ComponentFactory.Krypton.Toolkit.RenderGlassHelpers.DrawBackGlassThreeEdge C# (CSharp) Method

        public static IDisposable DrawBackGlassThreeEdge(RenderContext context,
                                                         Rectangle rect,
                                                         Color backColor1,
                                                         Color backColor2,
                                                         VisualOrientation orientation,
                                                         GraphicsPath path,
                                                         IDisposable memento)
        {
            using (Clipping clip = new Clipping(context.Graphics, path))
            {
                bool generate = true;
                MementoBackGlassThreeEdge cache;

                // Access a cache instance and decide if cache resources need generating
                if ((memento == null) || !(memento is MementoBackGlassThreeEdge))
                {
                    if (memento != null)
                        memento.Dispose();

                    cache = new MementoBackGlassThreeEdge(rect, backColor1, backColor2, orientation);
                    memento = cache;
                }
                else
                {
                    cache = (MementoBackGlassThreeEdge)memento;
                    generate = !cache.UseCachedValues(rect, backColor1, backColor2, orientation);
                }

                // Do we need to generate the contents of the cache?
                if (generate)
                {
                    // Dispose of existing values
                    cache.Dispose();

                    // Generate color values
                    cache.colorA1L = CommonHelper.MergeColors(backColor1, 0.7f, Color.White, 0.3f);
                    cache.colorA2L = CommonHelper.MergeColors(backColor2, 0.7f, Color.White, 0.3f);
                    cache.colorA2LL = CommonHelper.MergeColors(cache.colorA2L, 0.8f, Color.White, 0.2f);
                    cache.colorB2LL = CommonHelper.MergeColors(backColor2, 0.8f, Color.White, 0.2f);
                    cache.rectB = new Rectangle(rect.X + 1, rect.Y + 1, rect.Width - 1, rect.Height - 2);
                }

                // Draw entire area in a lighter version
                cache.first = DrawBackGlassLinear(rect, rect,
                                                  cache.colorA1L, _glassColorLight,
                                                  cache.colorA2L, cache.colorA2LL,
                                                  orientation,
                                                  context.Graphics,
                                                  _fullGlassLength,
                                                  cache.first);

                // Draw the inside area in the full color
                cache.second = DrawBackGlassLinear(cache.rectB, cache.rectB,
                                                   backColor1, _glassColorLight,
                                                   backColor2, cache.colorB2LL,
                                                   orientation,
                                                   context.Graphics,
                                                   _fullGlassLength,
                                                   cache.second);

                return cache;
            }
        }