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/*
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Polhemus Tracker Terminal version 1.0.0 -- Terminal Interface to Polhemus Trackers: Fastrak, Patriot, and Liberty
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Copyright © 2009 Polhemus, Inc.
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This file is part of Tracker Terminal.
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Tracker Terminal is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Tracker Terminal is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Tracker Terminal. If not, see <http://www.gnu.org/licenses/>.
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*************************************************************************
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Tracker Terminal version 1.0.0 uses the libusb library version 1.0
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libusb Copyright © 2007-2008 Daniel Drake <dsd@gentoo.org>
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libusb Copyright © 2001 Johannes Erdfelt <johannes@erdfelt.com>
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Licensed under the GNU Lesser General Public License version 2.1 or later.
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*/
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#include <pthread.h>
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#include "PingPong.h"
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#include <string.h>
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PingPong::PingPong(){
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for (int i=0;i<NUMBUFS;i++){
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m_buf[i]=NULL;
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m_len[i]=0;
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}
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m_readInd=m_writeInd=m_size=0;
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// init the mutex to synchronize reads and writes between different threads
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pthread_mutex_init(&m_mutex,NULL);
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}
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PingPong::~PingPong(){
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// need to clean up
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for (int i=0;i<NUMBUFS;i++){
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if (m_buf[i])
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delete[] m_buf[i];
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}
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}
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// create buffers
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int PingPong::InitPingPong(int bufSize){
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int memerr=0;
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for (int i=0;i<NUMBUFS;i++){
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m_buf[i]=new BYTE[bufSize];
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if (!m_buf[i]){
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memerr=1;
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break;
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}
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}
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if (memerr){
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for (int i=0;i<NUMBUFS;i++){
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if (m_buf[i]){
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delete[] m_buf[i];
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m_buf[i]=NULL;
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}
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}
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return -1;
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}
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m_size=bufSize;
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return 0;
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}
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int PingPong::GetBufferSize(){
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return m_size;
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}
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// return number of bytes available in read buffer
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int PingPong::IsDataAvail(){
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return m_len[m_readInd];
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}
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//#include <stdio.h>
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// read from the read buffer
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int PingPong::ReadPP(BYTE* buf){
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pthread_mutex_lock(&m_mutex);
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int len=m_len[m_readInd];
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if (len==0){
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pthread_mutex_unlock(&m_mutex);
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return 0;
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}
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memcpy(buf,m_buf[m_readInd],len);
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m_len[m_readInd]=0;
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// printf("Read %d bytes from buffer %d\n",len,m_readInd);
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IncrInd(m_readInd);
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pthread_mutex_unlock(&m_mutex);
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return len;
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}
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// write to the write buffer
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int PingPong::WritePP(BYTE* buf,int len){
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int rv=0;
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pthread_mutex_lock(&m_mutex);
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if(len>m_size)
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len=m_size;
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if (m_len[m_writeInd]==0){ // don't overwrite unread data
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memcpy(m_buf[m_writeInd],buf,len);
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m_len[m_writeInd]=len;
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// printf("Wrote %d bytes to buffer %d\n",len,m_writeInd);
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IncrInd(m_writeInd);
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rv=len;
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}
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pthread_mutex_unlock(&m_mutex);
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return rv;
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}
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// increment the index to the next in progression
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void PingPong::IncrInd(int& index){
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index++;
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if (index==NUMBUFS)
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index=0;
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}
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void PingPong::ClearBuffers(){
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pthread_mutex_lock(&m_mutex);
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for (int i=0;i<NUMBUFS;i++)
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m_len[i]=0;
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m_readInd=m_writeInd=0;
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pthread_mutex_unlock(&m_mutex);
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}
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