cs-midi/AH/Containers/BitArray.hpp

143 lines
3.8 KiB
C++

/* ✔ */
#pragma once
#include <AH/Error/Error.hpp>
#include <AH/Settings/NamespaceSettings.hpp>
#include <stdint.h>
BEGIN_AH_NAMESPACE
/// @addtogroup AH_Containers
/// @{
/**
* @brief A class for arrays of bits.
*
* @tparam N
* The number of bits.
*/
template <uint16_t N>
class BitArray {
public:
/**
* @brief Get the value of the given bit.
*
* @param bitIndex
* The (zero-based) index of the bit to read.
*/
bool get(uint16_t bitIndex) const {
return buffer[getBufferIndex(bitIndex)] & getBufferMask(bitIndex);
}
/**
* @brief Set the value of the given bit to 1.
*
* @param bitIndex
* The (zero-based) index of the bit to set.
*/
void set(uint16_t bitIndex) {
buffer[getBufferIndex(bitIndex)] |= getBufferMask(bitIndex);
}
/**
* @brief Clear the value of the given bit to 0.
*
* @param bitIndex
* The (zero-based) index of the bit to clear.
*/
void clear(uint16_t bitIndex) {
buffer[getBufferIndex(bitIndex)] &= ~getBufferMask(bitIndex);
}
/**
* @brief Set the value of the given bit to the given state.
*
* @param bitIndex
* The (zero-based) index of the bit to set.
* @param state
* The value to set the bit to.
*/
void set(uint16_t bitIndex, bool state) {
state ? set(bitIndex) : clear(bitIndex);
}
/**
* @brief Check the given byte index, and return it if it is within the
* bounds of the array, otherwise, throw an error, and return
* the last valid index.
*
* @param byteIndex
* The index to check.
*/
uint16_t safeIndex(uint16_t byteIndex) const {
if (byteIndex >= getBufferLength()) {
ERROR(F("Error: index out of bounds (")
<< byteIndex << F(", length is ") << getBufferLength()
<< ')',
0xFFFF);
return getBufferLength() - 1; // LCOV_EXCL_LINE
}
return byteIndex;
}
/**
* @brief Get the byte at the given index.
*
* This function can be used to quickly access all of the bits, to send
* them out to a shift register, for example.
*
* @note No bounds checking is performed.
*
* @param byteIndex
* The index of the byte within the array.
*/
const uint8_t &getByte(uint16_t byteIndex) const {
return buffer[byteIndex];
// return buffer[safeIndex(byteIndex)];
}
/// @copydoc AH::BitArray::getByte(uint16_t) const
uint8_t &getByte(uint16_t byteIndex) {
return buffer[byteIndex];
// return buffer[safeIndex(byteIndex)];
}
/**
* @brief Set the byte at the given index.
*
* This function can be used to quickly write all of the bits, when reading
* them in from an I/O expander, for example.
*
* @note No bounds checking is performed.
*
* @param byteIndex
* The index of the byte within the array.
* @param value
* The byte to write.
*/
void setByte(uint16_t byteIndex, uint8_t value) {
buffer[byteIndex] = value;
}
/**
* @brief Get the buffer length in bytes.
*/
uint16_t getBufferLength() const { return bufferLength; }
private:
uint16_t getBufferIndex(uint16_t bitIndex) const {
return safeIndex(bitIndex / 8);
}
uint8_t getBufferBit(uint16_t bitIndex) const { return bitIndex % 8; }
uint8_t getBufferMask(uint16_t bitIndex) const {
return 1 << getBufferBit(bitIndex);
}
constexpr static uint16_t bufferLength = (uint16_t)((N + 7) / 8);
uint8_t buffer[bufferLength] = {};
};
/// @}
END_AH_NAMESPACE