Index: src/Monster.m
==================================================================
--- src/Monster.m
+++ src/Monster.m
@@ -270,11 +270,11 @@
 		if (self.targetYaw > self.yaw)
 			self.yaw = self.targetYaw;
 	}
 
 	float disttoenemy =
-	    OFDistanceOfVectors3D(self.origin, self.enemy.origin);
+	    OFDistanceOfVectors3D(self.enemy.origin, self.origin);
 	self.pitch =
 	    atan2(self.enemy.origin.z - self.origin.z, disttoenemy) * 180 / PI;
 
 	// special case: if we run into scenery
 	if (self.blocked) {
@@ -468,11 +468,11 @@
 					moveplayer(monster, 1, false);
 				}
 			} else {
 				v.z += monster.eyeHeight;
 				float dist =
-				    OFDistanceOfVectors3D(monster.origin, v);
+				    OFDistanceOfVectors3D(v, monster.origin);
 				v.z -= monster.eyeHeight;
 
 				if (dist < 4)
 					teleport(i, monster);
 			}

Index: src/entities.m
==================================================================
--- src/entities.m
+++ src/entities.m
@@ -319,11 +319,11 @@
 		if (OUTBORD(e.x, e.y))
 			return;
 
 		OFVector3D v = OFMakeVector3D(
 		    e.x, e.y, (float)S(e.x, e.y)->floor + player1.eyeHeight);
-		float dist = OFDistanceOfVectors3D(player1.origin, v);
+		float dist = OFDistanceOfVectors3D(v, player1.origin);
 
 		if (dist < (e.type == TELEPORT ? 4 : 2.5))
 			pickup(i, player1);
 	}];
 }

Index: src/renderparticles.m
==================================================================
--- src/renderparticles.m
+++ src/renderparticles.m
@@ -148,12 +148,12 @@
 }
 
 void
 particle_trail(int type, int fade, OFVector3D s, OFVector3D e)
 {
-	float d = OFDistanceOfVectors3D(s, e);
-	OFVector3D v = OFSubtractVectors3D(s, e);
+	float d = OFDistanceOfVectors3D(e, s);
+	OFVector3D v = OFSubtractVectors3D(e, s);
 	v = OFMultiplyVector3D(v, 1.0f / (d * 2 + 0.1f));
 	for (int i = 0; i < ((int)d * 2); i++) {
 		s = OFAddVectors3D(s, v);
 		OFVector3D d =
 		    OFMakeVector3D(rnd(11) - 5, rnd(11) - 5, rnd(11) - 5);

Index: src/savegamedemo.m
==================================================================
--- src/savegamedemo.m
+++ src/savegamedemo.m
@@ -496,11 +496,11 @@
 				    (float)(b.lastUpdate - a.lastUpdate);
 				fixwrap(a, player1);
 				fixwrap(c, player1);
 				fixwrap(z, player1);
 				float dist =
-				    OFDistanceOfVectors3D(z.origin, c.origin);
+				    OFDistanceOfVectors3D(c.origin, z.origin);
 				// if teleport or spawn, don't interpolate
 				if (dist < 16) {
 					catmulrom(z.origin, a.origin, b.origin,
 					    c.origin, bf, player1.origin);
 					OFVector3D vz = OFMakeVector3D(

Index: src/sound.m
==================================================================
--- src/sound.m
+++ src/sound.m
@@ -112,12 +112,12 @@
 {
 	int vol = soundvol, pan = 255 / 2;
 
 	if (loc) {
 		OFVector3D origin = player1.origin;
-		float dist = OFDistanceOfVectors3D(*loc, origin);
-		OFVector3D v = OFSubtractVectors3D(*loc, origin);
+		float dist = OFDistanceOfVectors3D(origin, *loc);
+		OFVector3D v = OFSubtractVectors3D(origin, *loc);
 
 		// simple mono distance attenuation
 		vol -= (int)(dist * 3 * soundvol / 255);
 
 		if (stereo && (v.x != 0 || v.y != 0)) {

Index: src/weapon.m
==================================================================
--- src/weapon.m
+++ src/weapon.m
@@ -71,11 +71,11 @@
 
 // create random spread of rays for the shotgun
 void
 createrays(OFVector3D from, OFVector3D to)
 {
-	float dist = OFDistanceOfVectors3D(from, to);
+	float dist = OFDistanceOfVectors3D(to, from);
 	float f = dist * SGSPREAD / 1000;
 	for (int i = 0; i < SGRAYS; i++)
 #define RNDD (rnd(101) - 50) * f
 		sg[i] = OFAddVectors3D(to, OFMakeVector3D(RNDD, RNDD, RNDD));
 }
@@ -183,21 +183,20 @@
 {
 	if (o.state != CS_ALIVE)
 		return;
 
 	OFVector3D origin = o.origin;
-	float dist = OFDistanceOfVectors3D(v, origin);
-	OFVector3D temp = OFSubtractVectors3D(v, origin);
+	float dist = OFDistanceOfVectors3D(origin, v);
+	OFVector3D temp = OFSubtractVectors3D(origin, v);
 	dist -= 2; // account for eye distance imprecision
 
 	if (dist < RL_DAMRAD) {
 		if (dist < 0)
 			dist = 0;
 
 		int damage = (int)(qdam * (1 - (dist / RL_DAMRAD)));
 		hit(cn, damage, o, at);
-
 		temp =
 		    OFMultiplyVector3D(temp, (RL_DAMRAD - dist) * damage / 800);
 		o.velocity = OFAddVectors3D(o.velocity, temp);
 	}
 }
@@ -265,18 +264,18 @@
 			continue;
 
 		int qdam = guns[p.gun].damage * (p.owner.quadMillis ? 4 : 1);
 		if ([p.owner isKindOfClass:Monster.class])
 			qdam /= MONSTERDAMAGEFACTOR;
-		OFVector3D po = p.o, pto = pto;
-		float dist = OFDistanceOfVectors3D(po, pto);
-		OFVector3D v = OFSubtractVectors3D(po, pto);
+		OFVector3D po = p.o, pto = p.to;
+		float dist = OFDistanceOfVectors3D(pto, po);
+		OFVector3D v = OFSubtractVectors3D(pto, po);
 		float dtime = dist * 1000 / p.speed;
 		if (time > dtime)
 			dtime = time;
 		v = OFMultiplyVector3D(v, time / dtime);
-		v = OFAddVectors3D(v, p.o);
+		v = OFAddVectors3D(v, po);
 		if (p.local) {
 			for (id player in players)
 				if (player != [OFNull null])
 					projdamage(player, p, v, i, -1, qdam);
 
@@ -348,12 +347,12 @@
 void
 hitpush(int target, int damage, DynamicEntity *d, DynamicEntity *at,
     OFVector3D from, OFVector3D to)
 {
 	hit(target, damage, d, at);
-	float dist = OFDistanceOfVectors3D(from, to);
-	OFVector3D v = OFSubtractVectors3D(from, to);
+	float dist = OFDistanceOfVectors3D(to, from);
+	OFVector3D v = OFSubtractVectors3D(to, from);
 	v = OFMultiplyVector3D(v, damage / dist / 50);
 	d.velocity = OFAddVectors3D(d.velocity, v);
 }
 
 void
@@ -399,12 +398,12 @@
 		d.ammo[d.gunSelect]--;
 	OFVector3D from = d.origin;
 	OFVector3D to = targ;
 	from.z -= 0.2f; // below eye
 
-	float dist = OFDistanceOfVectors3D(from, to);
-	OFVector3D unitv = OFSubtractVectors3D(from, to);
+	float dist = OFDistanceOfVectors3D(to, from);
+	OFVector3D unitv = OFSubtractVectors3D(to, from);
 	unitv = OFMultiplyVector3D(unitv, 1.0f / dist);
 	OFVector3D kickback =
 	    OFMultiplyVector3D(unitv, guns[d.gunSelect].kickamount * -0.01f);
 	d.velocity = OFAddVectors3D(d.velocity, kickback);
 	if (d.pitch < 80.0f)

Index: src/world.m
==================================================================
--- src/world.m
+++ src/world.m
@@ -296,11 +296,11 @@
 	[ents enumerateObjectsUsingBlock:^(Entity *e, size_t i, bool *stop) {
 		if (e.type == NOTUSED)
 			return;
 
 		OFVector3D v = OFMakeVector3D(e.x, e.y, e.z);
-		float dist = OFDistanceOfVectors3D(player1.origin, v);
+		float dist = OFDistanceOfVectors3D(v, player1.origin);
 		if (dist < bdist) {
 			best = i;
 			bdist = dist;
 		}
 	}];