PRINCE: script code refactored

engines/prince/prince.cpp

@@ -74,10 +74,10 @@ void PrinceEngine::debugEngine(const char *s, ...) {
 }
 
 PrinceEngine::PrinceEngine(OSystem *syst, const PrinceGameDescription *gameDesc) : 
-	Engine(syst), _gameDescription(gameDesc), _graph(NULL), _script(NULL),
+	Engine(syst), _gameDescription(gameDesc), _graph(nullptr), _script(nullptr), _interpreter(nullptr), _flags(nullptr),
-	_locationNr(0), _debugger(NULL), _midiPlayer(NULL),
+	_locationNr(0), _debugger(nullptr), _midiPlayer(nullptr),
-	_cameraX(0), _newCameraX(0), _frameNr(0), _cursor1(NULL), _cursor2(NULL), _font(NULL),
+	_cameraX(0), _newCameraX(0), _frameNr(0), _cursor1(nullptr), _cursor2(nullptr), _font(nullptr),
-	_walizkaBmp(NULL), _roomBmp(NULL), _cursorNr(0) {
+	_walizkaBmp(nullptr), _roomBmp(nullptr), _cursorNr(0) {
 
 	// Debug/console setup
 	DebugMan.addDebugChannel(DebugChannel::kScript, "script", "Prince Script debug channel");
@@ -99,6 +99,8 @@ PrinceEngine::~PrinceEngine() {
 	delete _cursor2;
 	delete _midiPlayer;
 	delete _script;
+	delete _flags;
+	delete _interpreter;
 	delete _font;
 	delete _roomBmp;
 	delete _walizkaBmp;
@@ -153,9 +155,12 @@ void PrinceEngine::init() {
 	_walizkaBmp = new MhwanhDecoder();
 	Resource::loadResource(_walizkaBmp, "all/walizka");
 
-	_script = new Script(this);
+	_script = new Script();
 	Resource::loadResource(_script, "all/skrypt.dat");
 
+	_flags = new InterpreterFlags();
+	_interpreter = new Interpreter(this, _script, _flags);
+
 	_variaTxt = new VariaTxt();
 	Resource::loadResource(_variaTxt, "all/variatxt.dat");
 	
@@ -249,8 +254,8 @@ bool PrinceEngine::loadLocation(uint16 locationNr) {
 	_cameraX = 0;
 	_newCameraX = 0;
 	
-	_script->setFlagValue(Flags::CURRROOM, _locationNr);
+	_flags->setFlagValue(Flags::CURRROOM, _locationNr);
-	_script->stopBg();
+	_interpreter->stopBg();
 
 	changeCursor(0);
 
@@ -290,7 +295,7 @@ bool PrinceEngine::loadLocation(uint16 locationNr) {
 void PrinceEngine::changeCursor(uint16 curId) {
 	_debugger->_cursorNr = curId;
 
-	const Graphics::Surface *curSurface = NULL;
+	const Graphics::Surface *curSurface = nullptr;
 
 	uint16 hotspotX = 0;
 	uint16 hotspotY = 0;
@@ -353,7 +358,7 @@ void PrinceEngine::playSample(uint16 sampleId, uint16 loopType) {
 
 void PrinceEngine::stopSample(uint16 sampleId) {
 	_mixer->stopID(sampleId);
-	_voiceStream[sampleId] = NULL;
+	_voiceStream[sampleId] = nullptr;
 }
 
 bool PrinceEngine::loadSample(uint32 sampleSlot, const Common::String &streamName) {
@@ -364,12 +369,12 @@ bool PrinceEngine::loadSample(uint32 sampleSlot, const Common::String &streamNam
 	debugEngine("loadSample slot %d, name %s", sampleSlot, normalizedPath.c_str());
 
 	_mixer->stopID(sampleSlot);
-	_voiceStream[sampleSlot] = NULL;
+	_voiceStream[sampleSlot] = nullptr;
 	_voiceStream[sampleSlot] = SearchMan.createReadStreamForMember(normalizedPath);
-	if (_voiceStream[sampleSlot] == NULL) {
+	if (_voiceStream[sampleSlot] == nullptr) {
 		error("Can't load sample %s to slot %d", normalizedPath.c_str(), sampleSlot);
 	}
-	return _voiceStream[sampleSlot] == NULL;
+	return _voiceStream[sampleSlot] == nullptr;
 }
 
 bool PrinceEngine::loadVoice(uint32 slot, uint32 sampleSlot, const Common::String &streamName) {
@@ -466,7 +471,7 @@ void PrinceEngine::keyHandler(Common::Event event) {
 		scrollCameraRight(32);
 		break;
 	case Common::KEYCODE_ESCAPE:
-		_script->setFlagValue(Flags::ESCAPED2, 1);
+		_flags->setFlagValue(Flags::ESCAPED2, 1);
 		break;
 	}
 }
@@ -551,7 +556,7 @@ void PrinceEngine::showTexts() {
 
 		--text._time;
 		if (text._time == 0) {
-			text._str = NULL;
+			text._str = nullptr;
 		}
 	}
 }
@@ -587,7 +592,6 @@ void PrinceEngine::drawScreen() {
 
 void PrinceEngine::mainLoop() {
 
-	loadLocation(4);
 	changeCursor(0);
 
 	while (!shouldQuit()) {
@@ -622,7 +626,7 @@ void PrinceEngine::mainLoop() {
 
 		// TODO: Update all structures, animations, naks, heros etc.
 
-		_script->step();
+		_interpreter->step();
 
 		drawScreen();
 

engines/prince/prince.h

@@ -53,6 +53,8 @@ struct PrinceGameDescription;
 class PrinceEngine;
 class GraphicsMan;
 class Script;
+class Interpreter;
+class InterpreterFlags;
 class Debugger;
 class MusicPlayer;
 class VariaTxt;
@@ -162,6 +164,8 @@ private:
 	Debugger *_debugger;
 	GraphicsMan *_graph;
 	Script *_script;
+	InterpreterFlags *_flags;
+	Interpreter *_interpreter;
 	Font *_font;
 	MusicPlayer *_midiPlayer;
 

engines/prince/script.h

@@ -24,6 +24,7 @@
 #define PRINCE_SCRIPT_H
 
 #include "common/random.h"
+#include "common/endian.h"
 
 #include "audio/mixer.h"
 
@@ -37,25 +38,68 @@ namespace Prince {
 
 class PrinceEngine;
 
+namespace Detail {
+	template <typename T> T LittleEndianReader(void *data);
+	template <> inline uint8 LittleEndianReader<uint8>(void *data) { return *(uint8*)(data); }
+	template <> inline uint16 LittleEndianReader<uint16>(void *data) { return READ_LE_UINT16(data); }
+	template <> inline uint32 LittleEndianReader<uint32>(void *data) { return READ_LE_UINT32(data); }
+}
+
 class Script {
 public:
-	Script(PrinceEngine *vm);
+	Script();
-	virtual ~Script();
+	~Script();
 
 	bool loadFromStream(Common::SeekableReadStream &stream);
 
-	void step();
+	template <typename T>
+	T read(uint32 address) {
+		assert((_data + address + sizeof(T)) <= (_data + _dataSize));
+		return Detail::LittleEndianReader<T>(&_data[address]);
+	}
+
+	// Some magic numbers for now, data stored in header
+	uint32 getRoomTableOffset() { return read<uint32>(0); }
+	uint32 getStartGameOffset() { return read<uint32>(4); }
+
+	const char *getString(uint32 offset) {
+		return (const char *)(&_data[offset]);
+	}
+
+private:
+	uint8 *_data;
+	uint32 _dataSize;
+};
+
+class InterpreterFlags {
+public:
+	InterpreterFlags();
 
 	void setFlagValue(Flags::Id flag, uint16 value);
 	uint16 getFlagValue(Flags::Id flag);
 
+	void resetAllFlags();
+
+	static const uint16 FLAG_MASK = 0x8000;
+
+private:
+	static const uint16 MAX_FLAGS = 2000;
+	int16 _flags[MAX_FLAGS];
+};
+
+class Interpreter {
+public:
+	Interpreter(PrinceEngine *vm, Script *script, InterpreterFlags *flags);
+
 	void stopBg() { _bgOpcodePC = 0; }
 
+	void step();
+
 private:
 	PrinceEngine *_vm;
+	Script *_script;
+	InterpreterFlags *_flags;
 
-	byte *_code;
-	uint32 _codeSize;
 	uint32 _currentInstruction;
 
 	uint32 _bgOpcodePC;
@@ -64,13 +108,9 @@ private:
 	uint16 _lastOpcode;
 	uint32 _lastInstruction;
 	byte _result;
-	static const uint16 MAX_FLAGS = 2000;
-	static const uint16 FLAG_MASK = 0x8000;
-	int16 _flags[MAX_FLAGS];
-	bool _opcodeNF;
 
+	bool _opcodeNF; // break interpreter loop
 
-	// Stack
 	static const uint32 _STACK_SIZE = 500;
 	uint32 _stack[_STACK_SIZE];
 	uint8 _stacktop;
@@ -83,21 +123,19 @@ private:
 
 	// Helper functions
 	uint32 step(uint32 opcodePC);
-	void checkPC(uint32 address);
-	uint8 getCodeByte(uint32 address);
-	uint8 readScript8bits();
-	uint16 readScript16bits();
 
-	uint32 readScript32bits();
+	void checkPC(uint32 address);
-	uint16 readScript8or16bits();
 
 	uint16 readScriptValue();
-	Flags::Id readScriptFlagId() { return (Flags::Id)readScript16bits(); }
+	Flags::Id readScriptFlagId();
 
-	void debugScript(const char *s, ...);
+	// instantiation not needed here
+	template <typename T> T readScript();
+
+	void debugInterpreter(const char *s, ...);
 	void SetVoice(uint32 slot);
 
-	typedef void (Script::*OpcodeFunc)();
+	typedef void (Interpreter::*OpcodeFunc)();
 	static OpcodeFunc _opcodes[];
 
 	// Keep opcode handlers names as they are in original code 
@@ -246,6 +284,7 @@ private:
 	void O_INPUTLINE();
 	void O_SETVOICED();
 	void O_BREAK_POINT();
+
 };
 
 }