gfx/webrender_bindings/RendererScreenshotGrabber.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef mozilla_layers_RendererScreenshotGrabber_h
   6 #define mozilla_layers_RendererScreenshotGrabber_h
   7
   8 #include "mozilla/TimeStamp.h"
   9 #include "mozilla/UniquePtr.h"
  10 #include "mozilla/gfx/Point.h"
  11 #include "mozilla/layers/ProfilerScreenshots.h"
  12 #include "nsTArray.h"
  13
  14 namespace mozilla {
  15 namespace wr {
  16
  17 /**
  18  * Used by |RendererOGL| to grab screenshots from WebRender and submit them to
  19  * the Gecko profiler.
  20  *
  21  * If the profiler is not running or the screenshots feature is disabled, no
  22  * work will be done.
  23  */
  24 class RendererScreenshotGrabber final {
  25  public:
  26   RendererScreenshotGrabber();
  27
  28   /**
  29    * Grab a screenshot from WebRender if we are profiling and screenshots are
  30    * enabled.
  31    *
  32    * The captured screenshot will not be mapped until the second call to
  33    * |MaybeProcessQueue| after this call to |MaybeGrabScreenshot|.
  34    */
  35   void MaybeGrabScreenshot(Renderer* aRenderer,
  36                            const gfx::IntSize& aWindowSize);
  37
  38   /**
  39    * Process the screenshots pending in the queue if we are profiling and
  40    * screenshots are enabled.
  41    */
  42   void MaybeProcessQueue(Renderer* aRenderer);
  43
  44  private:
  45   /**
  46    * Drop all our allocated memory when we are no longer profiling.
  47    *
  48    * This will also instruct WebRender to drop all its Gecko profiler
  49    * associated memory.
  50    */
  51   void Destroy(Renderer* aRenderer);
  52
  53   /**
  54    * Actually grab a screenshot from WebRender.
  55    */
  56   void GrabScreenshot(Renderer* aRenderer, const gfx::IntSize& aWindowSize);
  57
  58   /**
  59    * Process the screenshots pending in the queue.
  60    */
  61   void ProcessQueue(Renderer* aRenderer);
  62
  63   struct QueueItem {
  64     mozilla::TimeStamp mTimeStamp;
  65     AsyncScreenshotHandle mHandle;
  66     gfx::IntSize mScreenshotSize;
  67     gfx::IntSize mWindowSize;
  68     uintptr_t mWindowIdentifier;
  69   };
  70
  71   /**
  72    * The maximum size for screenshots, as dictated by
  73    * |ProfilerScrenshots::ScreenshotSize|.
  74    */
  75   gfx::IntSize mMaxScreenshotSize;
  76
  77   /**
  78    * The queue of screenshots waiting to be processed and submitted.
  79    */
  80   nsTArray<QueueItem> mQueue;
  81
  82   /**
  83    * The queue item for the current frame. This will be inserted into the queue
  84    * after a call to |MaybeProcessQueue| so it will be not be processed until
  85    * the next frame.
  86    */
  87   Maybe<QueueItem> mCurrentFrameQueueItem;
  88
  89   /**
  90    * Our handle to the profiler screenshots object.
  91    */
  92   RefPtr<mozilla::layers::ProfilerScreenshots> mProfilerScreenshots;
  93 };
  94
  95 }  // namespace wr
  96 }  // namespace mozilla
  97
  98 #endif  // mozilla_layers_RendererScreenshotGrabber_h