gecko-dev/gfx/layers/wr/WebRenderCommandBuilder.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef GFX_WEBRENDERCOMMANDBUILDER_H
#define GFX_WEBRENDERCOMMANDBUILDER_H

#include "mozilla/webrender/WebRenderAPI.h"
#include "mozilla/layers/ClipManager.h"
#include "mozilla/layers/RenderRootBoundary.h"
#include "mozilla/layers/WebRenderMessages.h"
#include "mozilla/layers/WebRenderScrollData.h"
#include "mozilla/layers/WebRenderUserData.h"
#include "nsDisplayList.h"
#include "nsIFrame.h"

namespace mozilla {

namespace layers {

class CanvasLayer;
class ImageClient;
class ImageContainer;
class WebRenderBridgeChild;
class WebRenderCanvasData;
class WebRenderCanvasRendererAsync;
class WebRenderImageData;
class WebRenderFallbackData;
class WebRenderParentCommand;
class WebRenderUserData;

class WebRenderScrollDataCollection {
 public:
  WebRenderScrollDataCollection() : mSeenRenderRoot{} {}

  std::vector<WebRenderLayerScrollData>& operator[](
      wr::RenderRoot aRenderRoot) {
    return mInternalScrollDatas[aRenderRoot];
  }

  bool IsEmpty() const {
    for (auto renderRoot : wr::kRenderRoots) {
      if (!mInternalScrollDatas[renderRoot].empty()) {
        return false;
      }
    }
    return true;
  }

  void AppendRoot(Maybe<ScrollMetadata>& aRootMetadata,
                  wr::RenderRootArray<WebRenderScrollData>& aScrollDatas);

  void AppendWrapper(const RenderRootBoundary& aBoundary,
                     size_t aLayerCountBeforeRecursing);

  void AppendScrollData(const wr::DisplayListBuilder& aBuilder,
                        WebRenderLayerManager* aManager, nsDisplayItem* aItem,
                        size_t aLayerCountBeforeRecursing,
                        const ActiveScrolledRoot* aStopAtAsr,
                        const Maybe<gfx::Matrix4x4>& aAncestorTransform);

  size_t GetLayerCount(wr::RenderRoot aRenderRoot) const;

  void Clear() {
    for (auto renderRoot : wr::kRenderRoots) {
      mInternalScrollDatas[renderRoot].clear();
      mSeenRenderRoot[renderRoot] = false;
    }
  }

 private:
  wr::RenderRootArray<std::vector<WebRenderLayerScrollData>>
      mInternalScrollDatas;
  wr::RenderRootArray<bool> mSeenRenderRoot;
};

class WebRenderCommandBuilder {
  typedef nsTHashtable<nsRefPtrHashKey<WebRenderUserData>>
      WebRenderUserDataRefTable;
  typedef nsTHashtable<nsRefPtrHashKey<WebRenderCanvasData>> CanvasDataSet;

 public:
  explicit WebRenderCommandBuilder(WebRenderLayerManager* aManager)
      : mManager(aManager),
        mRootStackingContexts(nullptr),
        mCurrentClipManager(nullptr),
        mLastAsr(nullptr),
        mBuilderDumpIndex(0),
        mDumpIndent(0),
        mDoGrouping(false),
        mContainsSVGGroup(false) {}

  void Destroy();

  void EmptyTransaction();

  bool NeedsEmptyTransaction();

  void BuildWebRenderCommands(
      wr::DisplayListBuilder& aBuilder,
      wr::IpcResourceUpdateQueue& aResourceUpdates, nsDisplayList* aDisplayList,
      nsDisplayListBuilder* aDisplayListBuilder,
      wr::RenderRootArray<WebRenderScrollData>& aScrollDatas,
      WrFiltersHolder&& aFilters);

  void PushOverrideForASR(const ActiveScrolledRoot* aASR,
                          const wr::WrSpatialId& aSpatialId);
  void PopOverrideForASR(const ActiveScrolledRoot* aASR);

  Maybe<wr::ImageKey> CreateImageKey(
      nsDisplayItem* aItem, ImageContainer* aContainer,
      mozilla::wr::DisplayListBuilder& aBuilder,
      mozilla::wr::IpcResourceUpdateQueue& aResources,
      mozilla::wr::ImageRendering aRendering, const StackingContextHelper& aSc,
      gfx::IntSize& aSize, const Maybe<LayoutDeviceRect>& aAsyncImageBounds);

  WebRenderUserDataRefTable* GetWebRenderUserDataTable() {
    return &mWebRenderUserDatas;
  }

  bool PushImage(nsDisplayItem* aItem, ImageContainer* aContainer,
                 mozilla::wr::DisplayListBuilder& aBuilder,
                 mozilla::wr::IpcResourceUpdateQueue& aResources,
                 const StackingContextHelper& aSc,
                 const LayoutDeviceRect& aRect, const LayoutDeviceRect& aClip);

  Maybe<wr::ImageMask> BuildWrMaskImage(
      nsDisplayMasksAndClipPaths* aMaskItem, wr::DisplayListBuilder& aBuilder,
      wr::IpcResourceUpdateQueue& aResources, const StackingContextHelper& aSc,
      nsDisplayListBuilder* aDisplayListBuilder,
      const LayoutDeviceRect& aBounds);

  bool PushItemAsImage(nsDisplayItem* aItem, wr::DisplayListBuilder& aBuilder,
                       wr::IpcResourceUpdateQueue& aResources,
                       const StackingContextHelper& aSc,
                       nsDisplayListBuilder* aDisplayListBuilder);

  void CreateWebRenderCommandsFromDisplayList(
      nsDisplayList* aDisplayList, nsDisplayItem* aWrappingItem,
      nsDisplayListBuilder* aDisplayListBuilder,
      const StackingContextHelper& aSc, wr::DisplayListBuilder& aBuilder,
      wr::IpcResourceUpdateQueue& aResources);

  // aWrappingItem has to be non-null.
  void DoGroupingForDisplayList(nsDisplayList* aDisplayList,
                                nsDisplayItem* aWrappingItem,
                                nsDisplayListBuilder* aDisplayListBuilder,
                                const StackingContextHelper& aSc,
                                wr::DisplayListBuilder& aBuilder,
                                wr::IpcResourceUpdateQueue& aResources);

  already_AddRefed<WebRenderFallbackData> GenerateFallbackData(
      nsDisplayItem* aItem, wr::DisplayListBuilder& aBuilder,
      wr::IpcResourceUpdateQueue& aResources, const StackingContextHelper& aSc,
      nsDisplayListBuilder* aDisplayListBuilder, LayoutDeviceRect& aImageRect);

  void RemoveUnusedAndResetWebRenderUserData();
  void ClearCachedResources();

  bool ShouldDumpDisplayList(nsDisplayListBuilder* aBuilder);
  wr::usize GetBuilderDumpIndex() { return mBuilderDumpIndex; }

  bool GetContainsSVGGroup() { return mContainsSVGGroup; }

  const StackingContextHelper& GetRootStackingContextHelper(
      wr::RenderRoot aRenderRoot) const {
    return *(*mRootStackingContexts)[aRenderRoot];
  }

  // Those are data that we kept between transactions. We used to cache some
  // data in the layer. But in layers free mode, we don't have layer which
  // means we need some other place to cached the data between transaction.
  // We store the data in frame's property.
  template <class T>
  already_AddRefed<T> CreateOrRecycleWebRenderUserData(
      nsDisplayItem* aItem, wr::RenderRoot aRenderRoot,
      bool* aOutIsRecycled = nullptr) {
    MOZ_ASSERT(aItem);
    nsIFrame* frame = aItem->Frame();
    if (aOutIsRecycled) {
      *aOutIsRecycled = true;
    }

    WebRenderUserDataTable* userDataTable =
        frame->GetProperty(WebRenderUserDataProperty::Key());

    if (!userDataTable) {
      userDataTable = new WebRenderUserDataTable();
      frame->AddProperty(WebRenderUserDataProperty::Key(), userDataTable);
    }

    RefPtr<WebRenderUserData>& data = userDataTable->GetOrInsert(
        WebRenderUserDataKey(aItem->GetPerFrameKey(), T::Type()));
    if (!data) {
      data = new T(GetRenderRootStateManager(aRenderRoot), aItem);
      mWebRenderUserDatas.PutEntry(data);
      if (aOutIsRecycled) {
        *aOutIsRecycled = false;
      }
    }

    MOZ_ASSERT(data);
    MOZ_ASSERT(data->GetType() == T::Type());

    // Mark the data as being used. We will remove unused user data in the end
    // of EndTransaction.
    data->SetUsed(true);

    if (T::Type() == WebRenderUserData::UserDataType::eCanvas) {
      mLastCanvasDatas.PutEntry(data->AsCanvasData());
    }
    RefPtr<T> res = static_cast<T*>(data.get());
    return res.forget();
  }

  WebRenderLayerManager* mManager;

  class MOZ_RAII ScrollDataBoundaryWrapper {
   public:
    ScrollDataBoundaryWrapper(WebRenderCommandBuilder& aBuilder,
                              RenderRootBoundary& aBoundary);
    ~ScrollDataBoundaryWrapper();

   private:
    WebRenderCommandBuilder& mBuilder;
    RenderRootBoundary mBoundary;
    size_t mLayerCountBeforeRecursing;
  };
  friend class ScrollDataBoundaryWrapper;

 private:
  RenderRootStateManager* GetRenderRootStateManager(wr::RenderRoot aRenderRoot);

  wr::RenderRootArray<Maybe<StackingContextHelper>>* mRootStackingContexts;
  wr::RenderRootArray<ClipManager> mClipManagers;
  ClipManager* mCurrentClipManager;

  // We use this as a temporary data structure while building the mScrollData
  // inside a layers-free transaction.
  WebRenderScrollDataCollection mLayerScrollDatas;
  // We use this as a temporary data structure to track the current display
  // item's ASR as we recurse in CreateWebRenderCommandsFromDisplayList. We
  // need this so that WebRenderLayerScrollData items that deeper in the
  // tree don't duplicate scroll metadata that their ancestors already have.
  std::vector<const ActiveScrolledRoot*> mAsrStack;
  const ActiveScrolledRoot* mLastAsr;

  WebRenderUserDataRefTable mWebRenderUserDatas;

  // Store of WebRenderCanvasData objects for use in empty transactions
  CanvasDataSet mLastCanvasDatas;

  wr::usize mBuilderDumpIndex;
  wr::usize mDumpIndent;

 public:
  // Whether consecutive inactive display items should be grouped into one
  // blob image.
  bool mDoGrouping;
  Maybe<nsRect> mClippedGroupBounds;

  // True if the most recently build display list contained an svg that
  // we did grouping for.
  bool mContainsSVGGroup;
};

}  // namespace layers
}  // namespace mozilla

#endif /* GFX_WEBRENDERCOMMANDBUILDER_H */