gecko-dev/gfx/layers/mlgpu/MLGPUScreenshotGrabber.h

60 строки
2.2 KiB
C++

/* -*- 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 mozilla_layers_MLGPUScreenshotGrabber_h
#define mozilla_layers_MLGPUScreenshotGrabber_h
#include "mozilla/UniquePtr.h"
#include "mozilla/layers/MLGDevice.h"
namespace mozilla {
namespace layers {
class MLGPUScreenshotGrabberImpl;
/**
* Used by LayerManagerComposite to grab snapshots from the compositor and
* submit them to the Gecko profiler.
* Doesn't do any work if the profiler is not running or the "screenshots"
* feature is not enabled.
* Screenshots are scaled down to fit within a fixed size, and read back to
* main memory using async readback. Scaling is done in multiple scale-by-0.5x
* steps using CompositingRenderTargets and Compositor::BlitFromRenderTarget,
* and readback is done using AsyncReadbackBuffers.
*/
class MLGPUScreenshotGrabber final {
public:
MLGPUScreenshotGrabber() = default;
~MLGPUScreenshotGrabber();
// Scale the contents of aTexture into an appropriately sized MLGTexture
// and read its contents into an AsyncReadbackBuffer. The AsyncReadbackBuffer
// is not mapped into main memory until the second call to
// MaybeProcessQueue() after this call to MaybeGrabScreenshot().
void MaybeGrabScreenshot(MLGDevice* aDevice, MLGTexture* aTexture);
// Map the contents of any outstanding AsyncReadbackBuffers from previous
// composites into main memory and submit each screenshot to the profiler.
void MaybeProcessQueue();
// Insert a special profiler marker for a composite that didn't do any actual
// compositing, so that the profiler knows why no screenshot was taken for
// this frame.
void NotifyEmptyFrame();
// Destroy all Compositor-related resources that this class is holding on to.
void Destroy();
private:
// non-null while ProfilerScreenshots::IsEnabled() returns true
UniquePtr<MLGPUScreenshotGrabberImpl> mImpl;
};
} // namespace layers
} // namespace mozilla
#endif // mozilla_layers_MLGPUScreenshotGrabber_h