TouchScript.TouchManagerInstance.AddLayer C# (CSharp) Method

        public bool AddLayer(TouchLayer layer, int index = -1, bool addIfExists = true)
        {
            if (layer == null) return false;

            var i = layers.IndexOf(layer);
            if (i != -1)
            {
                if (!addIfExists) return false;
                layers.RemoveAt(i);
                layerCount--;
            }
            if (index == 0)
            {
                layers.Insert(0, layer);
                layerCount++;
                return i == -1;
            }
            if (index == -1 || index >= layerCount)
            {
                layers.Add(layer);
                layerCount++;
                return i == -1;
            }
            if (i != -1)
            {
                if (index < i) layers.Insert(index, layer);
                else layers.Insert(index - 1, layer);
                layerCount++;
                return false;
            }
            layers.Insert(index, layer);
            layerCount++;
            return true;
        }