C#•10mo ago

How can i ref in a lambda

I want that the you can overgive a float value in this method which by running the action will overwrite it

public Tween SetProperty(ref float value, float time, float delay, float start, float end)
{

   Action<float> lerp = (past) =>
   {
    value = Raymath.Lerp(start, end, past);
  };
}

public Tween SetProperty(ref float value, float time, float delay, float start, float end)
{

   Action<float> lerp = (past) =>
   {
    value = Raymath.Lerp(start, end, past);
  };
}

17 Replies

Jimmacle•10mo ago

so you want past to be ref? or value

KaganoOP•10mo ago

no, value i want that the user can overgive a variable value which will set to it, by every executing of the action

Jimmacle•10mo ago

can you not define a delegate with a ref argument in this situation?

KaganoOP•10mo ago

idk i dont tried

Jimmacle•10mo ago

i mean you can, it's a matter of whether that works for you example from one of my projects

public delegate T LabViewReadDel<out T>(ref LabViewMessageReader reader);
public int[] ReadArrayInt() => ReadArray((ref LabViewMessageReader reader) => reader.ReadInt());

public delegate T LabViewReadDel<out T>(ref LabViewMessageReader reader);
public int[] ReadArrayInt() => ReadArray((ref LabViewMessageReader reader) => reader.ReadInt());

KaganoOP•10mo ago

the variable is always 0

//runs in the update function
float useless = 0;
property.Lerp(time,ref useless);
//

public Tween SetProperty(float value, float time, float delay, float start, float end)
{
  TweenProperty property = new TweenProperty(time, delay);
  property.OnLerp += (float past, ref float f) =>  Lerp(past,ref value,start,end);
  tweenElements.Add(property);
  return this;
}

    public class TweenProperty(float time, float delay, Action<float> action = default)
    {
        public readonly float Delay = delay;
        public readonly float Time = time;
        public Action<float>? Action = action;
        
        internal event Property OnLerp;
        
        public void Lerp(float past,ref float value)
        {
            OnLerp?.Invoke(past, ref value);
        }
    }

//runs in the update function
float useless = 0;
property.Lerp(time,ref useless);
//

public Tween SetProperty(float value, float time, float delay, float start, float end)
{
  TweenProperty property = new TweenProperty(time, delay);
  property.OnLerp += (float past, ref float f) =>  Lerp(past,ref value,start,end);
  tweenElements.Add(property);
  return this;
}

    public class TweenProperty(float time, float delay, Action<float> action = default)
    {
        public readonly float Delay = delay;
        public readonly float Time = time;
        public Action<float>? Action = action;
        
        internal event Property OnLerp;
        
        public void Lerp(float past,ref float value)
        {
            OnLerp?.Invoke(past, ref value);
        }
    }

My button

public int test;

//in the constructor
tween.SetProperty(test, 10, 0, 5, 10);

//runs in the update function
Logger.Warn(test+"");


//output
[Test.RainbowButton:78][21:42] [WARN]: 0

public int test;

//in the constructor
tween.SetProperty(test, 10, 0, 5, 10);

//runs in the update function
Logger.Warn(test+"");


//output
[Test.RainbowButton:78][21:42] [WARN]: 0

KaganoOP•10mo ago

i forgot to ref value in the parameter, but same problem

reflectronic•10mo ago

test is 0 because you did not pass it by ref nothing is editing it

KaganoOP•10mo ago

reflectronic•10mo ago

yes, the parameter needs to be a ref parameter too

KaganoOP•10mo ago

here we go again

reflectronic•10mo ago

ok, so, this will not work well, it will have to be done differently

KaganoOP•10mo ago

i don't had a idea here is the class

reflectronic•10mo ago

do you read from value inside of Lerp, or do you only write to it

KaganoOP•10mo ago

i just try rewrite it

    private void Lerp(float past, ref float value,float start, float end)
    {
        value = Raymath.Lerp(start,end, past);
    }

    private void Lerp(float past, ref float value,float start, float end)
    {
        value = Raymath.Lerp(start,end, past);
    }

reflectronic•10mo ago

what you can do instead is pass an Action<float> it won't look that great, but, it would work

SetProperty(x => this.Whatever = x, a, b, c);
// ...

Tween SetProperty(Action<float> setValue, ...)
{

    property.OnLerp += (past) => setValue(Lerp(...));
}

SetProperty(x => this.Whatever = x, a, b, c);
// ...

Tween SetProperty(Action<float> setValue, ...)
{

    property.OnLerp += (past) => setValue(Lerp(...));
}

KaganoOP•10mo ago

yeah that could work :/ but i wanted to do that you can via parameter tell which value should set looks like there isn't a good way

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How can i ref in a lambda

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