1 files changed, 67 insertions, 2 deletions

diff --git a/engines/adl/hires4.cpp b/engines/adl/hires4.cpp
index 22fd9c2f81..1ce2a44c4a 100644
--- a/engines/adl/hires4.cpp
+++ b/engines/adl/hires4.cpp
@@ -27,24 +27,89 @@
 #include "common/stream.h"
 
 #include "adl/hires4.h"
+#include "adl/detection.h"
 #include "adl/display.h"
 #include "adl/graphics.h"
 #include "adl/disk.h"
 
 namespace Adl {
 
-void HiRes4Engine::runIntro() const {
+HiRes4Engine::~HiRes4Engine() {
+	delete _disk2;
+	delete _disk3;
 }
 
 void HiRes4Engine::init() {
 	_graphics = new Graphics_v2(*_display);
+
+	const char *const *names = getDiskImageNames();
+
+	_disk = new DiskImage();
+	if (!_disk->open(names[0]))
+		error("Failed to open disk image '%s'", names[0]);
+
+	_disk2 = new DiskImage();
+	if (!_disk2->open(names[1]))
+		error("Failed to open disk image '%s'", names[1]);
+
+	_disk3 = new DiskImage();
+	if (!_disk3->open(names[2]))
+		error("Failed to open disk image '%s'", names[2]);
+
+	StreamPtr stream(createReadStream(_disk, 0x06, 0xd, 0x12, 2));
+	loadItemDescriptions(*stream, IDI_HR4_NUM_ITEM_DESCS);
+
+	stream.reset(createReadStream(_disk, 0x05, 0x4, 0x00, 3));
+	loadWords(*stream, _verbs, _priVerbs);
+
+	stream.reset(createReadStream(_disk, 0x03, 0xb, 0x00, 6));
+	loadWords(*stream, _nouns, _priNouns);
 }
 
 void HiRes4Engine::initGameState() {
+	StreamPtr stream(createReadStream(_disk, 0x02, 0xc, 0x00, 12));
+	loadItems(*stream);
+}
+
+Common::SeekableReadStream *HiRes4Engine::createReadStream(DiskImage *disk, byte track, byte sector, byte offset, byte size) const {
+	adjustDataBlockPtr(track, sector, offset, size);
+	return disk->createReadStream(track, sector, offset, size);
+}
+
+void HiRes4Engine_Atari::adjustDataBlockPtr(byte &track, byte &sector, byte &offset, byte &size) const {
+	// Convert the Apple II disk offsets in the game, to Atari disk offsets
+	uint sectorIndex = (track * 16 + sector + 1) << 1;
+
+	// Atari uses 128 bytes per sector vs. 256 on the Apple II
+	// Note that size indicates *additional* sectors to read after reading one sector
+	size *= 2;
+
+	if (offset >= 128) {
+		// Offset in the second half of an Apple II sector, skip one sector and adjust offset
+		++sectorIndex;
+		offset -= 128;
+	} else {
+		// Offset in the first half of an Apple II sector, we need to read one additional sector
+		++size;
+	}
+
+	// Compute track/sector for Atari's 18 sectors per track (sectorIndex is 1-based)
+	track = (sectorIndex - 1) / 18;
+	sector = (sectorIndex - 1) % 18;
+}
+
+const char *const *HiRes4Engine_Atari::getDiskImageNames() const {
+	static const char *const disks[] = { "ULYS1A.XFD", "ULYS1B.XFD", "ULYS2C.XFD" };
+	return disks;
 }
 
 Engine *HiRes4Engine_create(OSystem *syst, const AdlGameDescription *gd) {
-	return new HiRes4Engine(syst, gd);
+	switch (gd->desc.platform) {
+	case Common::kPlatformAtariST:
+		return new HiRes4Engine_Atari(syst, gd);
+	default:
+		error("Unsupported platform");
+	}
 }
 
 } // End of namespace Adl