/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- * 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 FRAMELAYERBUILDER_H_ #define FRAMELAYERBUILDER_H_ #include "nsTHashtable.h" #include "nsHashKeys.h" #include "nsTArray.h" #include "nsRegion.h" #include "nsIFrame.h" #include "ImageLayers.h" #include "DisplayItemClip.h" #include "mozilla/layers/LayersTypes.h" #include "LayerState.h" class nsDisplayListBuilder; class nsDisplayList; class nsDisplayItem; class gfxContext; class nsDisplayItemGeometry; namespace mozilla { namespace layers { class ContainerLayer; class LayerManager; class BasicLayerManager; class PaintedLayer; } // namespace layers namespace gfx { class Matrix4x4; } // namespace gfx class FrameLayerBuilder; class LayerManagerData; class PaintedLayerData; class ContainerState; class RefCountedRegion { private: ~RefCountedRegion() {} public: NS_INLINE_DECL_REFCOUNTING(RefCountedRegion) RefCountedRegion() : mIsInfinite(false) {} nsRegion mRegion; bool mIsInfinite; }; struct ContainerLayerParameters { ContainerLayerParameters() : mXScale(1) , mYScale(1) , mLayerContentsVisibleRect(nullptr) , mBackgroundColor(NS_RGBA(0,0,0,0)) , mInTransformedSubtree(false) , mInActiveTransformedSubtree(false) , mDisableSubpixelAntialiasingInDescendants(false) , mInLowPrecisionDisplayPort(false) {} ContainerLayerParameters(float aXScale, float aYScale) : mXScale(aXScale) , mYScale(aYScale) , mLayerContentsVisibleRect(nullptr) , mBackgroundColor(NS_RGBA(0,0,0,0)) , mInTransformedSubtree(false) , mInActiveTransformedSubtree(false) , mDisableSubpixelAntialiasingInDescendants(false) , mInLowPrecisionDisplayPort(false) {} ContainerLayerParameters(float aXScale, float aYScale, const nsIntPoint& aOffset, const ContainerLayerParameters& aParent) : mXScale(aXScale) , mYScale(aYScale) , mLayerContentsVisibleRect(nullptr) , mOffset(aOffset) , mBackgroundColor(aParent.mBackgroundColor) , mInTransformedSubtree(aParent.mInTransformedSubtree) , mInActiveTransformedSubtree(aParent.mInActiveTransformedSubtree) , mDisableSubpixelAntialiasingInDescendants(aParent.mDisableSubpixelAntialiasingInDescendants) , mInLowPrecisionDisplayPort(aParent.mInLowPrecisionDisplayPort) {} float mXScale, mYScale; LayoutDeviceToLayerScale2D Scale() const { return LayoutDeviceToLayerScale2D(mXScale, mYScale); } /** * If non-null, the rectangle in which BuildContainerLayerFor stores the * visible rect of the layer, in the coordinate system of the created layer. */ nsIntRect* mLayerContentsVisibleRect; /** * An offset to apply to all child layers created. */ nsIntPoint mOffset; LayerIntPoint Offset() const { return LayerIntPoint::FromUntyped(mOffset); } nscolor mBackgroundColor; bool mInTransformedSubtree; bool mInActiveTransformedSubtree; bool mDisableSubpixelAntialiasingInDescendants; bool mInLowPrecisionDisplayPort; /** * When this is false, PaintedLayer coordinates are drawn to with an integer * translation and the scale in mXScale/mYScale. */ bool AllowResidualTranslation() { // If we're in a transformed subtree, but no ancestor transform is actively // changing, we'll use the residual translation when drawing into the // PaintedLayer to ensure that snapping exactly matches the ideal transform. return mInTransformedSubtree && !mInActiveTransformedSubtree; } }; /** * The FrameLayerBuilder is responsible for converting display lists * into layer trees. Every LayerManager needs a unique FrameLayerBuilder * to build layers. * * The most important API in this class is BuildContainerLayerFor. This * method takes a display list as input and constructs a ContainerLayer * with child layers that render the contents of the display list. It * records the relationship between frames and layers. * * That data enables us to retain layer trees. When constructing a * ContainerLayer, we first check to see if there's an existing * ContainerLayer for the same frame that can be recycled. If we recycle * it, we also try to reuse its existing PaintedLayer children to render * the display items without layers of their own. The idea is that by * recycling layers deterministically, we can ensure that when nothing * changes in a display list, we will reuse the existing layers without * changes. * * We expose a GetLeafLayerFor method that can be called by display items * that make their own layers (e.g. canvas and video); this method * locates the last layer used to render the display item, if any, and * return it as a candidate for recycling. * * FrameLayerBuilder sets up PaintedLayers so that 0,0 in the Painted layer * corresponds to the (pixel-snapped) top-left of the aAnimatedGeometryRoot. * It sets up ContainerLayers so that 0,0 in the container layer * corresponds to the snapped top-left of the display item reference frame. * * When we construct a container layer, we know the transform that will be * applied to the layer. If the transform scales the content, we can get * better results when intermediate buffers are used by pushing some scale * from the container's transform down to the children. For PaintedLayer * children, the scaling can be achieved by changing the size of the layer * and drawing into it with increased or decreased resolution. By convention, * integer types (nsIntPoint/nsIntSize/nsIntRect/nsIntRegion) are all in layer * coordinates, post-scaling, whereas appunit types are all pre-scaling. */ class FrameLayerBuilder : public layers::LayerUserData { public: typedef layers::ContainerLayer ContainerLayer; typedef layers::Layer Layer; typedef layers::PaintedLayer PaintedLayer; typedef layers::ImageLayer ImageLayer; typedef layers::LayerManager LayerManager; typedef layers::BasicLayerManager BasicLayerManager; typedef layers::EventRegions EventRegions; FrameLayerBuilder() : mRetainingManager(nullptr), mDetectedDOMModification(false), mInvalidateAllLayers(false), mInLayerTreeCompressionMode(false), mContainerLayerGeneration(0), mMaxContainerLayerGeneration(0) { MOZ_COUNT_CTOR(FrameLayerBuilder); } ~FrameLayerBuilder() { MOZ_COUNT_DTOR(FrameLayerBuilder); } static void Shutdown(); void Init(nsDisplayListBuilder* aBuilder, LayerManager* aManager, PaintedLayerData* aLayerData = nullptr); /** * Call this to notify that we have just started a transaction on the * retained layer manager aManager. */ void DidBeginRetainedLayerTransaction(LayerManager* aManager); /** * Call this just before we end a transaction. */ void WillEndTransaction(); /** * Call this after we end a transaction. */ void DidEndTransaction(); enum { CONTAINER_NOT_CLIPPED_BY_ANCESTORS = 0x01, /** * Set this when pulling an opaque background color from behind the * container layer into the container doesn't change the visual results, * given the effects you're going to apply to the container layer. * For example, this is compatible with opacity or clipping/masking, but * not with non-OVER blend modes or filters. */ CONTAINER_ALLOW_PULL_BACKGROUND_COLOR = 0x02 }; /** * Build a container layer for a display item that contains a child * list, either reusing an existing one or creating a new one. It * sets the container layer children to layers which together render * the contents of the display list. It reuses existing layers from * the retained layer manager if possible. * aContainerItem may be null, in which case we construct a root layer. * This gets called by display list code. It calls BuildLayer on the * items in the display list, making items with their own layers * children of the new container, and assigning all other items to * PaintedLayer children created and managed by the FrameLayerBuilder. * Returns a layer with clip rect cleared; it is the * caller's responsibility to add any clip rect. The visible region * is set based on what's in the layer. * The container layer is transformed by aTransform (if non-null), and * the result is transformed by the scale factors in aContainerParameters. * aChildren is modified due to display item merging and flattening. * The visible region of the returned layer is set only if aContainerItem * is null. */ already_AddRefed BuildContainerLayerFor(nsDisplayListBuilder* aBuilder, LayerManager* aManager, nsIFrame* aContainerFrame, nsDisplayItem* aContainerItem, nsDisplayList* aChildren, const ContainerLayerParameters& aContainerParameters, const gfx::Matrix4x4* aTransform, uint32_t aFlags = 0); /** * Get a retained layer for a display item that needs to create its own * layer for rendering (i.e. under nsDisplayItem::BuildLayer). Returns * null if no retained layer is available, which usually means that this * display item didn't have a layer before so the caller will * need to create one. * Returns a layer with clip rect cleared; it is the * caller's responsibility to add any clip rect and set the visible * region. */ Layer* GetLeafLayerFor(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem); /** * Call this to force all retained layers to be discarded and recreated at * the next paint. */ static void InvalidateAllLayers(LayerManager* aManager); static void InvalidateAllLayersForFrame(nsIFrame *aFrame); /** * Call this to determine if a frame has a dedicated (non-Painted) layer * for the given display item key. If there isn't one, we return null, * otherwise we return the layer. */ static Layer* GetDedicatedLayer(nsIFrame* aFrame, uint32_t aDisplayItemKey); /** * This callback must be provided to EndTransaction. The callback data * must be the nsDisplayListBuilder containing this FrameLayerBuilder. * This function can be called multiple times in a row to draw * different regions. This will occur when, for example, progressive paint is * enabled. In these cases aDirtyRegion can optionally be used to specify the * total region that will be drawn during the transaction, possibly allowing * the callback to make optimizations. */ static void DrawPaintedLayer(PaintedLayer* aLayer, gfxContext* aContext, const nsIntRegion& aRegionToDraw, const nsIntRegion* aDirtyRegion, mozilla::layers::DrawRegionClip aClip, const nsIntRegion& aRegionToInvalidate, void* aCallbackData); /** * Dumps this FrameLayerBuilder's retained layer manager's retained * layer tree. Defaults to dumping to stdout in non-HTML format. */ static void DumpRetainedLayerTree(LayerManager* aManager, std::stringstream& aStream, bool aDumpHtml = false); /** * Returns the most recently allocated geometry item for the given display * item. * * XXX(seth): The current implementation must iterate through all display * items allocated for this display item's frame. This may lead to O(n^2) * behavior in some situations. */ static nsDisplayItemGeometry* GetMostRecentGeometry(nsDisplayItem* aItem); /******* PRIVATE METHODS to FrameLayerBuilder.cpp ********/ /* These are only in the public section because they need * to be called by file-scope helper functions in FrameLayerBuilder.cpp. */ /** * Record aItem as a display item that is rendered by aLayer. * * @param aLayer Layer that the display item will be rendered into * @param aItem Display item to be drawn. * @param aLayerState What LayerState the item is using. * @param aTopLeft offset from active scrolled root to reference frame * @param aManager If the layer is in the LAYER_INACTIVE state, * then this is the temporary layer manager to draw with. */ void AddLayerDisplayItem(Layer* aLayer, nsDisplayItem* aItem, LayerState aLayerState, const nsPoint& aTopLeft, BasicLayerManager* aManager); /** * Record aItem as a display item that is rendered by the PaintedLayer * aLayer, with aClipRect, where aContainerLayerFrame is the frame * for the container layer this ThebesItem belongs to. * aItem must have an underlying frame. * @param aTopLeft offset from active scrolled root to reference frame */ void AddPaintedDisplayItem(PaintedLayerData* aLayer, nsDisplayItem* aItem, const DisplayItemClip& aClip, ContainerState& aContainerState, LayerState aLayerState, const nsPoint& aTopLeft); /** * Calls GetOldLayerForFrame on the underlying frame of the display item, * and each subsequent merged frame if no layer is found for the underlying * frame. */ Layer* GetOldLayerFor(nsDisplayItem* aItem, nsDisplayItemGeometry** aOldGeometry = nullptr, DisplayItemClip** aOldClip = nullptr); void ClearCachedGeometry(nsDisplayItem* aItem); static Layer* GetDebugOldLayerFor(nsIFrame* aFrame, uint32_t aDisplayItemKey); /** * Return the layer that all display items of aFrame were assigned to in the * last paint, or nullptr if there was no single layer assigned to all of the * frame's display items (i.e. zero, or more than one). * This function is for testing purposes and not performance sensitive. */ static Layer* GetDebugSingleOldLayerForFrame(nsIFrame* aFrame); /** * Destroy any stored LayerManagerDataProperty and the associated data for * aFrame. */ static void DestroyDisplayItemDataFor(nsIFrame* aFrame); LayerManager* GetRetainingLayerManager() { return mRetainingManager; } /** * Returns true if the given display item was rendered during the previous * paint. Returns false otherwise. */ static bool HasRetainedDataFor(nsIFrame* aFrame, uint32_t aDisplayItemKey); class DisplayItemData; typedef void (*DisplayItemDataCallback)(nsIFrame *aFrame, DisplayItemData* aItem); static void IterateRetainedDataFor(nsIFrame* aFrame, DisplayItemDataCallback aCallback); /** * Save transform that was in aLayer when we last painted, and the position * of the active scrolled root frame. It must be an integer * translation. */ void SavePreviousDataForLayer(PaintedLayer* aLayer, uint32_t aClipCount); /** * Get the translation transform that was in aLayer when we last painted. It's either * the transform saved by SaveLastPaintTransform, or else the transform * that's currently in the layer (which must be an integer translation). */ nsIntPoint GetLastPaintOffset(PaintedLayer* aLayer); /** * Return the resolution at which we expect to render aFrame's contents, * assuming they are being painted to retained layers. This takes into account * the resolution the contents of the ContainerLayer containing aFrame are * being rendered at, as well as any currently-inactive transforms between * aFrame and that container layer. */ static gfxSize GetPaintedLayerScaleForFrame(nsIFrame* aFrame); /** * Stores a Layer as the dedicated layer in the DisplayItemData for a given frame/key pair. * * Used when we optimize a PaintedLayer into an ImageLayer and want to retroactively update the * DisplayItemData so we can retrieve the layer from within layout. */ void StoreOptimizedLayerForFrame(nsDisplayItem* aItem, Layer* aLayer); NS_DECLARE_FRAME_PROPERTY_WITH_FRAME_IN_DTOR(LayerManagerDataProperty, RemoveFrameFromLayerManager) /** * Retained data storage: * * Each layer manager (widget, and inactive) stores a LayerManagerData object * that keeps a hash-set of DisplayItemData items that were drawn into it. * Each frame also keeps a list of DisplayItemData pointers that were * created for that frame. DisplayItemData objects manage these lists automatically. * * During layer construction we update the data in the LayerManagerData object, marking * items that are modified. At the end we sweep the LayerManagerData hash-set and remove * all items that haven't been modified. */ /** * Retained data for a display item. */ class DisplayItemData final { public: friend class FrameLayerBuilder; uint32_t GetDisplayItemKey() { return mDisplayItemKey; } Layer* GetLayer() { return mLayer; } nsDisplayItemGeometry* GetGeometry() const { return mGeometry.get(); } void Invalidate() { mIsInvalid = true; } private: DisplayItemData(LayerManagerData* aParent, uint32_t aKey, Layer* aLayer, nsIFrame* aFrame = nullptr); /** * Removes any references to this object from frames * in mFrameList. */ ~DisplayItemData(); NS_INLINE_DECL_REFCOUNTING(DisplayItemData) /** * Associates this DisplayItemData with a frame, and adds it * to the LayerManagerDataProperty list on the frame. */ void AddFrame(nsIFrame* aFrame); void RemoveFrame(nsIFrame* aFrame); const nsTArray& GetFrameListChanges(); /** * Updates the contents of this item to a new set of data, instead of allocating a new * object. * Set the passed in parameters, and clears the opt layer and inactive manager. * Parent, and display item key are assumed to be the same. * * EndUpdate must be called before the end of the transaction to complete the update. */ void BeginUpdate(Layer* aLayer, LayerState aState, uint32_t aContainerLayerGeneration, nsDisplayItem* aItem = nullptr); /** * Completes the update of this, and removes any references to data that won't live * longer than the transaction. * * Updates the geometry, frame list and clip. * For items within a PaintedLayer, a geometry object must be specified to retain * until the next transaction. * */ void EndUpdate(nsAutoPtr aGeometry); void EndUpdate(); LayerManagerData* mParent; nsRefPtr mLayer; nsRefPtr mOptLayer; nsRefPtr mInactiveManager; nsAutoTArray mFrameList; nsAutoPtr mGeometry; DisplayItemClip mClip; uint32_t mDisplayItemKey; uint32_t mContainerLayerGeneration; LayerState mLayerState; /** * Temporary stoarage of the display item being referenced, only valid between * BeginUpdate and EndUpdate. */ nsDisplayItem* mItem; nsAutoTArray mFrameListChanges; /** * Used to track if data currently stored in mFramesWithLayers (from an existing * paint) has been updated in the current paint. */ bool mUsed; bool mIsInvalid; }; protected: friend class LayerManagerData; static void RemoveFrameFromLayerManager(nsIFrame* aFrame, void* aPropertyValue); /** * Given a frame and a display item key that uniquely identifies a * display item for the frame, find the layer that was last used to * render that display item. Returns null if there is no such layer. * This could be a dedicated layer for the display item, or a PaintedLayer * that renders many display items. */ DisplayItemData* GetOldLayerForFrame(nsIFrame* aFrame, uint32_t aDisplayItemKey); /** * Stores DisplayItemData associated with aFrame, stores the data in * mNewDisplayItemData. */ DisplayItemData* StoreDataForFrame(nsDisplayItem* aItem, Layer* aLayer, LayerState aState); void StoreDataForFrame(nsIFrame* aFrame, uint32_t aDisplayItemKey, Layer* aLayer, LayerState aState); // Flash the area within the context clip if paint flashing is enabled. static void FlashPaint(gfxContext *aContext); /* * Get the DisplayItemData array associated with this frame, or null if one * doesn't exist. * * Note that the pointer returned here is only valid so long as you don't * poke the LayerManagerData's mFramesWithLayers hashtable. */ DisplayItemData* GetDisplayItemData(nsIFrame *aFrame, uint32_t aKey); /* * Get the DisplayItemData associated with this frame / display item pair, * using the LayerManager instead of FrameLayerBuilder. */ static DisplayItemData* GetDisplayItemDataForManager(nsIFrame* aFrame, uint32_t aDisplayItemKey, LayerManager* aManager); static DisplayItemData* GetDisplayItemDataForManager(nsIFrame* aFrame, uint32_t aDisplayItemKey); static DisplayItemData* GetDisplayItemDataForManager(nsDisplayItem* aItem, LayerManager* aManager); static DisplayItemData* GetDisplayItemDataForManager(nsIFrame* aFrame, uint32_t aDisplayItemKey, LayerManagerData* aData); /** * We store one of these for each display item associated with a * PaintedLayer, in a hashtable that maps each PaintedLayer to an array * of ClippedDisplayItems. (PaintedLayerItemsEntry is the hash entry * for that hashtable.) * These are only stored during the paint process, so that the * DrawPaintedLayer callback can figure out which items to draw for the * PaintedLayer. */ struct ClippedDisplayItem { ClippedDisplayItem(nsDisplayItem* aItem, uint32_t aGeneration) : mItem(aItem), mContainerLayerGeneration(aGeneration) { } ~ClippedDisplayItem(); nsDisplayItem* mItem; /** * If the display item is being rendered as an inactive * layer, then this stores the layer manager being * used for the inactive transaction. */ nsRefPtr mInactiveLayerManager; uint32_t mContainerLayerGeneration; }; static void RecomputeVisibilityForItems(nsTArray& aItems, nsDisplayListBuilder* aBuilder, const nsIntRegion& aRegionToDraw, const nsIntPoint& aOffset, int32_t aAppUnitsPerDevPixel, float aXScale, float aYScale); void PaintItems(nsTArray& aItems, const nsIntRect& aRect, gfxContext* aContext, nsRenderingContext* aRC, nsDisplayListBuilder* aBuilder, nsPresContext* aPresContext, const nsIntPoint& aOffset, float aXScale, float aYScale, int32_t aCommonClipCount); /** * We accumulate ClippedDisplayItem elements in a hashtable during * the paint process. This is the hashentry for that hashtable. */ public: class PaintedLayerItemsEntry : public nsPtrHashKey { public: explicit PaintedLayerItemsEntry(const PaintedLayer *key) : nsPtrHashKey(key) , mContainerLayerFrame(nullptr) , mLastCommonClipCount(0) , mContainerLayerGeneration(0) , mHasExplicitLastPaintOffset(false) , mCommonClipCount(0) {} PaintedLayerItemsEntry(const PaintedLayerItemsEntry &toCopy) : nsPtrHashKey(toCopy.mKey), mItems(toCopy.mItems) { NS_ERROR("Should never be called, since we ALLOW_MEMMOVE"); } nsTArray mItems; nsIFrame* mContainerLayerFrame; // The translation set on this PaintedLayer before we started updating the // layer tree. nsIntPoint mLastPaintOffset; uint32_t mLastCommonClipCount; uint32_t mContainerLayerGeneration; bool mHasExplicitLastPaintOffset; /** * The first mCommonClipCount rounded rectangle clips are identical for * all items in the layer. Computed in PaintedLayerData. */ uint32_t mCommonClipCount; enum { ALLOW_MEMMOVE = true }; }; /** * Get the PaintedLayerItemsEntry object associated with aLayer in this * FrameLayerBuilder */ PaintedLayerItemsEntry* GetPaintedLayerItemsEntry(PaintedLayer* aLayer) { return mPaintedLayerItems.GetEntry(aLayer); } PaintedLayerData* GetContainingPaintedLayerData() { return mContainingPaintedLayer; } bool IsBuildingRetainedLayers() { return !mContainingPaintedLayer && mRetainingManager; } /** * Attempt to build the most compressed layer tree possible, even if it means * throwing away existing retained buffers. */ void SetLayerTreeCompressionMode() { mInLayerTreeCompressionMode = true; } bool CheckInLayerTreeCompressionMode(); void ComputeGeometryChangeForItem(DisplayItemData* aData); protected: /** * Returns true if the DOM has been modified since we started painting, * in which case we should bail out and not paint anymore. This should * never happen, but plugins can trigger it in some cases. */ bool CheckDOMModified(); /** * The layer manager belonging to the widget that is being retained * across paints. */ LayerManager* mRetainingManager; /** * The root prescontext for the display list builder reference frame */ nsRefPtr mRootPresContext; /** * The display list builder being used. */ nsDisplayListBuilder* mDisplayListBuilder; /** * A map from PaintedLayers to the list of display items (plus * clipping data) to be rendered in the layer. */ nsTHashtable mPaintedLayerItems; /** * When building layers for an inactive layer, this is where the * inactive layer will be placed. */ PaintedLayerData* mContainingPaintedLayer; /** * Saved generation counter so we can detect DOM changes. */ uint32_t mInitialDOMGeneration; /** * Set to true if we have detected and reported DOM modification during * the current paint. */ bool mDetectedDOMModification; /** * Indicates that the entire layer tree should be rerendered * during this paint. */ bool mInvalidateAllLayers; bool mInLayerTreeCompressionMode; uint32_t mContainerLayerGeneration; uint32_t mMaxContainerLayerGeneration; }; } // namespace mozilla #endif /* FRAMELAYERBUILDER_H_ */