v2.2.0: overhauled retreating enemy AI

SPD-classes/src/main/java/com/watabou/utils/PathFinder.java

@@ -31,6 +31,7 @@ public class PathFinder {
 	
 	private static boolean[] goals;
 	private static int[] queue;
+	private static boolean[] queued; //currently only used in getStepBack, other can piggyback on distance
 	
 	private static int size = 0;
 	private static int width = 0;
@@ -57,6 +58,7 @@ public class PathFinder {
 		distance = new int[size];
 		goals = new boolean[size];
 		queue = new int[size];
+		queued = new boolean[size];
 
 		maxVal = new int[size];
 		Arrays.fill(maxVal, Integer.MAX_VALUE);
@@ -127,9 +129,51 @@ public class PathFinder {
 		return best;
 	}
 	
-	public static int getStepBack( int cur, int from, boolean[] passable ) {
+	public static int getStepBack( int cur, int from, int lookahead, boolean[] passable, boolean canApproachFromPos ) {
+
+		int d = buildEscapeDistanceMap( cur, from, lookahead, passable );
+		if (d == 0) return -1;
+
+		if (!canApproachFromPos) {
+			//We can't approach the position we are retreating from
+			//re-calculate based on this, and reduce the target distance if need-be
+			int head = 0;
+			int tail = 0;
+
+			int newD = distance[cur];
+			BArray.setFalse(queued);
+
+			queue[tail++] = cur;
+			queued[cur] = true;
+
+			while (head < tail) {
+				int step = queue[head++];
+
+				if (distance[step] > newD) {
+					newD = distance[step];
+				}
+
+				int start = (step % width == 0 ? 3 : 0);
+				int end = ((step + 1) % width == 0 ? 3 : 0);
+				for (int i = start; i < dirLR.length - end; i++) {
+
+					int n = step + dirLR[i];
+					if (n >= 0 && n < size && passable[n]) {
+						if (distance[n] < distance[cur]) {
+							passable[n] = false;
+						} else if (distance[n] >= distance[step] && !queued[n]) {
+							// Add to queue
+							queue[tail++] = n;
+							queued[n] = true;
+						}
+					}
+				}
+
+			}
+
+			d = Math.min(newD, d);
+		}
 
-		int d = buildEscapeDistanceMap( cur, from, 5, passable );
 		for (int i=0; i < size; i++) {
 			goals[i] = distance[i] == d;
 		}
@@ -284,7 +328,9 @@ public class PathFinder {
 		
 		return pathFound;
 	}
-	
+
+	//the lookahead is the target number of cells to retreat toward from our current position's
+	// distance from the position we are escaping from. Returns the highest found distance, up to the lookahead
 	private static int buildEscapeDistanceMap( int cur, int from, int lookAhead, boolean[] passable ) {
 		
 		System.arraycopy(maxVal, 0, distance, 0, maxVal.length);

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/Dungeon.java

@@ -26,10 +26,12 @@ import com.shatteredpixel.shatteredpixeldungeon.actors.Char;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Amok;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.AscensionChallenge;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Awareness;
+import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Dread;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Light;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.MagicalSight;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.MindVision;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.RevealedArea;
+import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Terror;
 import com.shatteredpixel.shatteredpixeldungeon.actors.hero.Hero;
 import com.shatteredpixel.shatteredpixeldungeon.actors.hero.Talent;
 import com.shatteredpixel.shatteredpixeldungeon.actors.hero.abilities.huntress.SpiritHawk;
@@ -1013,16 +1015,21 @@ public class Dungeon {
 	}
 	
 	public static int flee( Char ch, int from, boolean[] pass, boolean[] visible, boolean chars ) {
-		//only consider chars impassable if our retreat path runs into them
 		boolean[] passable = findPassable(ch, pass, visible, false, true);
 		passable[ch.pos] = true;
 
-		int step = PathFinder.getStepBack( ch.pos, from, passable );
+		//only consider other chars impassable if our retreat step may collide with them
-		while (step != -1 && Actor.findChar(step) != null && chars){
+		if (chars) {
-			passable[step] = false;
+			for (Char c : Actor.chars()) {
-			step = PathFinder.getStepBack( ch.pos, from, passable );
+				if (c.pos == from || Dungeon.level.adjacent(c.pos, ch.pos)) {
+					passable[c.pos] = false;
+				}
+			}
 		}
-		return step;
+
+		//chars affected by terror have a shorter lookahead and can't approach the fear source
+		boolean canApproachFromPos = ch.buff(Terror.class) == null && ch.buff(Dread.class) == null;
+		return PathFinder.getStepBack( ch.pos, from, canApproachFromPos ? 8 : 4, passable, canApproachFromPos );
 		
 	}
 

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

@@ -25,11 +25,8 @@ import com.shatteredpixel.shatteredpixeldungeon.Assets;
 import com.shatteredpixel.shatteredpixeldungeon.Dungeon;
 import com.shatteredpixel.shatteredpixeldungeon.actors.Actor;
 import com.shatteredpixel.shatteredpixeldungeon.actors.Char;
-import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.AllyBuff;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Buff;
-import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Dread;
 import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Haste;
-import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Terror;
 import com.shatteredpixel.shatteredpixeldungeon.actors.hero.Hero;
 import com.shatteredpixel.shatteredpixeldungeon.effects.CellEmitter;
 import com.shatteredpixel.shatteredpixeldungeon.effects.Speck;
@@ -41,7 +38,6 @@ import com.shatteredpixel.shatteredpixeldungeon.items.rings.Ring;
 import com.shatteredpixel.shatteredpixeldungeon.items.scrolls.ScrollOfTeleportation;
 import com.shatteredpixel.shatteredpixeldungeon.items.wands.Wand;
 import com.shatteredpixel.shatteredpixeldungeon.messages.Messages;
-import com.shatteredpixel.shatteredpixeldungeon.sprites.CharSprite;
 import com.shatteredpixel.shatteredpixeldungeon.sprites.MimicSprite;
 import com.shatteredpixel.shatteredpixeldungeon.utils.GLog;
 import com.watabou.noosa.audio.Sample;
@@ -182,25 +178,23 @@ public class CrystalMimic extends Mimic {
 		}
 	}
 
-	private class Fleeing extends Mob.Fleeing{
+	private class Fleeing extends Mob.Fleeing {
+		@Override
+		protected void escaped() {
+			if (!Dungeon.level.heroFOV[pos] && Dungeon.level.distance(Dungeon.hero.pos, pos) >= 6) {
+				GLog.n(Messages.get(CrystalMimic.class, "escaped"));
+				destroy();
+				sprite.killAndErase();
+			} else {
+				state = WANDERING;
+			}
+		}
+
 		@Override
 		protected void nowhereToRun() {
-			if (buff( Terror.class ) == null
+			super.nowhereToRun();
-					&& buffs( AllyBuff.class ).isEmpty()
+			if (state == HUNTING){
-					&& buff( Dread.class ) == null) {
+				spend(-TICK); //crystal mimics are fast!
-				if (enemySeen) {
-					sprite.showStatus(CharSprite.NEGATIVE, Messages.get(Mob.class, "rage"));
-					state = HUNTING;
-				} else if (!Dungeon.level.heroFOV[pos] && Dungeon.level.distance(Dungeon.hero.pos, pos) >= 6) {
-					GLog.n( Messages.get(CrystalMimic.class, "escaped"));
-					if (Dungeon.level.heroFOV[pos]) CellEmitter.get(pos).burst(Speck.factory(Speck.WOOL), 6);
-					destroy();
-					sprite.killAndErase();
-				} else {
-					state = WANDERING;
-				}
-			} else {
-				super.nowhereToRun();
 			}
 		}
 	}

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

@@ -1151,7 +1151,6 @@ public abstract class Mob extends Char {
 		}
 	}
 
-	//FIXME this works fairly well but is coded poorly. Should refactor
 	protected class Fleeing implements AiState {
 
 		public static final String TAG	= "FLEEING";
@@ -1159,9 +1158,12 @@ public abstract class Mob extends Char {
 		@Override
 		public boolean act( boolean enemyInFOV, boolean justAlerted ) {
 			enemySeen = enemyInFOV;
-			//loses target when 0-dist rolls a 6 or greater.
+			//triggers escape logic when 0-dist rolls a 6 or greater.
 			if (enemy == null || !enemyInFOV && 1 + Random.Int(Dungeon.level.distance(pos, target)) >= 6){
-				target = -1;
+				escaped();
+				if (state != FLEEING){
+					return true;
+				}
 			
 			//if enemy isn't in FOV, keep running from their previous position.
 			} else if (enemyInFOV) {
@@ -1183,7 +1185,22 @@ public abstract class Mob extends Char {
 			}
 		}
 
+		protected void escaped(){
+			//does nothing by default, some enemies have special logic for this
+		}
+
+		//enemies will turn and fight if they have nowhere to run and aren't affect by terror
 		protected void nowhereToRun() {
+			if (buff( Terror.class ) == null
+					&& buffs( AllyBuff.class ).isEmpty()
+					&& buff( Dread.class ) == null) {
+				if (enemySeen) {
+					sprite.showStatus(CharSprite.NEGATIVE, Messages.get(Mob.class, "rage"));
+					state = HUNTING;
+				} else {
+					state = WANDERING;
+				}
+			}
 		}
 	}
 

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

@@ -266,13 +266,5 @@ public class Spinner extends Mob {
 			return super.act(enemyInFOV, justAlerted);
 		}
 
-		@Override
-		protected void nowhereToRun() {
-			if (buff(Terror.class) == null && buff(Dread.class) == null) {
-				state = HUNTING;
-			} else {
-				super.nowhereToRun();
-			}
-		}
 	}
 }

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

@@ -23,9 +23,6 @@ package com.shatteredpixel.shatteredpixeldungeon.actors.mobs;
 
 import com.shatteredpixel.shatteredpixeldungeon.Dungeon;
 import com.shatteredpixel.shatteredpixeldungeon.actors.Char;
-import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.AllyBuff;
-import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Dread;
-import com.shatteredpixel.shatteredpixeldungeon.actors.buffs.Terror;
 import com.shatteredpixel.shatteredpixeldungeon.actors.hero.Hero;
 import com.shatteredpixel.shatteredpixeldungeon.effects.CellEmitter;
 import com.shatteredpixel.shatteredpixeldungeon.effects.Speck;
@@ -34,7 +31,6 @@ import com.shatteredpixel.shatteredpixeldungeon.items.Gold;
 import com.shatteredpixel.shatteredpixeldungeon.items.Honeypot;
 import com.shatteredpixel.shatteredpixeldungeon.items.Item;
 import com.shatteredpixel.shatteredpixeldungeon.messages.Messages;
-import com.shatteredpixel.shatteredpixeldungeon.sprites.CharSprite;
 import com.shatteredpixel.shatteredpixeldungeon.sprites.ThiefSprite;
 import com.shatteredpixel.shatteredpixeldungeon.utils.GLog;
 import com.watabou.utils.Bundle;
@@ -200,44 +196,34 @@ public class Thief extends Mob {
 
 	private class Fleeing extends Mob.Fleeing {
 		@Override
-		protected void nowhereToRun() {
+		protected void escaped() {
-			if (buff( Terror.class ) == null
+			if (item != null
-					&& buff( Dread.class ) == null
+					&& !Dungeon.level.heroFOV[pos]
-					&& buffs( AllyBuff.class ).isEmpty() ) {
+					&& Dungeon.level.distance(Dungeon.hero.pos, pos) >= 6) {
-				if (enemySeen) {
-					sprite.showStatus(CharSprite.NEGATIVE, Messages.get(Mob.class, "rage"));
-					state = HUNTING;
-				} else if (item != null
-						&& !Dungeon.level.heroFOV[pos]
-						&& Dungeon.level.distance(Dungeon.hero.pos, pos) >= 6) {
-
-					int count = 32;
-					int newPos;
-					do {
-						newPos = Dungeon.level.randomRespawnCell( Thief.this );
-						if (count-- <= 0) {
-							break;
-						}
-					} while (newPos == -1 || Dungeon.level.heroFOV[newPos] || Dungeon.level.distance(newPos, pos) < (count/3));
-
-					if (newPos != -1) {
-
-						if (Dungeon.level.heroFOV[pos]) CellEmitter.get(pos).burst(Speck.factory(Speck.WOOL), 6);
-						pos = newPos;
-						sprite.place( pos );
-						sprite.visible = Dungeon.level.heroFOV[pos];
-						if (Dungeon.level.heroFOV[pos]) CellEmitter.get(pos).burst(Speck.factory(Speck.WOOL), 6);
 
+				int count = 32;
+				int newPos;
+				do {
+					newPos = Dungeon.level.randomRespawnCell( Thief.this );
+					if (count-- <= 0) {
+						break;
 					}
+				} while (newPos == -1 || Dungeon.level.heroFOV[newPos] || Dungeon.level.distance(newPos, pos) < (count/3));
+
+				if (newPos != -1) {
+
+					pos = newPos;
+					sprite.place( pos );
+					sprite.visible = Dungeon.level.heroFOV[pos];
+					if (Dungeon.level.heroFOV[pos]) CellEmitter.get(pos).burst(Speck.factory(Speck.WOOL), 6);
 
-					if (item != null) GLog.n( Messages.get(Thief.class, "escapes", item.name()));
-					item = null;
-					state = WANDERING;
-				} else {
-					state = WANDERING;
 				}
+
+				if (item != null) GLog.n( Messages.get(Thief.class, "escapes", item.name()));
+				item = null;
+				state = WANDERING;
 			} else {
-				super.nowhereToRun();
+				state = WANDERING;
 			}
 		}
 	}