Painting System for Unity

using UnityEngine;

public class Draw : MonoBehaviour {

    [SerializeField] Sprite brush;
    [SerializeField] float brushRadius = 0.75f;
    [SerializeField] float eraserRadius = 0.37f;
    [SerializeField] Color color;
    Vector2 mouse;

    #region Start
    void Start(){
        CreateCursor();
    }
    #endregion
    #region Update
    void Update(){
        mouse = Camera.main.ScreenToWorldPoint(Input.mousePosition);
        ChangeCursor();

        if(Input.GetMouseButton(0)) CreateStroke();
        if(Input.GetMouseButton(1)) Erase();
        if(Input.GetKeyDown(KeyCode.Escape)) Clear();
    }
    #endregion
    #region Create Brush Stroke
    void CreateStroke(){
        Transform stroke = new GameObject("Stroke").transform;
        stroke.position = mouse;
        stroke.localScale = brushRadius * Vector2.one;
        stroke.SetParent(transform);

        SpriteRenderer renderer = stroke.gameObject.AddComponent<SpriteRenderer>();
        renderer.sprite = brush;
        renderer.color = color;
    }
    #endregion
    #region Clear
    void Clear(){
        foreach(Transform child in transform)
        {
            if(child != transform)
            {
                Destroy(child.gameObject);
            }
        }
    }
    #endregion
    #region Erase
    void Erase(){
        Vector2 EraserX = new Vector2(mouse.x + eraserRadius, mouse.x - eraserRadius);
        Vector2 EraserY = new Vector2(mouse.y + eraserRadius, mouse.y - eraserRadius);

        foreach(Transform child in transform)
        {
            Vector2 pos = child.position;

            bool x = (EraserX.y < pos.x) && (pos.x < EraserX.x);
            bool y = (EraserY.y < pos.y) && (pos.y < EraserY.x);

            if(x && y) Destroy(child.gameObject);
        }
    }
    #endregion
    #region Set Cursor
    void CreateCursor(){
        GameObject cursor = new GameObject("Cursor");
        SpriteRenderer renderer = cursor.AddComponent<SpriteRenderer>();
        renderer.sprite = brush;
        renderer.sortingOrder = 1;
    }

    void ChangeCursor()
    {
        Cursor.visible = false;
        GameObject cursor = GameObject.Find("Cursor");

        cursor.transform.position = mouse;
        cursor.transform.localScale = brushRadius * Vector2.one;
    }
    #endregion
}