begin_frame_source.h | Explore in Territory

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_VIZ_COMMON_FRAME_SINKS_BEGIN_FRAME_SOURCE_H_
#define COMPONENTS_VIZ_COMMON_FRAME_SINKS_BEGIN_FRAME_SOURCE_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <vector>

#include "base/check.h"
#include "base/containers/flat_set.h"
#include "base/memory/raw_ptr.h"
#include "base/time/time.h"
#include "build/build_config.h"
#include "components/viz/common/display/update_vsync_parameters_callback.h"
#include "components/viz/common/frame_sinks/begin_frame_args.h"
#include "components/viz/common/frame_sinks/delay_based_time_source.h"

namespace perfetto {
class EventContext;
namespace protos {
namespace pbzero {
class BeginFrameObserverStateV2;
class BeginFrameSourceStateV2;
}  // namespace pbzero
}  // namespace protos
}  // namespace perfetto

namespace viz {

// (Pure) Interface for observing BeginFrame messages from BeginFrameSource
// objects.
class VIZ_COMMON_EXPORT BeginFrameObserver { … };

// Simple base class which implements a BeginFrameObserver which checks the
// incoming values meet the BeginFrameObserver requirements and implements the
// required LastUsedBeginFrameArgs behaviour.
//
// Users of this class should;
//  - Implement the OnBeginFrameDerivedImpl function.
//  - Recommended (but not required) to call
//    BeginFrameObserverBase::OnValueInto in their overridden OnValueInto
//    function.
class VIZ_COMMON_EXPORT BeginFrameObserverBase : public BeginFrameObserver { … };

class VIZ_COMMON_EXPORT DynamicBeginFrameDeadlineOffsetSource { … };

// Interface for a class which produces BeginFrame calls to a
// BeginFrameObserver.
//
// BeginFrame calls *normally* occur just after a vsync interrupt when input
// processing has been finished and provide information about the time values
// of the vsync times. *However*, these values can be heavily modified or even
// plain made up (when no vsync signal is available or vsync throttling is
// turned off). See the BeginFrameObserver for information about the guarantees
// all BeginFrameSources *must* provide.
class VIZ_COMMON_EXPORT BeginFrameSource { … };

// A BeginFrameSource that does nothing.
class VIZ_COMMON_EXPORT StubBeginFrameSource : public BeginFrameSource { … };

// A frame source which ticks itself independently.
class VIZ_COMMON_EXPORT SyntheticBeginFrameSource : public BeginFrameSource { … };

// A frame source which calls BeginFrame (at the next possible time) as soon as
// an observer acknowledges the prior BeginFrame.
class VIZ_COMMON_EXPORT BackToBackBeginFrameSource
    : public SyntheticBeginFrameSource,
      public DelayBasedTimeSourceClient { … };

// A frame source which is locked to an external parameters provides from a
// vsync source and generates BeginFrameArgs for it.
class VIZ_COMMON_EXPORT DelayBasedBeginFrameSource
    : public SyntheticBeginFrameSource,
      public DelayBasedTimeSourceClient { … };

class VIZ_COMMON_EXPORT ExternalBeginFrameSourceClient { … };

// A BeginFrameSource that is only ticked manually.  Usually the endpoint
// of messages from some other thread/process that send OnBeginFrame and
// receive SetNeedsBeginFrame messages.  This turns such messages back into
// an observable BeginFrameSource.
class VIZ_COMMON_EXPORT ExternalBeginFrameSource : public BeginFrameSource { … };

}  // namespace viz

#endif  // COMPONENTS_VIZ_COMMON_FRAME_SINKS_BEGIN_FRAME_SOURCE_H_
chromium/components/viz/common/frame_sinks/begin_frame_source.h
