ADL: Add support for reading .xfd Atari disk images

4 files changed, 58 insertions, 40 deletions

diff --git a/engines/adl/disk.cpp b/engines/adl/disk.cpp
index 49e01f9d0f..6a5cf0b20c 100644
--- a/engines/adl/disk.cpp
+++ b/engines/adl/disk.cpp
@@ -28,15 +28,7 @@
 
 namespace Adl {
 
-#define TRACKS 35
-// The Apple II uses either 13- or 16-sector disks. We currently pad out
-// 13-sector disks, so we set SECTORS_PER_TRACK to 16 here.
-#define SECTORS_PER_TRACK 16
-#define BYTES_PER_SECTOR 256
-#define RAW_IMAGE_SIZE(S) (TRACKS * (S) * BYTES_PER_SECTOR)
-#define NIB_IMAGE_SIZE (RAW_IMAGE_SIZE(13) * 2)
-
-static Common::SeekableReadStream *readImage_DSK(const Common::String &filename) {
+static Common::SeekableReadStream *readImage(const Common::String &filename) {
 	Common::File *f = new Common::File;
 
 	if (!f->open(filename)) {
@@ -44,9 +36,6 @@ static Common::SeekableReadStream *readImage_DSK(const Common::String &filename)
 		return nullptr;
 	}
 
-	if (f->size() != RAW_IMAGE_SIZE(16))
-		error("Unrecognized DSK image '%s' of size %d bytes", filename.c_str(), f->size());
-
 	return f;
 }
 
@@ -63,7 +52,7 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename)
 	if (!f.open(filename))
 		return nullptr;
 
-	if (f.size() != NIB_IMAGE_SIZE)
+	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)
@@ -73,7 +62,9 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename)
 
 	// we always pad it out
 	const uint sectorsPerTrack = 16;
-	byte *diskImage = (byte *)calloc(RAW_IMAGE_SIZE(sectorsPerTrack), 1);
+	const uint bytesPerSector = 256;
+	const uint imageSize = 35 * sectorsPerTrack * bytesPerSector;
+	byte *const diskImage = (byte *)calloc(imageSize, 1);
 
 	bool sawAddress = false;
 	uint8 volNo, track, sector;
@@ -120,13 +111,13 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename)
 
 		// We should always find the data field after an address field.
 		// TODO: we ignore volNo?
-		byte *output = diskImage + (track * sectorsPerTrack + sector) * BYTES_PER_SECTOR;
+		byte *output = diskImage + (track * sectorsPerTrack + sector) * bytesPerSector;
 
 		if (newStyle) {
 			// We hardcode the DOS 3.3 mapping here. TODO: Do we also need raw/prodos?
 			int raw2dos[16] = { 0, 7, 14, 6, 13, 5, 12, 4, 11, 3, 10, 2, 9, 1, 8, 15 };
 			sector = raw2dos[sector];
-			output = diskImage + (track * sectorsPerTrack + sector) * BYTES_PER_SECTOR;
+			output = diskImage + (track * sectorsPerTrack + sector) * bytesPerSector;
 
 			// 6-and-2 uses 342 on-disk bytes
 			byte inbuffer[342];
@@ -216,36 +207,59 @@ static Common::SeekableReadStream *readImage_NIB(const Common::String &filename)
 		}
 	}
 
-	return new Common::MemoryReadStream(diskImage, RAW_IMAGE_SIZE(sectorsPerTrack), DisposeAfterUse::YES);
+	return new Common::MemoryReadStream(diskImage, imageSize, DisposeAfterUse::YES);
 }
 
 bool DiskImage::open(const Common::String &filename) {
 	Common::String lcName(filename);
 	lcName.toLowercase();
 
-	if (lcName.hasSuffix(".dsk"))
-		_stream = readImage_DSK(filename);
-	else if (lcName.hasSuffix(".nib"))
+	if (lcName.hasSuffix(".dsk")) {
+		_stream = readImage(filename);
+		_tracks = 35;
+		_sectorsPerTrack = 16;
+		_bytesPerSector = 256;
+	} else if (lcName.hasSuffix(".nib")) {
 		_stream = readImage_NIB(filename);
+		_tracks = 35;
+		_sectorsPerTrack = 16;
+		_bytesPerSector = 256;
+	} else if (lcName.hasSuffix(".xfd")) {
+		_stream = readImage(filename);
+		_tracks = 40;
+		_sectorsPerTrack = 18;
+		_bytesPerSector = 128;
+	}
+
+	int expectedSize = _tracks * _sectorsPerTrack * _bytesPerSector;
+
+	if (!_stream)
+		return false;
+
+	if (_stream->size() != expectedSize)
+		error("Unrecognized disk image '%s' of size %d bytes (expected %d bytes)", filename.c_str(), _stream->size(), expectedSize);
 
-	return _stream != nullptr;
+	return true;
 }
 
 const DataBlockPtr DiskImage::getDataBlock(uint track, uint sector, uint offset, uint size) const {
-	return DataBlockPtr(new DiskImage::DataBlock(this, track, sector, offset, size, _mode13));
+	return DataBlockPtr(new DiskImage::DataBlock(this, track, sector, offset, size, _sectorLimit));
 }
 
-Common::SeekableReadStream *DiskImage::createReadStream(uint track, uint sector, uint offset, uint size, uint sectorsPerTrackToRead) const {
-	const uint bytesToRead = size * BYTES_PER_SECTOR + BYTES_PER_SECTOR - offset;
+Common::SeekableReadStream *DiskImage::createReadStream(uint track, uint sector, uint offset, uint size, uint sectorLimit) const {
+	const uint bytesToRead = size * _bytesPerSector + _bytesPerSector - offset;
 	byte *const data = (byte *)malloc(bytesToRead);
 	uint dataOffset = 0;
 
-	if (sector > sectorsPerTrackToRead - 1)
-		error("Sector %i is out of bounds for %i-sector reading", sector, sectorsPerTrackToRead);
+	if (sectorLimit == 0)
+		sectorLimit = _sectorsPerTrack;
+
+	if (sector >= sectorLimit)
+		error("Sector %i is out of bounds for %i-sector reading", sector, sectorLimit);
 
 	while (dataOffset < bytesToRead) {
-		uint bytesRemInTrack = (sectorsPerTrackToRead - 1 - sector) * BYTES_PER_SECTOR + BYTES_PER_SECTOR - offset;
-		_stream->seek((track * SECTORS_PER_TRACK + sector) * BYTES_PER_SECTOR + offset);
+		uint bytesRemInTrack = (sectorLimit - 1 - sector) * _bytesPerSector + _bytesPerSector - offset;
+		_stream->seek((track * _sectorsPerTrack + sector) * _bytesPerSector + offset);
 
 		if (bytesToRead - dataOffset < bytesRemInTrack)
 			bytesRemInTrack = bytesToRead - dataOffset;
diff --git a/engines/adl/disk.h b/engines/adl/disk.h
index 1041f0cebd..653d76ff10 100644
--- a/engines/adl/disk.h
+++ b/engines/adl/disk.h
@@ -74,7 +74,10 @@ class DiskImage {
 public:
 	DiskImage() :
 			_stream(nullptr),
-			_mode13(false) { }
+			_tracks(0),
+			_sectorsPerTrack(0),
+			_bytesPerSector(0),
+			_sectorLimit(0) { }
 
 	~DiskImage() {
 		delete _stream;
@@ -82,32 +85,33 @@ public:
 
 	bool open(const Common::String &filename);
 	const DataBlockPtr getDataBlock(uint track, uint sector, uint offset = 0, uint size = 0) const;
-	Common::SeekableReadStream *createReadStream(uint track, uint sector, uint offset = 0, uint size = 0, uint sectorsPerTrackToRead = 16) const;
-	void setMode13(bool enable) { _mode13 = enable; }
+	Common::SeekableReadStream *createReadStream(uint track, uint sector, uint offset = 0, uint size = 0, uint sectorsUsed = 0) const;
+	void setSectorLimit(uint sectorLimit) { _sectorLimit = sectorLimit; } // Maximum number of sectors to read per track before stepping
 
 protected:
 	class DataBlock : public Adl::DataBlock {
 	public:
-		DataBlock(const DiskImage *disk, uint track, uint sector, uint offset, uint size, bool mode13) :
+		DataBlock(const DiskImage *disk, uint track, uint sector, uint offset, uint size, uint sectorLimit) :
 				_track(track),
 				_sector(sector),
 				_offset(offset),
 				_size(size),
-				_mode13(mode13),
+				_sectorLimit(sectorLimit),
 				_disk(disk) { }
 
 		Common::SeekableReadStream *createReadStream() const {
-			return _disk->createReadStream(_track, _sector, _offset, _size, (_mode13 ? 13 : 16));
+			return _disk->createReadStream(_track, _sector, _offset, _size, _sectorLimit);
 		}
 
 	private:
 		uint _track, _sector, _offset, _size;
-		bool _mode13;
+		uint _sectorLimit;
 		const DiskImage *_disk;
 	};
 
 	Common::SeekableReadStream *_stream;
-	bool _mode13; // Older 13-sector format
+	uint _tracks, _sectorsPerTrack, _bytesPerSector;
+	uint _sectorLimit;
 };
 
 // Data in plain files
diff --git a/engines/adl/hires0.cpp b/engines/adl/hires0.cpp
index a348779e89..875a06c73d 100644
--- a/engines/adl/hires0.cpp
+++ b/engines/adl/hires0.cpp
@@ -35,7 +35,7 @@ void HiRes0Engine::init() {
 	if (!_disk->open(IDS_HR0_DISK_IMAGE))
 		error("Failed to open disk image '" IDS_HR0_DISK_IMAGE "'");
 
-	_disk->setMode13(true);
+	_disk->setSectorLimit(13);
 
 	StreamPtr stream(_disk->createReadStream(0x1f, 0x2, 0x00, 2));
 
diff --git a/engines/adl/hires2.cpp b/engines/adl/hires2.cpp
index 14db237d82..d0e459c96c 100644
--- a/engines/adl/hires2.cpp
+++ b/engines/adl/hires2.cpp
@@ -37,7 +37,7 @@ void HiRes2Engine::runIntro() const {
 	// This only works for the 16-sector re-release. The original
 	// release is not supported at this time, because we don't have
 	// access to it.
-	_disk->setMode13(false);
+	_disk->setSectorLimit(0);
 	StreamPtr stream(_disk->createReadStream(0x00, 0xd, 0x17, 1));
 
 	_display->setMode(DISPLAY_MODE_TEXT);
@@ -50,7 +50,7 @@ void HiRes2Engine::runIntro() const {
 	_display->printString(str);
 	delay(2000);
 
-	_disk->setMode13(true);
+	_disk->setSectorLimit(13);
 }
 
 void HiRes2Engine::init() {
@@ -60,7 +60,7 @@ void HiRes2Engine::init() {
 	if (!_disk->open(IDS_HR2_DISK_IMAGE))
 		error("Failed to open disk image '" IDS_HR2_DISK_IMAGE "'");
 
-	_disk->setMode13(true);
+	_disk->setSectorLimit(13);
 
 	StreamPtr stream(_disk->createReadStream(0x1f, 0x2, 0x00, 4));