SCUMM: Document and cleanup resource type mode

4 files changed, 74 insertions, 49 deletions

diff --git a/engines/scumm/resource.cpp b/engines/scumm/resource.cpp
index 76b6830137..7f88def0ad 100644
--- a/engines/scumm/resource.cpp
+++ b/engines/scumm/resource.cpp
@@ -526,28 +526,28 @@ int ScummEngine_v70he::readResTypeList(int id) {
 	return num;
 }
 
-void ResourceManager::allocResTypeData(int id, uint32 tag, int num_, const char *name_, int mode_) {
-	debug(9, "allocResTypeData(%s/%s,%s,%d,%d)", resTypeFromId(id), name_, tag2str(TO_BE_32(tag)), num_, mode_);
+void ResourceManager::allocResTypeData(int id, uint32 tag, int num, const char *name, ResTypeMode mode) {
+	debug(9, "allocResTypeData(%s/%s,%s,%d,%d)", resTypeFromId(id), name, tag2str(TO_BE_32(tag)), num, mode);
 	assert(id >= 0 && id < (int)(ARRAYSIZE(_types)));
 
-	if (num_ >= 8000)
-		error("Too many %ss (%d) in directory", name_, num_);
+	if (num >= 8000)
+		error("Too many %ss (%d) in directory", name, num);
 
-	_types[id].mode = mode_;
-	_types[id].num = num_;
-	_types[id].tags = tag;
-	_types[id].name = name_;
-	_types[id].address = (byte **)calloc(num_, sizeof(void *));
-	_types[id].flags = (byte *)calloc(num_, sizeof(byte));
-	_types[id].status = (byte *)calloc(num_, sizeof(byte));
+	_types[id]._mode = mode;
+	_types[id].num = num;
+	_types[id].tag = tag;
+	_types[id].name = name;
+	_types[id].address = (byte **)calloc(num, sizeof(void *));
+	_types[id].flags = (byte *)calloc(num, sizeof(byte));
+	_types[id].status = (byte *)calloc(num, sizeof(byte));
 
-	if (mode_) {
-		_types[id].roomno = (byte *)calloc(num_, sizeof(byte));
-		_types[id].roomoffs = (uint32 *)calloc(num_, sizeof(uint32));
+	if (mode) {
+		_types[id].roomno = (byte *)calloc(num, sizeof(byte));
+		_types[id].roomoffs = (uint32 *)calloc(num, sizeof(uint32));
 	}
 
 	if (_vm->_game.heversion >= 70) {
-		_types[id].globsize = (uint32 *)calloc(num_, sizeof(uint32));
+		_types[id].globsize = (uint32 *)calloc(num, sizeof(uint32));
 	}
 
 }
@@ -669,7 +669,7 @@ int ScummEngine::loadResource(int type, int idx) {
 
 		tag = _fileHandle->readUint32BE();
 
-		if (tag != _res->_types[type].tags && _game.heversion < 70) {
+		if (tag != _res->_types[type].tag && _game.heversion < 70) {
 			error("%s %d not in room %d at %d+%d in file %s",
 					_res->_types[type].name, idx, roomNr,
 					_fileOffset, fileOffs, _fileHandle->getName());
@@ -734,11 +734,13 @@ byte *ScummEngine::getResourceAddress(int type, int idx) {
 		return NULL;
 	}
 
-	if (_res->_types[type].mode && !_res->_types[type].address[idx]) {
+	// If the resource is missing, but loadable from the game data files, try to do so.
+	if (!_res->_types[type].address[idx] && _res->_types[type]._mode != kDynamicResTypeMode) {
 		ensureResourceLoaded(type, idx);
 	}
 
-	if (!(ptr = (byte *)_res->_types[type].address[idx])) {
+	ptr = (byte *)_res->_types[type].address[idx];
+	if (!ptr) {
 		debugC(DEBUG_RESOURCE, "getResourceAddress(%s,%d) == NULL", resTypeFromId(type), idx);
 		return NULL;
 	}
@@ -978,7 +980,9 @@ void ResourceManager::expireResources(uint32 size) {
 		best_counter = 2;
 
 		for (i = rtFirst; i <= rtLast; i++)
-			if (_types[i].mode) {
+			if (_types[i]._mode != kDynamicResTypeMode) {
+				// Resources of this type can be reloaded from the data files,
+				// so we can potentially unload them to free memory.
 				for (j = _types[i].num; --j >= 0;) {
 					flag = _types[i].flags[j];
 					if (!(flag & RF_LOCK) && flag >= best_counter && _types[i].address[j] && !_vm->isResourceInUse(i, j)) {
@@ -1275,30 +1279,30 @@ void ScummEngine::allocateArrays() {
 	}
 
 	_res->allocResTypeData(rtCostume, (_game.features & GF_NEW_COSTUMES) ? MKTAG('A','K','O','S') : MKTAG('C','O','S','T'),
-								_numCostumes, "costume", 1);
-	_res->allocResTypeData(rtRoom, MKTAG('R','O','O','M'), _numRooms, "room", 1);
-	_res->allocResTypeData(rtRoomImage, MKTAG('R','M','I','M'), _numRooms, "room image", 1);
-	_res->allocResTypeData(rtRoomScripts, MKTAG('R','M','S','C'), _numRooms, "room script", 1);
-	_res->allocResTypeData(rtSound, MKTAG('S','O','U','N'), _numSounds, "sound", 2);
-	_res->allocResTypeData(rtScript, MKTAG('S','C','R','P'), _numScripts, "script", 1);
-	_res->allocResTypeData(rtCharset, MKTAG('C','H','A','R'), _numCharsets, "charset", 1);
-	_res->allocResTypeData(rtObjectName, 0, _numNewNames, "new name", 0);
-	_res->allocResTypeData(rtInventory, 0, _numInventory, "inventory", 0);
-	_res->allocResTypeData(rtTemp, 0, 10, "temp", 0);
-	_res->allocResTypeData(rtScaleTable, 0, 5, "scale table", 0);
-	_res->allocResTypeData(rtActorName, 0, _numActors, "actor name", 0);
-	_res->allocResTypeData(rtVerb, 0, _numVerbs, "verb", 0);
-	_res->allocResTypeData(rtString, 0, _numArray, "array", 0);
-	_res->allocResTypeData(rtFlObject, 0, _numFlObject, "flobject", 0);
-	_res->allocResTypeData(rtMatrix, 0, 10, "boxes", 0);
-	_res->allocResTypeData(rtImage, MKTAG('A','W','I','Z'), _numImages, "images", 1);
-	_res->allocResTypeData(rtTalkie, MKTAG('T','L','K','E'), _numTalkies, "talkie", 1);
+								_numCostumes, "costume", kStaticResTypeMode);
+	_res->allocResTypeData(rtRoom, MKTAG('R','O','O','M'), _numRooms, "room", kStaticResTypeMode);
+	_res->allocResTypeData(rtRoomImage, MKTAG('R','M','I','M'), _numRooms, "room image", kStaticResTypeMode);
+	_res->allocResTypeData(rtRoomScripts, MKTAG('R','M','S','C'), _numRooms, "room script", kStaticResTypeMode);
+	_res->allocResTypeData(rtSound, MKTAG('S','O','U','N'), _numSounds, "sound", kSoundResTypeMode);
+	_res->allocResTypeData(rtScript, MKTAG('S','C','R','P'), _numScripts, "script", kStaticResTypeMode);
+	_res->allocResTypeData(rtCharset, MKTAG('C','H','A','R'), _numCharsets, "charset", kStaticResTypeMode);
+	_res->allocResTypeData(rtObjectName, 0, _numNewNames, "new name", kDynamicResTypeMode);
+	_res->allocResTypeData(rtInventory, 0, _numInventory, "inventory", kDynamicResTypeMode);
+	_res->allocResTypeData(rtTemp, 0, 10, "temp", kDynamicResTypeMode);
+	_res->allocResTypeData(rtScaleTable, 0, 5, "scale table", kDynamicResTypeMode);
+	_res->allocResTypeData(rtActorName, 0, _numActors, "actor name", kDynamicResTypeMode);
+	_res->allocResTypeData(rtVerb, 0, _numVerbs, "verb", kDynamicResTypeMode);
+	_res->allocResTypeData(rtString, 0, _numArray, "array", kDynamicResTypeMode);
+	_res->allocResTypeData(rtFlObject, 0, _numFlObject, "flobject", kDynamicResTypeMode);
+	_res->allocResTypeData(rtMatrix, 0, 10, "boxes", kDynamicResTypeMode);
+	_res->allocResTypeData(rtImage, MKTAG('A','W','I','Z'), _numImages, "images", kStaticResTypeMode);
+	_res->allocResTypeData(rtTalkie, MKTAG('T','L','K','E'), _numTalkies, "talkie", kStaticResTypeMode);
 }
 
 void ScummEngine_v70he::allocateArrays() {
 	ScummEngine::allocateArrays();
 
-	_res->allocResTypeData(rtSpoolBuffer, 0, 9, "spool buffer", 1);
+	_res->allocResTypeData(rtSpoolBuffer, 0, 9, "spool buffer", kStaticResTypeMode);
 	_heV7RoomIntOffsets = (uint32 *)calloc(_numRooms, sizeof(uint32));
 }
 
diff --git a/engines/scumm/resource.h b/engines/scumm/resource.h
index b3cb424d4f..8540ef3138 100644
--- a/engines/scumm/resource.h
+++ b/engines/scumm/resource.h
@@ -50,6 +50,24 @@ enum {
 class ScummEngine;
 
 /**
+ * The mode of a resource type indicates whether the resource can be restored
+ * from the game data files or not.
+ * This affects for example whether the resource is stored in savestates.
+ *
+ * Note that we treat sound resources somewhat differently: On the one hand,
+ * these behave mostly like a kStaticResTypeMode res type. However, when we
+ * create a savestate, we do save *some* information about them: Namely, which
+ * sound resources are loaded in memory at the time the save is made. And when
+ * loading, we invoke ensureResourceLoaded() for each sound resource that was
+ * marked in this way.
+ */
+enum ResTypeMode {
+	kDynamicResTypeMode = 0,	///!< Resource is generated during runtime and may change
+	kStaticResTypeMode = 1,		///!< Resource comes from data files, does not change
+	kSoundResTypeMode = 2		///!< Resource comes from data files, but may change
+};
+
+/**
  * The 'resource manager' class. Currently doesn't really deserve to be called
  * a 'class', at least until somebody gets around to OOfying this more.
  */
@@ -60,12 +78,15 @@ protected:
 	ScummEngine *_vm;
 
 public:
+	/**
+	 * This struct represents a resource type and all resource of that type.
+	 */
 	class ResTypeData {
 	friend class ResourceManager;
 	public:
-		byte mode;
+		ResTypeMode _mode;
 		uint16 num;
-		uint32 tags;
+		uint32 tag;
 		const char *name;
 		byte **address;
 	protected:
@@ -89,7 +110,7 @@ public:
 
 	void setHeapThreshold(int min, int max);
 
-	void allocResTypeData(int id, uint32 tag, int num, const char *name, int mode);
+	void allocResTypeData(int id, uint32 tag, int num, const char *name, ResTypeMode mode);
 	void freeResources();
 
 	byte *createResource(int type, int index, uint32 size);
diff --git a/engines/scumm/saveload.cpp b/engines/scumm/saveload.cpp
index 424e0005f4..40dc70af4b 100644
--- a/engines/scumm/saveload.cpp
+++ b/engines/scumm/saveload.cpp
@@ -1243,7 +1243,7 @@ void ScummEngine::saveOrLoad(Serializer *s) {
 		// number of script resources, savegames won't break.
 		if (s->isSaving()) {
 			for (type = rtFirst; type <= rtLast; type++) {
-				if (_res->_types[type].mode != 1 && type != rtTemp && type != rtBuffer) {
+				if (_res->_types[type]._mode != kStaticResTypeMode && type != rtTemp && type != rtBuffer) {
 					s->saveUint16(type);	// Save the res type...
 					for (idx = 0; idx < _res->_types[type].num; idx++) {
 						// Only save resources which actually exist...
@@ -1269,7 +1269,7 @@ void ScummEngine::saveOrLoad(Serializer *s) {
 		// with index 0, and breaks whenever we change the limit on a given
 		// resource type.
 		for (type = rtFirst; type <= rtLast; type++)
-			if (_res->_types[type].mode != 1 && type != rtTemp && type != rtBuffer) {
+			if (_res->_types[type]._mode != kStaticResTypeMode && type != rtTemp && type != rtBuffer) {
 				// For V1-V5 games, there used to be no object name resources.
 				// At some point this changed. But since old savegames rely on
 				// unchanged resource counts, we have to hard code the following check
@@ -1637,7 +1637,7 @@ void ScummEngine::saveLoadResource(Serializer *ser, int type, int idx) {
 	byte *ptr;
 	uint32 size;
 
-	if (!_res->_types[type].mode) {
+	if (_res->_types[type]._mode == kDynamicResTypeMode) {
 		if (ser->isSaving()) {
 			ptr = _res->_types[type].address[idx];
 			if (ptr == NULL) {
@@ -1676,7 +1676,7 @@ void ScummEngine::saveLoadResource(Serializer *ser, int type, int idx) {
 				}
 			}
 		}
-	} else if (_res->_types[type].mode == 2 && ser->getVersion() >= VER(23)) {
+	} else if (_res->_types[type]._mode == kSoundResTypeMode && ser->getVersion() >= VER(23)) {
 		// Save/load only a list of resource numbers that need to be reloaded.
 		if (ser->isSaving()) {
 			ser->saveUint16(_res->_types[type].address[idx] ? 1 : 0);
@@ -1690,7 +1690,7 @@ void ScummEngine::saveLoadResource(Serializer *ser, int type, int idx) {
 void ScummEngine::saveResource(Serializer *ser, int type, int idx) {
 	assert(_res->_types[type].address[idx]);
 
-	if (_res->_types[type].mode == 0) {
+	if (_res->_types[type]._mode == kDynamicResTypeMode) {
 		byte *ptr = _res->_types[type].address[idx];
 		uint32 size = ((MemBlkHeader *)ptr)->size;
 
@@ -1713,7 +1713,7 @@ void ScummEngine::loadResource(Serializer *ser, int type, int idx) {
 		assert(size);
 		_res->createResource(type, idx, size);
 		ser->loadBytes(getResourceAddress(type, idx), size);
-	} else if (_res->_types[type].mode == 0) {
+	} else if (_res->_types[type]._mode == kDynamicResTypeMode) {
 		uint32 size = ser->loadUint32();
 		assert(size);
 		_res->createResource(type, idx, size);
@@ -1725,7 +1725,7 @@ void ScummEngine::loadResource(Serializer *ser, int type, int idx) {
 		if (type == rtObjectName) {
 			_newNames[idx] = ser->loadUint16();
 		}
-	} else if (_res->_types[type].mode == 2) {
+	} else if (_res->_types[type]._mode == kSoundResTypeMode) {
 		// HE Games use sound resource 1 for speech
 		if (_game.heversion >= 60 && idx == 1)
 			return;
diff --git a/engines/scumm/scumm.cpp b/engines/scumm/scumm.cpp
index d5c2b2eeb9..e89100688a 100644
--- a/engines/scumm/scumm.cpp
+++ b/engines/scumm/scumm.cpp
@@ -1233,7 +1233,7 @@ void ScummEngine::setupScumm() {
 		requestLoad(ConfMan.getInt("save_slot"));
 	}
 
-	_res->allocResTypeData(rtBuffer, 0, 10, "buffer", 0);
+	_res->allocResTypeData(rtBuffer, 0, 10, "buffer", kDynamicResTypeMode);
 
 	setupScummVars();