gecko-dev/gfx/layers/composite/ImageComposite.h

108 строки
3.1 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_GFX_IMAGECOMPOSITE_H
#define MOZILLA_GFX_IMAGECOMPOSITE_H
#include "CompositableHost.h" // for CompositableTextureHostRef
#include "mozilla/gfx/2D.h"
#include "mozilla/TimeStamp.h" // for TimeStamp
#include "nsTArray.h"
namespace mozilla {
namespace layers {
/**
* Implements Image selection logic.
*/
class ImageComposite {
public:
static const float BIAS_TIME_MS;
explicit ImageComposite();
virtual ~ImageComposite();
int32_t GetFrameID() {
const TimedImage* img = ChooseImage();
return img ? img->mFrameID : -1;
}
int32_t GetProducerID() {
const TimedImage* img = ChooseImage();
return img ? img->mProducerID : -1;
}
int32_t GetLastFrameID() const { return mLastFrameID; }
int32_t GetLastProducerID() const { return mLastProducerID; }
uint32_t GetDroppedFramesAndReset() {
uint32_t dropped = mDroppedFrames;
mDroppedFrames = 0;
return dropped;
}
enum Bias {
// Don't apply bias to frame times
BIAS_NONE,
// Apply a negative bias to frame times to keep them before the vsync time
BIAS_NEGATIVE,
// Apply a positive bias to frame times to keep them after the vsync time
BIAS_POSITIVE,
};
protected:
void UpdateBias(size_t aImageIndex);
virtual TimeStamp GetCompositionTime() const = 0;
struct TimedImage {
CompositableTextureHostRef mTextureHost;
TimeStamp mTimeStamp;
gfx::IntRect mPictureRect;
int32_t mFrameID;
int32_t mProducerID;
};
/**
* ChooseImage is guaranteed to return the same TimedImage every time it's
* called during the same composition, up to the end of Composite() ---
* it depends only on mImages, mCompositor->GetCompositionTime(), and mBias.
* mBias is updated at the end of Composite().
*/
const TimedImage* ChooseImage();
int ChooseImageIndex();
const TimedImage* GetImage(size_t aIndex) const;
size_t ImagesCount() const { return mImages.Length(); }
const nsTArray<TimedImage>& Images() const { return mImages; }
void RemoveImagesWithTextureHost(TextureHost* aTexture);
void ClearImages();
void SetImages(nsTArray<TimedImage>&& aNewImages);
int32_t mLastFrameID;
int32_t mLastProducerID;
private:
nsTArray<TimedImage> mImages;
TimeStamp GetBiasedTime(const TimeStamp& aInput) const;
// Scan new images and look for common ones in the existing mImages array.
// Will determine if an image has been dropped through gaps between images and
// adjust mDroppedFrames accordingly.
// Return the index of what the last returned image would have been.
uint32_t ScanForLastFrameIndex(const nsTArray<TimedImage>& aNewImages);
/**
* Bias to apply to the next frame.
*/
Bias mBias;
uint32_t mDroppedFrames;
uint32_t mLastChosenImageIndex;
};
} // namespace layers
} // namespace mozilla
#endif // MOZILLA_GFX_IMAGECOMPOSITE_H