public void ApplySource(int ch)
        {
                        #if UNITY_EDITOR
            if (srcArr[ch].alpha == null)
            {
                if (srcArr[ch].source != null)
                {
                    texArr.SetTexture(srcArr[ch].source, ch, apply: true);
                }
            }
            else
            {
                if (srcArr[ch].source != null)
                {
                    texArr.SetTextureAlpha(srcArr[ch].source, srcArr[ch].alpha, ch, apply: true);
                }
            }

            srcArr[ch].preview = null;             //resetting preview not keeping it. It will be generated on next get
                        #endif
        }