[SOLVED] ByteArray to convert ... Impossible ?

Hello,

I have a big problem :
During a project, I get a byte array contains the following values: '' 0 48 0 3 63 83 91 53 ... ''
It would appear that "0 48 0 3" means 3145731 (int), while "63 83 91 53" means 0.82561 (float).

The only information I have for this byte array is: *All of the values are in big-endian order and it's a format in 4-byte words.*

However, I do not arrive at these results, I tried everything and all converter ...
Someone would have any idea please ?

 

Code (CSharp):

1. using System;
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. public class TestScript : MonoBehaviour
7. {
8.     public static Byte[] test = new Byte[] { 0, 48, 0, 3, 63, 83, 91, 53 };
9.  
10.     private void Awake()
11.     {
12.         byte[] tempByteArray = new byte[4];
13.  
14.         for(int i=0; i < test.Length; i+=4)
15.         {
16.             tempByteArray[0] = test[i];
17.             tempByteArray[1] = test[i+1];
18.             tempByteArray[2] = test[i+2];
19.             tempByteArray[3] = test[i+3];
20.  
21.             if(BitConverter.IsLittleEndian)
22.                 Array.Reverse(tempByteArray);
23.             int tempInt = BitConverter.ToInt32(tempByteArray, 0);
24.             Debug.Log(tempInt);
25.         }
26.     }
27. }
28.  

And of course you can optimize this whole thing a whole lot. It was just a crude quickie for ints.

But, and it's important: you don't know if the value is float or int. Is there anything which identifies such cases?

 

I get those result

Code (CSharp):

1.             var test = new byte[] { 0, 48, 0, 3, 63, 83, 91, 53 };
2.             if (BitConverter.IsLittleEndian)
3.                 Array.Reverse(test);
4.  
5.             var f = BitConverter.ToSingle(test, 0);
6.             var i = BitConverter.ToInt32(test, 4);

 

Not sure how you're supposed to tell the difference between the data type just by the received value, is there any additional data you receive? If not, that's only possible when your code knows the pattern that was used to write the values.

However, if you only expect either of both types, I wouldn't convert every single entry, but instead:

• determine the endianess of the system you're running on, as shown by the other posts and reverse it if necessary.
• make a quick copy using System.Buffer.BlockCopy from the byte array to either int or float array
  
• if you didn't reverse it, you're done - if you reversed it, you can either read the array backwards or reverse it and read it normally

 

I'm guessing it's position based by a convention?

 

Hey, thank you for your answers !

In fact, my byte array has this same repeated pattern. I will have (always) an int then float then int then float ... several times: {int0, float0, int1, float1, int2, float2, ...} (I dont know how much time but I have my bytearray size).

The idea is :
I wanted to check in a Vector2 list if for my first element Vector2[0].X = int0 so I put Vector2[0].Y = float0 (I do this for all).

 

Note that the equality operator in float == int will implictly convert the integer to float, which is okay, but you'll end up comparing exact floats. So if the x value of the vector does not exactly represent the converted integer, it'll return false. In such cases, you should use Mathf.Approximately.
If you want to floor, ceil or round the float to an integer for the comparison, you'll find the corresponding methods in the Mathf class as well.

 

Ah ok, thank you !

[Resolved]