DM: Add support for Dungeon.dat uncompression

Add DungeonMan class with support for loading and uncompressing
Dungeon.dat file into memory

5 files changed, 94 insertions, 2 deletions

diff --git a/engines/dm/dm.cpp b/engines/dm/dm.cpp
index d6fc1f3d7d..61e68dfaa7 100644
--- a/engines/dm/dm.cpp
+++ b/engines/dm/dm.cpp
@@ -12,6 +12,7 @@
 
 #include "dm/dm.h"
 #include "dm/gfx.h"
+#include "dm/dungeonman.h"
 
 namespace DM {
 
@@ -39,17 +40,23 @@ DMEngine::~DMEngine() {
 	delete _rnd;
 	delete _console;
 	delete _displayMan;
+	delete _dungeonMan;
 
 	// clear debug channels
 	DebugMan.clearAllDebugChannels();
 }
 
+
 Common::Error DMEngine::run() {
 	initGraphics(320, 200, false);
 	_console = new Console(this);
 	_displayMan = new DisplayMan(this);
+	_dungeonMan = new DungeonMan(this);
 	_displayMan->setUpScreens(320, 200);
 	_displayMan->loadGraphics();
+	_dungeonMan->loadDungeonFile();
+
+
 
 
 	byte *palette = new byte[256 * 3];
@@ -79,7 +86,6 @@ Common::Error DMEngine::run() {
 		_displayMan->updateScreen();
 	}
 
-
 	return Common::kNoError;
 }
 
diff --git a/engines/dm/dm.h b/engines/dm/dm.h
index 6820640d18..705939cc63 100644
--- a/engines/dm/dm.h
+++ b/engines/dm/dm.h
@@ -10,6 +10,7 @@ namespace DM {
 
 class Console;
 class DisplayMan;
+class DungeonMan;
 
 enum {
 	// engine debug channels
@@ -28,6 +29,7 @@ private:
 	Console *_console;
 	Common::RandomSource *_rnd;
 	DisplayMan *_displayMan;
+	DungeonMan *_dungeonMan;
 };
 
 class Console : public GUI::Debugger {
diff --git a/engines/dm/dungeonman.cpp b/engines/dm/dungeonman.cpp
new file mode 100644
index 0000000000..6ddf966eb9
--- /dev/null
+++ b/engines/dm/dungeonman.cpp
@@ -0,0 +1,62 @@
+#include "dungeonman.h"
+#include "common/file.h"
+
+
+namespace DM {
+DungeonMan::DungeonMan(DMEngine *dmEngine) : _vm(dmEngine), _dungeonDataSize(0), _dungeonData(NULL) {}
+DungeonMan::~DungeonMan() { delete[] _dungeonData; }
+void DungeonMan::loadDungeonFile() {
+	Common::File f;
+	f.open("Dungeon.dat");
+	if (f.readUint16BE() == 0x8104) {
+		_dungeonDataSize = f.readUint32BE();
+		_dungeonData = new byte[_dungeonDataSize];
+		f.readUint16BE();
+		byte common[4];
+		for (uint16 i = 0; i < 4; ++i)
+			common[i] = f.readByte();
+		byte lessCommon[16];
+		for (uint16 i = 0; i < 16; ++i)
+			lessCommon[i] = f.readByte();
+
+		// start unpacking
+		uint32 uncompIndex = 0;
+		uint8 bitsUsedInWord = 0;
+		uint16 wordBuff = f.readUint16BE();
+		uint8 bitsLeftInByte = 8;
+		byte byteBuff = f.readByte();
+		while (uncompIndex < _dungeonDataSize) {
+			while (bitsUsedInWord != 0) {
+				uint8 shiftVal;
+				if (f.eos()) {
+					shiftVal = bitsUsedInWord;
+					wordBuff <<= shiftVal;
+				} else {
+					shiftVal = MIN(bitsLeftInByte, bitsUsedInWord);
+					wordBuff <<= shiftVal;
+					wordBuff |= (byteBuff >> (8 - shiftVal));
+					byteBuff <<= shiftVal;
+					bitsLeftInByte -= shiftVal;
+					if (!bitsLeftInByte) {
+						byteBuff = f.readByte();
+						bitsLeftInByte = 8;
+					}
+				}
+				bitsUsedInWord -= shiftVal;
+			}
+			if (((wordBuff >> 15) & 1) == 0) {
+				_dungeonData[uncompIndex++] = common[(wordBuff >> 13) & 3];
+				bitsUsedInWord += 3;
+			} else if (((wordBuff >> 14) & 3) == 2) {
+				_dungeonData[uncompIndex++] = lessCommon[(wordBuff >> 10) & 15];
+				bitsUsedInWord += 6;
+			} else if (((wordBuff >> 14) & 3) == 3) {
+				_dungeonData[uncompIndex++] = (wordBuff >> 6) & 255;
+				bitsUsedInWord += 10;
+			}
+		}
+	}
+	f.close();
+}
+
+}
\ No newline at end of file
diff --git a/engines/dm/dungeonman.h b/engines/dm/dungeonman.h
new file mode 100644
index 0000000000..b820bb2b58
--- /dev/null
+++ b/engines/dm/dungeonman.h
@@ -0,0 +1,22 @@
+#ifndef DUNGEONMAN_H
+#define DUNGEONMAN_H
+
+#include "dm.h"
+
+namespace DM {
+
+class DungeonMan {
+	DMEngine *_vm;
+	uint32 _dungeonDataSize;
+	byte *_dungeonData;
+	DungeonMan(const DungeonMan &other); // no implementation on purpose
+	void operator=(const DungeonMan &rhs); // no implementation on purpose
+public:
+	DungeonMan(DMEngine *dmEngine);
+	~DungeonMan();
+	void loadDungeonFile();
+};
+
+}
+
+#endif
diff --git a/engines/dm/gfx.h b/engines/dm/gfx.h
index 91cf7e1ca2..98d035be2c 100644
--- a/engines/dm/gfx.h
+++ b/engines/dm/gfx.h
@@ -15,7 +15,7 @@ class DisplayMan {
 	uint16 _itemCount;
 	uint32 *_indexBytePos;
 	uint8 *_compressedData;
-	DisplayMan(const DMEngine &dmEngine); // no implementation on purpose
+	DisplayMan(const DisplayMan &other); // no implementation on purpose
 	void operator=(const DisplayMan &rhs); // no implementation on purpose
 public:
 	DisplayMan(DMEngine *dmEngine);