fix off by one bug in gfxUsageBits code; fixed small glitch the actor iteration cleanup

svn-id: r6485

3 files changed, 16 insertions, 7 deletions

diff --git a/scumm/actor.cpp b/scumm/actor.cpp
index 5c37f12285..d04dfc495b 100644
--- a/scumm/actor.cpp
+++ b/scumm/actor.cpp
@@ -1117,6 +1117,7 @@ void Scumm::setActorRedrawFlags(bool fg, bool bg)
 				for (j = 1; j < NUM_ACTORS; j++) {
 					if (testGfxUsageBit(strip, j) && testGfxOtherUsageBits(strip, j)) {
 						Actor *a = derefActor(j);
+						assert(a->number == j);
 						if (fg)
 							a->needRedraw = true;
 						if (bg)
@@ -1136,6 +1137,7 @@ int Scumm::getActorFromPos(int x, int y)
 		return 0;
 	for (i = 1; i < NUM_ACTORS; i++) {
 		Actor *a = derefActor(i);
+		assert(a->number == i);
 		if (testGfxUsageBit(x >> 3, i) && !getClass(i, 32) && y >= a->top && y <= a->bottom) {
 			return i;
 		}
@@ -1554,7 +1556,7 @@ void Scumm::resetActorBgs()
 	}
 
 	for (i = 1; i < NUM_ACTORS; i++) {
-		a = derefActor(j);
+		a = derefActor(i);
 		a->needBgReset = false;
 	}
 }
diff --git a/scumm/saveload.cpp b/scumm/saveload.cpp
index 67230f64b7..db9a7dc2d4 100644
--- a/scumm/saveload.cpp
+++ b/scumm/saveload.cpp
@@ -580,8 +580,7 @@ void Scumm::saveOrLoad(Serializer *s, uint32 savegameVersion)
 	if (!s->isSaving() && savegameVersion < VER_V13) {
 		// Since roughly v13 of the save games, the objs storage has changed a bit
 		for (i = _numObjectsInRoom; i < _numLocalObjects; i++) {
-			if (_objs[i].fl_object_index == 0)
-				_objs[i].obj_nr = 0;
+			_objs[i].obj_nr = 0;
 		}
 
 	}
diff --git a/scumm/usage_bits.cpp b/scumm/usage_bits.cpp
index 47bd80593a..450b8cae84 100644
--- a/scumm/usage_bits.cpp
+++ b/scumm/usage_bits.cpp
@@ -39,17 +39,23 @@ void Scumm::upgradeGfxUsageBits()
 
 void Scumm::setGfxUsageBit(int strip, int bit)
 {
-	gfxUsageBits[3 * strip + bit / 32] |= (1 << ((bit - 1) % 32));
+	assert(1 <= bit && bit <= 96);
+	bit--;
+	gfxUsageBits[3 * strip + bit / 32] |= (1 << (bit % 32));
 }
 
 void Scumm::clearGfxUsageBit(int strip, int bit)
 {
-	gfxUsageBits[3 * strip + bit / 32] &= ~(1 << ((bit - 1) % 32));
+	assert(1 <= bit && bit <= 96);
+	bit--;
+	gfxUsageBits[3 * strip + bit / 32] &= ~(1 << (bit % 32));
 }
 
 bool Scumm::testGfxUsageBit(int strip, int bit)
 {
-	return (gfxUsageBits[3 * strip + bit / 32] & (1 << ((bit - 1) % 32))) != 0;
+	assert(1 <= bit && bit <= 96);
+	bit--;
+	return (gfxUsageBits[3 * strip + bit / 32] & (1 << (bit % 32))) != 0;
 }
 
 bool Scumm::testGfxAnyUsageBits(int strip)
@@ -71,7 +77,9 @@ bool Scumm::testGfxOtherUsageBits(int strip, int bit)
 	uint32 bitmask[3] = { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
 	int i;
 
-	bitmask[bit / 32] &= ~(1 << ((bit - 1) % 32));
+	assert(1 <= bit && bit <= 96);
+	bit--;
+	bitmask[bit / 32] &= ~(1 << (bit % 32));
 
 	for (i = 0; i < 3; i++)
 		if (gfxUsageBits[3 * strip + i] & bitmask[i])