v0.6.1: refactored and adjusted logic for ethereal chains

Most significantly, chains can no longer be used to go to places where
it is impossible to get there by walking (e.g. through locked doors)

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/artifacts/EtherealChains.java

@@ -38,8 +38,10 @@ import com.shatteredpixel.shatteredpixeldungeon.scenes.GameScene;
 import com.shatteredpixel.shatteredpixeldungeon.sprites.ItemSpriteSheet;
 import com.shatteredpixel.shatteredpixeldungeon.tiles.DungeonTilemap;
 import com.shatteredpixel.shatteredpixeldungeon.ui.QuickSlotButton;
+import com.shatteredpixel.shatteredpixeldungeon.utils.BArray;
 import com.shatteredpixel.shatteredpixeldungeon.utils.GLog;
 import com.watabou.utils.Callback;
+import com.watabou.utils.PathFinder;
 import com.watabou.utils.Random;
 
 import java.util.ArrayList;
@@ -102,92 +104,29 @@ public class EtherealChains extends Artifact {
 		public void onSelect(Integer target) {
 			if (target != null && (Dungeon.level.visited[target] || Dungeon.level.mapped[target])){
 
-				//ballistica does not go through walls on pre-rework boss arenas
+				//chains cannot be used to go where it is impossible to walk to
-				int missileProperties = (Dungeon.depth == 10 || Dungeon.depth == 15 || Dungeon.depth == 20 || Dungeon.depth == 25) ?
+				PathFinder.buildDistanceMap(target, BArray.or(Level.passable, Level.avoid, null));
-						Ballistica.PROJECTILE : Ballistica.STOP_CHARS | Ballistica.STOP_TARGET;
+				if (PathFinder.distance[curUser.pos] == Integer.MAX_VALUE){
-
+					GLog.w( Messages.get(EtherealChains.class, "cant_reach") );
-				final Ballistica chain = new Ballistica(curUser.pos, target, missileProperties);
+					return;
-
+				}
-				//determine if we're grabbing an enemy, pulling to a location, or doing nothing.
+				
+				final Ballistica chain = new Ballistica(curUser.pos, target, Ballistica.STOP_TARGET);
+				
+				//chains do not go through walls on locked levels
+				if (curUser.buff(LockedFloor.class) != null){
+					for (int i : chain.subPath(1, chain.dist)){
+						if (Level.solid[i]){
+							GLog.w( Messages.get(EtherealChains.class, "locked") );
+							return;
+						}
+					}
+				}
+				
 				if (Actor.findChar( chain.collisionPos ) != null){
-					int newPos = -1;
+					chainEnemy( chain, curUser, Actor.findChar( chain.collisionPos ));
-					for (int i : chain.subPath(1, chain.dist)){
-						if (!Level.solid[i] && Actor.findChar(i) == null){
-							newPos = i;
-							break;
-						}
-					}
-					if (newPos == -1){
-						GLog.w( Messages.get(EtherealChains.class, "does_nothing") );
-					} else {
-						final int newMobPos = newPos;
-						final Char affected = Actor.findChar( chain.collisionPos );
-						int chargeUse = Dungeon.level.distance(affected.pos, newMobPos);
-						if (chargeUse > charge) {
-							GLog.w( Messages.get(EtherealChains.class, "no_charge") );
-							return;
-						} else if (affected.properties().contains(Char.Property.IMMOVABLE)) {
-							GLog.w( Messages.get(EtherealChains.class, "cant_pull") );
-							return;
-						} else {
-							charge -= chargeUse;
-							updateQuickslot();
-						}
-						curUser.busy();
-						curUser.sprite.parent.add(new Chains(curUser.sprite.center(), affected.sprite.center(), new Callback() {
-							public void call() {
-								Actor.add(new Pushing(affected, affected.pos, newMobPos, new Callback() {
-									public void call() {
-										Dungeon.level.press(newMobPos, affected);
-									}
-								}));
-								affected.pos = newMobPos;
-								Dungeon.observe();
-								GameScene.updateFog();
-								curUser.spendAndNext(1f);
-							}
-						}));
-					}
-
-				} else if (Level.solid[chain.path.get(chain.dist)]
-						|| (chain.dist > 0 && Level.solid[chain.path.get(chain.dist-1)])
-						|| (chain.path.size() > chain.dist+1 && Level.solid[chain.path.get(chain.dist+1)])
-						//if the player is trying to grapple the edge of the map, let them.
-						|| (chain.path.size() == chain.dist+1)) {
-					int newPos = -1;
-					for (int i : chain.subPath(1, chain.dist)){
-						if (!Level.solid[i] && Actor.findChar(i) == null) newPos = i;
-						}
-					if (newPos == -1) {
-						GLog.w( Messages.get(EtherealChains.class, "does_nothing") );
-					} else {
-						final int newHeroPos = newPos;
-						int chargeUse = Dungeon.level.distance(curUser.pos, newHeroPos);
-						if (chargeUse > charge){
-							GLog.w( Messages.get(EtherealChains.class, "no_charge") );
-							return;
-						} else {
-							charge -= chargeUse;
-							updateQuickslot();
-						}
-						curUser.busy();
-						curUser.sprite.parent.add(new Chains(curUser.sprite.center(), DungeonTilemap.tileCenterToWorld(target), new Callback() {
-							public void call() {
-								Actor.add(new Pushing(curUser, curUser.pos, newHeroPos, new Callback() {
-									public void call() {
-										Dungeon.level.press(newHeroPos, curUser);
-									}
-								}));
-								curUser.spendAndNext(1f);
-								curUser.pos = newHeroPos;
-								Dungeon.observe();
-								GameScene.updateFog();
-							}
-						}));
-					}
-
 				} else {
-					GLog.i( Messages.get(EtherealChains.class, "nothing_to_grab") );
+					chainLocation( chain, curUser );
 				}
 
 			}
@@ -199,6 +138,104 @@ public class EtherealChains extends Artifact {
 			return Messages.get(EtherealChains.class, "prompt");
 		}
 	};
+	
+	//pulls an enemy to a position along the chain's path, as close to the hero as possible
+	private void chainEnemy( Ballistica chain, final Hero hero, final Char enemy ){
+		
+		if (enemy.properties().contains(Char.Property.IMMOVABLE)) {
+			GLog.w( Messages.get(this, "cant_pull") );
+			return;
+		}
+		
+		int bestPos = -1;
+		for (int i : chain.subPath(1, chain.dist)){
+			//prefer to the earliest point on the path
+			if (!Level.solid[i] && Actor.findChar(i) == null){
+				bestPos = i;
+				break;
+			}
+		}
+		
+		if (bestPos == -1) {
+			GLog.i(Messages.get(this, "does_nothing"));
+			return;
+		}
+		
+		final int pulledPos = bestPos;
+		
+		int chargeUse = Dungeon.level.distance(enemy.pos, pulledPos);
+		if (chargeUse > charge) {
+			GLog.w( Messages.get(this, "no_charge") );
+			return;
+		} else {
+			charge -= chargeUse;
+			updateQuickslot();
+		}
+		
+		hero.busy();
+		hero.sprite.parent.add(new Chains(hero.sprite.center(), enemy.sprite.center(), new Callback() {
+			public void call() {
+				Actor.add(new Pushing(enemy, enemy.pos, pulledPos, new Callback() {
+					public void call() {
+						Dungeon.level.press(pulledPos, enemy);
+					}
+				}));
+				enemy.pos = pulledPos;
+				Dungeon.observe();
+				GameScene.updateFog();
+				hero.spendAndNext(1f);
+			}
+		}));
+	}
+	
+	//pulls the hero along the chain to the collosionPos, if possible.
+	private void chainLocation( Ballistica chain, final Hero hero ){
+		
+		//don't pull if the collision spot is in a wall
+		if (Level.solid[chain.collisionPos]){
+			GLog.i( Messages.get(this, "inside_wall"));
+			return;
+		}
+		
+		//don't pull if there are no solid objects next to the pull location
+		boolean solidFound = false;
+		for (int i : PathFinder.NEIGHBOURS4){
+			if (Level.solid[chain.collisionPos + i]){
+				solidFound = true;
+				break;
+			}
+		}
+		if (!solidFound){
+			GLog.i( Messages.get(EtherealChains.class, "nothing_to_grab") );
+			return;
+		}
+		
+		final int newHeroPos = chain.collisionPos;
+		
+		int chargeUse = Dungeon.level.distance(hero.pos, newHeroPos);
+		if (chargeUse > charge){
+			GLog.w( Messages.get(EtherealChains.class, "no_charge") );
+			return;
+		} else {
+			charge -= chargeUse;
+			updateQuickslot();
+		}
+		
+		hero.busy();
+		hero.sprite.parent.add(new Chains(hero.sprite.center(), DungeonTilemap.raisedTileCenterToWorld(newHeroPos), new Callback() {
+			public void call() {
+				Actor.add(new Pushing(hero, hero.pos, newHeroPos, new Callback() {
+					public void call() {
+						Dungeon.level.press(newHeroPos, hero);
+					}
+				}));
+				hero.spendAndNext(1f);
+				hero.pos = newHeroPos;
+				Dungeon.observe();
+				GameScene.updateFog();
+			}
+		}));
+	}
 
 	@Override
 	protected ArtifactBuff passiveBuff() {

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

@@ -195,6 +195,9 @@ items.artifacts.etherealchains.no_charge=Your chains do not have enough charge.
 items.artifacts.etherealchains.cursed=You can't use cursed chains.
 items.artifacts.etherealchains.does_nothing=That won't do anything.
 items.artifacts.etherealchains.cant_pull=Your chains cannot pull that target.
+items.artifacts.etherealchains.cant_reach=Your chains can't reach there.
+items.artifacts.etherealchains.inside_wall=Your chains can only pull you through walls, not into them.
+items.artifacts.etherealchains.locked=The chains cannot reach through walls while the floor is locked.
 items.artifacts.etherealchains.nothing_to_grab=There is nothing to grab there.
 items.artifacts.etherealchains.prompt=Choose a location to target.
 items.artifacts.etherealchains.desc=These large yet lightweight chains glow with spiritual energy. They can be used to pull you towards terrain, or pull enemies toward you. The ethereal nature of the chains even allows them to extend through walls!