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vcmi/AI/BattleAI/BattleEvaluator.cpp

757 lines
21 KiB
C++

/*
* BattleAI.cpp, part of VCMI engine
*
* Authors: listed in file AUTHORS in main folder
*
* License: GNU General Public License v2.0 or later
* Full text of license available in license.txt file, in main folder
*
*/
#include "StdInc.h"
#include "BattleEvaluator.h"
#include "BattleExchangeVariant.h"
#include "StackWithBonuses.h"
#include "EnemyInfo.h"
#include "tbb/parallel_for.h"
#include "../../lib/CStopWatch.h"
#include "../../lib/CThreadHelper.h"
#include "../../lib/mapObjects/CGTownInstance.h"
#include "../../lib/spells/CSpellHandler.h"
#include "../../lib/spells/ISpellMechanics.h"
#include "../../lib/battle/BattleStateInfoForRetreat.h"
#include "../../lib/battle/CObstacleInstance.h"
#include "../../lib/battle/BattleAction.h"
#include "../../lib/CRandomGenerator.h"
// TODO: remove
// Eventually only IBattleInfoCallback and battle::Unit should be used,
// CUnitState should be private and CStack should be removed completely
#include "../../lib/CStack.h"
#define LOGL(text) print(text)
#define LOGFL(text, formattingEl) print(boost::str(boost::format(text) % formattingEl))
enum class SpellTypes
{
ADVENTURE, BATTLE, OTHER
};
SpellTypes spellType(const CSpell * spell)
{
if(!spell->isCombat() || spell->isCreatureAbility())
return SpellTypes::OTHER;
if(spell->isOffensive() || spell->hasEffects() || spell->hasBattleEffects())
return SpellTypes::BATTLE;
return SpellTypes::OTHER;
}
std::vector<BattleHex> BattleEvaluator::getBrokenWallMoatHexes() const
{
std::vector<BattleHex> result;
for(EWallPart wallPart : { EWallPart::BOTTOM_WALL, EWallPart::BELOW_GATE, EWallPart::OVER_GATE, EWallPart::UPPER_WALL })
{
auto state = cb->getBattle(battleID)->battleGetWallState(wallPart);
if(state != EWallState::DESTROYED)
continue;
auto wallHex = cb->getBattle(battleID)->wallPartToBattleHex(wallPart);
auto moatHex = wallHex.cloneInDirection(BattleHex::LEFT);
result.push_back(moatHex);
moatHex = moatHex.cloneInDirection(BattleHex::LEFT);
auto obstaclesSecondRow = cb->getBattle(battleID)->battleGetAllObstaclesOnPos(moatHex, false);
for(auto obstacle : obstaclesSecondRow)
{
if(obstacle->obstacleType == CObstacleInstance::EObstacleType::MOAT)
{
result.push_back(moatHex);
break;
}
}
}
return result;
}
std::optional<PossibleSpellcast> BattleEvaluator::findBestCreatureSpell(const CStack *stack)
{
//TODO: faerie dragon type spell should be selected by server
SpellID creatureSpellToCast = cb->getBattle(battleID)->getRandomCastedSpell(CRandomGenerator::getDefault(), stack);
if(stack->canCast() && creatureSpellToCast != SpellID::NONE)
{
const CSpell * spell = creatureSpellToCast.toSpell();
if(spell->canBeCast(cb->getBattle(battleID).get(), spells::Mode::CREATURE_ACTIVE, stack))
{
std::vector<PossibleSpellcast> possibleCasts;
spells::BattleCast temp(cb->getBattle(battleID).get(), stack, spells::Mode::CREATURE_ACTIVE, spell);
for(auto & target : temp.findPotentialTargets())
{
PossibleSpellcast ps;
ps.dest = target;
ps.spell = spell;
evaluateCreatureSpellcast(stack, ps);
possibleCasts.push_back(ps);
}
std::sort(possibleCasts.begin(), possibleCasts.end(), [&](const PossibleSpellcast & lhs, const PossibleSpellcast & rhs) { return lhs.value > rhs.value; });
if(!possibleCasts.empty() && possibleCasts.front().value > 0)
{
return possibleCasts.front();
}
}
}
return std::nullopt;
}
BattleAction BattleEvaluator::selectStackAction(const CStack * stack)
{
#if BATTLE_TRACE_LEVEL >= 1
logAi->trace("Select stack action");
#endif
//evaluate casting spell for spellcasting stack
std::optional<PossibleSpellcast> bestSpellcast = findBestCreatureSpell(stack);
auto moveTarget = scoreEvaluator.findMoveTowardsUnreachable(stack, *targets, damageCache, hb);
float score = EvaluationResult::INEFFECTIVE_SCORE;
if(targets->possibleAttacks.empty() && bestSpellcast.has_value())
{
activeActionMade = true;
return BattleAction::makeCreatureSpellcast(stack, bestSpellcast->dest, bestSpellcast->spell->id);
}
if(!targets->possibleAttacks.empty())
{
#if BATTLE_TRACE_LEVEL>=1
logAi->trace("Evaluating attack for %s", stack->getDescription());
#endif
auto evaluationResult = scoreEvaluator.findBestTarget(stack, *targets, damageCache, hb);
auto & bestAttack = evaluationResult.bestAttack;
cachedAttack = bestAttack;
cachedScore = evaluationResult.score;
//TODO: consider more complex spellcast evaluation, f.e. because "re-retaliation" during enemy move in same turn for melee attack etc.
if(bestSpellcast.has_value() && bestSpellcast->value > bestAttack.damageDiff())
{
// return because spellcast value is damage dealt and score is dps reduce
activeActionMade = true;
return BattleAction::makeCreatureSpellcast(stack, bestSpellcast->dest, bestSpellcast->spell->id);
}
if(evaluationResult.score > score)
{
score = evaluationResult.score;
logAi->debug("BattleAI: %s -> %s x %d, from %d curpos %d dist %d speed %d: +%2f -%2f = %2f",
bestAttack.attackerState->unitType()->getJsonKey(),
bestAttack.affectedUnits[0]->unitType()->getJsonKey(),
bestAttack.affectedUnits[0]->getCount(),
(int)bestAttack.from,
(int)bestAttack.attack.attacker->getPosition().hex,
bestAttack.attack.chargeDistance,
bestAttack.attack.attacker->getMovementRange(0),
bestAttack.defenderDamageReduce,
bestAttack.attackerDamageReduce,
score
);
if (moveTarget.scorePerTurn <= score)
{
if(evaluationResult.wait)
{
return BattleAction::makeWait(stack);
}
else if(bestAttack.attack.shooting)
{
activeActionMade = true;
return BattleAction::makeShotAttack(stack, bestAttack.attack.defender);
}
else
{
if(bestAttack.collateralDamageReduce
&& bestAttack.collateralDamageReduce >= bestAttack.defenderDamageReduce / 2
&& score < 0)
{
return BattleAction::makeDefend(stack);
}
else
{
activeActionMade = true;
return BattleAction::makeMeleeAttack(stack, bestAttack.attack.defender->getPosition(), bestAttack.from);
}
}
}
}
}
//ThreatMap threatsToUs(stack); // These lines may be usefull but they are't used in the code.
if(moveTarget.scorePerTurn > score)
{
score = moveTarget.score;
cachedAttack = moveTarget.cachedAttack;
cachedScore = score;
if(stack->waited())
{
logAi->debug(
"Moving %s towards hex %s[%d], score: %2f/%2f",
stack->getDescription(),
moveTarget.cachedAttack->attack.defender->getDescription(),
moveTarget.cachedAttack->attack.defender->getPosition().hex,
moveTarget.score,
moveTarget.scorePerTurn);
return goTowardsNearest(stack, moveTarget.positions);
}
else
{
return BattleAction::makeWait(stack);
}
}
if(score <= EvaluationResult::INEFFECTIVE_SCORE
&& !stack->hasBonusOfType(BonusType::FLYING)
&& stack->unitSide() == BattleSide::ATTACKER
&& cb->getBattle(battleID)->battleGetSiegeLevel() >= CGTownInstance::CITADEL)
{
auto brokenWallMoat = getBrokenWallMoatHexes();
if(brokenWallMoat.size())
{
activeActionMade = true;
if(stack->doubleWide() && vstd::contains(brokenWallMoat, stack->getPosition()))
return BattleAction::makeMove(stack, stack->getPosition().cloneInDirection(BattleHex::RIGHT));
else
return goTowardsNearest(stack, brokenWallMoat);
}
}
return stack->waited() ? BattleAction::makeDefend(stack) : BattleAction::makeWait(stack);
}
uint64_t timeElapsed(std::chrono::time_point<std::chrono::high_resolution_clock> start)
{
auto end = std::chrono::high_resolution_clock::now();
return std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count();
}
BattleAction BattleEvaluator::goTowardsNearest(const CStack * stack, std::vector<BattleHex> hexes)
{
auto reachability = cb->getBattle(battleID)->getReachability(stack);
auto avHexes = cb->getBattle(battleID)->battleGetAvailableHexes(reachability, stack, false);
if(!avHexes.size() || !hexes.size()) //we are blocked or dest is blocked
{
return BattleAction::makeDefend(stack);
}
std::vector<BattleHex> targetHexes = hexes;
for(int i = 0; i < 5; i++)
{
std::sort(targetHexes.begin(), targetHexes.end(), [&](BattleHex h1, BattleHex h2) -> bool
{
return reachability.distances[h1] < reachability.distances[h2];
});
for(auto hex : targetHexes)
{
if(vstd::contains(avHexes, hex))
{
return BattleAction::makeMove(stack, hex);
}
if(stack->coversPos(hex))
{
logAi->warn("Warning: already standing on neighbouring tile!");
//We shouldn't even be here...
return BattleAction::makeDefend(stack);
}
}
if(reachability.distances[targetHexes.front()] <= GameConstants::BFIELD_SIZE)
{
break;
}
std::vector<BattleHex> copy = targetHexes;
for(auto hex : copy)
{
vstd::concatenate(targetHexes, hex.allNeighbouringTiles());
}
vstd::removeDuplicates(targetHexes);
}
BattleHex bestNeighbor = targetHexes.front();
if(reachability.distances[bestNeighbor] > GameConstants::BFIELD_SIZE)
{
return BattleAction::makeDefend(stack);
}
scoreEvaluator.updateReachabilityMap(hb);
if(stack->hasBonusOfType(BonusType::FLYING))
{
std::set<BattleHex> obstacleHexes;
auto insertAffected = [](const CObstacleInstance & spellObst, std::set<BattleHex> obstacleHexes) {
auto affectedHexes = spellObst.getAffectedTiles();
obstacleHexes.insert(affectedHexes.cbegin(), affectedHexes.cend());
};
const auto & obstacles = hb->battleGetAllObstacles();
for (const auto & obst: obstacles) {
if(obst->triggersEffects())
{
auto triggerAbility = VLC->spells()->getById(obst->getTrigger());
auto triggerIsNegative = triggerAbility->isNegative() || triggerAbility->isDamage();
if(triggerIsNegative)
insertAffected(*obst, obstacleHexes);
}
}
// Flying stack doesn't go hex by hex, so we can't backtrack using predecessors.
// We just check all available hexes and pick the one closest to the target.
auto nearestAvailableHex = vstd::minElementByFun(avHexes, [&](BattleHex hex) -> int
{
const int NEGATIVE_OBSTACLE_PENALTY = 100; // avoid landing on negative obstacle (moat, fire wall, etc)
const int BLOCKED_STACK_PENALTY = 100; // avoid landing on moat
auto distance = BattleHex::getDistance(bestNeighbor, hex);
if(vstd::contains(obstacleHexes, hex))
distance += NEGATIVE_OBSTACLE_PENALTY;
return scoreEvaluator.checkPositionBlocksOurStacks(*hb, stack, hex) ? BLOCKED_STACK_PENALTY + distance : distance;
});
return BattleAction::makeMove(stack, *nearestAvailableHex);
}
else
{
BattleHex currentDest = bestNeighbor;
while(true)
{
if(!currentDest.isValid())
{
return BattleAction::makeDefend(stack);
}
if(vstd::contains(avHexes, currentDest)
&& !scoreEvaluator.checkPositionBlocksOurStacks(*hb, stack, currentDest))
return BattleAction::makeMove(stack, currentDest);
currentDest = reachability.predecessors[currentDest];
}
}
}
bool BattleEvaluator::canCastSpell()
{
auto hero = cb->getBattle(battleID)->battleGetMyHero();
if(!hero)
return false;
return cb->getBattle(battleID)->battleCanCastSpell(hero, spells::Mode::HERO) == ESpellCastProblem::OK;
}
bool BattleEvaluator::attemptCastingSpell(const CStack * activeStack)
{
auto hero = cb->getBattle(battleID)->battleGetMyHero();
if(!hero)
return false;
LOGL("Casting spells sounds like fun. Let's see...");
//Get all spells we can cast
std::vector<const CSpell*> possibleSpells;
for (auto const & s : VLC->spellh->objects)
if (s->canBeCast(cb->getBattle(battleID).get(), spells::Mode::HERO, hero))
possibleSpells.push_back(s.get());
LOGFL("I can cast %d spells.", possibleSpells.size());
vstd::erase_if(possibleSpells, [](const CSpell *s)
{
return spellType(s) != SpellTypes::BATTLE || s->getTargetType() == spells::AimType::LOCATION;
});
LOGFL("I know how %d of them works.", possibleSpells.size());
//Get possible spell-target pairs
std::vector<PossibleSpellcast> possibleCasts;
for(auto spell : possibleSpells)
{
spells::BattleCast temp(cb->getBattle(battleID).get(), hero, spells::Mode::HERO, spell);
if(spell->getTargetType() == spells::AimType::LOCATION)
continue;
const bool FAST = true;
for(auto & target : temp.findPotentialTargets(FAST))
{
PossibleSpellcast ps;
ps.dest = target;
ps.spell = spell;
possibleCasts.push_back(ps);
}
}
LOGFL("Found %d spell-target combinations.", possibleCasts.size());
if(possibleCasts.empty())
return false;
using ValueMap = PossibleSpellcast::ValueMap;
auto evaluateQueue = [&](ValueMap & values, const std::vector<battle::Units> & queue, std::shared_ptr<HypotheticBattle> state, size_t minTurnSpan, bool * enemyHadTurnOut) -> bool
{
bool firstRound = true;
bool enemyHadTurn = false;
size_t ourTurnSpan = 0;
bool stop = false;
for(auto & round : queue)
{
if(!firstRound)
state->nextRound();
for(auto unit : round)
{
if(!vstd::contains(values, unit->unitId()))
values[unit->unitId()] = 0;
if(!unit->alive())
continue;
if(state->battleGetOwner(unit) != playerID)
{
enemyHadTurn = true;
if(!firstRound || state->battleCastSpells(unit->unitSide()) == 0)
{
//enemy could counter our spell at this point
//anyway, we do not know what enemy will do
//just stop evaluation
stop = true;
break;
}
}
else if(!enemyHadTurn)
{
ourTurnSpan++;
}
state->nextTurn(unit->unitId());
PotentialTargets potentialTargets(unit, damageCache, state);
if(!potentialTargets.possibleAttacks.empty())
{
AttackPossibility attackPossibility = potentialTargets.bestAction();
auto stackWithBonuses = state->getForUpdate(unit->unitId());
*stackWithBonuses = *attackPossibility.attackerState;
if(attackPossibility.defenderDamageReduce > 0)
{
stackWithBonuses->removeUnitBonus(Bonus::UntilAttack);
stackWithBonuses->removeUnitBonus(Bonus::UntilOwnAttack);
}
if(attackPossibility.attackerDamageReduce > 0)
stackWithBonuses->removeUnitBonus(Bonus::UntilBeingAttacked);
for(auto affected : attackPossibility.affectedUnits)
{
stackWithBonuses = state->getForUpdate(affected->unitId());
*stackWithBonuses = *affected;
if(attackPossibility.defenderDamageReduce > 0)
stackWithBonuses->removeUnitBonus(Bonus::UntilBeingAttacked);
if(attackPossibility.attackerDamageReduce > 0 && attackPossibility.attack.defender->unitId() == affected->unitId())
stackWithBonuses->removeUnitBonus(Bonus::UntilAttack);
}
}
auto bav = potentialTargets.bestActionValue();
//best action is from effective owner`s point if view, we need to convert to our point if view
if(state->battleGetOwner(unit) != playerID)
bav = -bav;
values[unit->unitId()] += bav;
}
firstRound = false;
if(stop)
break;
}
if(enemyHadTurnOut)
*enemyHadTurnOut = enemyHadTurn;
return ourTurnSpan >= minTurnSpan;
};
ValueMap valueOfStack;
ValueMap healthOfStack;
TStacks all = cb->getBattle(battleID)->battleGetAllStacks(false);
size_t ourRemainingTurns = 0;
for(auto unit : all)
{
healthOfStack[unit->unitId()] = unit->getAvailableHealth();
valueOfStack[unit->unitId()] = 0;
if(cb->getBattle(battleID)->battleGetOwner(unit) == playerID && unit->canMove() && !unit->moved())
ourRemainingTurns++;
}
LOGFL("I have %d turns left in this round", ourRemainingTurns);
const bool castNow = ourRemainingTurns <= 1;
if(castNow)
print("I should try to cast a spell now");
else
print("I could wait better moment to cast a spell");
auto amount = all.size();
std::vector<battle::Units> turnOrder;
cb->getBattle(battleID)->battleGetTurnOrder(turnOrder, amount, 2); //no more than 1 turn after current, each unit at least once
{
bool enemyHadTurn = false;
auto state = std::make_shared<HypotheticBattle>(env.get(), cb->getBattle(battleID));
evaluateQueue(valueOfStack, turnOrder, state, 0, &enemyHadTurn);
if(!enemyHadTurn)
{
auto battleIsFinishedOpt = state->battleIsFinished();
if(battleIsFinishedOpt)
{
print("No need to cast a spell. Battle will finish soon.");
return false;
}
}
}
CStopWatch timer;
#if BATTLE_TRACE_LEVEL >= 1
tbb::blocked_range<size_t> r(0, possibleCasts.size());
#else
tbb::parallel_for(tbb::blocked_range<size_t>(0, possibleCasts.size()), [&](const tbb::blocked_range<size_t> & r)
{
#endif
for(auto i = r.begin(); i != r.end(); i++)
{
auto & ps = possibleCasts[i];
#if BATTLE_TRACE_LEVEL >= 1
logAi->trace("Evaluating %s", ps.spell->getNameTranslated());
#endif
auto state = std::make_shared<HypotheticBattle>(env.get(), cb->getBattle(battleID));
spells::BattleCast cast(state.get(), hero, spells::Mode::HERO, ps.spell);
cast.castEval(state->getServerCallback(), ps.dest);
auto allUnits = state->battleGetUnitsIf([](const battle::Unit * u) -> bool { return true; });
auto needFullEval = vstd::contains_if(allUnits, [&](const battle::Unit * u) -> bool
{
auto original = cb->getBattle(battleID)->battleGetUnitByID(u->unitId());
return !original || u->getMovementRange() != original->getMovementRange();
});
DamageCache safeCopy = damageCache;
DamageCache innerCache(&safeCopy);
innerCache.buildDamageCache(state, side);
if(needFullEval || !cachedAttack)
{
#if BATTLE_TRACE_LEVEL >= 1
logAi->trace("Full evaluation is started due to stack speed affected.");
#endif
PotentialTargets innerTargets(activeStack, innerCache, state);
BattleExchangeEvaluator innerEvaluator(state, env, strengthRatio);
if(!innerTargets.possibleAttacks.empty())
{
innerEvaluator.updateReachabilityMap(state);
auto newStackAction = innerEvaluator.findBestTarget(activeStack, innerTargets, innerCache, state);
ps.value = newStackAction.score;
}
else
{
ps.value = 0;
}
}
else
{
ps.value = scoreEvaluator.evaluateExchange(*cachedAttack, 0, *targets, innerCache, state);
}
for(auto unit : allUnits)
{
auto newHealth = unit->getAvailableHealth();
auto oldHealth = healthOfStack[unit->unitId()];
if(oldHealth != newHealth)
{
auto damage = std::abs(oldHealth - newHealth);
auto originalDefender = cb->getBattle(battleID)->battleGetUnitByID(unit->unitId());
auto dpsReduce = AttackPossibility::calculateDamageReduce(
nullptr,
originalDefender && originalDefender->alive() ? originalDefender : unit,
damage,
innerCache,
state);
auto ourUnit = unit->unitSide() == side ? 1 : -1;
auto goodEffect = newHealth > oldHealth ? 1 : -1;
if(ourUnit * goodEffect == 1)
{
if(ourUnit && goodEffect && (unit->isClone() || unit->isGhost()))
continue;
ps.value += dpsReduce * scoreEvaluator.getPositiveEffectMultiplier();
}
else
ps.value -= dpsReduce * scoreEvaluator.getNegativeEffectMultiplier();
#if BATTLE_TRACE_LEVEL >= 1
logAi->trace(
"Spell affects %s (%d), dps: %2f",
unit->creatureId().toCreature()->getNameSingularTranslated(),
unit->getCount(),
dpsReduce);
#endif
}
}
#if BATTLE_TRACE_LEVEL >= 1
logAi->trace("Total score: %2f", ps.value);
#endif
}
#if BATTLE_TRACE_LEVEL == 0
});
#endif
LOGFL("Evaluation took %d ms", timer.getDiff());
auto pscValue = [](const PossibleSpellcast &ps) -> float
{
return ps.value;
};
auto castToPerform = *vstd::maxElementByFun(possibleCasts, pscValue);
if(castToPerform.value > cachedScore)
{
LOGFL("Best spell is %s (value %d). Will cast.", castToPerform.spell->getNameTranslated() % castToPerform.value);
BattleAction spellcast;
spellcast.actionType = EActionType::HERO_SPELL;
spellcast.spell = castToPerform.spell->id;
spellcast.setTarget(castToPerform.dest);
spellcast.side = side;
spellcast.stackNumber = (!side) ? -1 : -2;
cb->battleMakeSpellAction(battleID, spellcast);
activeActionMade = true;
return true;
}
LOGFL("Best spell is %s. But it is actually useless (value %d).", castToPerform.spell->getNameTranslated() % castToPerform.value);
return false;
}
//Below method works only for offensive spells
void BattleEvaluator::evaluateCreatureSpellcast(const CStack * stack, PossibleSpellcast & ps)
{
using ValueMap = PossibleSpellcast::ValueMap;
RNGStub rngStub;
HypotheticBattle state(env.get(), cb->getBattle(battleID));
TStacks all = cb->getBattle(battleID)->battleGetAllStacks(false);
ValueMap healthOfStack;
ValueMap newHealthOfStack;
for(auto unit : all)
{
healthOfStack[unit->unitId()] = unit->getAvailableHealth();
}
spells::BattleCast cast(&state, stack, spells::Mode::CREATURE_ACTIVE, ps.spell);
cast.castEval(state.getServerCallback(), ps.dest);
for(auto unit : all)
{
auto unitId = unit->unitId();
auto localUnit = state.battleGetUnitByID(unitId);
newHealthOfStack[unitId] = localUnit->getAvailableHealth();
}
int64_t totalGain = 0;
for(auto unit : all)
{
auto unitId = unit->unitId();
auto localUnit = state.battleGetUnitByID(unitId);
auto healthDiff = newHealthOfStack[unitId] - healthOfStack[unitId];
if(localUnit->unitOwner() != cb->getBattle(battleID)->getPlayerID())
healthDiff = -healthDiff;
if(healthDiff < 0)
{
ps.value = -1;
return; //do not damage own units at all
}
totalGain += healthDiff;
}
ps.value = totalGain;
}
void BattleEvaluator::print(const std::string & text) const
{
logAi->trace("%s Battle AI[%p]: %s", playerID.toString(), this, text);
}