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// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_OSCILLATOR_HANDLER_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_OSCILLATOR_HANDLER_H_
#include "base/memory/scoped_refptr.h"
#include "base/memory/weak_ptr.h"
#include "third_party/blink/renderer/bindings/modules/v8/v8_oscillator_options.h"
#include "third_party/blink/renderer/bindings/modules/v8/v8_oscillator_type.h"
#include "third_party/blink/renderer/modules/webaudio/audio_param.h"
#include "third_party/blink/renderer/modules/webaudio/audio_scheduled_source_node.h"
#include "third_party/blink/renderer/platform/audio/audio_bus.h"
#include "third_party/blink/renderer/platform/heap/cross_thread_persistent.h"
#include "third_party/blink/renderer/platform/wtf/threading.h"
namespace blink {
class BaseAudioContext;
class ExceptionState;
class OscillatorOptions;
class PeriodicWave;
class PeriodicWaveImpl;
class OscillatorHandler final : public AudioScheduledSourceHandler {
public:
// The waveform type.
// These must be defined as in the .idl file.
enum : uint8_t {
SINE = 0,
SQUARE = 1,
SAWTOOTH = 2,
TRIANGLE = 3,
CUSTOM = 4
};
// Breakpoints where we decide to do linear interpolation, 3-point
// interpolation or 5-point interpolation. See DoInterpolation().
static constexpr float kInterpolate2Point = 0.3f;
static constexpr float kInterpolate3Point = 0.16f;
static scoped_refptr<OscillatorHandler> Create(AudioNode&,
float sample_rate,
const String& oscillator_type,
PeriodicWaveImpl* wave_table,
AudioParamHandler& frequency,
AudioParamHandler& detune);
~OscillatorHandler() override;
// AudioHandler
void Process(uint32_t frames_to_process) override;
V8OscillatorType::Enum GetType() const;
void SetType(V8OscillatorType::Enum, ExceptionState&);
void SetPeriodicWave(PeriodicWaveImpl*);
void HandleStoppableSourceNode() override;
private:
OscillatorHandler(AudioNode&,
float sample_rate,
const String& oscillator_type,
PeriodicWaveImpl* wave_table,
AudioParamHandler& frequency,
AudioParamHandler& detune);
bool SetType(uint8_t); // Returns true on success.
// Returns true if there are sample-accurate timeline parameter changes.
bool CalculateSampleAccuratePhaseIncrements(uint32_t frames_to_process);
bool PropagatesSilence() const override;
base::WeakPtr<AudioScheduledSourceHandler> AsWeakPtr() override;
// Compute the output for k-rate AudioParams
double ProcessKRate(int n, float* dest_p, double virtual_read_index) const;
// Scalar version for the main loop in ProcessKRate(). Returns the updated
// virtual_read_index.
double ProcessKRateScalar(int start_index,
int n,
float* dest_p,
double virtual_read_index,
float frequency,
float rate_scale) const;
// Vectorized version (if available) for the main loop in ProcessKRate().
// Returns the number of elements processed and the updated
// virtual_read_index.
std::tuple<int, double> ProcessKRateVector(int n,
float* dest_p,
double virtual_read_index,
float frequency,
float rate_scale) const;
// Compute the output for a-rate AudioParams
double ProcessARate(int n,
float* dest_p,
double virtual_read_index,
float* phase_increments) const;
// Scalar version of ProcessARate(). Also handles any values not handled by
// the vector version.
//
// k
// start index for where to write the result (and read phase_increments)
// n
// total number of frames to process
// destination
// Array where the samples values are written
// virtual_read_index
// index into the wave data tables containing the waveform
// phase_increments
// phase change to use for each frame of output
//
// Returns the updated virtual_read_index.
double ProcessARateScalar(int k,
int n,
float* destination,
double virtual_read_index,
const float* phase_increments) const;
// Vector version of ProcessARate(). Returns the number of frames processed
// and the update virtual_read_index.
std::tuple<int, double> ProcessARateVector(
int n,
float* destination,
double virtual_read_index,
const float* phase_increments) const;
// Handles the linear interpolation in ProcessARateVector().
//
// destination
// Where the interpolated values are written.
// virtual_read_index
// index into the wave table data
// phase_increments
// phase increments array
// periodic_wave_size
// Length of the periodic wave stored in the wave tables
// lower_wave_data
// Array of the 4 lower wave table arrays
// higher_wave_data
// Array of the 4 higher wave table arrays
// table_interpolation_factor
// Array of linear interpolation factors to use between the lower and
// higher wave tables.
//
// Returns the updated virtual_read_index
double ProcessARateVectorKernel(
float* destination,
double virtual_read_index,
const float* phase_increments,
unsigned periodic_wave_size,
const float* const lower_wave_data[4],
const float* const higher_wave_data[4],
const float table_interpolation_factor[4]) const;
// One of the waveform types defined in the enum.
uint8_t type_;
// Frequency value in Hertz.
scoped_refptr<AudioParamHandler> frequency_;
// Detune value (deviating from the frequency) in Cents.
scoped_refptr<AudioParamHandler> detune_;
bool first_render_ = true;
// m_virtualReadIndex is a sample-frame index into our buffer representing the
// current playback position. Since it's floating-point, it has sub-sample
// accuracy.
double virtual_read_index_ = 0;
// Stores sample-accurate values calculated according to frequency and detune.
AudioFloatArray phase_increments_;
AudioFloatArray detune_values_;
// PeriodicWaveImpl cannot cause cycles with OscillatorNode as it is not
// scriptable.
CrossThreadPersistent<PeriodicWaveImpl> periodic_wave_;
base::WeakPtrFactory<AudioScheduledSourceHandler> weak_ptr_factory_{this};
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_MODULES_WEBAUDIO_OSCILLATOR_HANDLER_H_
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