C++ TransformState::applyTransform方法代码示例

void RenderGeometryMap::mapToContainer(TransformState& transformState, const RenderLayerModelObject* container) const
{
    // If the mapping includes something like columns, we have to go via renderers.
    if (hasNonUniformStep()) {
        m_mapping.last().m_renderer->mapLocalToContainer(container, transformState, ApplyContainerFlip | m_mapCoordinatesFlags);
        transformState.flatten();
        return;
    }
    
    bool inFixed = false;
#if !ASSERT_DISABLED
    bool foundContainer = !container || (m_mapping.size() && m_mapping[0].m_renderer == container);
#endif

    for (int i = m_mapping.size() - 1; i >= 0; --i) {
        const RenderGeometryMapStep& currentStep = m_mapping[i];

        // If container is the RenderView (step 0) we want to apply its scroll offset.
        if (i > 0 && currentStep.m_renderer == container) {
#if !ASSERT_DISABLED
            foundContainer = true;
#endif
            break;
        }

        // If this box has a transform, it acts as a fixed position container
        // for fixed descendants, which prevents the propagation of 'fixed'
        // unless the layer itself is also fixed position.
        if (i && currentStep.m_hasTransform && !currentStep.m_isFixedPosition)
            inFixed = false;
        else if (currentStep.m_isFixedPosition)
            inFixed = true;

        if (!i) {
            // The root gets special treatment for fixed position
            if (inFixed)
                transformState.move(currentStep.m_offset.width(), currentStep.m_offset.height());

            // A null container indicates mapping through the RenderView, so including its transform (the page scale).
            if (!container && currentStep.m_transform)
                transformState.applyTransform(*currentStep.m_transform.get());
        } else {
            TransformState::TransformAccumulation accumulate = currentStep.m_accumulatingTransform ? TransformState::AccumulateTransform : TransformState::FlattenTransform;
            if (currentStep.m_transform)
                transformState.applyTransform(*currentStep.m_transform.get(), accumulate);
            else
                transformState.move(currentStep.m_offset.width(), currentStep.m_offset.height(), accumulate);
        }
    }

    ASSERT(foundContainer);
    transformState.flatten();    
}

void RenderGeometryMap::mapToContainer(TransformState& transformState,
                                       const RenderBox* container) const {
  // If the mapping includes something like columns, we have to go via
  // renderers.
  if (hasNonUniformStep()) {
    m_mapping.last().m_renderer->mapLocalToContainer(
        container, transformState, ApplyContainerFlip | m_mapCoordinatesFlags);
    transformState.flatten();
    return;
  }

#if ENABLE(ASSERT)
  bool foundContainer =
      !container || (m_mapping.size() && m_mapping[0].m_renderer == container);
#endif

  for (int i = m_mapping.size() - 1; i >= 0; --i) {
    const RenderGeometryMapStep& currentStep = m_mapping[i];

    // If container is the root RenderView (step 0) we want to apply its fixed
    // position offset.
    if (i > 0 && currentStep.m_renderer == container) {
#if ENABLE(ASSERT)
      foundContainer = true;
#endif
      break;
    }

    ASSERT(!i == isTopmostRenderView(currentStep.m_renderer));

    if (!i) {
      // A null container indicates mapping through the root RenderView, so
      // including its transform (the page scale).
      if (!container && currentStep.m_transform)
        transformState.applyTransform(*currentStep.m_transform.get());
    } else {
      TransformState::TransformAccumulation accumulate =
          currentStep.m_accumulatingTransform
              ? TransformState::AccumulateTransform
              : TransformState::FlattenTransform;
      if (currentStep.m_transform)
        transformState.applyTransform(*currentStep.m_transform.get(),
                                      accumulate);
      else
        transformState.move(currentStep.m_offset.width(),
                            currentStep.m_offset.height(), accumulate);
    }
  }

  ASSERT(foundContainer);
  transformState.flatten();
}

void SVGRenderSupport::mapLocalToContainer(const RenderObject* object, const RenderLayerModelObject* repaintContainer, TransformState& transformState, bool* wasFixed)
{
    transformState.applyTransform(object->localToParentTransform());

    RenderObject* parent = object->parent();

    // At the SVG/HTML boundary (aka RenderSVGRoot), we apply the localToBorderBoxTransform
    // to map an element from SVG viewport coordinates to CSS box coordinates.
    // RenderSVGRoot's mapLocalToContainer method expects CSS box coordinates.
    if (parent->isSVGRoot())
        transformState.applyTransform(toRenderSVGRoot(parent)->localToBorderBoxTransform());

    MapCoordinatesFlags mode = UseTransforms;
    parent->mapLocalToContainer(repaintContainer, transformState, mode, wasFixed);
}

void RenderMultiColumnFlowThread::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState& transformState) const
{
    // First get the transform state's point into the block flow thread's physical coordinate space.
    parent()->mapAbsoluteToLocalPoint(mode, transformState);
    LayoutPoint transformPoint = roundedLayoutPoint(transformState.mappedPoint());

    // Now walk through each region.
    const RenderMultiColumnSet* candidateColumnSet = nullptr;
    LayoutPoint candidatePoint;
    LayoutSize candidateContainerOffset;

    for (const auto& columnSet : childrenOfType<RenderMultiColumnSet>(*parent())) {
        candidateContainerOffset = columnSet.offsetFromContainer(parent(), LayoutPoint());

        candidatePoint = transformPoint - candidateContainerOffset;
        candidateColumnSet = &columnSet;

        // We really have no clue what to do with overflow. We'll just use the closest region to the point in that case.
        LayoutUnit pointOffset = isHorizontalWritingMode() ? candidatePoint.y() : candidatePoint.x();
        LayoutUnit regionOffset = isHorizontalWritingMode() ? columnSet.topLeftLocation().y() : columnSet.topLeftLocation().x();
        if (pointOffset < regionOffset + columnSet.logicalHeight())
            break;
    }

    // Once we have a good guess as to which region we hit tested through (and yes, this was just a heuristic, but it's
    // the best we could do), then we can map from the region into the flow thread.
    LayoutSize translationOffset = physicalTranslationFromRegionToFlow(candidateColumnSet, candidatePoint) + candidateContainerOffset;
    bool preserve3D = mode & UseTransforms && (parent()->style().preserves3D() || style().preserves3D());
    if (mode & UseTransforms && shouldUseTransformFromContainer(parent())) {
        TransformationMatrix t;
        getTransformFromContainer(parent(), translationOffset, t);
        transformState.applyTransform(t, preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
    } else
        transformState.move(translationOffset.width(), translationOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
}

void RenderView::mapLocalToContainer(const RenderLayerModelObject* paintInvalidationContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed, const PaintInvalidationState* paintInvalidationState) const
{
    ASSERT_UNUSED(wasFixed, !wasFixed || *wasFixed == static_cast<bool>(mode & IsFixed));

    if (!paintInvalidationContainer && mode & UseTransforms && shouldUseTransformFromContainer(0)) {
        TransformationMatrix t;
        getTransformFromContainer(0, LayoutSize(), t);
        transformState.applyTransform(t);
    }

    if ((mode & IsFixed) && m_frameView) {
        transformState.move(m_frameView->scrollOffsetForFixedPosition());
        // IsFixed flag is only applicable within this RenderView.
        mode &= ~IsFixed;
    }

    if (paintInvalidationContainer == this)
        return;

    if (mode & TraverseDocumentBoundaries) {
        if (RenderObject* parentDocRenderer = frame()->ownerRenderer()) {
            transformState.move(-frame()->view()->scrollOffset());
            if (parentDocRenderer->isBox())
                transformState.move(toLayoutSize(toRenderBox(parentDocRenderer)->contentBoxRect().location()));
            parentDocRenderer->mapLocalToContainer(paintInvalidationContainer, transformState, mode, wasFixed, paintInvalidationState);
            return;
        }
    }
}

void RenderView::mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed) const
{
    ASSERT_UNUSED(wasFixed, !wasFixed || *wasFixed == static_cast<bool>(mode & IsFixed));

    if (!repaintContainer && mode & UseTransforms && shouldUseTransformFromContainer(0)) {
        TransformationMatrix t;
        getTransformFromContainer(0, LayoutSize(), t);
        transformState.applyTransform(t);
    }

    if (mode & IsFixed && m_frameView)
        transformState.move(m_frameView->scrollOffsetForFixedPosition());

    if (repaintContainer == this)
        return;

    if (mode & TraverseDocumentBoundaries) {
        if (RenderObject* parentDocRenderer = frame()->ownerRenderer()) {
            transformState.move(-frame()->view()->scrollOffset());
            if (parentDocRenderer->isBox())
                transformState.move(toLayoutSize(toRenderBox(parentDocRenderer)->contentBoxRect().location()));
            parentDocRenderer->mapLocalToContainer(repaintContainer, transformState, mode, wasFixed);
            return;
        }
    }

    // If a container was specified, and was not 0 or the RenderView,
    // then we should have found it by now.
    ASSERT_ARG(repaintContainer, !repaintContainer);
}

void SVGRenderBase::mapLocalToContainer(const RenderObject* object, RenderBoxModelObject* repaintContainer, bool fixed , bool useTransforms, TransformState& transformState)
{
    ASSERT(!fixed); // We should have no fixed content in the SVG rendering tree.
    ASSERT(useTransforms); // Mapping a point through SVG w/o respecting transforms is useless.
    transformState.applyTransform(object->localToParentTransform());
    object->parent()->mapLocalToContainer(repaintContainer, fixed, useTransforms, transformState);
}

void RenderBoxModelObject::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState& transformState) const
{
    RenderObject* o = container();
    if (!o)
        return;

    if (o->isRenderFlowThread())
        transformState.move(o->columnOffset(LayoutPoint(transformState.mappedPoint())));

    o->mapAbsoluteToLocalPoint(mode, transformState);

    LayoutSize containerOffset = offsetFromContainer(o, LayoutPoint());

    if (!style()->hasOutOfFlowPosition() && o->hasColumns()) {
        RenderBlock* block = toRenderBlock(o);
        LayoutPoint point(roundedLayoutPoint(transformState.mappedPoint()));
        point -= containerOffset;
        block->adjustForColumnRect(containerOffset, point);
    }

    bool preserve3D = mode & UseTransforms && (o->style()->preserves3D() || style()->preserves3D());
    if (mode & UseTransforms && shouldUseTransformFromContainer(o)) {
        TransformationMatrix t;
        getTransformFromContainer(o, containerOffset, t);
        transformState.applyTransform(t, preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
    } else
        transformState.move(containerOffset.width(), containerOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
}

void RenderView::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState& transformState) const
{
    if (mode & UseTransforms && shouldUseTransformFromContainer(0)) {
        TransformationMatrix t;
        getTransformFromContainer(0, LayoutSize(), t);
        transformState.applyTransform(t);
    }
}

void RenderView::mapLocalToContainer(const RenderBox* paintInvalidationContainer, TransformState& transformState, MapCoordinatesFlags mode) const
{
    if (!paintInvalidationContainer && mode & UseTransforms && shouldUseTransformFromContainer(0)) {
        TransformationMatrix t;
        getTransformFromContainer(0, LayoutSize(), t);
        transformState.applyTransform(t);
    }
}

void RenderSVGRoot::mapLocalToContainer(RenderBoxModelObject* repaintContainer, bool fixed , bool useTransforms, TransformState& transformState) const
{
    ASSERT(!fixed); // We should have no fixed content in the SVG rendering tree.
    ASSERT(useTransforms); // mapping a point through SVG w/o respecting trasnforms is useless.

    // Transform to our border box and let RenderBox transform the rest of the way.
    transformState.applyTransform(localToBorderBoxTransform());
    RenderBox::mapLocalToContainer(repaintContainer, fixed, useTransforms, transformState);
}

void SVGRenderSupport::mapLocalToContainer(const RenderElement& renderer, const RenderLayerModelObject* repaintContainer, TransformState& transformState, bool* wasFixed)
{
    AffineTransform transform;
    auto& parent = localToParentTransform(renderer, transform);

    transformState.applyTransform(transform);

    MapCoordinatesFlags mode = UseTransforms;
    parent.mapLocalToContainer(repaintContainer, transformState, mode, wasFixed);
}

void RenderGeometryMap::mapToAbsolute(TransformState& transformState) const
{
    // If the mapping includes something like columns, we have to go via renderers.
    if (hasNonUniformStep()) {
        bool fixed = false;
        m_mapping.last()->m_renderer->mapLocalToContainer(0, fixed, true, transformState, RenderObject::ApplyContainerFlip);
        return;
    }

    bool inFixed = false;

    for (int i = m_mapping.size() - 1; i >= 0; --i) {
        const RenderGeometryMapStep* currStep = m_mapping[i].get();

        // If this box has a transform, it acts as a fixed position container
        // for fixed descendants, which prevents the propagation of 'fixed'
        // unless the layer itself is also fixed position.
        if (currStep->m_hasTransform && !currStep->m_isFixedPosition)
            inFixed = false;
        else if (currStep->m_isFixedPosition)
            inFixed = true;

        if (!i) {
            if (currStep->m_transform)
                transformState.applyTransform(*currStep->m_transform.get());

            // The root gets special treatment for fixed position
            if (inFixed)
                transformState.move(currStep->m_offset.width(), currStep->m_offset.height());
        } else {
            TransformState::TransformAccumulation accumulate = currStep->m_accumulatingTransform ? TransformState::AccumulateTransform : TransformState::FlattenTransform;
            if (currStep->m_transform)
                transformState.applyTransform(*currStep->m_transform.get(), accumulate);
            else
                transformState.move(currStep->m_offset.width(), currStep->m_offset.height(), accumulate);
        }
    }

    transformState.flatten();
}

void SVGLayoutSupport::mapLocalToContainer(const LayoutObject* object, const LayoutBoxModelObject* paintInvalidationContainer, TransformState& transformState, bool* wasFixed, const PaintInvalidationState* paintInvalidationState)
{
    transformState.applyTransform(object->localToParentTransform());

    if (paintInvalidationState && paintInvalidationState->canMapToContainer(paintInvalidationContainer)) {
        // |svgTransform| contains localToBorderBoxTransform mentioned below.
        transformState.applyTransform(paintInvalidationState->svgTransform());
        transformState.move(paintInvalidationState->paintOffset());
        return;
    }

    LayoutObject* parent = object->parent();

    // At the SVG/HTML boundary (aka LayoutSVGRoot), we apply the localToBorderBoxTransform
    // to map an element from SVG viewport coordinates to CSS box coordinates.
    // LayoutSVGRoot's mapLocalToContainer method expects CSS box coordinates.
    if (parent->isSVGRoot())
        transformState.applyTransform(toLayoutSVGRoot(parent)->localToBorderBoxTransform());

    MapCoordinatesFlags mode = UseTransforms;
    parent->mapLocalToContainer(paintInvalidationContainer, transformState, mode, wasFixed, paintInvalidationState);
}