// Fill a EPMTransferFrameHeaderInfo structure with the corresponding values from an EPM Transfer Frame packet.
// The bytes are in ESA/EPM order in the packet, and need to be reversed to be used by Intel/Windows.
void ExtractEPMTransferFrameHeaderInfo ( EPMTransferFrameHeaderInfo *header, const EPMTelemetryPacket *epm_packet ) {
unsigned char *ptr = ((unsigned char *) epm_packet);
header->epmLanSyncMarker = ExtractReversedLong( ptr );
header->spare1 = ExtractChar( ptr );
header->softwareUnitID = ExtractChar( ptr );
header->packetType = ExtractReversedShort( ptr );
header->spare2 = ExtractReversedShort( ptr );
header->numberOfWords = ExtractReversedShort( ptr );
}
void Scanner::AtIdentifier() //判断其余字符
{
while(isalnum(c) || c == '_') //字母数字或下划线
{
AddToBuffer(c); //加入
ExtractChar(); //读取下一个字符，一直到不满足条件
}
IdentifyAndMake();
}
// Extract a Grip housekeeping packet from an EPM packet.
// Careful! It is not complete. Not all values are filled.
void ExtractGripHealthAndStatusInfo( GripHealthAndStatusInfo *health_packet, const EPMTelemetryPacket *epm_packet ) {
const char *ptr;
// Point to the actual data in the packet.
ptr = epm_packet->sections.rawData;
// Skip to the values of interest to us.
// DEX-ICD-00383-QS Section 5.2.4.58 says that these items should be at an offset of 68 bytes.
// To this must be added an addtional 8 bytes to take into account information about the number
// of housekeeping values and the location of the HK Value Check Status List within the packet,
// as indicated in EPM-OHB-LI-0039 Table 6-5.
ptr += 76;
health_packet->horizontalTargetFeedback = ExtractReversedShort( ptr );
health_packet->verticalTargetFeedback = ExtractReversedShort( ptr );
health_packet->toneFeedback = ExtractChar( ptr );
health_packet->cradleDetectors = ExtractChar( ptr );
health_packet->user = ExtractReversedShort( ptr );
health_packet->protocol = ExtractReversedShort( ptr );
health_packet->task = ExtractReversedShort( ptr );
health_packet->step = ExtractReversedShort( ptr );
health_packet->scriptEngineStatusEnum = ExtractReversedShort( ptr );
health_packet->iochannelStatusEnum = ExtractReversedShort( ptr );
health_packet->motionTrackerStatusEnum = ExtractReversedShort( ptr );
health_packet->crewCameraStatusEnum = ExtractReversedShort( ptr );
health_packet->crewCameraRate = ExtractReversedShort( ptr );
health_packet->runningBits = ExtractReversedShort( ptr );
health_packet->cpuUsage = ExtractReversedShort( ptr );
health_packet->memoryUsage = ExtractReversedShort( ptr );
health_packet->freeDiskSpaceC = ExtractReversedLong( ptr );
health_packet->freeDiskSpaceD = ExtractReversedLong( ptr );
health_packet->freeDiskSpaceE = ExtractReversedLong( ptr );
health_packet->crc = ExtractReversedShort( ptr );
}
//注释
void Scanner::AtLineComment() //如果以/开头
{
if (c == '/'&&in.peek() == '/') //下一个字符是/
{
do
{
ExtractChar();//提取字符 ，即提取下一个字符 /
} while (c != '\n'&&!in.eof());// c=='\n'说明换行了
}
}
void Scanner::AtInterger()
{
while (isdigit(c)) //
{
AddToBuffer(c);
ExtractChar();
}
/*if (tolower(c) == 'e' || (c == '.' && in.peek() != '.'))
{
AddToBuffer(c);
ExtractChar();
EatRealFractPart();
}*/
MakeToken(INT_CONST);
}
void Scanner::AtOperation() //运算符的判断
{
bool match = false;
if (!in.eof() && !isalnum(c) && c != '_'&&!isspace(c))
{
AddToBuffer(c);
if (TryToIdentify()) //判断关系操作符 for example <=此时为真
{
match = true;
ExtractChar();
}
else
ReduceBuffer();
}
if (!match && !TryToIdentify())
throw "illegal expression";
}
// Extract a real-time science data packet from an EPM packet.
void ExtractGripRealtimeDataInfo( GripRealtimeDataInfo *realtime_packet, const EPMTelemetryPacket *epm_packet ) {
const char *ptr;
int slice;
int sensor;
int i;
short value;
long lvalue;
EPMTelemetryHeaderInfo telemetry_header;
long double timestamp;
// Point to the actual data in the packet.
ptr = epm_packet->sections.rawData;
// Get the acquisition ID and packet count for that acquisition.
realtime_packet->acquisitionID = (unsigned long) ExtractReversedLong( ptr );
realtime_packet->rtPacketCount = ExtractReversedLong( ptr );
for ( slice = 0; slice < RT_SLICES_PER_PACKET; slice++ ) {
// Get the manipulandum pose data.
realtime_packet->dataSlice[slice].poseTick = ExtractReversedLong( ptr );
for ( i = X; i <= Z; i++ ) realtime_packet->dataSlice[slice].position[i] = (double) ExtractReversedShort( ptr );
for ( i = X; i <= M; i++ ) realtime_packet->dataSlice[slice].quaternion[i] = ExtractReversedFloat( ptr );
for ( i = 0; i < 2; i++ ) realtime_packet->dataSlice[slice].markerVisibility[i] = ExtractReversedLong( ptr );
realtime_packet->dataSlice[slice].manipulandumVisibility = ExtractChar( ptr );
// Get the analog data.
realtime_packet->dataSlice[slice].analogTick = ExtractReversedLong( ptr );
for ( sensor = 0; sensor < 2; sensor++ ) {
for ( i = X; i <=Z; i++ ) {
value = ExtractReversedShort( ptr );
realtime_packet->dataSlice[slice].ft[sensor].force[i] = (double) value / 100.0;
}
for ( i = X; i <=Z; i++ ) {
value = ExtractReversedShort( ptr );
realtime_packet->dataSlice[slice].ft[sensor].torque[i] = (double) value / 1000.0;
}
}
for ( i = X; i <= Z; i++ ) {
lvalue = ExtractReversedLong( ptr );
realtime_packet->dataSlice[slice].acceleration[i] = ((double) lvalue) / 1000.0 / 9.8;
}
}
// Now timestamp the individual slices as best we can.
// First, get the time stamp from the EPM telemetry packet header.
ExtractEPMTelemetryHeaderInfo( &telemetry_header, epm_packet );
timestamp = EPMtoSeconds( (&telemetry_header) );
realtime_packet->packetTimestamp = timestamp;
// EPM-OHB-SP-0005_iss4 says about EPM Coarse time:
// "This double word gives the command execution time (UTC) in elapsed seconds from a defined epoch.
// The defined epoch is GPS time, i.e. midnight 5-6 January 1980."
// and:
// "The time shall be set once all data for a telemetry packet are available by the originator."
// Therefore, the last slice is presumed to have been taken just before the time of the packet UTC timestamp.
realtime_packet->dataSlice[RT_SLICES_PER_PACKET - 1].bestGuessPoseTimestamp = timestamp;
realtime_packet->dataSlice[RT_SLICES_PER_PACKET - 1].bestGuessAnalogTimestamp = timestamp;
// Earlier slices are offset from there.
for ( slice = RT_SLICES_PER_PACKET - 2; slice >= 0; slice-- ) {
#if 0
// Theoretically, we could get a better estimate of the precise time of the slice.
// But how the ticks are determined for each slice is not very clear. This code was
// intended to use the tick info, but I have commented it out because I cannot figure
// out from the documetation that has been provided if this will be better than the
// approximate solution that is in the #else below.
// If we have a tick for the slice, we use it to compute the offset from the slice
// that comes just after it. Otherwise, we assume RT_DEFAULT_SECONDS_PER_SLICE between slices.
if ( realtime_packet->dataSlice[slice].poseTick != realtime_packet->dataSlice[slice+1].poseTick ) {
realtime_packet->dataSlice[slice].bestGuessPoseTimestamp =
realtime_packet->dataSlice[slice+1].bestGuessPoseTimestamp -
RT_SECONDS_PER_TICK * ( realtime_packet->dataSlice[slice+1].poseTick - realtime_packet->dataSlice[slice].poseTick );
}
else {
realtime_packet->dataSlice[slice].bestGuessPoseTimestamp =
realtime_packet->dataSlice[slice+1].bestGuessPoseTimestamp - RT_DEFAULT_SECONDS_PER_SLICE;
}
if ( realtime_packet->dataSlice[slice].analogTick != realtime_packet->dataSlice[slice+1].analogTick ) {
realtime_packet->dataSlice[slice].bestGuessAnalogTimestamp =
realtime_packet->dataSlice[slice+1].bestGuessAnalogTimestamp -
RT_SECONDS_PER_TICK * ( realtime_packet->dataSlice[slice+1].analogTick - realtime_packet->dataSlice[slice].analogTick );
}
else {
realtime_packet->dataSlice[slice].bestGuessAnalogTimestamp =
realtime_packet->dataSlice[slice+1].bestGuessAnalogTimestamp - RT_DEFAULT_SECONDS_PER_SLICE;
}
#else
// Here we assume that slices are spaced equally in time and that the marker and analog
// data are aligned such that the last slice occurred at the same time as the packet timestamp.
// This is not completely true, but I am not able to do better by reverse engineering the packets
// that we have. We don't need millisecond precision anyway for these purposes.
realtime_packet->dataSlice[slice].bestGuessPoseTimestamp =
realtime_packet->dataSlice[slice+1].bestGuessPoseTimestamp - RT_DEFAULT_SECONDS_PER_SLICE;
realtime_packet->dataSlice[slice].bestGuessAnalogTimestamp =
realtime_packet->dataSlice[slice+1].bestGuessAnalogTimestamp - RT_DEFAULT_SECONDS_PER_SLICE;
#endif
}
}
// Extract EPM Telemetry Header information into a usable form, taking into account byte order.
void ExtractEPMTelemetryHeaderInfo ( EPMTelemetryHeaderInfo *header, const EPMTelemetryPacket *epm_packet ) {
// Fill a structure with the header values from an EPM TCP packet.
// The bytes are in ESA/EPM order in the TCP packet, and need to be reversed for Windows.
unsigned char *ptr = ((unsigned char *) epm_packet);
header->transferFrameInfo.epmLanSyncMarker = ExtractReversedLong( ptr );
header->transferFrameInfo.spare1 = ExtractChar( ptr );
header->transferFrameInfo.softwareUnitID = ExtractChar( ptr );
header->transferFrameInfo.packetType = ExtractReversedShort( ptr );
header->transferFrameInfo.spare2 = ExtractReversedShort( ptr );
header->transferFrameInfo.numberOfWords = ExtractReversedShort( ptr );
header->epmSyncMarker = ExtractReversedLong( ptr );
header->subsystemMode = ExtractChar( ptr );
header->subsystemID = ExtractChar( ptr );
header->destination= ExtractChar( ptr );
header->subsystemUnitID = ExtractChar( ptr );
header->TMIdentifier = ExtractReversedShort( ptr );
header->TMCounter = ExtractReversedShort( ptr );
header->model = ExtractChar( ptr );
header->taskID = ExtractChar( ptr );
header->subsystemUnitVersion = ExtractReversedShort( ptr );
header->coarseTime = ExtractReversedLong( ptr );
header->fineTime = ExtractReversedShort( ptr );
header->timerStatus = ExtractChar( ptr );
header->experimentMode = *ptr; ptr++;
header->checksumIndicator = ExtractReversedShort( ptr );
header->receiverSubsystemID = ExtractChar( ptr );
header->receiverSubsystemUnitID = ExtractChar( ptr );
header->numberOfWords = ExtractReversedShort( ptr );
}
Token Scanner::GetNextToken()
{
bool match = false;
do
{
ExtractChar(); //从文件中获取一个字符 //列如 begin,首先c=b;加入缓冲区,重新读取c=e
if (state != NONE_ST) match = true; //此时状态为标识符，则调用AtIdentifier
switch (state)
{
case IDENTIFIER_ST:
AtIdentifier();
break;
case INTEGER_ST:
AtInterger();
break;
case OPERATION_ST:
AtOperation();
break;
case EOF_ST:
MakeToken(END_OF_FILE);
break;
case NONE_ST: //不做运算
break;
default:
break;
}
if (state == NONE_ST)
{
AtLineComment(); //注释
if (c == '\n')
{
++row;
column= 0;
}
else
{
first_line= row; //第几列
first_pos = column; //第几行
if (in.eof())
{
state = EOF_ST;
}
else if (!isspace(c)) //空格
{
if (isalpha(c) || c == '_') //字母或下划线开头
{
state = IDENTIFIER_ST; //表明其实标识符
}
else if (isdigit(c))
{
state = INTEGER_ST;
}
else
{
state = OPERATION_ST;
}
AddToBuffer(c);
}
}
}
} while (!match);
return token;
}
