diff options
Diffstat (limited to 'Projects/Magstripe/Lib/CircularBitBuffer.c')
-rw-r--r-- | Projects/Magstripe/Lib/CircularBitBuffer.c | 226 |
1 files changed, 113 insertions, 113 deletions
diff --git a/Projects/Magstripe/Lib/CircularBitBuffer.c b/Projects/Magstripe/Lib/CircularBitBuffer.c index 128639413..8be527b4d 100644 --- a/Projects/Magstripe/Lib/CircularBitBuffer.c +++ b/Projects/Magstripe/Lib/CircularBitBuffer.c @@ -1,113 +1,113 @@ -/*
- LUFA Library
- Copyright (C) Dean Camera, 2010.
-
- dean [at] fourwalledcubicle [dot] com
- www.fourwalledcubicle.com
-*/
-
-/*
- Copyright 2010 Denver Gingerich (denver [at] ossguy [dot] com)
- Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)
-
- Permission to use, copy, modify, distribute, and sell this
- software and its documentation for any purpose is hereby granted
- without fee, provided that the above copyright notice appear in
- all copies and that both that the copyright notice and this
- permission notice and warranty disclaimer appear in supporting
- documentation, and that the name of the author not be used in
- advertising or publicity pertaining to distribution of the
- software without specific, written prior permission.
-
- The author disclaim all warranties with regard to this
- software, including all implied warranties of merchantability
- and fitness. In no event shall the author be liable for any
- special, indirect or consequential damages or any damages
- whatsoever resulting from loss of use, data or profits, whether
- in an action of contract, negligence or other tortious action,
- arising out of or in connection with the use or performance of
- this software.
-*/
-
-/** Circular bit buffer library. This will allow for individual bits
- * to be stored in packed form inside circular buffers, to reduce
- * overall RAM usage.
- */
-
-#include "CircularBitBuffer.h"
-
-/** Function to initialize or reset a bit buffer, ready for data to be stored into it. */
-void BitBuffer_Init(BitBuffer_t* const Buffer)
-{
- /* Reset the number of stored bits in the buffer */
- Buffer->Elements = 0;
-
- /* Reset the data in and out pointer structures in the buffer to the first buffer bit */
- Buffer->In.CurrentByte = Buffer->Data;
- Buffer->In.ByteMask = (1 << 0);
- Buffer->Out.CurrentByte = Buffer->Data;
- Buffer->Out.ByteMask = (1 << 0);
-}
-
-/** Function to store the given bit into the given bit buffer. */
-void BitBuffer_StoreNextBit(BitBuffer_t* const Buffer, const bool Bit)
-{
- /* If the bit to store is true, set the next bit in the buffer */
- if (Bit)
- *Buffer->In.CurrentByte |= Buffer->In.ByteMask;
-
- /* Increment the number of stored bits in the buffer counter */
- Buffer->Elements++;
-
- /* Check if the current buffer byte is full of stored bits */
- if (Buffer->In.ByteMask == (1 << 7))
- {
- /* Check if the end of the buffer has been reached, if so reset to start of buffer, otherwise advance to next bit */
- if (Buffer->In.CurrentByte != &Buffer->Data[sizeof(Buffer->Data) - 1])
- Buffer->In.CurrentByte++;
- else
- Buffer->In.CurrentByte = Buffer->Data;
-
- /* Reset the storage bit mask in the current buffer byte to the first bit */
- Buffer->In.ByteMask = (1 << 0);
- }
- else
- {
- /* Shift the current storage bit mask to the next bit in the current byte */
- Buffer->In.ByteMask <<= 1;
- }
-}
-
-/** Function to retrieve the next bit stored in the given bit buffer. */
-bool BitBuffer_GetNextBit(BitBuffer_t* const Buffer)
-{
- /* Retrieve the value of the next bit stored in the buffer */
- bool Bit = ((*Buffer->Out.CurrentByte & Buffer->Out.ByteMask) != 0);
-
- /* Clear the buffer bit */
- *Buffer->Out.CurrentByte &= ~Buffer->Out.ByteMask;
-
- /* Decrement the number of stored bits in the buffer counter */
- Buffer->Elements--;
-
- /* Check if the current buffer byte is empty of stored bits */
- if (Buffer->Out.ByteMask == (1 << 7))
- {
- /* Check if the end of the buffer has been reached, if so reset to start of buffer, otherwise advance to next bit */
- if (Buffer->Out.CurrentByte != &Buffer->Data[sizeof(Buffer->Data) - 1])
- Buffer->Out.CurrentByte++;
- else
- Buffer->Out.CurrentByte = Buffer->Data;
-
- /* Reset the retrieval bit mask in the current buffer byte to the first bit */
- Buffer->Out.ByteMask = (1 << 0);
- }
- else
- {
- /* Shift the current retrieval bit mask to the next bit in the current byte */
- Buffer->Out.ByteMask <<= 1;
- }
-
- /* Return the retrieved bit from the buffer */
- return Bit;
-}
+/* + LUFA Library + Copyright (C) Dean Camera, 2010. + + dean [at] fourwalledcubicle [dot] com + www.fourwalledcubicle.com +*/ + +/* + Copyright 2010 Denver Gingerich (denver [at] ossguy [dot] com) + Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com) + + Permission to use, copy, modify, distribute, and sell this + software and its documentation for any purpose is hereby granted + without fee, provided that the above copyright notice appear in + all copies and that both that the copyright notice and this + permission notice and warranty disclaimer appear in supporting + documentation, and that the name of the author not be used in + advertising or publicity pertaining to distribution of the + software without specific, written prior permission. + + The author disclaim all warranties with regard to this + software, including all implied warranties of merchantability + and fitness. In no event shall the author be liable for any + special, indirect or consequential damages or any damages + whatsoever resulting from loss of use, data or profits, whether + in an action of contract, negligence or other tortious action, + arising out of or in connection with the use or performance of + this software. +*/ + +/** Circular bit buffer library. This will allow for individual bits + * to be stored in packed form inside circular buffers, to reduce + * overall RAM usage. + */ + +#include "CircularBitBuffer.h" + +/** Function to initialize or reset a bit buffer, ready for data to be stored into it. */ +void BitBuffer_Init(BitBuffer_t* const Buffer) +{ + /* Reset the number of stored bits in the buffer */ + Buffer->Elements = 0; + + /* Reset the data in and out pointer structures in the buffer to the first buffer bit */ + Buffer->In.CurrentByte = Buffer->Data; + Buffer->In.ByteMask = (1 << 0); + Buffer->Out.CurrentByte = Buffer->Data; + Buffer->Out.ByteMask = (1 << 0); +} + +/** Function to store the given bit into the given bit buffer. */ +void BitBuffer_StoreNextBit(BitBuffer_t* const Buffer, const bool Bit) +{ + /* If the bit to store is true, set the next bit in the buffer */ + if (Bit) + *Buffer->In.CurrentByte |= Buffer->In.ByteMask; + + /* Increment the number of stored bits in the buffer counter */ + Buffer->Elements++; + + /* Check if the current buffer byte is full of stored bits */ + if (Buffer->In.ByteMask == (1 << 7)) + { + /* Check if the end of the buffer has been reached, if so reset to start of buffer, otherwise advance to next bit */ + if (Buffer->In.CurrentByte != &Buffer->Data[sizeof(Buffer->Data) - 1]) + Buffer->In.CurrentByte++; + else + Buffer->In.CurrentByte = Buffer->Data; + + /* Reset the storage bit mask in the current buffer byte to the first bit */ + Buffer->In.ByteMask = (1 << 0); + } + else + { + /* Shift the current storage bit mask to the next bit in the current byte */ + Buffer->In.ByteMask <<= 1; + } +} + +/** Function to retrieve the next bit stored in the given bit buffer. */ +bool BitBuffer_GetNextBit(BitBuffer_t* const Buffer) +{ + /* Retrieve the value of the next bit stored in the buffer */ + bool Bit = ((*Buffer->Out.CurrentByte & Buffer->Out.ByteMask) != 0); + + /* Clear the buffer bit */ + *Buffer->Out.CurrentByte &= ~Buffer->Out.ByteMask; + + /* Decrement the number of stored bits in the buffer counter */ + Buffer->Elements--; + + /* Check if the current buffer byte is empty of stored bits */ + if (Buffer->Out.ByteMask == (1 << 7)) + { + /* Check if the end of the buffer has been reached, if so reset to start of buffer, otherwise advance to next bit */ + if (Buffer->Out.CurrentByte != &Buffer->Data[sizeof(Buffer->Data) - 1]) + Buffer->Out.CurrentByte++; + else + Buffer->Out.CurrentByte = Buffer->Data; + + /* Reset the retrieval bit mask in the current buffer byte to the first bit */ + Buffer->Out.ByteMask = (1 << 0); + } + else + { + /* Shift the current retrieval bit mask to the next bit in the current byte */ + Buffer->Out.ByteMask <<= 1; + } + + /* Return the retrieved bit from the buffer */ + return Bit; +} |