v0.8.0: substantially improved logic for damage immunity:

- now referred to as invulnerability, with standardized logic for all chars
- chars now ignore enemies who are invulnerable
- combo no longer builds on invulnerable targets
- allies can now target Yog's eye when it is vulnerable

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/Char.java

@@ -416,6 +416,11 @@ public abstract class Char extends Actor {
 			return;
 		}
 
+		if(isInvulnerable(src.getClass())){
+			sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "invulnerable"));
+			return;
+		}
+
 		if (!(src instanceof LifeLink) && buff(LifeLink.class) != null){
 			HashSet<LifeLink> links = buffs(LifeLink.class);
 			for (LifeLink link : links.toArray(new LifeLink[0])){
@@ -697,6 +702,12 @@ public abstract class Char extends Actor {
 		return false;
 	}
 
+	//similar to isImmune, but only factors in damage.
+	//Is used in AI decision-making
+	public boolean isInvulnerable( Class effect ){
+		return false;
+	}
+
 	protected HashSet<Property> properties = new HashSet<>();
 
 	public HashSet<Property> properties() {

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/buffs/Combo.java

@@ -74,7 +74,8 @@ public class Combo extends Buff implements ActionIndicator.Action {
 	
 	public void hit( Char enemy ) {
 
-		count++;
+		//doesn't increment combo count if enemy invulnerable
+		if (!enemy.isInvulnerable(target.getClass())) count++;
 		comboTime = 4f;
 		misses = 0;
 		BuffIndicator.refreshHero();

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/DwarfKing.java

@@ -354,10 +354,15 @@ public class DwarfKing extends Mob {
 		}
 	}
 
+	@Override
+	public boolean isInvulnerable(Class effect) {
+		return phase == 2 && effect != KingDamager.class;
+	}
+
 	@Override
 	public void damage(int dmg, Object src) {
-		if (phase == 2 && !(src instanceof KingDamager)){
+		if (isInvulnerable(src.getClass())){
-			sprite.showStatus( CharSprite.POSITIVE, Messages.get(this, "immune") );
+			super.damage(dmg, src);
 			return;
 		} else if (phase == 3 && !(src instanceof Viscosity.DeferedDamage)){
 			Viscosity.DeferedDamage deferred = Buff.affect( this, Viscosity.DeferedDamage.class );
@@ -378,7 +383,7 @@ public class DwarfKing extends Mob {
 			summonCooldown -= dmgTaken/8f;
 			if (HP <= 50) {
 				HP = 50;
-				sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "immune"));
+				sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "invulnerable"));
 				ScrollOfTeleportation.appear(this, NewCityBossLevel.throne);
 				properties.add(Property.IMMOVABLE);
 				phase = 2;

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/Mob.java

@@ -215,17 +215,21 @@ public abstract class Mob extends Char {
 		//find a new enemy if..
 		boolean newEnemy = false;
 		//we have no enemy, or the current one is dead/missing
-		if ( enemy == null || !enemy.isAlive() || !Actor.chars().contains(enemy) || state == WANDERING)
+		if ( enemy == null || !enemy.isAlive() || !Actor.chars().contains(enemy) || state == WANDERING) {
 			newEnemy = true;
 		//We are an ally, and current enemy is another ally.
-		else if (alignment == Alignment.ALLY && enemy.alignment == Alignment.ALLY)
+		} else if (alignment == Alignment.ALLY && enemy.alignment == Alignment.ALLY) {
 			newEnemy = true;
 		//We are amoked and current enemy is the hero
-		else if (buff( Amok.class ) != null && enemy == Dungeon.hero)
+		} else if (buff( Amok.class ) != null && enemy == Dungeon.hero) {
 			newEnemy = true;
 		//We are charmed and current enemy is what charmed us
-		else if (buff(Charm.class) != null && buff(Charm.class).object == enemy.id())
+		} else if (buff(Charm.class) != null && buff(Charm.class).object == enemy.id()) {
 			newEnemy = true;
+		//we aren't amoked and current enemy is invulnerable to us
+		} else if (buff( Amok.class ) == null && enemy.isInvulnerable(getClass())) {
+			newEnemy = true;
+		}
 
 		if ( newEnemy ) {
 
@@ -285,6 +289,15 @@ public abstract class Mob extends Char {
 				}
 			}
 
+			//if we are not amoked, remove any enemies which are invulnerable to us.
+			if (buff(Amok.class) == null) {
+				for (Char enemy : enemies.toArray(new Char[0])) {
+					if (enemy.isInvulnerable(getClass())){
+						enemies.remove(enemy);
+					}
+				}
+			}
+
 			//neutral characters in particular do not choose enemies.
 			if (enemies.isEmpty()){
 				return null;

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/NewDM300.java

@@ -407,13 +407,11 @@ public class NewDM300 extends Mob {
 
 	@Override
 	public void damage(int dmg, Object src) {
-		if (supercharged){
+		super.damage(dmg, src);
-			sprite.showStatus( CharSprite.POSITIVE, Messages.get(this, "immune") );
+		if (isInvulnerable(src.getClass())){
 			return;
 		}
 
-		super.damage(dmg, src);
-
 		LockedFloor lock = Dungeon.hero.buff(LockedFloor.class);
 		if (lock != null && !isImmune(src.getClass())) lock.addTime(dmg);
 
@@ -426,6 +424,11 @@ public class NewDM300 extends Mob {
 
 	}
 
+	@Override
+	public boolean isInvulnerable(Class effect) {
+		return supercharged;
+	}
+
 	public void supercharge(){
 		supercharged = true;
 		((NewCavesBossLevel)Dungeon.level).activatePylon();
@@ -433,7 +436,7 @@ public class NewDM300 extends Mob {
 
 		spend(3f);
 		yell(Messages.get(this, "charging"));
-		sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "immune"));
+		sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "invulnerable"));
 		sprite.resetColor();
 		chargeAnnounced = false;
 	}

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/YogDzewa.java

@@ -69,7 +69,8 @@ public class YogDzewa extends Mob {
 
 		EXP = 50;
 
-		state = PASSIVE;
+		//so that allies can attack it. States are never actually used.
+		state = HUNTING;
 
 		properties.add(Property.BOSS);
 		properties.add(Property.IMMOVABLE);
@@ -113,8 +114,10 @@ public class YogDzewa extends Mob {
 
 	@Override
 	protected boolean act() {
-		if (phase == 0 && Dungeon.hero.viewDistance >= Dungeon.level.distance(pos, Dungeon.hero.pos)){
+		if (phase == 0){
-			Dungeon.observe();
+			if (Dungeon.hero.viewDistance >= Dungeon.level.distance(pos, Dungeon.hero.pos)) {
+				Dungeon.observe();
+			}
 			if (Dungeon.level.heroFOV[pos]) {
 				notice();
 			}
@@ -269,12 +272,12 @@ public class YogDzewa extends Mob {
 	}
 
 	@Override
-	public void damage( int dmg, Object src ) {
+	public boolean isInvulnerable(Class effect) {
+		return phase == 0 || findFist() != null;
+	}
 
-		if (phase == 0 || findFist() != null){
+	@Override
-			sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "immune"));
+	public void damage( int dmg, Object src ) {
-			return;
-		}
 
 		int preHP = HP;
 		super.damage( dmg, src );
@@ -292,7 +295,7 @@ public class YogDzewa extends Mob {
 			}
 			Dungeon.observe();
 			GLog.n(Messages.get(this, "darkness"));
-			sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "immune"));
+			sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "invulnerable"));
 
 			YogFist fist = (YogFist) Reflection.newInstance(fistSummons.remove(0));
 			fist.pos = Dungeon.level.exit;
@@ -319,7 +322,7 @@ public class YogDzewa extends Mob {
 		}
 
 		LockedFloor lock = Dungeon.hero.buff(LockedFloor.class);
-		if (lock != null) lock.addTime(dmg);
+		if (lock != null) lock.addTime(dmgTaken);
 
 	}
 

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/actors/mobs/YogFist.java

@@ -91,22 +91,25 @@ public abstract class YogFist extends Mob {
 		}
 	}
 
-	boolean immuneWarned = false;
+	boolean invulnWarned = false;
 
 	protected boolean isNearYog(){
 		int yogPos = Dungeon.level.exit + 3*Dungeon.level.width();
 		return Dungeon.level.distance(pos, yogPos) <= 4;
 	}
 
+	@Override
+	public boolean isInvulnerable(Class effect) {
+		return isNearYog();
+	}
+
 	@Override
 	public void damage(int dmg, Object src) {
-		if (isNearYog()){
+		if (isInvulnerable(src.getClass())){
-			sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "immune"));
+			if (!invulnWarned){
-			if (!immuneWarned){
+				invulnWarned = true;
-				immuneWarned = true;
+				GLog.w(Messages.get(this, "invuln_warn"));
-				GLog.w(Messages.get(this, "immune_hint"));
 			}
-			return;
 		}
 		super.damage(dmg, src);
 	}
@@ -344,15 +347,7 @@ public abstract class YogFist extends Mob {
 
 		@Override
 		public void damage(int dmg, Object src) {
-			if (isNearYog()){
+			if (!isInvulnerable(src.getClass()) && !(src instanceof Bleeding)){
-				sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "immune"));
-				if (!immuneWarned){
-					immuneWarned = true;
-					GLog.w(Messages.get(this, "immune_hint"));
-				}
-				return;
-			}
-			if (!(src instanceof Bleeding)){
 				Bleeding b = buff(Bleeding.class);
 				if (b == null){
 					b = new Bleeding();
@@ -406,15 +401,7 @@ public abstract class YogFist extends Mob {
 
 		@Override
 		public void damage(int dmg, Object src) {
-			if (isNearYog()){
+			if (!isInvulnerable(src.getClass()) && !(src instanceof Viscosity.DeferedDamage)){
-				sprite.showStatus(CharSprite.POSITIVE, Messages.get(this, "immune"));
-				if (!immuneWarned){
-					immuneWarned = true;
-					GLog.w(Messages.get(this, "immune_hint"));
-				}
-				return;
-			}
-			if (!(src instanceof Viscosity.DeferedDamage)){
 				Buff.affect(this, Viscosity.DeferedDamage.class).prolong(dmg);
 				sprite.showStatus( CharSprite.WARNING, Messages.get(Viscosity.class, "deferred", dmg) );
 			} else{

core/src/main/resources/com/shatteredpixel/shatteredpixeldungeon/messages/actors/actors.properties

@@ -511,7 +511,6 @@ actors.mobs.newdm300.supercharged=SUPERCHARGE COMPLETE, OPERATING AT 200% POWER!
 actors.mobs.newdm300.charge_lost=POWER GRID DAMAGED, REVERTING TO LOCAL POWER!
 actors.mobs.newdm300.pylons_destroyed=ALERT, INSTABILITY DETECTED IN POWER GRID!
 actors.mobs.newdm300.rankings_desc=Crushed by the DM-300
-actors.mobs.newdm300.immune=IMMUNE
 actors.mobs.newdm300.def_verb=blocked
 actors.mobs.newdm300.defeated=CRITICAL DAMAGE! ATTEMPTING SHUTDO-
 actors.mobs.newdm300.desc=The DM-300 is the largest and most powerful 'defense machine' that the dwarves ever built. Such an awesome machine is difficult to manufacture, so the dwarves only ever made a few to guard the entrances to their underground metropolis.\n\nIt is equipped with vents to jet its toxic exhaust fumes and a high power drill that it can use both to attack and disrupt the earth. DM-300 can also connect to an energy grid, further enhancing its power.
@@ -524,7 +523,6 @@ actors.mobs.dwarfking.lifelink_1=I need of your essence, slave!
 actors.mobs.dwarfking.lifelink_2=Bleed for me, slave!
 actors.mobs.dwarfking.teleport_1=Deal with them, slave!
 actors.mobs.dwarfking.teleport_2=Keep them busy, slave!
-actors.mobs.dwarfking.immune=IMMUNE
 actors.mobs.dwarfking.wave_1=Enough! Arise my slaves!
 actors.mobs.dwarfking.wave_2=More! Bleed for your king!
 actors.mobs.dwarfking.wave_3=Useless! KILL THEM NOW!
@@ -747,7 +745,6 @@ actors.mobs.yog$larva.desc=Yog-Dzewa is an Old God, a powerful entity from the r
 
 actors.mobs.yogdzewa.name=Yog-Dzewa
 actors.mobs.yogdzewa.notice=I. SEE. YOU.
-actors.mobs.yogdzewa.immune=IMMUNE
 actors.mobs.yogdzewa.darkness=The darkness pulls in closer...
 actors.mobs.yogdzewa.hope=YOUR. HOPE. IS. AN. ILLUSION!
 actors.mobs.yogdzewa.defeated=...
@@ -759,8 +756,7 @@ actors.mobs.yogdzewa$larva.rankings_desc=Devoured by Yog-Dzewa
 actors.mobs.yogdzewa$larva.desc=These tiny spawn of Yog-Dzewa are simple minions that are easy to produce. While individually weak, they are summoned quickly and can become overwhelming in large numbers.
 actors.mobs.yogdzewa$yogripper.rankings_desc=Devoured by Yog-Dzewa
 
-actors.mobs.yogfist.immune=IMMUNE
+actors.mobs.yogfist.invuln_warn=The fist is invulnerable while near to the eye!
-actors.mobs.yogfist.immune_hint=The fist is immune while near to the eye!
 actors.mobs.yogfist.rankings_desc=Devoured by Yog-Dzewa
 actors.mobs.yogfist.desc=This fist is an aspect of Yog-Dzewa's power. Fists are linked to the power of Yog-Dzewa, and will be protected from all damage when they are close to the eye.
 actors.mobs.yogfist$burning.name=burning fist
@@ -782,3 +778,4 @@ actors.mobs.yogfist$dark.desc=This fist is formed out of pure dark energy. It is
 actors.char.kill=%s killed you...
 actors.char.defeat=You defeated %s.
 actors.char.def_verb=dodged
+actors.char.invulnerable=invulnerable