dsp/delay/buffer.hpp

/* 
 * jayDSP, A cross-platform Digital Signal Processing library written in modern C++.
 * Copyright (C) 2025 Jens Ahrensfeld, All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all 
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 * File: buffer.hpp.hpp
 * Author Jens Ahrensfeld on 26.10.2025.
 */

#ifndef DSP_BUFFER_H
#define DSP_BUFFER_H

#include <cstddef>
#include <math.h>
#include <stdint.h>
#include <sys/types.h>
#include <dsp_types.hpp>

namespace dsp {

template <typename T>
class Buffer 
{
	uint m_index;
	uint m_mask;
	int m_offset;
	uint m_increment;
	size_t m_capacity;
	size_t m_allocated_capacity;

	std::vector<T> m_buffer;
	
	public:
	Buffer(size_t capacity)
	: m_index(0)
	, m_mask(0)
	, m_offset(0)
	, m_increment(1)
	, m_capacity(0)
	, m_buffer()
	, m_allocated_capacity(1)
	{
		resize(capacity);
		m_buffer.assign(m_allocated_capacity, T());
	}

	Buffer(const Buffer<T> &buffer, int offset=0, uint increment=1)
	: m_buffer(buffer.m_buffer)
	, m_index(buffer.m_index)
	, m_mask(buffer.m_mask)
	, m_offset(offset)
	, m_increment(increment)
	, m_capacity(buffer.m_capacity)
	, m_allocated_capacity(buffer.m_allocated_capacity)
	{
	}

	Buffer(const std::vector<T> &v)
	: m_index(0)
	, m_mask(0)
	, m_offset(0)
	, m_increment(1)
	, m_capacity(v.capacity())
	, m_buffer(v)
	, m_allocated_capacity(1)
	{
		resize(v.capacity());
	}

	size_t capacity()
	{
		return m_capacity/m_increment;
	}

	void reset()
	{
		m_index = 0;
	}

	void resize(uint capacity)
	{
		m_allocated_capacity = 1;
		while (m_allocated_capacity < capacity)
		{
			m_allocated_capacity *= 2;
		}
		 
		m_capacity = capacity;
		m_mask = unsigned(m_allocated_capacity - 1);
		m_index = 0;
	}

	T & operator[](int offset)
	{	
		return at(offset);
	}

	const T & operator[](int offset) const
	{
		return at(offset);
	}

	Buffer & operator ++() 
	{
		++m_index;
		m_index &= m_mask;
		return *this;
	}

	Buffer & operator +=(int i) 
	{
		m_index += (uint)i;
		m_index &= m_mask;
		return *this;
	}

	Buffer & operator --() 
	{
		--m_index;
		m_index &= m_mask;
		return *this;
	}

	Buffer & operator -=(int i) 
	{
		m_index -= (uint)i;
		m_index &= m_mask;
		return *this;
	}

	bool operator == (const Buffer &other) const
	{
		return m_buffer == other.m_buffer;
	}


protected:

	T& at(int offset)
	{
		int i = (m_offset + m_index + (uint)offset*m_increment) & m_mask;
		return m_buffer[i];
	}

	T const & at(int offset) const
	{
		int i = (m_offset + m_index + (uint)offset*m_increment) & m_mask;
		return m_buffer[i];
	}

};
}


#endif // DSP_BUFFER_H