| 457 | } |
| 458 | |
| 459 | private string DecodeGeneric(byte[] bytes, int bitsPerChar, Func<byte, char> mapper) |
| 460 | { |
| 461 | if (bytes.Length == 0) |
| 462 | { |
| 463 | return string.Empty; |
| 464 | } |
| 465 | |
| 466 | bool stripLast = (bytes[0] & 0x80) != 0; |
| 467 | int totalBits = bytes.Length * 8; |
| 468 | int bitIndex = 1; |
| 469 | StringBuilder sb = new(bytes.Length); |
| 470 | while (bitIndex + bitsPerChar <= totalBits && |
| 471 | !(stripLast && (bitIndex + 2 * bitsPerChar > totalBits))) |
| 472 | { |
| 473 | byte value = 0; |
| 474 | for (var i = 0; i < bitsPerChar; i++) |
| 475 | { |
| 476 | int byteIndex = bitIndex / 8; |
| 477 | int intra = bitIndex % 8; |
| 478 | byte bit = (byte)((bytes[byteIndex] >> (7 - intra)) & 0x01); |
| 479 | value = (byte)((value << 1) | bit); |
| 480 | bitIndex++; |
| 481 | } |
| 482 | |
| 483 | sb.Append(mapper(value)); |
| 484 | } |
| 485 | |
| 486 | return sb.ToString(); |
| 487 | } |
| 488 | |
| 489 | private static char UnmapLowerSpecial(byte value) |
| 490 | { |