Merge branch 'ai-improvements' into 'master'

Various AI improvements.

See merge request core-developers/forge!1066

forge-ai/src/main/java/forge/ai/AiProps.java

@@ -74,6 +74,8 @@ public enum AiProps { /** */
     DESTROY_IMMEDIATELY_UNBLOCKABLE_THRESHOLD ("2"), /** */
     DESTROY_IMMEDIATELY_UNBLOCKABLE_ONLY_IN_DNGR ("true"), /** */
     DESTROY_IMMEDIATELY_UNBLOCKABLE_LIFE_IN_DNGR ("5"), /** */
+    AVOID_TARGETING_CREATS_THAT_WILL_DIE ("true"), /** */
+    DONT_EVAL_KILLSPELLS_ON_STACK_WITH_PERMISSION ("true"), /** */
     PRIORITY_REDUCTION_FOR_STORM_SPELLS ("0"), /** */
     USE_BERSERK_AGGRESSIVELY ("false"), /** */
     MIN_COUNT_FOR_STORM_SPELLS ("0"), /** */

forge-ai/src/main/java/forge/ai/ComputerUtil.java

@@ -1770,7 +1770,68 @@ public class ComputerUtil {
         Iterables.addAll(threatened, ComputerUtil.predictThreatenedObjects(aiPlayer, saviour, topStack.getSubAbility()));
         return threatened;
     }
-    
+
+    /**
+     * Returns true if the specified creature will die this turn either from lethal damage in combat
+     * or from a killing spell on stack.
+     * TODO: This currently does not account for the fact that spells on stack can be countered, can be improved.
+     *
+     * @param creature
+     *            A creature to check
+     * @return true if the creature dies according to current board position.
+     */
+    public static boolean predictCreatureWillDieThisTurn(final Player ai, final Card creature) {
+        final Game game = creature.getGame();
+
+        // a creature will die as a result of combat
+        boolean willDieInCombat = game.getPhaseHandler().inCombat()
+                && ComputerUtilCombat.combatantWouldBeDestroyed(creature.getController(), creature, game.getCombat());
+
+        // a creature will [hopefully] die from a spell on stack
+        boolean willDieFromSpell = false;
+        boolean noStackCheck = false;
+        AiController aic = ((PlayerControllerAi)ai.getController()).getAi();
+        if (aic.getBooleanProperty(AiProps.DONT_EVAL_KILLSPELLS_ON_STACK_WITH_PERMISSION)) {
+            // See if permission is on stack and ignore this check if there is and the relevant AI flag is set
+            // TODO: improve this so that this flag is not needed and the AI can properly evaluate spells in presence of counterspells.
+            for (SpellAbilityStackInstance si : game.getStack()) {
+                if (si.getSpellAbility(false).getApi() == ApiType.Counter) {
+                    noStackCheck = true;
+                    break;
+                }
+            }
+        }
+        willDieFromSpell = !noStackCheck && ComputerUtil.predictThreatenedObjects(creature.getController(), null).contains(creature);
+
+        return willDieInCombat || willDieFromSpell;
+    }
+
+    /**
+     * Returns a list of cards excluding any creatures that will die in active combat or from a spell on stack.
+     * Works only on AI profiles which have AVOID_TARGETING_CREATS_THAT_WILL_DIE enabled, otherwise returns
+     * the original list.
+     *
+     * @param ai
+     *            The AI player performing this evaluation
+     * @param list
+     *            The list of cards to work with
+     * @return a filtered list with no dying creatures in it
+     */
+    public static CardCollection filterCreaturesThatWillDieThisTurn(final Player ai, final CardCollection list) {
+        AiController aic = ((PlayerControllerAi)ai.getController()).getAi();
+        if (aic.getBooleanProperty(AiProps.AVOID_TARGETING_CREATS_THAT_WILL_DIE)) {
+            // Try to avoid targeting creatures that are dead on board
+            List<Card> willBeKilled = CardLists.filter(list, new Predicate<Card>() {
+                @Override
+                public boolean apply(Card card) {
+                    return card.isCreature() && ComputerUtil.predictCreatureWillDieThisTurn(ai, card);
+                }
+            });
+            list.removeAll(willBeKilled);
+        }
+        return list;
+    }
+
     public static boolean playImmediately(Player ai, SpellAbility sa) {
         final Card source = sa.getHostCard();
         final Zone zone = source.getZone();
@@ -2779,6 +2840,10 @@ public class ComputerUtil {
                 if (ab.getApi() == null) {
                     // only API-based SAs are supported, other things may lead to a NPE (e.g. Ancestral Vision Suspend SA)
                     continue;
+                } else if (ab.getApi() == ApiType.Mana && "ManaRitual".equals(ab.getParam("AILogic"))) {
+                    // Mana Ritual cards are too complex for the AI to consider casting through a spell effect and will
+                    // lead to a stack overflow. Consider improving.
+                    continue;
                 }
                 SpellAbility abTest = withoutPayingManaCost ? ab.copyWithNoManaCost() : ab.copy();
                 // at this point, we're assuming that card will be castable from whichever zone it's in by the AI player.

forge-ai/src/main/java/forge/ai/ability/DamageDealAi.java

@@ -275,7 +275,7 @@ public class DamageDealAi extends DamageAiBase {
         final Game game = source.getGame();
         List<Card> hPlay = getTargetableCards(ai, sa, pl, tgt, activator, source, game);
 
-        List<Card> killables = CardLists.filter(hPlay, new Predicate<Card>() {
+        CardCollection killables = CardLists.filter(hPlay, new Predicate<Card>() {
             @Override
             public boolean apply(final Card c) {
                 return c.getSVar("Targeting").equals("Dies")
@@ -286,7 +286,10 @@ public class DamageDealAi extends DamageAiBase {
         });
 
         // Filter AI-specific targets if provided
-        killables = ComputerUtil.filterAITgts(sa, ai, new CardCollection(killables), true);
+        killables = ComputerUtil.filterAITgts(sa, ai, killables, true);
+
+        // Try not to target anything which will already be dead by the time the spell resolves
+        killables = ComputerUtil.filterCreaturesThatWillDieThisTurn(ai, killables);
 
         Card targetCard = null;
         if (pl.isOpponentOf(ai) && activator.equals(ai) && !killables.isEmpty()) {

forge-ai/src/main/java/forge/ai/ability/DestroyAi.java

@@ -178,6 +178,8 @@ public class DestroyAi extends SpellAbilityAi {
                 });
             }
 
+            // Try to avoid targeting creatures that are dead on board
+            list = ComputerUtil.filterCreaturesThatWillDieThisTurn(ai, list);
             if (list.isEmpty()) {
                 return false;
             }
@@ -313,6 +315,9 @@ public class DestroyAi extends SpellAbilityAi {
             CardCollection list = CardLists.getTargetableCards(ai.getGame().getCardsIn(ZoneType.Battlefield), sa);
             list = CardLists.getValidCards(list, tgt.getValidTgts(), source.getController(), source, sa);
 
+            // Try to avoid targeting creatures that are dead on board
+            list = ComputerUtil.filterCreaturesThatWillDieThisTurn(ai, list);
+
             if (list.isEmpty() || list.size() < tgt.getMinTargets(sa.getHostCard(), sa)) {
                 return false;
             }

forge-ai/src/main/java/forge/ai/ability/PlayAi.java

@@ -175,6 +175,13 @@ public class PlayAi extends SpellAbilityAi {
                         spell = (Spell) spell.copyWithDefinedCost(abCost);
                     }
                     if( AiPlayDecision.WillPlay == ((PlayerControllerAi)ai.getController()).getAi().canPlayFromEffectAI(spell, !isOptional, true)) {
+                        // Before accepting, see if the spell has a valid number of targets (it should at this point).
+                        // Proceeding past this point if the spell is not correctly targeted will result
+                        // in "Failed to add to stack" error and the card disappearing from the game completely.
+                        if (!spell.isTargetNumberValid()) {
+                            return false;
+                        }
+
                         return true;
                     }
                 }

forge-gui/res/ai/Cautious.ai

@@ -66,6 +66,14 @@ THRESHOLD_TOKEN_CHUMP_TO_SAVE_PLANESWALKER=135
 # If enabled, the AI will not bother chump blocking to protect a planeswalker unless lethal damage is threatened to it
 CHUMP_TO_SAVE_PLANESWALKER_ONLY_ON_LETHAL=true
 
+# Options that allow the AI to attempt to optimize targeting for removal and damaging spells.
+# If enabled, the AI will try not to target a creature with a damaging spell or spot removal in case
+# this creature will die in current combat or to a spell which is currently on stack targeting it.
+AVOID_TARGETING_CREATS_THAT_WILL_DIE=true
+# If enabled, the AI will not evaluate the stack in case at least one counterspell is present on it,
+# since the current AI is not smart enough to predict whether a kill spell on stack is countered or not.
+DONT_EVAL_KILLSPELLS_ON_STACK_WITH_PERMISSION=true
+
 # Only works when AI cheating is enabled in preferences, otherwise does nothing
 CHEAT_WITH_MANA_ON_SHUFFLE=true
 

forge-gui/res/ai/Default.ai

@@ -66,6 +66,14 @@ THRESHOLD_TOKEN_CHUMP_TO_SAVE_PLANESWALKER=135
 # If enabled, the AI will not bother chump blocking to protect a planeswalker unless lethal damage is threatened to it
 CHUMP_TO_SAVE_PLANESWALKER_ONLY_ON_LETHAL=true
 
+# Options that allow the AI to attempt to optimize targeting for removal and damaging spells.
+# If enabled, the AI will try not to target a creature with a damaging spell or spot removal in case
+# this creature will die in current combat or to a spell which is currently on stack targeting it.
+AVOID_TARGETING_CREATS_THAT_WILL_DIE=true
+# If enabled, the AI will not evaluate the stack in case at least one counterspell is present on it,
+# since the current AI is not smart enough to predict whether a kill spell on stack is countered or not.
+DONT_EVAL_KILLSPELLS_ON_STACK_WITH_PERMISSION=true
+
 # Only works when AI cheating is enabled in preferences, otherwise does nothing
 CHEAT_WITH_MANA_ON_SHUFFLE=true
 

forge-gui/res/ai/Experimental.ai

@@ -66,6 +66,14 @@ THRESHOLD_TOKEN_CHUMP_TO_SAVE_PLANESWALKER=135
 # If enabled, the AI will not bother chump blocking to protect a planeswalker unless lethal damage is threatened to it
 CHUMP_TO_SAVE_PLANESWALKER_ONLY_ON_LETHAL=false
 
+# Options that allow the AI to attempt to optimize targeting for removal and damaging spells.
+# If enabled, the AI will try not to target a creature with a damaging spell or spot removal in case
+# this creature will die in current combat or to a spell which is currently on stack targeting it.
+AVOID_TARGETING_CREATS_THAT_WILL_DIE=true
+# If enabled, the AI will not evaluate the stack in case at least one counterspell is present on it,
+# since the current AI is not smart enough to predict whether a kill spell on stack is countered or not.
+DONT_EVAL_KILLSPELLS_ON_STACK_WITH_PERMISSION=false
+
 # Only works when AI cheating is enabled in preferences, otherwise does nothing
 CHEAT_WITH_MANA_ON_SHUFFLE=true
 
@@ -219,4 +227,4 @@ AI_IN_DANGER_THRESHOLD=3
 # for each evaluation, introducing some unpredictability.
 AI_IN_DANGER_MAX_THRESHOLD=12
 
-# <-- there are no options here at the moment -->
+# <-- there are no other experimental options here at the moment -->

forge-gui/res/ai/Reckless.ai

@@ -66,6 +66,14 @@ THRESHOLD_TOKEN_CHUMP_TO_SAVE_PLANESWALKER=135
 # If enabled, the AI will not bother chump blocking to protect a planeswalker unless lethal damage is threatened to it
 CHUMP_TO_SAVE_PLANESWALKER_ONLY_ON_LETHAL=true
 
+# Options that allow the AI to attempt to optimize targeting for removal and damaging spells.
+# If enabled, the AI will try not to target a creature with a damaging spell or spot removal in case
+# this creature will die in current combat or to a spell which is currently on stack targeting it.
+AVOID_TARGETING_CREATS_THAT_WILL_DIE=true
+# If enabled, the AI will not evaluate the stack in case at least one counterspell is present on it,
+# since the current AI is not smart enough to predict whether a kill spell on stack is countered or not.
+DONT_EVAL_KILLSPELLS_ON_STACK_WITH_PERMISSION=true
+
 # Only works when AI cheating is enabled in preferences, otherwise does nothing
 CHEAT_WITH_MANA_ON_SHUFFLE=true
 

forge-gui/res/cardsfolder/c/charnel_troll.txt

@@ -9,6 +9,8 @@ SVar:DBPutCounter:DB$ PutCounter | Defined$ Self | CounterType$ P1P1 | Condition
 SVar:DBSac:DB$ Sacrifice | SacValid# Self | ConditionDefined$ Remembered | ConditionPresent$ Card.Creature | ConditionCompare$ EQ0 | SubAbility$ DBCleanup
 SVar:DBCleanup:DB$ Cleanup | ClearRemembered$ True
 A:AB$ PutCounter | Cost$ B G Discard<1/Creature> | CounterType$ P1P1 | CounterNum$ 1 | SpellDescription$ Put a +1/+1 counter on CARDNAME.
+SVar:NeedsToPlayVar:Z GE1
+SVar:Z:Count$ValidGraveyard Creature.YouCtrl
 AI:RemoveDeck:Random
 DeckNeeds:Ability$Graveyard
 DeckHas:Ability$Counters

forge-gui/res/cardsfolder/g/gruesome_menagerie.txt

@@ -6,5 +6,6 @@ SVar:DBChoose2:DB$ ChooseCard | Defined$ You | Choices$ Creature.YouOwn+cmcEQ2 |
 SVar:DBChoose3:DB$ ChooseCard | Defined$ You | Choices$ Creature.YouOwn+cmcEQ3 | ChoiceZone$ Graveyard | Amount$ 1 | SubAbility$ DBReturn | RememberChosen$ True | SpellDescription$ Choose a creature card with converted mana cost 3 in your graveyard.
 SVar:DBReturn:DB$ ChangeZoneAll | Origin$ Graveyard | Destination$ Battlefield | ChangeType$ Card.IsRemembered | SubAbility$ DBCleanup
 SVar:DBCleanup:DB$ Cleanup | ClearRemembered$ True
-SVar:NeedsToPlay:Creature.YouCtrl+inZoneGraveyard+cmcLE3
+SVar:NeedsToPlayVar:Z GE1
+SVar:Z:Count$ValidGraveyard Creature.YouCtrl+cmcLE3
 Oracle:Choose a creature card with converted mana cost 1 in your graveyard, then do the same for creature cards with converted mana costs 2 and 3. Return those cards to the battlefield.