mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-19 23:32:28 +00:00
76 lines
2.2 KiB
C++
76 lines
2.2 KiB
C++
//
|
|
// SampleSource.hpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 17/12/2017.
|
|
// Copyright 2017 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#ifndef SampleSource_hpp
|
|
#define SampleSource_hpp
|
|
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
|
|
namespace Outputs::Speaker {
|
|
|
|
/*!
|
|
A sample source is something that can provide a stream of audio.
|
|
This optional base class provides the interface expected to be exposed
|
|
by the template parameter to LowpassSpeaker.
|
|
*/
|
|
class SampleSource {
|
|
public:
|
|
/*!
|
|
Should write the next @c number_of_samples to @c target.
|
|
*/
|
|
void get_samples([[maybe_unused]] std::size_t number_of_samples, [[maybe_unused]] std::int16_t *target) {}
|
|
|
|
/*!
|
|
Should skip the next @c number_of_samples. Subclasses of this SampleSource
|
|
need not implement this if it would no more efficient to do so than it is
|
|
merely to call get_samples and throw the result away, as per the default
|
|
implementation below.
|
|
*/
|
|
void skip_samples(const std::size_t number_of_samples) {
|
|
std::int16_t scratch_pad[number_of_samples];
|
|
get_samples(number_of_samples, scratch_pad);
|
|
}
|
|
|
|
/*!
|
|
@returns @c true if it is trivially true that a call to get_samples would just
|
|
fill the target with zeroes; @c false if a call might return all zeroes or
|
|
might not.
|
|
*/
|
|
bool is_zero_level() const {
|
|
return false;
|
|
}
|
|
|
|
/*!
|
|
Sets the proper output range for this sample source; it should write values
|
|
between 0 and volume.
|
|
*/
|
|
void set_sample_volume_range([[maybe_unused]] std::int16_t volume) {}
|
|
|
|
/*!
|
|
Indicates whether this component will write stereo samples.
|
|
*/
|
|
static constexpr bool get_is_stereo() { return false; }
|
|
|
|
/*!
|
|
Permits a sample source to declare that, averaged over time, it will use only
|
|
a certain proportion of the allocated volume range. This commonly happens
|
|
in sample sources that use a time-multiplexed sound output — for example, if
|
|
one were to output only every other sample then it would return 0.5.
|
|
|
|
This is permitted to vary over time but there is no contract as to when it will be
|
|
used by a speaker. If it varies, it should do so very infrequently and only to
|
|
represent changes in hardware configuration.
|
|
*/
|
|
double get_average_output_peak() const { return 1.0; }
|
|
};
|
|
|
|
}
|
|
|
|
#endif /* SampleSource_hpp */
|