diff options
| -rw-r--r-- | engines/adl/disk.cpp | 177 |
1 files changed, 71 insertions, 106 deletions
diff --git a/engines/adl/disk.cpp b/engines/adl/disk.cpp index a77798c1b6..ba07f23c0b 100644 --- a/engines/adl/disk.cpp +++ b/engines/adl/disk.cpp @@ -28,25 +28,9 @@ namespace Adl { -static Common::SeekableReadStream *readImage(const Common::String &filename) { - Common::File *f = new Common::File; - - if (!f->open(filename)) { - delete f; - return nullptr; - } - - return f; -} - -static bool detectDOS33_NIB(const Common::String &filename) { - Common::File f; - - if (!f.open(filename)) - error("Failed to open '%s'", filename.c_str()); - +static bool detectDOS33_NIB(Common::SeekableReadStream &f) { if (f.size() != 232960) - error("Unrecognized NIB image '%s' of size %d bytes", filename.c_str(), f.size()); + return false; uint count = 0; uint dos32 = 0, dos33 = 0; @@ -58,7 +42,7 @@ static bool detectDOS33_NIB(const Common::String &filename) { window |= f.readByte(); if (f.err() || f.eos()) - error("Failed to read '%s'", filename.c_str()); + return false; if (window == 0xd5aa96) ++dos33; @@ -66,13 +50,51 @@ static bool detectDOS33_NIB(const Common::String &filename) { ++dos32; } - f.close(); - return dos33 > dos32; } const uint trackLen = 256 * 26; +static bool readSector_NIB(byte outBuf[], const byte inBuf[], uint size, uint &pos, const byte minNibble, const byte lookup[], const uint track, const uint sector) { + uint z = trackLen - (pos % trackLen); + if (z < size) { + memcpy(outBuf, inBuf + (pos % trackLen), z); + memcpy(outBuf + z, inBuf, size - z); + } else + memcpy(outBuf, inBuf + (pos % trackLen), size); + pos += size; + + byte oldVal = 0; + for (uint n = 0; n < size; ++n) { + // expand + assert(outBuf[n] >= minNibble); // corrupt file (TODO: assert?) + if (outBuf[n] == 0xd5) { + // Early end of block. + pos -= (size - n); + warning("NIB: early end of block @ %x (%d, %d)", n, track, sector); + return false; + } + byte val = lookup[outBuf[n] - minNibble]; + if (val == 0x40) { + // Badly-encoded nibbles, stop trying to decode here. + pos -= (size - n); + warning("NIB: bad nibble %02x @ %x (%d, %d)", outBuf[n], n, track, sector); + return false; + } + // undo checksum + oldVal = val ^ oldVal; + outBuf[n] = oldVal; + } + + byte checksum = inBuf[pos++ % trackLen]; + if (checksum < minNibble || oldVal != lookup[checksum - minNibble]) { + warning("NIB: checksum mismatch @ (%d, %d)", track, sector); + return false; + } + + return true; +} + // 4-and-4 encoding (odd-even) static uint8 read44(byte *buffer, uint &pos) { // 1s in the other fields, so we can just AND @@ -80,17 +102,14 @@ static uint8 read44(byte *buffer, uint &pos) { return ((ret << 1) | 1) & buffer[pos++ % trackLen]; } -static Common::SeekableReadStream *readImage_NIB(const Common::String &filename, bool dos33) { - Common::File f; - - if (!f.open(filename)) +static Common::SeekableReadStream *readImage_NIB(Common::File &f, bool dos33) { + if (f.size() != 232960) { + warning("NIB: image '%s' has invalid size of %d bytes", f.getName(), f.size()); return nullptr; + } - if (f.size() != 232960) - error("Unrecognized NIB image '%s' of size %d bytes", filename.c_str(), f.size()); - - // starting at 0xaa, 32 is invalid (see below) - const byte c_5and3_lookup[] = { 32, 0, 32, 1, 2, 3, 32, 32, 32, 32, 32, 4, 5, 6, 32, 32, 7, 8, 32, 9, 10, 11, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 12, 13, 32, 32, 14, 15, 32, 16, 17, 18, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 19, 20, 32, 21, 22, 23, 32, 32, 32, 32, 32, 24, 25, 26, 32, 32, 27, 28, 32, 29, 30, 31 }; + // starting at 0xaa, 64 is invalid (see below) + const byte c_5and3_lookup[] = { 64, 0, 64, 1, 2, 3, 64, 64, 64, 64, 64, 4, 5, 6, 64, 64, 7, 8, 64, 9, 10, 11, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 12, 13, 64, 64, 14, 15, 64, 16, 17, 18, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 19, 20, 64, 21, 22, 23, 64, 64, 64, 64, 64, 24, 25, 26, 64, 64, 27, 28, 64, 29, 30, 31 }; // starting at 0x96, 64 is invalid (see below) const byte c_6and2_lookup[] = { 0, 1, 64, 64, 2, 3, 64, 4, 5, 6, 64, 64, 64, 64, 64, 64, 7, 8, 64, 64, 64, 9, 10, 11, 12, 13, 64, 64, 14, 15, 16, 17, 18, 19, 64, 20, 21, 22, 23, 24, 25, 26, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 27, 64, 28, 29, 30, 64, 64, 64, 31, 64, 64, 32, 33, 64, 34, 35, 36, 37, 38, 39, 40, 64, 64, 64, 64, 64, 41, 42, 43, 64, 44, 45, 46, 47, 48, 49, 50, 64, 64, 51, 52, 53, 54, 55, 56, 64, 57, 58, 59, 60, 61, 62, 63 }; @@ -132,12 +151,10 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename, // We should always find the address field first. if (prologue != (dos33 ? 0x96 : 0xb5)) { // Accept a DOS 3.3(?) header at the start. - if (prologue == (dos33 ? 0xb5 : 0x96) || prologue == 0xad || prologue == 0xfd) { - sawAddress = false; - continue; - } else { - error("unknown NIB field prologue %02x", prologue); - } + if (prologue != (dos33 ? 0xb5 : 0x96) && prologue != 0xad && prologue != 0xfd) + warning("NIB: unknown field prologue %02x", prologue); + sawAddress = false; + continue; } volNo = read44(buffer, pos); @@ -145,7 +162,7 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename, sector = read44(buffer, pos); uint8 checksum = read44(buffer, pos); if ((volNo ^ track ^ sector) != checksum) { - warning("invalid NIB checksum (volNo %d, track %d, sector %d)", volNo, track, sector); + warning("NIB: invalid checksum (volNo %d, track %d, sector %d)", volNo, track, sector); sawAddress = false; continue; } @@ -175,34 +192,10 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename, sector = raw2dos[sector]; output = diskImage + (track * sectorsPerTrack + sector) * bytesPerSector; - // 6-and-2 uses 342 on-disk bytes byte inbuffer[342]; - uint z = trackLen - (pos % trackLen); - if (z < 342) { - memcpy(inbuffer, buffer + (pos % trackLen), z); - memcpy(inbuffer + z, buffer, 342 - z); - } else - memcpy(inbuffer, buffer + (pos % trackLen), 342); - pos += 342; - - byte oldVal = 0; - for (uint n = 0; n < 342; ++n) { - // expand - assert(inbuffer[n] >= 0x96); // corrupt file (TODO: assert?) - byte val = c_6and2_lookup[inbuffer[n] - 0x96]; - if (val == 0x40) { - error("NIB: invalid nibble value %02x", inbuffer[n]); - } - // undo checksum - oldVal = val ^ oldVal; - inbuffer[n] = oldVal; - } - byte checksum = buffer[pos++ % trackLen]; - if (checksum < 0x96 || oldVal != c_6and2_lookup[checksum - 0x96]) { - warning("NIB: checksum mismatch @ (%x, %x)", track, sector); + if (!readSector_NIB(inbuffer, buffer, sizeof(inbuffer), pos, 0x96, c_6and2_lookup, track, sector)) continue; - } for (uint n = 0; n < 256; ++n) { output[n] = inbuffer[86 + n] << 2; @@ -220,47 +213,9 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename, } else { // 5-and-3 uses 410 on-disk bytes, decoding to just over 256 bytes byte inbuffer[410]; - uint z = trackLen - (pos % trackLen); - if (z < 410) { - memcpy(inbuffer, buffer + (pos % trackLen), z); - memcpy(inbuffer + z, buffer, 410 - z); - } else - memcpy(inbuffer, buffer + (pos % trackLen), 410); - pos += 410; - - bool truncated = false; - byte oldVal = 0; - for (uint n = 0; n < 410; ++n) { - // expand - assert(inbuffer[n] >= 0xaa); // corrupt file (TODO: assert?) - if (inbuffer[n] == 0xd5) { - // Early end of block. - truncated = true; - pos -= (410 - n); - warning("NIB: early end of block @ 0x%x (%x, %x)", f.pos(), track, sector); - break; - } - byte val = c_5and3_lookup[inbuffer[n] - 0xaa]; - if (val == 0x20) { - // Badly-encoded nibbles, stop trying to decode here. - truncated = true; - warning("NIB: bad nibble %02x @ 0x%x (%x, %x)", inbuffer[n], f.pos(), track, sector); - pos -= (410 - n); - break; - } - // undo checksum - oldVal = val ^ oldVal; - inbuffer[n] = oldVal; - } - - if (truncated) - continue; - byte checksum = buffer[pos++ % trackLen]; - if (checksum < 0xaa || oldVal != c_5and3_lookup[checksum - 0xaa]) { - warning("NIB: checksum mismatch @ (%x, %x)", track, sector); + if (!readSector_NIB(inbuffer, buffer, sizeof(inbuffer), pos, 0xaa, c_5and3_lookup, track, sector)) continue; - } // 8 bytes of nibbles expand to 5 bytes // so we have 51 of these batches (255 bytes), plus 2 bytes of 'leftover' nibbles for byte 256 @@ -285,6 +240,14 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename, } bool DiskImage::open(const Common::String &filename) { + Common::File *f = new Common::File; + + if (!f->open(filename)) { + warning("Failed to open '%s'", filename.c_str()); + delete f; + return false; + } + Common::String lcName(filename); lcName.toLowercase(); @@ -292,27 +255,29 @@ bool DiskImage::open(const Common::String &filename) { _tracks = 35; _sectorsPerTrack = 16; _bytesPerSector = 256; - _stream = readImage(filename); + _stream = f; } else if (lcName.hasSuffix(".d13")) { _tracks = 35; _sectorsPerTrack = 13; _bytesPerSector = 256; - _stream = readImage(filename); + _stream = f; } else if (lcName.hasSuffix(".nib")) { _tracks = 35; - if (detectDOS33_NIB(filename)) + if (detectDOS33_NIB(*f)) _sectorsPerTrack = 16; else _sectorsPerTrack = 13; _bytesPerSector = 256; - _stream = readImage_NIB(filename, _sectorsPerTrack == 16); + f->seek(0); + _stream = readImage_NIB(*f, _sectorsPerTrack == 16); + delete f; } else if (lcName.hasSuffix(".xfd")) { _tracks = 40; _sectorsPerTrack = 18; _bytesPerSector = 128; - _stream = readImage(filename); + _stream = f; } int expectedSize = _tracks * _sectorsPerTrack * _bytesPerSector; |