AnimationCurveCreator.cs

using System.Text;
using UnityEditor;
using UnityEngine;

public class AnimationCurveCreator : EditorWindow
{
    private const string Title = "Curve Creator";

    [SerializeField]
    private AnimationCurve _curve = new AnimationCurve(new Keyframe(0, 0, 0, 0), new Keyframe(1, 1, 0, 1));

    [SerializeField]
    private string _output;

    private static GUIStyle TextBoxStyle => new GUIStyle(EditorStyles.textField) { wordWrap = true };

    [MenuItem("Window/" + Title)]
    public static void Open()
    {
        var window = GetWindow<AnimationCurveCreator>(true, Title);
        window.Show();
    }

    private void OnGUI()
    {
        using (var check = new EditorGUI.ChangeCheckScope())
        {
            _curve = EditorGUILayout.CurveField("Animation Curve", _curve);
            if (check.changed)
            {
                _output = GenerateCode(_curve);
                Repaint();
            }
        }

        // Disable generated code
        EditorGUILayout.SelectableLabel(_output, TextBoxStyle, GUILayout.ExpandHeight(true));
        if (GUILayout.Button("Copy"))
        {
            GUIUtility.systemCopyBuffer = _output;
        }
    }

    private static string GenerateCode(AnimationCurve curve)
    {
        var builder = new StringBuilder("new AnimationCurve(");

        var count = curve.keys.Length;
        const string keyFormat = "new Keyframe({0}f, {1}f, {2}f, {3}f)";
        for (var i = 0; i < count; ++i)
        {
            var key = curve.keys[i];
            builder.AppendFormat(keyFormat, key.time, key.value, key.inTangent, key.outTangent);

            if (i < count - 1)
            {
                builder.Append(", ");
            }
        }

        const string suffix = ");";
        builder.Append(suffix);
        return builder.ToString();
    }
}