Initial Arduino IDE based on Processing.

build/shared/lib/avrlib/bitbuf.c

@@ -0,0 +1,131 @@
+/*! \file bitbuf.c \brief Multipurpose bit buffer structure and methods. */
+//*****************************************************************************
+//
+// File Name	: 'bitbuf.c'
+// Title		: Multipurpose bit buffer structure and methods
+// Author		: Pascal Stang - Copyright (C) 2001-2002
+// Created		: 7/10/2002
+// Revised		: 7/10/2002
+// Version		: 0.5
+// Target MCU	: any
+// Editor Tabs	: 4
+//
+// This code is distributed under the GNU Public License
+//		which can be found at http://www.gnu.org/licenses/gpl.txt
+//
+//*****************************************************************************
+
+#include "bitbuf.h"
+
+// global variables
+
+//! Initialize the bit buffer
+//	sets the start location and size of the buffer in memory
+void bitbufInit(BitBuf* bitBuffer, unsigned char *start, unsigned short bytesize)
+{
+	// set start pointer of the buffer
+	bitBuffer->dataptr = start;
+	bitBuffer->size = bytesize;
+	// initialize indexing and length
+	bitBuffer->dataindex = 0;
+	bitbufFlush(bitBuffer);
+}
+
+// access routines
+
+//! Get a bit from the current position in the buffer
+//	returns the bit at the current position in the buffer
+//	and increments the bit position
+unsigned char bitbufGet(BitBuf* bitBuffer)
+{
+	unsigned char byte;
+	unsigned char bit;
+	
+	// get current working byte
+	byte = bitBuffer->dataptr[bitBuffer->bytePos];
+	// read data bit
+	bit = (byte & (1<<bitBuffer->bitPos))?(1):(0);
+
+	// increment bit counter
+	if(bitBuffer->bitPos < 7)
+	{
+		bitBuffer->bitPos++;
+	}
+	else
+	{
+		// increment byte counter
+		bitBuffer->bitPos = 0;
+		bitBuffer->bytePos++;
+	}
+
+	// return bit value
+	return bit;
+}
+
+//! Get a bit from a given index into the buffer
+//	returns the bit at position [bitIndex] in the buffer
+unsigned char bitbufGetAtIndex(BitBuf* bitBuffer, unsigned short bitIndex)
+{
+	// return bit at index in buffer
+	return (bitBuffer->dataptr[bitIndex>>3] & (1<<(bitIndex & 0x07)))?(1):(0);
+}
+
+//! Store a bit at the current position in the buffer
+//	stores the bit at the current position in the buffer
+//	and increments the bit position
+void bitbufStore(BitBuf* bitBuffer, unsigned char bit)
+{
+	unsigned char byte;
+	// get current working byte
+	byte = bitBuffer->dataptr[bitBuffer->bytePos];
+	// apply data bit
+	if(bit)
+		byte |=  (1<<bitBuffer->bitPos);
+	else
+		byte &= ~(1<<bitBuffer->bitPos);
+	// store data
+	bitBuffer->dataptr[bitBuffer->bytePos] = byte;
+	bitBuffer->datalength++;
+
+	// increment bit counter
+	if(bitBuffer->bitPos < 7)
+	{
+		bitBuffer->bitPos++;
+	}
+	else
+	{
+		// increment byte counter
+		bitBuffer->bitPos = 0;
+		bitBuffer->bytePos++;
+	}
+}
+
+void bitbufReset(BitBuf* bitBuffer)
+{
+	// reset counters
+	bitBuffer->bytePos = 0;
+	bitBuffer->bitPos = 0;
+}
+
+void bitbufFlush(BitBuf* bitBuffer)
+{
+	// flush contents of the buffer
+	bitBuffer->datalength = 0;
+	// reset indexing
+	bitbufReset(bitBuffer);
+}
+
+unsigned short bitbufGetDataLength(BitBuf* bitBuffer)
+{
+	return bitBuffer->datalength;
+}
+
+/*
+unsigned char bitbufIsNotFull(cBuffer* buffer)
+{
+	// check to see if the buffer has room
+	// return true if there is room
+	return (buffer->datalength < buffer->size);
+}
+*/
+