Vanilla AI combat decision making

aicombat.py

# This is a simplified version of the function that determines the next combat action (similar to OpenMW's prepareNextAction()).
# It's called regularly (on timer) during combat.
def shouldFlee(actor, target):
    if actor.isWerewolf:
        return False

    if should use potion: # Unresearched. Fairly long code.
        return False

    fleeRating = getFleeRating(actor, target)
    if fleeRating < 100.0:
        fleeRating = 0.0

    magicRating = getMagicCombatRating(actor, target)
    weaponRating, weapon = getWeaponCombatRating(actor, target)

    nextAction = None
    if weaponsRating > max(magicRating, fleeRating):
        nextAction = RANGED_FIGHT if weapon.type >= MARKSMAN_BOW else MELEE_FIGHT
        # ...
        
    # some spell setting code?

    if fleeRating > max(weaponRating, magicRating):
        return True

    if fleeRating > 100.0:
        # NOTE: No check whether target is player...
        if actor is NPC and glob["PCKnownWerewolf"] != 0:
            return True

        if player.isWerewolf:
            return True

    if nextAction == None:
        nextAction = FIST_FIGHT
    elif nextAction != FIST_FIGHT:
        return False

    if actor has active SUMMON_X effect:
        return True # fists + active summon -> flee

    return False

def getFleeRating(actor, target):
    if actor.something24 != 0: # Seems to be the number of objects that are obstructing the actor's movement. This prevents actors from continuing to run into walls while fleeing.
        return 0.0

    if actor.flee >= 100:
        return actor.flee

    rating = (1.0 - actor.healthPercentage) * gmst["fAIFleeHealthMult"] + actor.flee * gmst["fAIFleeFleeMult"]

    if target.isWerewolf and actor.level < gmst["iWereWolfLevelToAttack"]:
        rating = gmst["iWereWolfFleeMod"]

    if rating != 0.0:
        rating += (gmst["iFightDistanceBase"] - gmst["fFightDistanceMultiplier"] * distance(actor, target))

    return rating

def getMagicCombatRating(actor, target):
    if actor.currentMagicka == 0.0
        return 0.0, None

    if actor has no spells:
        return 0.0, None

    maxRating = 0.0
    bestSpell = None

    for spell in actor.spells:
        if spell.type != REGULAR_SPELL: # skip powers, abilities etc.
            continue
        if spell has no HARMFUL effects: # MGEF flag 0x10
            continue
        if spell has UNREFLECTABLE effect: # MGEF flag 0x10000
            continue
        if target.isCurrentlyAffectedBy(spell):
            continue

        if spell.magickaCost > actor.currentMagicka:
            continue

        if spell has TARGET effect: # range type
            if target.isSwimming:
                mult = 0.0
            else:
                mult = gmst["fAIRangeMagicSpellMult"]
        else:
            mult = gmst["fAIMagicSpellMult"]

        if spell.successChance(actor) * mult >= maxRating:
            maxRating = spell.successChance(actor) * mult
            bestSpell = spell

    return maxRating, bestSpell

def getWeaponCombatRating(actor, target):
    if actor is creature and not actor.crea.flags & WEAPON_AND_SHIELD:
        return 0.0

    bestDamageRating = 0.0
    bestWeapon = None

    weaponSkillsTable = [LONG_BLADE, AXE, SPEAR, SHORT_BLADE, MARKSMAN, BLUNT_WEAPON]

    for i in range(len(weaponSkillsTable)):
        skillMult = actor.skills[weaponSkillsTable[i]].totalValue * 0.01

        for weapon in actor.inventory:
            if weapon.type in [ARROW, BOLT]:
                continue

            if weaponTypeToSkill(item.weapon.type) == weaponSkillsTable[i]:
                chopMult = 0.0
                ammoDamage = 0.0

                if weapon.type >= MARKSMAN_BOW: # bows, crossbows and thrown weapons
                    found = False
                    for ammo in actor.inventory:
                        if (ammo.type == ARROW and weapon.type == BOW) or (ammo.type == BOLT and weapon.type == CROSSBOW):
                            ammoDamage = ammo.chopMax
                            found = True
                            break

                    if found and actor is not swimming:
                        if actor.Z >= water level or (actor.height + actor.Z) * 0.7 <= water level: # NOTE: Bug? Should probably be (actor.Z + actor.height * 0.7).
                            chopMult = gmst["fAIRangeMeleeWeaponMult"]
                else:
                    chopMult = gmst["fAIMeleeWeaponMult"]

                chopRating = (weapon.chopMax + ammoDamage) * skillMult * chopMult
                slashRating = weapon.slashMax * skillMult * gmst["fAIMeleeWeaponMult"]
                thrustRating = weapon.thrustMax * skillMult * gmst["fAIMeleeWeaponMult"]

                if weapon.type == MARKSMAN_THROWN and not actor.hasAnimationGroup("MarksmanThrown")
                    continue

                if chopRating != 0.0 and chopRating >= bestDamageRating:
                    chopRating = bestDamageRating
                    bestWeapon = weapon
                if slashRating != 0.0 and slashRating >= bestDamageRating:
                    slashRating = bestDamageRating
                    bestWeapon = weapon
                if thrustRating != 0.0 and thrustRating >= bestDamageRating:
                    thrustRating = bestDamageRating
                    bestWeapon = weapon

    if bestWeapon != None and bestWeapon.currentHealth > 0.0:
        return actor.getArmorRating() * gmst["fAIMeleeArmorMult"] + bestDamageRating

    return 0.0