layout/painting/WindowRenderer.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef MOZILLA_PAINTING_WINDOWRENDERER_H
   8 #define MOZILLA_PAINTING_WINDOWRENDERER_H
   9
  10 #include "mozilla/webrender/webrender_ffi.h"
  11 #include "mozilla/layers/LayersTypes.h"
  12 #include "mozilla/dom/Animation.h"  // for Animation
  13 #include "mozilla/layers/ScrollableLayerGuid.h"  // for ScrollableLayerGuid, ScrollableLayerGuid::ViewID
  14 #include "mozilla/ScrollPositionUpdate.h"  // for ScrollPositionUpdate
  15 #include "nsRefPtrHashtable.h"             // for nsRefPtrHashtable
  16 #include "gfxContext.h"
  17
  18 namespace mozilla {
  19 namespace layers {
  20 class LayerManager;
  21 class WebRenderLayerManager;
  22 class KnowsCompositor;
  23 class CompositorBridgeChild;
  24 class FrameUniformityData;
  25 class PersistentBufferProvider;
  26 }  // namespace layers
  27 class FallbackRenderer;
  28 class nsDisplayListBuilder;
  29 class nsDisplayList;
  30
  31 class FrameRecorder {
  32  public:
  33   /**
  34    * Record (and return) frame-intervals and paint-times for frames which were
  35    * presented between calling StartFrameTimeRecording and
  36    * StopFrameTimeRecording.
  37    *
  38    * - Uses a cyclic buffer and serves concurrent consumers, so if Stop is
  39    *   called too late
  40    *     (elements were overwritten since Start), result is considered invalid
  41    *      and hence empty.)
  42    * - Buffer is capable of holding 10 seconds @ 60fps (or more if frames were
  43    *   less frequent).
  44    *     Can be changed (up to 1 hour) via pref:
  45    *     toolkit.framesRecording.bufferSize.
  46    * - Note: the first frame-interval may be longer than expected because last
  47    *   frame
  48    *     might have been presented some time before calling
  49    *     StartFrameTimeRecording.
  50    */
  51
  52   /**
  53    * Returns a handle which represents current recording start position.
  54    */
  55   virtual uint32_t StartFrameTimeRecording(int32_t aBufferSize);
  56
  57   /**
  58    *  Clears, then populates aFrameIntervals with the recorded frame timing
  59    *  data. The array will be empty if data was overwritten since
  60    *  aStartIndex was obtained.
  61    */
  62   virtual void StopFrameTimeRecording(uint32_t aStartIndex,
  63                                       nsTArray<float>& aFrameIntervals);
  64
  65   void RecordFrame();
  66
  67  private:
  68   struct FramesTimingRecording {
  69     // Stores state and data for frame intervals and paint times recording.
  70     // see LayerManager::StartFrameTimeRecording() at Layers.cpp for more
  71     // details.
  72     FramesTimingRecording()
  73         : mNextIndex(0),
  74           mLatestStartIndex(0),
  75           mCurrentRunStartIndex(0),
  76           mIsPaused(true) {}
  77     nsTArray<float> mIntervals;
  78     TimeStamp mLastFrameTime;
  79     uint32_t mNextIndex;
  80     uint32_t mLatestStartIndex;
  81     uint32_t mCurrentRunStartIndex;
  82     bool mIsPaused;
  83   };
  84   FramesTimingRecording mRecording;
  85 };
  86
  87 /**
  88  * WindowRenderer is the retained rendering object owned by an nsIWidget for
  89  * drawing the contents of that window, the role previously handled by
  90  * LayerManager.
  91  *
  92  * It can be WebRender, (deprecated) Layers, or an immediate-mode
  93  * FallbackRenderer.
  94  *
  95  * The intention is for LayerManager to be removed entirely in the near future,
  96  * with WebRender inheriting directly from this class. It is likely that more
  97  * cleanup can be done once that happens.
  98  */
  99 class WindowRenderer : public FrameRecorder {
 100   NS_INLINE_DECL_REFCOUNTING(WindowRenderer)
 101
 102  public:
 103   // Cast to implementation types.
 104   virtual layers::WebRenderLayerManager* AsWebRender() { return nullptr; }
 105   virtual FallbackRenderer* AsFallback() { return nullptr; }
 106
 107   // Required functionality
 108
 109   /**
 110    * Start a new transaction. Nested transactions are not allowed so
 111    * there must be no transaction currently in progress.
 112    * This transaction will update the state of the window from which
 113    * this LayerManager was obtained.
 114    */
 115   virtual bool BeginTransaction(const nsCString& aURL = nsCString()) = 0;
 116
 117   enum EndTransactionFlags {
 118     END_DEFAULT = 0,
 119     END_NO_IMMEDIATE_REDRAW = 1 << 0,  // Do not perform the drawing phase
 120     END_NO_COMPOSITE =
 121         1 << 1,  // Do not composite after drawing painted layer contents.
 122     END_NO_REMOTE_COMPOSITE = 1 << 2  // Do not schedule a composition with a
 123                                       // remote Compositor, if one exists.
 124   };
 125
 126   /**
 127    * Attempts to end an "empty transaction". There must have been no
 128    * changes to the layer tree since the BeginTransaction().
 129    * It's possible for this to fail; PaintedLayers may need to be updated
 130    * due to VRAM data being lost, for example. In such cases this method
 131    * returns false, and the caller must proceed with a normal layer tree
 132    * update and EndTransaction.
 133    */
 134   virtual bool EndEmptyTransaction(
 135       EndTransactionFlags aFlags = END_DEFAULT) = 0;
 136
 137   virtual void Destroy() {}
 138
 139   /**
 140    * Type of layer manager this is. This is to be used sparsely in order to
 141    * avoid a lot of Layers backend specific code. It should be used only when
 142    * Layers backend specific functionality is necessary.
 143    */
 144   virtual layers::LayersBackend GetBackendType() = 0;
 145
 146   /**
 147    * Type of layers backend that will be used to composite this layer tree.
 148    * When compositing is done remotely, then this returns the layers type
 149    * of the compositor.
 150    */
 151   virtual layers::LayersBackend GetCompositorBackendType() {
 152     return GetBackendType();
 153   }
 154
 155   /**
 156    * Checks if we need to invalidate the OS widget to trigger
 157    * painting when updating this renderer.
 158    */
 159   virtual bool NeedsWidgetInvalidation() { return true; }
 160
 161   /**
 162    * Make sure that the previous transaction has been entirely
 163    * completed.
 164    *
 165    * Note: This may sychronously wait on a remote compositor
 166    * to complete rendering.
 167    */
 168   virtual void FlushRendering(wr::RenderReasons aReasons) {}
 169
 170   /**
 171    * Make sure that the previous transaction has been
 172    * received. This will synchronsly wait on a remote compositor.
 173    */
 174   virtual void WaitOnTransactionProcessed() {}
 175
 176   virtual bool IsCompositingCheap() { return true; }
 177
 178   /**
 179    * returns the maximum texture size on this layer backend, or INT32_MAX
 180    * if there is no maximum
 181    */
 182   virtual int32_t GetMaxTextureSize() const { return INT32_MAX; }
 183
 184   /**
 185    * Return the name of the layer manager's backend.
 186    */
 187   virtual void GetBackendName(nsAString& aName) = 0;
 188
 189   virtual void GetFrameUniformity(layers::FrameUniformityData* aOutData) {}
 190
 191   virtual bool AddPendingScrollUpdateForNextTransaction(
 192       layers::ScrollableLayerGuid::ViewID aScrollId,
 193       const ScrollPositionUpdate& aUpdateInfo) {
 194     return false;
 195   }
 196
 197   /**
 198    * Creates a PersistentBufferProvider for use with canvas which is optimized
 199    * for inter-operating with this layermanager.
 200    */
 201   virtual already_AddRefed<layers::PersistentBufferProvider>
 202   CreatePersistentBufferProvider(const mozilla::gfx::IntSize& aSize,
 203                                  mozilla::gfx::SurfaceFormat aFormat,
 204                                  bool aWillReadFrequently = false);
 205
 206   // Helper wrappers around cast to impl and then cast again.
 207
 208   virtual layers::KnowsCompositor* AsKnowsCompositor() { return nullptr; }
 209
 210   virtual layers::CompositorBridgeChild* GetCompositorBridgeChild() {
 211     return nullptr;
 212   }
 213
 214   // Provided functionality
 215
 216   void AddPartialPrerenderedAnimation(uint64_t aCompositorAnimationId,
 217                                       dom::Animation* aAnimation);
 218   void RemovePartialPrerenderedAnimation(uint64_t aCompositorAnimationId,
 219                                          dom::Animation* aAnimation);
 220   void UpdatePartialPrerenderedAnimations(
 221       const nsTArray<uint64_t>& aJankedAnimations);
 222
 223  protected:
 224   virtual ~WindowRenderer() = default;
 225
 226   // Transform animations which are not fully pre-rendered because it's on a
 227   // large frame.  We need to update the pre-rendered area once after we tried
 228   // to composite area which is outside of the pre-rendered area on the
 229   // compositor.
 230   nsRefPtrHashtable<nsUint64HashKey, dom::Animation>
 231       mPartialPrerenderedAnimations;
 232 };
 233
 234 /**
 235  * FallbackRenderer is non-retained renderer that acts as a direct wrapper
 236  * around calling Paint on the provided DisplayList. This is used for cases
 237  * where initializing WebRender is too costly, and we don't need
 238  * retaining/invalidation (like small popup windows).
 239  *
 240  * It doesn't support any sort of EmptyTransaction, and only draws during
 241  * EndTransaction if a composite is requested (no END_NO_COMPOSITE flag
 242  * provided)
 243  */
 244 class FallbackRenderer : public WindowRenderer {
 245  public:
 246   FallbackRenderer* AsFallback() override { return this; }
 247
 248   void SetTarget(gfxContext* aContext, layers::BufferMode aDoubleBuffering);
 249
 250   bool BeginTransaction(const nsCString& aURL = nsCString()) override;
 251
 252   bool EndEmptyTransaction(EndTransactionFlags aFlags = END_DEFAULT) override {
 253     return false;
 254   }
 255
 256   layers::LayersBackend GetBackendType() override {
 257     return layers::LayersBackend::LAYERS_NONE;
 258   }
 259
 260   virtual void GetBackendName(nsAString& name) override {
 261     name.AssignLiteral("Fallback");
 262   }
 263
 264   bool IsCompositingCheap() override { return false; }
 265
 266   void EndTransactionWithColor(const nsIntRect& aRect,
 267                                const gfx::DeviceColor& aColor);
 268   void EndTransactionWithList(nsDisplayListBuilder* aBuilder,
 269                               nsDisplayList* aList,
 270                               int32_t aAppUnitsPerDevPixel,
 271                               EndTransactionFlags aFlags);
 272
 273   gfxContext* mTarget;
 274   layers::BufferMode mBufferMode;
 275 };
 276
 277 }  // namespace mozilla
 278
 279 #endif /* MOZILLA_PAINTING_WINDOWRENDERER_H */