Signal PDU data length is in bytes but should be in bits (DIS 7)

[adamwrobinson5]

Fixes issue #56

[leif81]

Thanks @adamwrobinson5 , I'll take a closer look shortly.

Do you happen to have a sample dis7 signal and transmitter pdu to include in a unit test?

[adamwrobinson5]

Thanks for getting back to me so quickly! Unfortunately, I do not have a sample pdu that I can provide.

[leif81]

@adamwrobinson5 Could you explain the importance of checking length for 0 and the line that follows?

We didn't do that on the DIS 6 equivalent Signal PDU and wondering if it's required.

[adamwrobinson5]

Not required, it was just a way to abstract a DIS-ism. IAW the standard, the data length should be the length of the data field in bits. Since data is a byte array, the data length field would be the length of the byte array multiplied by 8.

I can take it out though if you'd prefer it not be in there.

[leif81]

Ok yes let's take it out and just rely on returning the dataLength.

[leif81]

@adamwrobinson5 I think we may also need to modify the unmarshall and marshall methods like we did when making the equivalent fix for the DIS 6 Signal PDU (seen below) .

This change was required to the unmarshall method so that we allocated the right length to the data array.

open-dis-java/src/main/java/edu/nps/moves/dis/SignalPdu.java

Lines 270 to 271 in 4ba5e51

	final int dataLengthBytes = dataLength / Byte.SIZE;
	data = new byte[dataLengthBytes];

And in the marshall method we needed to pad the data on 32 bit boundary.

open-dis-java/src/main/java/edu/nps/moves/dis/SignalPdu.java

Lines 232 to 249 in 4ba5e51

	nrOfBytes = dataLength / Byte.SIZE;
	buff.put(data);
	int paddingBytes = nrOfBytes % 4;//Padding to hit 32 bit boundry
	switch (paddingBytes) {
	case 0:
	break;//No padding needed
	case 1:
	buff.put((byte) 0);
	buff.putShort((short) 0);
	break;//adding 3 byte padding
	case 2:
	buff.putShort((short) 0);
	break;//adding 2 byte padding
	case 3:
	buff.put((byte) 0);
	break;//adding 1 byte padding
	}

[adamwrobinson5]

@leif81 Added those changes

[leif81]

Thank-you @adamwrobinson5 !