Creating a fill animation for sprite renderer

Hi, i want to recreate a fill animation (like that used into Image) for the Sprite Renderer, i've create this one, but if i call it every frame (or every time a value change) it create lags into the game

 static Sprite Function(/*passed values*/)
 {
   for (int x = 0; x < sprite.texture.width; x++)
                     {
                         for (int y = 0; y < sprite.texture.height; y++)
                         {
                             float div = (float)x / width;
                             Color m_color;
                             if(div <= percentage01)
                             {
                                 m_color = sprite.texture.GetPixel(x, y).a == 0 ?
                                     newTexture.GetPixel(x, y) :
                                     sprite.texture.GetPixel(x, y);
                             }
                             else
                             {
                                 return newTexture;
                             }
                             newTexture.SetPixel(x, y, m_color);
                         }
                     }
 
             newTexture.Apply();
             Rect rect = new Rect(0, 0, newTexture.width, newTexture.height);
             var m_finalSprite = Sprite.Create(newTexture, rect, new Vector2(0.5f, 0.5f), sprite.pixelsPerUnit, 0, SpriteMeshType.FullRect);
             m_finalSprite.name = spriteName;
             return m_finalSprite;
 }

can you help me to make the animation smooth and without lags?