Some bmp converter that should convert 256 color bitmap data to an Crash Bandicoot Texture Chunk.

bmpconversionstuff.cs

        private void Menu_ConvertBMP()
        {
            byte[] data = FileUtil.OpenFile(out string fileName, FileFilters.BMP);
            if (data == null)
                return;
            string ename = fileName.Substring(0, 5);
            // first things first generate some stuff.
            List<byte> fileHeader = new List<byte>();
            fileHeader.AddRange(BitConverter.GetBytes((short)0x1234));
            fileHeader.AddRange(BitConverter.GetBytes((short)1));
            fileHeader.AddRange(BitConverter.GetBytes(Entry.ENameToEID(ename)));
            fileHeader.AddRange(BitConverter.GetBytes(5));
            fileHeader.AddRange(new byte[] { (byte)0, (byte)0, (byte)0, (byte)0 });
            using (MemoryStream ms = new MemoryStream(data))
            using (Bitmap bmp = new Bitmap(ms))
            {
                List<List<short>> paletteDatas = new List<List<short>>();
                ColorPalette palette = bmp.Palette;
                List<Color> colors = palette.Entries.ToList();
                // now we must row out the palette data properly.
                for (int row = 0; row < 16; row++)
                {
                    List<short> paletteData = new List<short>();
                    if (row == 0)
                    {
                        // paletteData.AddRange(new short[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 });
                        foreach (var palcol in colors)
                        {
                            paletteData.Add(PixelConv.Convert8888_5551(palcol));
                        }
                        // after this now we must finish off the first row.
                        // for (int i = 256; i < 512; i++)
                        // {
                            // paletteData.Add(PixelConv.Pack1555(1, 0, 0, 0));
                        //     paletteData.Add(PixelConv.Convert8888_5551(Color.FromArgb(0, 0, 0)));
                        // }
                        paletteDatas.Add(paletteData);
                    }
                    else
                    {
                        // for (int i = 0; i < 256; i++)
                        // {
                        //     paletteData.Add(PixelConv.Convert8888_5551(Color.FromArgb(0, 0, 0)));
                        // }
                        // paletteDatas.Add(paletteData);
                    }
                }
                // now we need the raw pixel data that references the palette indexes somehow...
                BitmapData bitmapData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, bmp.PixelFormat);
                int length = bitmapData.Stride * bitmapData.Height;
                byte[] bytes = new byte[length];
                // Copy bitmap to byte[]
                Marshal.Copy(bitmapData.Scan0, bytes, 0, length);
                bmp.UnlockBits(bitmapData);
                List<byte> converted = new List<byte>();
                foreach (List<short> paletteData in paletteDatas)
                {
                    foreach (short paletteCol in paletteData)
                    {
                        converted.Add(Convert.ToByte(paletteCol));
                    }
                }
                // paletteDatas.RemoveRange(0, paletteDatas.Count);
                if (converted.Count + bytes.Length < 0xFFF0)
                {
                    do
                    {
                        converted.Add((byte)0);
                    }
                    while (converted.Count + bytes.Length < 0xFFF0);
                    // Debug.WriteLine($"Texture data is {converted.Count + bytes.Length}/65520 bytes!!!");
                }
                else
                {
                    Debug.WriteLine($"Texture data is {converted.Count + bytes.Length}/65520 bytes!!!");
                }
                converted.AddRange(bytes);
                if (converted.Count == 0xFFF0)
                {
                    Debug.WriteLine($"Texture data should be ok now.");
                }
                else
                {
                    Debug.WriteLine($"Texture data is bad: over by {converted.Count - 65520} bytes!!!");
                }
                fileHeader.AddRange(converted);
                byte[] fileBytes = fileHeader.ToArray();
                int current_checksum = BitConv.FromInt32(fileBytes, 12);
                int correct_checksum = Chunk.CalculateChecksum(fileBytes);
                if (current_checksum == correct_checksum)
                {
                    Debug.WriteLine("Checksum was already correct.");
                    _ = FileUtil.SaveFile(fileBytes, FileFilters.Any);
                    return;
                }
                BitConv.ToInt32(fileBytes, 12, correct_checksum);
                Debug.WriteLine("Checksum was incorrect and has been corrected.");
                _ = FileUtil.SaveFile(fileBytes, FileFilters.Any);
            }
        }