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/*
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef AudioParam_h
#define AudioParam_h
#include "bindings/core/v8/ScriptWrappable.h"
#include "core/dom/DOMTypedArray.h"
#include "modules/webaudio/AbstractAudioContext.h"
#include "modules/webaudio/AudioParamTimeline.h"
#include "modules/webaudio/AudioSummingJunction.h"
#include "wtf/PassRefPtr.h"
#include "wtf/text/WTFString.h"
#include <sys/types.h>
namespace blink {
class AudioNodeOutput;
// AudioParamHandler is an actual implementation of web-exposed AudioParam
// interface. Each of AudioParam object creates and owns an AudioParamHandler,
// and it is responsible for all of AudioParam tasks. An AudioParamHandler
// object is owned by the originator AudioParam object, and some audio
// processing classes have additional references. An AudioParamHandler can
// outlive the owner AudioParam, and it never dies before the owner AudioParam
// dies.
class AudioParamHandler final : public ThreadSafeRefCounted<AudioParamHandler>, public AudioSummingJunction {
public:
static const double DefaultSmoothingConstant;
static const double SnapThreshold;
static PassRefPtr<AudioParamHandler> create(AbstractAudioContext& context, double defaultValue)
{
return adoptRef(new AudioParamHandler(context, defaultValue));
}
// This should be used only in audio rendering thread.
AbstractAudioContext* context() const;
// AudioSummingJunction
void didUpdate() override { }
AudioParamTimeline& timeline() { return m_timeline; }
// Intrinsic value.
float value();
void setValue(float);
// Final value for k-rate parameters, otherwise use calculateSampleAccurateValues() for a-rate.
// Must be called in the audio thread.
float finalValue();
float defaultValue() const { return static_cast<float>(m_defaultValue); }
// Value smoothing:
// When a new value is set with setValue(), in our internal use of the parameter we don't immediately jump to it.
// Instead we smoothly approach this value to avoid glitching.
float smoothedValue();
// Smoothly exponentially approaches to (de-zippers) the desired value.
// Returns true if smoothed value has already snapped exactly to value.
bool smooth();
void resetSmoothedValue() { m_smoothedValue = intrinsicValue(); }
bool hasSampleAccurateValues() { return m_timeline.hasValues() || numberOfRenderingConnections(); }
// Calculates numberOfValues parameter values starting at the context's current time.
// Must be called in the context's render thread.
void calculateSampleAccurateValues(float* values, unsigned numberOfValues);
// Connect an audio-rate signal to control this parameter.
void connect(AudioNodeOutput&);
void disconnect(AudioNodeOutput&);
private:
AudioParamHandler(AbstractAudioContext& context, double defaultValue)
: AudioSummingJunction(context.deferredTaskHandler())
, m_intrinsicValue(defaultValue)
, m_defaultValue(defaultValue)
, m_smoothedValue(defaultValue)
, m_context(&context) { }
// sampleAccurate corresponds to a-rate (audio rate) vs. k-rate in the Web Audio specification.
void calculateFinalValues(float* values, unsigned numberOfValues, bool sampleAccurate);
void calculateTimelineValues(float* values, unsigned numberOfValues);
// Intrinsic value
float m_intrinsicValue;
float intrinsicValue() const { return noBarrierLoad(&m_intrinsicValue); }
void setIntrinsicValue(float newValue) { noBarrierStore(&m_intrinsicValue, newValue); }
float m_defaultValue;
// Smoothing (de-zippering)
float m_smoothedValue;
AudioParamTimeline m_timeline;
// We can't make this Persistent because of a reference cycle. It's safe to
// access this field only when we're rendering audio.
UntracedMember<AbstractAudioContext> m_context;
};
// AudioParam class represents web-exposed AudioParam interface.
class AudioParam final : public GarbageCollectedFinalized<AudioParam>, public ScriptWrappable {
DEFINE_WRAPPERTYPEINFO();
public:
static AudioParam* create(AbstractAudioContext&, double defaultValue);
DECLARE_TRACE();
// |handler| always returns a valid object.
AudioParamHandler& handler() const { return *m_handler; }
// |context| always returns a valid object.
AbstractAudioContext* context() const { return m_context; }
float value() const;
void setValue(float);
float defaultValue() const;
AudioParam* setValueAtTime(float value, double time, ExceptionState&);
AudioParam* linearRampToValueAtTime(float value, double time, ExceptionState&);
AudioParam* exponentialRampToValueAtTime(float value, double time, ExceptionState&);
AudioParam* setTargetAtTime(float target, double time, double timeConstant, ExceptionState&);
AudioParam* setValueCurveAtTime(DOMFloat32Array* curve, double time, double duration, ExceptionState&);
AudioParam* cancelScheduledValues(double startTime, ExceptionState&);
private:
AudioParam(AbstractAudioContext&, double defaultValue);
RefPtr<AudioParamHandler> m_handler;
Member<AbstractAudioContext> m_context;
};
} // namespace blink
#endif // AudioParam_h
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