Vector2.Set() in a List of Vector2's problem

Hey all,

How does .Set() work? I have a single test Vector2 and it works as expected, and (1,1) is displayed in the debug.

Code (csharp):

1. //Works!
2. Vector2 test = new Vector2(0,0);
3. test.Set(1, 1);
4. Debug.Log("test" + test);
5. //(1,1) displayed
6.  

However, in my project I have a List of Vector2's in a class's attributes to make my code cleaner. In the update function, I iterate through the list and modify each using .Set(), but the Vector2's aren't being modified and still display (0,0) as shown below:

Code (csharp):

1. //doesn't work :(
2. List<Vector2> testList = new List<Vector2>();
3. for(int j = 0; j < 5; j++){
4.      testList.Add(new Vector2(0,0));
5.      testList[j].Set(1, 1);
6.      Debug.Log(testList[j]); //(0,0) still displayed
7. }

I can set the vectors from the list using "testList[j] = new Vector2(1,1);" but this code is being run in every fixed update for every entity, and I don't want to call new that many times when I can just use my original Vector2. Any help on the matter is appreciated, thanks.

 

Having same problem when trying to set the velocity vector.
obj.rigidbody2D.velocity.Set(this.maxSpeed , obj.rigidbody2D.velocity.y);

But I don't have your problem so I guess the velocity isn't possible to change with the Set or its a bug.

Vector2 test = Vector2.zero;
Debug.Log (test);
test.Set (1, 1);
Debug.Log (test);

Works good for me.

 

It's not a bug. Vector2 is a struct so it's a value type. When you pick it out of a list you're getting a copy back, not the one in the list. In terms of velocity - it's actually a property. Value type properties return a copy.

 

You'll have to do

list[index] = new Vector2(x,y).

 

Or treat it the same way you do properties

Code (csharp):

1.  
2. Vector2 item = list[0];
3. item.Set(1, 1);
4. list[0] = item;
5.  

 

Ok, so in the velocity case this is the way to handle it
if you don't want to use new?
Vector2 tmp;
tmp = rigidBody2D.velocity;
tmp.Set(0,5f);
rigidBody2D.velocity = tmp;

 

Aside from the fact that lines 1 and 2 could be combined - yes