SCUMM: Introduced new method ScummEngine_v5::jumpRelative; unified some v0 and v2 opcodes

svn-id: r40025

7 files changed, 95 insertions, 284 deletions

diff --git a/engines/scumm/script_v0.cpp b/engines/scumm/script_v0.cpp
index 23f1ef7de2..1b8368d636 100644
--- a/engines/scumm/script_v0.cpp
+++ b/engines/scumm/script_v0.cpp
@@ -41,12 +41,12 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x02, o5_startMusic);
 	OPCODE(0x03, o_doSentence);
 	/* 04 */
-	OPCODE(0x04, o_isGreaterEqual);
+	OPCODE(0x04, o2_isGreaterEqual);
 	OPCODE(0x05, o_stopCurrentScript);
 	OPCODE(0x06, o5_getDist);
 	OPCODE(0x07, o5_getActorRoom);
 	/* 08 */
-	OPCODE(0x08, o_isNotEqual);
+	OPCODE(0x08, o5_isNotEqual);
 	OPCODE(0x09, o_stopCurrentScript);
 	OPCODE(0x0a, o_stopCurrentScript);
 	OPCODE(0x0b, o_setActorBitVar);
@@ -64,9 +64,9 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x14, o_print_c64);
 	OPCODE(0x15, o5_walkActorToActor);
 	OPCODE(0x16, o5_getRandomNr);
-	OPCODE(0x17, o_clearState08);
+	OPCODE(0x17, o2_clearState08);
 	/* 18 */
-	OPCODE(0x18, o_jumpRelative);
+	OPCODE(0x18, o5_jumpRelative);
 	OPCODE(0x19, o_stopCurrentScript);
 	OPCODE(0x1a, o5_move);
 	OPCODE(0x1b, o_getActorBitVar);
@@ -86,7 +86,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x26, o_getClosestObjActor);
 	OPCODE(0x27, o2_getActorY);
 	/* 28 */
-	OPCODE(0x28, o_equalZero);
+	OPCODE(0x28, o5_equalZero);
 	OPCODE(0x29, o_setOwnerOf);
 	OPCODE(0x2a, o2_delay);
 	OPCODE(0x2b, o_setActorBitVar);
@@ -106,7 +106,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x36, o2_walkActorToObject);
 	OPCODE(0x37, o2_clearState04);
 	/* 38 */
-	OPCODE(0x38, o_isLessEqual);
+	OPCODE(0x38, o2_isLessEqual);
 	OPCODE(0x39, o_stopCurrentScript);
 	OPCODE(0x3a, o2_subtract);
 	OPCODE(0x3b, o_stopCurrentScript);
@@ -121,12 +121,12 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x42, o2_startScript);
 	OPCODE(0x43, o_doSentence);
 	/* 44 */
-	OPCODE(0x44, o_isLess);
+	OPCODE(0x44, o2_isLess);
 	OPCODE(0x45, o_stopCurrentScript);
 	OPCODE(0x46, o5_increment);
 	OPCODE(0x47, o2_getActorX);
 	/* 48 */
-	OPCODE(0x48, o_isEqual);
+	OPCODE(0x48, o5_isEqual);
 	OPCODE(0x49, o_stopCurrentScript);
 	OPCODE(0x4a, o_loadRoom);
 	OPCODE(0x4b, o_setActorBitVar);
@@ -144,7 +144,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x54, o_setObjectName);
 	OPCODE(0x55, o5_walkActorToActor);
 	OPCODE(0x56, o_getActorMoving);
-	OPCODE(0x57, o_clearState08);
+	OPCODE(0x57, o2_clearState08);
 	/* 58 */
 	OPCODE(0x58, o_beginOverride);
 	OPCODE(0x59, o_stopCurrentScript);
@@ -186,7 +186,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x76, o2_walkActorToObject);
 	OPCODE(0x77, o2_clearState04);
 	/* 78 */
-	OPCODE(0x78, o_isGreater);
+	OPCODE(0x78, o2_isGreater);
 	OPCODE(0x79, o_stopCurrentScript);
 	OPCODE(0x7a, o_stopCurrentScript);
 	OPCODE(0x7b, o_stopCurrentScript);
@@ -201,12 +201,12 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x82, o_stopCurrentScript);
 	OPCODE(0x83, o_doSentence);
 	/* 84 */
-	OPCODE(0x84, o_isGreaterEqual);
+	OPCODE(0x84, o2_isGreaterEqual);
 	OPCODE(0x85, o_stopCurrentScript);
 	OPCODE(0x86, o_nop);
 	OPCODE(0x87, o5_getActorRoom);
 	/* 88 */
-	OPCODE(0x88, o_isNotEqual);
+	OPCODE(0x88, o5_isNotEqual);
 	OPCODE(0x89, o_stopCurrentScript);
 	OPCODE(0x8a, o_stopCurrentScript);
 	OPCODE(0x8b, o_setActorBitVar);
@@ -224,7 +224,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0x94, o5_print);
 	OPCODE(0x95, o2_actorFromPos);
 	OPCODE(0x96, o_stopCurrentScript);
-	OPCODE(0x97, o_setState08);
+	OPCODE(0x97, o2_setState08);
 	/* 98 */
 	OPCODE(0x98, o2_restart);
 	OPCODE(0x99, o_stopCurrentScript);
@@ -246,7 +246,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0xa6, o_stopCurrentScript);
 	OPCODE(0xa7, o2_getActorY);
 	/* A8 */
-	OPCODE(0xa8, o_notEqualZero);
+	OPCODE(0xa8, o5_notEqualZero);
 	OPCODE(0xa9, o_setOwnerOf);
 	OPCODE(0xaa, o_stopCurrentScript);
 	OPCODE(0xab, o_setActorBitVar);
@@ -266,7 +266,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0xb6, o2_walkActorToObject);
 	OPCODE(0xb7, o2_setState04);
 	/* B8 */
-	OPCODE(0xb8, o_isLessEqual);
+	OPCODE(0xb8, o2_isLessEqual);
 	OPCODE(0xb9, o_stopCurrentScript);
 	OPCODE(0xba, o2_subtract);
 	OPCODE(0xbb, o_stopCurrentScript);
@@ -281,12 +281,12 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0xc2, o2_startScript);
 	OPCODE(0xc3, o_doSentence);
 	/* C4 */
-	OPCODE(0xc4, o_isLess);
+	OPCODE(0xc4, o2_isLess);
 	OPCODE(0xc5, o_stopCurrentScript);
 	OPCODE(0xc6, o5_decrement);
 	OPCODE(0xc7, o2_getActorX);
 	/* C8 */
-	OPCODE(0xc8, o_isEqual);
+	OPCODE(0xc8, o5_isEqual);
 	OPCODE(0xc9, o_stopCurrentScript);
 	OPCODE(0xca, o_loadRoom);
 	OPCODE(0xcb, o_setActorBitVar);
@@ -304,7 +304,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0xd4, o_setObjectName);
 	OPCODE(0xd5, o2_actorFromPos);
 	OPCODE(0xd6, o_getActorMoving);
-	OPCODE(0xd7, o_setState08);
+	OPCODE(0xd7, o2_setState08);
 	/* D8 */
 	OPCODE(0xd8, o_stopCurrentScript);
 	OPCODE(0xd9, o_stopCurrentScript);
@@ -346,7 +346,7 @@ void ScummEngine_v0::setupOpcodes() {
 	OPCODE(0xf6, o2_walkActorToObject);
 	OPCODE(0xf7, o2_setState04);
 	/* F8 */
-	OPCODE(0xf8, o_isGreater);
+	OPCODE(0xf8, o2_isGreater);
 	OPCODE(0xf9, o_stopCurrentScript);
 	OPCODE(0xfa, o_stopCurrentScript);
 	OPCODE(0xfb, o_stopCurrentScript);
@@ -367,8 +367,8 @@ uint ScummEngine_v0::fetchScriptWord() {
 	return fetchScriptByte();
 }
 
-int ScummEngine_v0::getObjectFlag() {
-	if (_opcode & 0x40)
+int ScummEngine_v0::getActiveObject() {
+	if (_opcode & PARAM_2)
 		return _activeObject;
 
 	return fetchScriptByte();
@@ -410,34 +410,6 @@ void ScummEngine_v0::decodeParseString() {
 	actorTalk(buffer);
 }
 
-void ScummEngine_v0::setStateCommon(byte type) {
-	int obj = getObjectFlag();
-	putState(obj, getState(obj) | type);
-}
-
-void ScummEngine_v0::clearStateCommon(byte type) {
-	int obj = getObjectFlag();
-	putState(obj, getState(obj) & ~type);
-}
-
-void ScummEngine_v0::ifStateCommon(byte type) {
-	int obj = getObjectFlag();
-
-	if ((getState(obj) & type) != 0)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
-void ScummEngine_v0::ifNotStateCommon(byte type) {
-	int obj = getObjectFlag();
-
-	if ((getState(obj) & type) == 0)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
 void ScummEngine_v0::drawSentence() {
 	Common::Rect sentenceline;
 	const byte *temp;
@@ -541,20 +513,6 @@ void ScummEngine_v0::drawSentence() {
 	drawString(2, (byte*)string);
 }
 
-void ScummEngine_v0::o_setState08() {
-	int obj = getObjectFlag();
-	putState(obj, getState(obj) | kObjectState_08);
-	markObjectRectAsDirty(obj);
-	clearDrawObjectQueue();
-}
-
-void ScummEngine_v0::o_clearState08() {
-	int obj = getObjectFlag();
-	putState(obj, getState(obj) & ~kObjectState_08);
-	markObjectRectAsDirty(obj);
-	clearDrawObjectQueue();
-}
-
 void ScummEngine_v0::o_stopCurrentScript() {
 	int script;
 
@@ -850,10 +808,7 @@ void ScummEngine_v0::o_unknown2() {
 void ScummEngine_v0::o_ifActiveObject() {
 	byte obj = fetchScriptByte();
 
-	if (obj == _activeInventory)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
+	jumpRelative(obj == _activeInventory);
 }
 
 void ScummEngine_v0::o_getClosestObjActor() {
@@ -870,7 +825,7 @@ void ScummEngine_v0::o_getClosestObjActor() {
 	getResultPos();
 
 	act = getVarOrDirectByte(PARAM_1);
-	obj = (_opcode & 0x40) ? 25 : 7;
+	obj = (_opcode & PARAM_2) ? 25 : 7;
 
 	do {
 		dist = getObjActToObjActDist(act, obj);
@@ -933,88 +888,6 @@ void ScummEngine_v0::o_beginOverride() {
 	VAR(VAR_OVERRIDE) = 0;
 }
 
-void ScummEngine_v0::o_isEqual() {
-	int16 a, b;
-	int var;
-
-	var = fetchScriptByte();
-	a = readVar(var);
-	b = getVarOrDirectByte(PARAM_1);
-
-	if (b == a)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-
-}
-
-void ScummEngine_v0::o_isGreater() {
-	int16 a = getVar();
-	int16 b = getVarOrDirectByte(PARAM_1);
-	if (b > a)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
-void ScummEngine_v0::o_isGreaterEqual() {
-	int16 a = getVar();
-	int16 b = getVarOrDirectByte(PARAM_1);
-	if (b >= a)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
-void ScummEngine_v0::o_isLess() {
-	int16 a = getVar();
-	int16 b = getVarOrDirectByte(PARAM_1);
-	if (b < a)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
-void ScummEngine_v0::o_isLessEqual() {
-	int16 a = getVar();
-	int16 b = getVarOrDirectByte(PARAM_1);
-
-	if (b <= a)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
-void ScummEngine_v0::o_isNotEqual() {
-	int16 a = getVar();
-	int16 b = getVarOrDirectByte(PARAM_1);
-	if (b != a)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
-void ScummEngine_v0::o_notEqualZero() {
-	int a = getVar();
-	if (a != 0)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
-void ScummEngine_v0::o_equalZero() {
-	int a = getVar();
-	if (a == 0)
-		ScummEngine::fetchScriptWord();
-	else
-		o_jumpRelative();
-}
-
-void ScummEngine_v0::o_jumpRelative() {
-	int16 offset = (int16)ScummEngine::fetchScriptWord();
-	_scriptPointer += offset;
-}
-
 void ScummEngine_v0::o_setOwnerOf() {
 	int obj, owner;
 
diff --git a/engines/scumm/script_v2.cpp b/engines/scumm/script_v2.cpp
index 941c3246b1..b2793fbb5f 100644
--- a/engines/scumm/script_v2.cpp
+++ b/engines/scumm/script_v2.cpp
@@ -23,7 +23,6 @@
  *
  */
 
-
 #include "scumm/actor.h"
 #include "scumm/charset.h"
 #include "scumm/object.h"
@@ -444,25 +443,41 @@ void ScummEngine_v2::getResultPos() {
 	_resultVarNumber = fetchScriptByte();
 }
 
+int ScummEngine_v2::getActiveObject() {
+	return getVarOrDirectWord(PARAM_1);
+}
+
 void ScummEngine_v2::setStateCommon(byte type) {
-	int obj = getVarOrDirectWord(PARAM_1);
+	int obj = getActiveObject();
 	putState(obj, getState(obj) | type);
 }
 
 void ScummEngine_v2::clearStateCommon(byte type) {
-	int obj = getVarOrDirectWord(PARAM_1);
+	int obj = getActiveObject();
 	putState(obj, getState(obj) & ~type);
 }
 
+void ScummEngine_v2::ifStateCommon(byte type) {
+	int obj = getActiveObject();
+
+	jumpRelative((getState(obj) & type) != 0);
+}
+
+void ScummEngine_v2::ifNotStateCommon(byte type) {
+	int obj = getActiveObject();
+
+	jumpRelative((getState(obj) & type) == 0);
+}
+
 void ScummEngine_v2::o2_setState08() {
-	int obj = getVarOrDirectWord(PARAM_1);
+	int obj = getActiveObject();
 	putState(obj, getState(obj) | kObjectState_08);
 	markObjectRectAsDirty(obj);
 	clearDrawObjectQueue();
 }
 
 void ScummEngine_v2::o2_clearState08() {
-	int obj = getVarOrDirectWord(PARAM_1);
+	int obj = getActiveObject();
 	putState(obj, getState(obj) & ~kObjectState_08);
 	markObjectRectAsDirty(obj);
 	clearDrawObjectQueue();
@@ -556,24 +571,6 @@ void ScummEngine_v2::o2_getBitVar() {
 	setResult((_scummVars[bit_var] & (1 << bit_offset)) ? 1 : 0);
 }
 
-void ScummEngine_v2::ifStateCommon(byte type) {
-	int obj = getVarOrDirectWord(PARAM_1);
-
-	if ((getState(obj) & type) != 0)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
-}
-
-void ScummEngine_v2::ifNotStateCommon(byte type) {
-	int obj = getVarOrDirectWord(PARAM_1);
-
-	if ((getState(obj) & type) == 0)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
-}
-
 void ScummEngine_v2::o2_ifState08() {
 	ifStateCommon(kObjectState_08);
 }
@@ -1087,6 +1084,8 @@ void ScummEngine_v2::o2_drawSentence() {
 void ScummEngine_v2::o2_ifClassOfIs() {
 	int obj = getVarOrDirectWord(PARAM_1);
 	int clsop = getVarOrDirectByte(PARAM_2);
+
+
 	byte *obcd = getOBCDFromObject(obj);
 
 	if (obcd == 0) {
@@ -1095,11 +1094,7 @@ void ScummEngine_v2::o2_ifClassOfIs() {
 	}
 
 	byte cls = *(obcd + 6);
-	if ((cls & clsop) != clsop) {
-		o5_jumpRelative();
-		return;
-	}
-	ignoreScriptWord();
+	jumpRelative((cls & clsop) == clsop);
 }
 
 void ScummEngine_v2::o2_walkActorTo() {
@@ -1127,7 +1122,6 @@ void ScummEngine_v2::o2_putActor() {
 	Actor *a;
 
 	a = derefActor(act, "o2_putActor");
-
 	x = getVarOrDirectByte(PARAM_2);
 	y = getVarOrDirectByte(PARAM_3);
 
@@ -1283,38 +1277,26 @@ void ScummEngine_v2::o2_getActorY() {
 void ScummEngine_v2::o2_isGreater() {
 	uint16 a = getVar();
 	uint16 b = getVarOrDirectWord(PARAM_1);
-	if (b > a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b > a);
 }
 
 void ScummEngine_v2::o2_isGreaterEqual() {
 	uint16 a = getVar();
 	uint16 b = getVarOrDirectWord(PARAM_1);
-	if (b >= a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b >= a);
 }
 
 void ScummEngine_v2::o2_isLess() {
 	uint16 a = getVar();
 	uint16 b = getVarOrDirectWord(PARAM_1);
 
-	if (b < a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b < a);
 }
 
 void ScummEngine_v2::o2_isLessEqual() {
 	uint16 a = getVar();
 	uint16 b = getVarOrDirectWord(PARAM_1);
-	if (b <= a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b <= a);
 }
 
 void ScummEngine_v2::o2_lights() {
diff --git a/engines/scumm/script_v4.cpp b/engines/scumm/script_v4.cpp
index b8964c4194..a8702a5d79 100644
--- a/engines/scumm/script_v4.cpp
+++ b/engines/scumm/script_v4.cpp
@@ -66,20 +66,14 @@ void ScummEngine_v4::o4_ifState() {
 	int a = getVarOrDirectWord(PARAM_1);
 	int b = getVarOrDirectByte(PARAM_2);
 
-	if (getState(a) != b)
-		o5_jumpRelative();
-	else
-		ignoreScriptWord();
+	jumpRelative(getState(a) == b);
 }
 
 void ScummEngine_v4::o4_ifNotState() {
 	int a = getVarOrDirectWord(PARAM_1);
 	int b = getVarOrDirectByte(PARAM_2);
 
-	if (getState(a) == b)
-		o5_jumpRelative();
-	else
-		ignoreScriptWord();
+	jumpRelative(getState(a) != b);
 }
 
 void ScummEngine_v4::o4_pickupObject() {
diff --git a/engines/scumm/script_v5.cpp b/engines/scumm/script_v5.cpp
index 84c299183c..191826f492 100644
--- a/engines/scumm/script_v5.cpp
+++ b/engines/scumm/script_v5.cpp
@@ -110,7 +110,7 @@ void ScummEngine_v5::setupOpcodes() {
 	OPCODE(0x36, o5_walkActorToObject);
 	OPCODE(0x37, o5_startObject);
 	/* 38 */
-	OPCODE(0x38, o5_lessOrEqual);
+	OPCODE(0x38, o5_isLessEqual);
 	OPCODE(0x39, o5_doSentence);
 	OPCODE(0x3a, o5_subtract);
 	OPCODE(0x3b, o5_getActorScale);
@@ -270,7 +270,7 @@ void ScummEngine_v5::setupOpcodes() {
 	OPCODE(0xb6, o5_walkActorToObject);
 	OPCODE(0xb7, o5_startObject);
 	/* B8 */
-	OPCODE(0xb8, o5_lessOrEqual);
+	OPCODE(0xb8, o5_isLessEqual);
 	OPCODE(0xb9, o5_doSentence);
 	OPCODE(0xba, o5_subtract);
 	OPCODE(0xbb, o5_getActorScale);
@@ -374,7 +374,17 @@ int ScummEngine_v5::getVarOrDirectByte(byte mask) {
 int ScummEngine_v5::getVarOrDirectWord(byte mask) {
 	if (_opcode & mask)
 		return getVar();
-	return (int16)fetchScriptWord();
+	return fetchScriptWordSigned();
+}
+
+void ScummEngine_v5::jumpRelative(bool cond) {
+	// We explicitly call ScummEngine::fetchScriptWordSigned()
+	// to make this method work also in v0, which overloads
+	// fetchScriptWord to only read bytes (which is the right thing
+	// to do for most opcodes, but not for jump offsets).
+	int16 offset = ScummEngine::fetchScriptWordSigned();
+	if (!cond)
+		_scriptPointer += offset;
 }
 
 void ScummEngine_v5::o5_actorFollowCamera() {
@@ -1121,21 +1131,18 @@ void ScummEngine_v5::o5_getVerbEntrypoint() {
 }
 
 void ScummEngine_v5::o5_ifClassOfIs() {
-	int act, cls, b = 0;
+	int obj, cls, b = 0;
 	bool cond = true;
 
-	act = getVarOrDirectWord(PARAM_1);
+	obj = getVarOrDirectWord(PARAM_1);
 
 	while ((_opcode = fetchScriptByte()) != 0xFF) {
 		cls = getVarOrDirectWord(PARAM_1);
-		b = getClass(act, cls);
+		b = getClass(obj, cls);
 		if (((cls & 0x80) && !b) || (!(cls & 0x80) && b))
 			cond = false;
 	}
-	if (cond)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(cond);
 }
 
 void ScummEngine_v5::o5_increment() {
@@ -1148,10 +1155,7 @@ void ScummEngine_v5::o5_isActorInBox() {
 	int box = getVarOrDirectByte(PARAM_2);
 	Actor *a = derefActor(act, "o5_isActorInBox");
 
-	if (!checkXYInBoxBounds(box, a->getRealPos().x, a->getRealPos().y))
-		o5_jumpRelative();
-	else
-		ignoreScriptWord();
+	jumpRelative(checkXYInBoxBounds(box, a->getRealPos().x, a->getRealPos().y));
 }
 
 void ScummEngine_v5::o5_isEqual() {
@@ -1178,41 +1182,28 @@ void ScummEngine_v5::o5_isEqual() {
 	if (_game.id == GID_MANIAC && _game.version == 2 && (_game.features & GF_DEMO) && isScriptRunning(173) && b == 180)
 		b = 100;
 
-	if (b == a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
-
+	jumpRelative(b == a);
 }
 
 void ScummEngine_v5::o5_isGreater() {
 	int16 a = getVar();
 	int16 b = getVarOrDirectWord(PARAM_1);
-	if (b > a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b > a);
 }
 
 void ScummEngine_v5::o5_isGreaterEqual() {
 	int16 a = getVar();
 	int16 b = getVarOrDirectWord(PARAM_1);
-	if (b >= a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b >= a);
 }
 
 void ScummEngine_v5::o5_isLess() {
 	int16 a = getVar();
 	int16 b = getVarOrDirectWord(PARAM_1);
-	if (b < a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b < a);
 }
 
-void ScummEngine_v5::o5_lessOrEqual() {
+void ScummEngine_v5::o5_isLessEqual() {
 	int16 a = getVar();
 	int16 b = getVarOrDirectWord(PARAM_1);
 
@@ -1224,47 +1215,27 @@ void ScummEngine_v5::o5_lessOrEqual() {
 		return;
 	}
 
-	if (b <= a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b <= a);
 }
 
 void ScummEngine_v5::o5_isNotEqual() {
 	int16 a = getVar();
 	int16 b = getVarOrDirectWord(PARAM_1);
-	if (b != a)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(b != a);
 }
 
 void ScummEngine_v5::o5_notEqualZero() {
 	int a = getVar();
-	if (a != 0)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(a != 0);
 }
 
 void ScummEngine_v5::o5_equalZero() {
 	int a = getVar();
-	if (a == 0)
-		ignoreScriptWord();
-	else
-		o5_jumpRelative();
+	jumpRelative(a == 0);
 }
 
 void ScummEngine_v5::o5_jumpRelative() {
-	// Note that calling fetchScriptWord() will also modify _scriptPointer,
-	// so *don't* do this: _scriptPointer += (int16)fetchScriptWord();
-	//
-	// I'm not enough of a language lawyer to say for certain that this is
-	// undefined, but I do know that GCC 4.0 doesn't think it means what
-	// we want it to mean.
-
-	int16 offset = (int16)fetchScriptWord();
-	_scriptPointer += offset;
+	jumpRelative(false);
 }
 
 void ScummEngine_v5::o5_lights() {
@@ -1311,8 +1282,8 @@ void ScummEngine_v5::o5_loadRoomWithEgo() {
 	oldDir = a->getFacing();
 	_egoPositioned = false;
 
-	x = (int16)fetchScriptWord();
-	y = (int16)fetchScriptWord();
+	x = fetchScriptWordSigned();
+	y = fetchScriptWordSigned();
 
 	VAR(VAR_WALKTO_OBJ) = obj;
 	startScene(a->_room, a, obj);
diff --git a/engines/scumm/scumm_v0.h b/engines/scumm/scumm_v0.h
index 13e99b8591..ccca5df0d3 100644
--- a/engines/scumm/scumm_v0.h
+++ b/engines/scumm/scumm_v0.h
@@ -66,18 +66,11 @@ protected:
 	virtual int getVarOrDirectWord(byte mask);
 	virtual uint fetchScriptWord();
 
-	virtual void ifStateCommon(byte type);
-	virtual void ifNotStateCommon(byte type);
-	virtual void setStateCommon(byte type);
-	virtual void clearStateCommon(byte type);
+	virtual int getActiveObject();
 
 	virtual void resetSentence();
 
-	int getObjectFlag();
-
 	/* Version C64 script opcodes */
-	void o_setState08();
-	void o_clearState08();
 	void o_stopCurrentScript();
 	void o_loadSound();
 	void o_getActorMoving();
@@ -114,15 +107,6 @@ protected:
 	void o_cutscene();
 	void o_endCutscene();
 	void o_beginOverride();
-	void o_isEqual();
-	void o_isGreater();
-	void o_isGreaterEqual();
-	void o_isLess();
-	void o_isLessEqual();
-	void o_isNotEqual();
-	void o_notEqualZero();
-	void o_equalZero();
-	void o_jumpRelative();
 	void o_setOwnerOf();
 };
 
diff --git a/engines/scumm/scumm_v2.h b/engines/scumm/scumm_v2.h
index e40d6dc40f..338b5f6167 100644
--- a/engines/scumm/scumm_v2.h
+++ b/engines/scumm/scumm_v2.h
@@ -84,10 +84,11 @@ protected:
 	virtual int readVar(uint var);
 	virtual void writeVar(uint var, int value);
 
-	virtual void ifStateCommon(byte type);
-	virtual void ifNotStateCommon(byte type);
-	virtual void setStateCommon(byte type);
-	virtual void clearStateCommon(byte type);
+	virtual int getActiveObject();
+	void ifStateCommon(byte type);
+	void ifNotStateCommon(byte type);
+	void setStateCommon(byte type);
+	void clearStateCommon(byte type);
 
 	virtual void resetSentence();
 	void setUserState(byte state);
diff --git a/engines/scumm/scumm_v5.h b/engines/scumm/scumm_v5.h
index a8e2417017..2580384fd8 100644
--- a/engines/scumm/scumm_v5.h
+++ b/engines/scumm/scumm_v5.h
@@ -85,6 +85,12 @@ protected:
 
 	void drawFlashlight();
 
+	/**
+	 * Fetch the next script word, then if cond is *false*, perform a relative jump.
+	 * So this corresponds to a "jne" jump instruction.
+	 */
+	void jumpRelative(bool cond);
+
 	/* Version 5 script opcodes */
 	void o5_actorFollowCamera();
 	void o5_actorFromPos();
@@ -138,11 +144,11 @@ protected:
 	void o5_isGreater();
 	void o5_isGreaterEqual();
 	void o5_isLess();
+	void o5_isLessEqual();
 	void o5_isNotEqual();
 	void o5_isScriptRunning();
 	void o5_isSoundRunning();
 	void o5_jumpRelative();
-	void o5_lessOrEqual();
 	void o5_lights();
 	void o5_loadRoom();
 	void o5_loadRoomWithEgo();