM, phase, styleColorSpace, compositeOp, destRect);
}

void SVGImage::drawPatternForContainer(GraphicsContext* context, const FloatSize containerSize, float zoom, const FloatRect& srcRect,
    const AffineTransform& patternTransform, const FloatPoint& phase, ColorSpace colorSpace, CompositeOperator compositeOp, const FloatRect& dstRect)
{
    FloatRect zoomedContainerRect = FloatRect(FloatPoint(), containerSize);
    zoomedContainerRect.scale(zoom);

    // The ImageBuffer size needs to be scaled to match the final resolution.
    AffineTransform transform = context->getCTM();
    FloatSize imageBufferScale = FloatSize(transform.xScale(), transform.yScale());
    ASSERT(imageBufferScale.width());
    ASSERT(imageBufferScale.height());

    FloatRect imageBufferSize = zoomedContainerRect;
    imageBufferSize.scale(imageBufferScale.width(), imageBufferScale.height());

    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(expandedIntSize(imageBufferSize.size()), 1);
    if (!buffer) // Failed to allocate buffer.
        return;
    drawForContainer(buffer->context(), containerSize, zoom, imageBufferSize, zoomedContainerRect, ColorSpaceDeviceRGB, CompositeSourceOver, BlendModeNormal);
    RefPtr<Image> image = buffer->copyImage(DontCopyBackingStore, Unscaled);

    // Adjust the source rect and transform due to the image buffer's scaling.
    FloatRect scaledSrcRect = srcRect;
    scaledSrcRect.scale(imageBufferScale.width(), imageBufferScale.height());
    AffineTransform unscaledPatternTransform(patternTransform);
    unscaledPatternTransform.scale(1 / imageBufferScale.width(), 1 / imageBufferScale.height());

    image->drawPattern(context, scaledSrcRect, unscaledPatternTransform, phase, colorSpace, compositeOp, dstRect);
}

void Image::drawPattern(GraphicsContext* context, const FloatRect& floatSrcRect, const FloatSize& scale,
    const FloatPoint& phase, SkXfermode::Mode compositeOp, const FloatRect& destRect, const IntSize& repeatSpacing)
{
    TRACE_EVENT0("skia", "Image::drawPattern");
    SkBitmap bitmap;
    if (!bitmapForCurrentFrame(&bitmap))
        return;

    FloatRect normSrcRect = floatSrcRect;

    normSrcRect.intersect(FloatRect(0, 0, bitmap.width(), bitmap.height()));
    if (destRect.isEmpty() || normSrcRect.isEmpty())
        return; // nothing to draw

    SkMatrix localMatrix;
    // We also need to translate it such that the origin of the pattern is the
    // origin of the destination rect, which is what WebKit expects. Skia uses
    // the coordinate system origin as the base for the pattern. If WebKit wants
    // a shifted image, it will shift it from there using the localMatrix.
    const float adjustedX = phase.x() + normSrcRect.x() * scale.width();
    const float adjustedY = phase.y() + normSrcRect.y() * scale.height();
    localMatrix.setTranslate(SkFloatToScalar(adjustedX), SkFloatToScalar(adjustedY));

    // Because no resizing occurred, the shader transform should be
    // set to the pattern's transform, which just includes scale.
    localMatrix.preScale(scale.width(), scale.height());

    SkBitmap bitmapToPaint;
    bitmap.extractSubset(&bitmapToPaint, enclosingIntRect(normSrcRect));
    if (!repeatSpacing.isZero()) {
        SkScalar ctmScaleX = 1.0;
        SkScalar ctmScaleY = 1.0;

        if (!RuntimeEnabledFeatures::slimmingPaintEnabled()) {
            AffineTransform ctm = context->getCTM();
            ctmScaleX = ctm.xScale();
            ctmScaleY = ctm.yScale();
        }

        bitmapToPaint = createBitmapWithSpace(
            bitmapToPaint,
            repeatSpacing.width() * ctmScaleX / scale.width(),
            repeatSpacing.height() * ctmScaleY / scale.height());
    }
    RefPtr<SkShader> shader = adoptRef(SkShader::CreateBitmapShader(bitmapToPaint, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, &localMatrix));

    bool isLazyDecoded = DeferredImageDecoder::isLazyDecoded(bitmap);
    {
        SkPaint paint;
        int initialSaveCount = context->preparePaintForDrawRectToRect(&paint, floatSrcRect,
            destRect, compositeOp, !bitmap.isOpaque(), isLazyDecoded, bitmap.isImmutable());
        paint.setShader(shader.get());
        context->drawRect(destRect, paint);
        context->canvas()->restoreToCount(initialSaveCount);
    }

    if (isLazyDecoded)
        PlatformInstrumentation::didDrawLazyPixelRef(bitmap.getGenerationID());
}

static void drawDeferredFilter(GraphicsContext* context, FilterData* filterData, SVGFilterElement* filterElement)
{
    SkiaImageFilterBuilder builder(context);
    SourceGraphic* sourceGraphic = static_cast<SourceGraphic*>(filterData->builder->getEffectById(SourceGraphic::effectName()));
    ASSERT(sourceGraphic);
    builder.setSourceGraphic(sourceGraphic);
    RefPtr<ImageFilter> imageFilter = builder.build(filterData->builder->lastEffect(), ColorSpaceDeviceRGB);
    FloatRect boundaries = filterData->boundaries;
    context->save();

    FloatSize deviceSize = context->getCTM().mapSize(boundaries.size());
    float scaledArea = deviceSize.width() * deviceSize.height();

    // If area of scaled size is bigger than the upper limit, adjust the scale
    // to fit. Note that this only really matters in the non-impl-side painting
    // case, since the impl-side case never allocates a full-sized backing
    // store, only tile-sized.
    // FIXME: remove this once all platforms are using impl-side painting.
    // crbug.com/169282.
    if (scaledArea > FilterEffect::maxFilterArea()) {
        float scale = sqrtf(FilterEffect::maxFilterArea() / scaledArea);
        context->scale(scale, scale);
    }
    // Clip drawing of filtered image to the minimum required paint rect.
    FilterEffect* lastEffect = filterData->builder->lastEffect();
    context->clipRect(lastEffect->determineAbsolutePaintRect(lastEffect->maxEffectRect()));
    if (filterElement->hasAttribute(SVGNames::filterResAttr)) {
        // Get boundaries in device coords.
        // FIXME: See crbug.com/382491. Is the use of getCTM OK here, given it does not include device
        // zoom or High DPI adjustments?
        FloatSize size = context->getCTM().mapSize(boundaries.size());
        // Compute the scale amount required so that the resulting offscreen is exactly filterResX by filterResY pixels.
        float filterResScaleX = filterElement->filterResX()->currentValue()->value() / size.width();
        float filterResScaleY = filterElement->filterResY()->currentValue()->value() / size.height();
        // Scale the CTM so the primitive is drawn to filterRes.
        context->scale(filterResScaleX, filterResScaleY);
        // Create a resize filter with the inverse scale.
        AffineTransform resizeMatrix;
        resizeMatrix.scale(1 / filterResScaleX, 1 / filterResScaleY);
        imageFilter = builder.buildTransform(resizeMatrix, imageFilter.get());
    }
    // If the CTM contains rotation or shearing, apply the filter to
    // the unsheared/unrotated matrix, and do the shearing/rotation
    // as a final pass.
    AffineTransform ctm = context->getCTM();
    if (ctm.b() || ctm.c()) {
        AffineTransform scaleAndTranslate;
        scaleAndTranslate.translate(ctm.e(), ctm.f());
        scaleAndTranslate.scale(ctm.xScale(), ctm.yScale());
        ASSERT(scaleAndTranslate.isInvertible());
        AffineTransform shearAndRotate = scaleAndTranslate.inverse();
        shearAndRotate.multiply(ctm);
        context->setCTM(scaleAndTranslate);
        imageFilter = builder.buildTransform(shearAndRotate, imageFilter.get());
    }
    context->beginLayer(1, CompositeSourceOver, &boundaries, ColorFilterNone, imageFilter.get());
    context->endLayer();
    context->restore();
}

bool GraphicsContext::isCompatibleWithBuffer(ImageBuffer* buffer) const
{
    AffineTransform localTransform = getCTM();
    AffineTransform bufferTransform = buffer->context()->getCTM();

    if (localTransform.xScale() != bufferTransform.xScale() || localTransform.yScale() != bufferTransform.yScale())
        return false;

    if (isAcceleratedContext() != buffer->context()->isAcceleratedContext())
        return false;

    return true;
}

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;
}

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;
}

static void paintFilteredContent(const LayoutObject& object, GraphicsContext& context, FilterData* filterData)
{
    ASSERT(filterData->m_state == FilterData::ReadyToPaint);
    ASSERT(filterData->filter->sourceGraphic());

    filterData->m_state = FilterData::PaintingFilter;

    SkiaImageFilterBuilder builder;
    RefPtr<SkImageFilter> imageFilter = builder.build(filterData->filter->lastEffect(), ColorSpaceDeviceRGB);
    FloatRect boundaries = filterData->filter->filterRegion();
    context.save();

    // Clip drawing of filtered image to the minimum required paint rect.
    FilterEffect* lastEffect = filterData->filter->lastEffect();
    context.clipRect(lastEffect->determineAbsolutePaintRect(lastEffect->maxEffectRect()));

#ifdef CHECK_CTM_FOR_TRANSFORMED_IMAGEFILTER
    // TODO: Remove this workaround once skew/rotation support is added in Skia
    // (https://code.google.com/p/skia/issues/detail?id=3288, crbug.com/446935).
    // If the CTM contains rotation or shearing, apply the filter to
    // the unsheared/unrotated matrix, and do the shearing/rotation
    // as a final pass.
    AffineTransform ctm = SVGLayoutSupport::deprecatedCalculateTransformToLayer(&object);
    if (ctm.b() || ctm.c()) {
        AffineTransform scaleAndTranslate;
        scaleAndTranslate.translate(ctm.e(), ctm.f());
        scaleAndTranslate.scale(ctm.xScale(), ctm.yScale());
        ASSERT(scaleAndTranslate.isInvertible());
        AffineTransform shearAndRotate = scaleAndTranslate.inverse();
        shearAndRotate.multiply(ctm);
        context.concatCTM(shearAndRotate.inverse());
        imageFilter = builder.buildTransform(shearAndRotate, imageFilter.get());
    }
#endif

    context.beginLayer(1, SkXfermode::kSrcOver_Mode, &boundaries, ColorFilterNone, imageFilter.get());
    context.endLayer();
    context.restore();

    filterData->m_state = FilterData::ReadyToPaint;
}

static void affineTransformDecompose(const AffineTransform& matrix, double sr[9])
{
    AffineTransform m(matrix);

    // Compute scaling factors
    double sx = matrix.xScale();
    double sy = matrix.yScale();

    // Compute cross product of transformed unit vectors. If negative,
    // one axis was flipped.
    if (m.a() * m.d() - m.c() * m.b() < 0.0) {
        // Flip axis with minimum unit vector dot product
        if (m.a() < m.d())
            sx = -sx;
        else
            sy = -sy;
    }

    // Remove scale from matrix
    m.scale(1.0 / sx, 1.0 / sy);

    // Compute rotation
    double angle = atan2(m.b(), m.a());

    // Remove rotation from matrix
    m.rotate(rad2deg(-angle));

    // Return results
    sr[0] = sx;
    sr[1] = sy;
    sr[2] = angle;
    sr[3] = m.a();
    sr[4] = m.b();
    sr[5] = m.c();
    sr[6] = m.d();
    sr[7] = m.e();
    sr[8] = m.f();
}

bool SVGRenderingContext::bufferForeground(std::unique_ptr<ImageBuffer>& imageBuffer)
{
    ASSERT(m_paintInfo);
    ASSERT(is<RenderSVGImage>(*m_renderer));
    FloatRect boundingBox = m_renderer->objectBoundingBox();

    // Invalidate an existing buffer if the scale is not correct.
    if (imageBuffer) {
        AffineTransform transform = m_paintInfo->context().getCTM(GraphicsContext::DefinitelyIncludeDeviceScale);
        IntSize expandedBoundingBox = expandedIntSize(boundingBox.size());
        IntSize bufferSize(static_cast<int>(ceil(expandedBoundingBox.width() * transform.xScale())), static_cast<int>(ceil(expandedBoundingBox.height() * transform.yScale())));
        if (bufferSize != imageBuffer->internalSize())
            imageBuffer.reset();
    }

    // Create a new buffer and paint the foreground into it.
    if (!imageBuffer) {
        if ((imageBuffer = ImageBuffer::createCompatibleBuffer(expandedIntSize(boundingBox.size()), ColorSpaceSRGB, m_paintInfo->context()))) {
            GraphicsContext& bufferedRenderingContext = imageBuffer->context();
            bufferedRenderingContext.translate(-boundingBox.x(), -boundingBox.y());
            PaintInfo bufferedInfo(*m_paintInfo);
            bufferedInfo.setContext(bufferedRenderingContext);
            downcast<RenderSVGImage>(*m_renderer).paintForeground(bufferedInfo);
        } else
            return false;
    }

    m_paintInfo->context().drawImageBuffer(*imageBuffer, boundingBox);
    return true;
}

float SVGRenderingContext::calculateScreenFontSizeScalingFactor(const RenderObject& renderer)
{
    AffineTransform ctm = calculateTransformationToOutermostCoordinateSystem(renderer);
    return narrowPrecisionToFloat(sqrt((pow(ctm.xScale(), 2) + pow(ctm.yScale(), 2)) / 2));
}

std::unique_ptr<ImageBuffer> GraphicsContext::createCompatibleBuffer(const FloatSize& size, bool hasAlpha) const
{
    // Make the buffer larger if the context's transform is scaling it so we need a higher
    // resolution than one pixel per unit. Also set up a corresponding scale factor on the
    // graphics context.

    AffineTransform transform = getCTM(DefinitelyIncludeDeviceScale);
    FloatSize scaledSize(static_cast<int>(ceil(size.width() * transform.xScale())), static_cast<int>(ceil(size.height() * transform.yScale())));

    std::unique_ptr<ImageBuffer> buffer = ImageBuffer::createCompatibleBuffer(scaledSize, 1, ColorSpaceSRGB, *this, hasAlpha);
    if (!buffer)
        return nullptr;

    buffer->context().scale(FloatSize(scaledSize.width() / size.width(), scaledSize.height() / size.height()));

    return buffer;
}

static bool scalesMatch(AffineTransform a, AffineTransform b)
{
    return a.xScale() == b.xScale() && a.yScale() == b.yScale();
}