CSharpImageLibrary.DDS.DDSGeneral.EstimateNumMipMaps C# (CSharp) Method

        public static int EstimateNumMipMaps(int Width, int Height)
        {
            int limitingDimension = Width > Height ? Height : Width;
            return (int)Math.Log(limitingDimension, 2); // There's 10 mipmaps besides the main top one.
        }

        /// <summary>
        /// Ensures all Mipmaps are generated in MipMaps.
        /// </summary>
        /// <param name="MipMaps">MipMaps to check.</param>
        /// <returns>Number of mipmaps present in MipMaps.</returns>
        internal static int BuildMipMaps(List <MipMap> MipMaps)
        {
            if (MipMaps?.Count == 0)
            {
                return(0);
            }

            MipMap currentMip = MipMaps[0];

            // KFreon: Check if mips required
            int estimatedMips = DDSGeneral.EstimateNumMipMaps(currentMip.Width, currentMip.Height);

            if (MipMaps.Count > 1)
            {
                return(estimatedMips);
            }

            // KFreon: Half dimensions until one == 1.
            MipMap[] newmips = new MipMap[estimatedMips];

            // TODO: Component size - pixels
            //var baseBMP = UsefulThings.WPF.Images.CreateWriteableBitmap(currentMip.Pixels, currentMip.Width, currentMip.Height);
            //baseBMP.Freeze();

            Action <int> action = new Action <int>(item =>
            {
                int index = item;
                MipMap newmip;
                var scale = 1d / (2 << (index - 1));  // Shifting is 2^index - Math.Pow seems extraordinarly slow.
                //newmip = ImageEngine.Resize(baseBMP, scale, scale, currentMip.Width, currentMip.Height, currentMip.LoadedFormatDetails);
                newmip             = ImageEngine.Resize(currentMip, scale, scale);
                newmips[index - 1] = newmip;
            });

            // Start at 1 to skip top mip
            if (ImageEngine.EnableThreading)
            {
                Parallel.For(1, estimatedMips + 1, new ParallelOptions {
                    MaxDegreeOfParallelism = ImageEngine.NumThreads
                }, action);
            }
            else
            {
                for (int item = 1; item < estimatedMips + 1; item++)
                {
                    action(item);
                }
            }

            MipMaps.AddRange(newmips);
            return(MipMaps.Count);
        }