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openmw-tes3mp/apps/openmw/mwmechanics/aicombat.cpp

799 lines
30 KiB
C++

#include "aicombat.hpp"
#include <components/misc/rng.hpp>
#include <components/esm/aisequence.hpp>
#include "../mwworld/class.hpp"
#include "../mwworld/esmstore.hpp"
#include "../mwbase/environment.hpp"
#include "../mwbase/dialoguemanager.hpp"
#include "../mwrender/animation.hpp"
#include "creaturestats.hpp"
#include "steering.hpp"
#include "movement.hpp"
#include "character.hpp"
#include "aicombataction.hpp"
#include "combat.hpp"
namespace
{
//chooses an attack depending on probability to avoid uniformity
ESM::Weapon::AttackType chooseBestAttack(const ESM::Weapon* weapon, MWMechanics::Movement &movement);
osg::Vec3f AimDirToMovingTarget(const MWWorld::Ptr& actor, const MWWorld::Ptr& target, const osg::Vec3f& vLastTargetPos,
float duration, int weapType, float strength);
float getZAngleToDir(const osg::Vec3f& dir)
{
return std::atan2(dir.x(), dir.y());
}
float getXAngleToDir(const osg::Vec3f& dir)
{
return -std::asin(dir.z() / dir.length());
}
const float REACTION_INTERVAL = 0.25f;
const float PATHFIND_Z_REACH = 50.0f;
// distance at which actor pays more attention to decide whether to shortcut or stick to pathgrid
const float PATHFIND_CAUTION_DIST = 500.0f;
// distance after which actor (failed previously to shortcut) will try again
const float PATHFIND_SHORTCUT_RETRY_DIST = 300.0f;
// cast up-down ray with some offset from actor position to check for pits/obstacles on the way to target;
// magnitude of pits/obstacles is defined by PATHFIND_Z_REACH
bool checkWayIsClear(const osg::Vec3f& from, const osg::Vec3f& to, float offsetXY)
{
if((to - from).length() >= PATHFIND_CAUTION_DIST || std::abs(from.z() - to.z()) <= PATHFIND_Z_REACH)
{
osg::Vec3f dir = to - from;
dir.z() = 0;
dir.normalize();
float verticalOffset = 200; // instead of '200' here we want the height of the actor
osg::Vec3f _from = from + dir*offsetXY + osg::Vec3f(0,0,1) * verticalOffset;
// cast up-down ray and find height in world space of hit
float h = _from.z() - MWBase::Environment::get().getWorld()->getDistToNearestRayHit(_from, osg::Vec3f(0,0,-1), verticalOffset + PATHFIND_Z_REACH + 1);
if(std::abs(from.z() - h) <= PATHFIND_Z_REACH)
return true;
}
return false;
}
}
namespace MWMechanics
{
/// \brief This class holds the variables AiCombat needs which are deleted if the package becomes inactive.
struct AiCombatStorage : AiTemporaryBase
{
float mAttackCooldown;
float mTimerReact;
float mTimerCombatMove;
bool mReadyToAttack;
bool mAttack;
bool mFollowTarget;
bool mCombatMove;
osg::Vec3f mLastTargetPos;
const MWWorld::CellStore* mCell;
boost::shared_ptr<Action> mCurrentAction;
float mActionCooldown;
float mStrength;
bool mForceNoShortcut;
ESM::Position mShortcutFailPos;
osg::Vec3f mLastActorPos;
MWMechanics::Movement mMovement;
AiCombatStorage():
mAttackCooldown(0),
mTimerReact(0),
mTimerCombatMove(0),
mReadyToAttack(false),
mAttack(false),
mFollowTarget(false),
mCombatMove(false),
mLastTargetPos(0,0,0),
mCell(NULL),
mCurrentAction(),
mActionCooldown(0),
mStrength(),
mForceNoShortcut(false),
mLastActorPos(0,0,0),
mMovement(){}
void startCombatMove(bool isNpc, bool isDistantCombat, float distToTarget, float rangeAttack);
void updateCombatMove(float duration);
void stopCombatMove();
void startAttackIfReady(const MWWorld::Ptr& actor, CharacterController& characterController,
const ESM::Weapon* weapon, bool distantCombat);
void updateAttack(CharacterController& characterController);
void stopAttack();
};
AiCombat::AiCombat(const MWWorld::Ptr& actor) :
mTargetActorId(actor.getClass().getCreatureStats(actor).getActorId())
{}
AiCombat::AiCombat(const ESM::AiSequence::AiCombat *combat)
{
mTargetActorId = combat->mTargetActorId;
}
void AiCombat::init()
{
}
/*
* Current AiCombat movement states (as of 0.29.0), ignoring the details of the
* attack states such as CombatMove, Strike and ReadyToAttack:
*
* +----(within strike range)----->attack--(beyond strike range)-->follow
* | | ^ | |
* | | | | |
* pursue<---(beyond follow range)-----+ +----(within strike range)---+ |
* ^ |
* | |
* +-------------------------(beyond follow range)--------------------+
*
*
* Below diagram is high level only, the code detail is a little different
* (but including those detail will just complicate the diagram w/o adding much)
*
* +----------(same)-------------->attack---------(same)---------->follow
* | |^^ |||
* | ||| |||
* | +--(same)-----------------+|+----------(same)------------+||
* | | | ||
* | | | (in range) ||
* | <---+ (too far) | ||
* pursue<-------------------------[door open]<-----+ ||
* ^^^ | ||
* ||| | ||
* ||+----------evade-----+ | ||
* || | [closed door] | ||
* |+----> maybe stuck, check --------------> back up, check door ||
* | ^ | ^ | ^ ||
* | | | | | | ||
* | | +---+ +---+ ||
* | +-------------------------------------------------------+|
* | |
* +---------------------------(same)---------------------------------+
*
* FIXME:
*
* The new scheme is way too complicated, should really be implemented as a
* proper state machine.
*
* TODO:
*
* Use the Observer Pattern to co-ordinate attacks, provide intelligence on
* whether the target was hit, etc.
*/
bool AiCombat::execute (const MWWorld::Ptr& actor, CharacterController& characterController, AiState& state, float duration)
{
// get or create temporary storage
AiCombatStorage& storage = state.get<AiCombatStorage>();
//General description
if (actor.getClass().getCreatureStats(actor).isDead())
return true;
MWWorld::Ptr target = MWBase::Environment::get().getWorld()->searchPtrViaActorId(mTargetActorId);
if (target.isEmpty())
return false;
if(!target.getRefData().getCount() || !target.getRefData().isEnabled() // Really we should be checking whether the target is currently registered
// with the MechanicsManager
|| target.getClass().getCreatureStats(target).isDead())
return true;
//Update every frame
storage.updateCombatMove(duration);
updateActorsMovement(actor, duration, storage.mMovement);
storage.updateAttack(characterController);
storage.mActionCooldown -= duration;
float& timerReact = storage.mTimerReact;
if(timerReact < REACTION_INTERVAL)
{
timerReact += duration;
return false;
}
else
{
timerReact = 0;
return reactionTimeActions(actor, characterController, storage, target);
}
}
bool AiCombat::reactionTimeActions(const MWWorld::Ptr& actor, CharacterController& characterController,
AiCombatStorage& storage, MWWorld::Ptr target)
{
MWMechanics::Movement& movement = storage.mMovement;
if (isTargetMagicallyHidden(target))
{
storage.stopAttack();
return false; // TODO: run away instead of doing nothing
}
const MWWorld::CellStore*& currentCell = storage.mCell;
bool cellChange = currentCell && (actor.getCell() != currentCell);
if(!currentCell || cellChange)
{
currentCell = actor.getCell();
}
const MWWorld::Class& actorClass = actor.getClass();
actorClass.getCreatureStats(actor).setMovementFlag(CreatureStats::Flag_Run, true);
float& actionCooldown = storage.mActionCooldown;
if (actionCooldown > 0)
return false;
float rangeAttack = 0;
float rangeFollow = 0;
boost::shared_ptr<Action>& currentAction = storage.mCurrentAction;
if (characterController.readyToPrepareAttack())
{
currentAction = prepareNextAction(actor, target);
actionCooldown = currentAction->getActionCooldown();
}
if (currentAction.get())
currentAction->getCombatRange(rangeAttack, rangeFollow);
// FIXME: consider moving this stuff to ActionWeapon::getCombatRange
const ESM::Weapon *weapon = NULL;
MWMechanics::WeaponType weaptype = WeapType_None;
float weapRange = 1.0f;
// Get weapon characteristics
MWBase::World* world = MWBase::Environment::get().getWorld();
if (actorClass.hasInventoryStore(actor))
{
//Get weapon range
MWWorld::ContainerStoreIterator weaponSlot =
MWMechanics::getActiveWeapon(actorClass.getCreatureStats(actor), actorClass.getInventoryStore(actor), &weaptype);
if (weaptype == WeapType_HandToHand)
{
static float fHandToHandReach =
world->getStore().get<ESM::GameSetting>().find("fHandToHandReach")->getFloat();
weapRange = fHandToHandReach;
}
else if (weaptype != WeapType_PickProbe && weaptype != WeapType_Spell && weaptype != WeapType_None)
{
// All other WeapTypes are actually weapons, so get<ESM::Weapon> is safe.
weapon = weaponSlot->get<ESM::Weapon>()->mBase;
weapRange = weapon->mData.mReach;
}
weapRange *= 100.0f;
}
else //is creature
{
weaptype = actorClass.getCreatureStats(actor).getDrawState() == DrawState_Spell ? WeapType_Spell : WeapType_HandToHand;
weapRange = 150.0f; //TODO: use true attack range (the same problem in Creature::hit)
}
bool distantCombat = false;
if (weaptype != WeapType_Spell)
{
// TODO: move to ActionWeapon
if (weaptype == WeapType_BowAndArrow || weaptype == WeapType_Crossbow || weaptype == WeapType_Thrown)
{
rangeAttack = 1000;
rangeFollow = 0; // not needed in ranged combat
distantCombat = true;
}
else
{
rangeAttack = weapRange;
rangeFollow = 300;
}
}
else
{
distantCombat = (rangeAttack > 500);
}
bool& readyToAttack = storage.mReadyToAttack;
// start new attack
storage.startAttackIfReady(actor, characterController, weapon, distantCombat);
/*
* Some notes on meanings of variables:
*
* rangeAttack:
*
* - Distance where attack using the actor's weapon is possible:
* longer for ranged weapons (obviously?) vs. melee weapons
* - Determined by weapon's reach parameter; hardcoded value
* for ranged weapon and for creatures
* - Once within this distance mFollowTarget is triggered
*
* rangeFollow:
*
* - Applies to melee weapons or hand to hand only (or creatures without
* weapons)
* - Distance a little further away than the actor's weapon reach
* i.e. rangeFollow > rangeAttack for melee weapons
* - Hardcoded value (0 for ranged weapons)
* - Once the target gets beyond this distance mFollowTarget is cleared
* and a path to the target needs to be found
*
* mFollowTarget:
*
* - Once triggered, the actor follows the target with LOS shortcut
* (the shortcut really only applies to cells where pathgrids are
* available, since the default path without pathgrids is direct to
* target even if LOS is not achieved)
*/
ESM::Position pos = actor.getRefData().getPosition();
osg::Vec3f vActorPos(pos.asVec3());
osg::Vec3f vTargetPos(target.getRefData().getPosition().asVec3());
osg::Vec3f vAimDir = MWBase::Environment::get().getWorld()->aimToTarget(actor, target);
float distToTarget = MWBase::Environment::get().getWorld()->getHitDistance(actor, target);
osg::Vec3f& lastActorPos = storage.mLastActorPos;
bool& followTarget = storage.mFollowTarget;
bool isStuck = false;
float speed = 0.0f;
if(movement.mPosition[1] && (lastActorPos - vActorPos).length() < (speed = actorClass.getSpeed(actor)) * REACTION_INTERVAL / 2)
isStuck = true;
lastActorPos = vActorPos;
// check if actor can move along z-axis
bool canMoveByZ = (actorClass.canSwim(actor) && world->isSwimming(actor))
|| world->isFlying(actor);
// can't fight if attacker can't go where target is. E.g. A fish can't attack person on land.
if (distToTarget >= rangeAttack
&& !actorClass.isNpc() && !MWMechanics::isEnvironmentCompatible(actor, target))
{
// TODO: start fleeing?
storage.stopAttack();
return false;
}
// for distant combat we should know if target is in LOS even if distToTarget < rangeAttack
bool inLOS = distantCombat ? world->getLOS(actor, target) : true;
// (within attack dist) || (not quite attack dist while following)
if(inLOS && (distToTarget < rangeAttack || (distToTarget <= rangeFollow && followTarget && !isStuck)))
{
mPathFinder.clearPath();
//Melee and Close-up combat
// getXAngleToDir determines vertical angle to target:
// if actor can move along z-axis it will control movement dir
// if can't - it will control correct aiming.
// note: in getZAngleToDir if we preserve dir.z then horizontal angle can be inaccurate
if (distantCombat)
{
osg::Vec3f& lastTargetPos = storage.mLastTargetPos;
vAimDir = AimDirToMovingTarget(actor, target, lastTargetPos, REACTION_INTERVAL, weaptype,
storage.mStrength);
lastTargetPos = vTargetPos;
movement.mRotation[0] = getXAngleToDir(vAimDir);
movement.mRotation[2] = getZAngleToDir(vAimDir);
}
else
{
movement.mRotation[0] = getXAngleToDir(vAimDir);
movement.mRotation[2] = getZAngleToDir((vTargetPos-vActorPos)); // using vAimDir results in spastic movements since the head is animated
}
// (not quite attack dist while following)
if (followTarget && distToTarget > rangeAttack)
{
//Close-up combat: just run up on target
storage.stopCombatMove();
movement.mPosition[1] = 1;
}
else // (within attack dist)
{
storage.startCombatMove(actorClass.isNpc(), distantCombat, distToTarget, rangeAttack);
readyToAttack = true;
//only once got in melee combat, actor is allowed to use close-up shortcutting
followTarget = true;
}
}
else // remote pathfinding
{
bool preferShortcut = false;
if (!distantCombat) inLOS = world->getLOS(actor, target);
// check if shortcut is available
bool& forceNoShortcut = storage.mForceNoShortcut;
ESM::Position& shortcutFailPos = storage.mShortcutFailPos;
if(inLOS && (!isStuck || readyToAttack)
&& (!forceNoShortcut || (shortcutFailPos.asVec3() - vActorPos).length() >= PATHFIND_SHORTCUT_RETRY_DIST))
{
if(speed == 0.0f) speed = actorClass.getSpeed(actor);
// maximum dist before pit/obstacle for actor to avoid them depending on his speed
float maxAvoidDist = REACTION_INTERVAL * speed + speed / MAX_VEL_ANGULAR_RADIANS * 2; // *2 - for reliability
preferShortcut = checkWayIsClear(vActorPos, vTargetPos, osg::Vec3f(vAimDir.x(), vAimDir.y(), 0).length() > maxAvoidDist*1.5? maxAvoidDist : maxAvoidDist/2);
}
// don't use pathgrid when actor can move in 3 dimensions
if (canMoveByZ)
{
preferShortcut = true;
movement.mRotation[0] = getXAngleToDir(vAimDir);
}
if(preferShortcut)
{
movement.mRotation[2] = getZAngleToDir((vTargetPos-vActorPos));
forceNoShortcut = false;
shortcutFailPos.pos[0] = shortcutFailPos.pos[1] = shortcutFailPos.pos[2] = 0;
mPathFinder.clearPath();
}
else // if shortcut failed stick to path grid
{
if(!isStuck && shortcutFailPos.pos[0] == 0.0f && shortcutFailPos.pos[1] == 0.0f && shortcutFailPos.pos[2] == 0.0f)
{
forceNoShortcut = true;
shortcutFailPos = pos;
}
followTarget = false;
buildNewPath(actor, target);
// should always return a path (even if it's just go straight on target.)
assert(mPathFinder.isPathConstructed());
}
if (readyToAttack)
{
// to stop possible sideway moving after target moved out of attack range
storage.stopCombatMove();
readyToAttack = false;
}
movement.mPosition[1] = 1;
}
return false;
}
void AiCombat::updateActorsMovement(const MWWorld::Ptr& actor, float duration, MWMechanics::Movement& desiredMovement)
{
MWMechanics::Movement& actorMovementSettings = actor.getClass().getMovementSettings(actor);
if (mPathFinder.isPathConstructed())
{
const ESM::Position& pos = actor.getRefData().getPosition();
if (mPathFinder.checkPathCompleted(pos.pos[0], pos.pos[1]))
{
actorMovementSettings.mPosition[1] = 0;
}
else
{
evadeObstacles(actor, duration, pos);
}
}
else
{
actorMovementSettings = desiredMovement;
rotateActorOnAxis(actor, 2, actorMovementSettings, desiredMovement);
rotateActorOnAxis(actor, 0, actorMovementSettings, desiredMovement);
}
}
void AiCombat::rotateActorOnAxis(const MWWorld::Ptr& actor, int axis,
MWMechanics::Movement& actorMovementSettings, MWMechanics::Movement& desiredMovement)
{
actorMovementSettings.mRotation[axis] = 0;
float& targetAngleRadians = desiredMovement.mRotation[axis];
if (targetAngleRadians != 0)
{
if (smoothTurn(actor, targetAngleRadians, axis))
{
// actor now facing desired direction, no need to turn any more
targetAngleRadians = 0;
}
}
}
bool AiCombat::doesPathNeedRecalc(ESM::Pathgrid::Point dest, const ESM::Cell *cell)
{
if (!mPathFinder.getPath().empty())
{
osg::Vec3f currPathTarget(PathFinder::MakeOsgVec3(mPathFinder.getPath().back()));
osg::Vec3f newPathTarget = PathFinder::MakeOsgVec3(dest);
float dist = (newPathTarget - currPathTarget).length();
float targetPosThreshold = (cell->isExterior()) ? 300.0f : 100.0f;
return dist > targetPosThreshold;
}
else
{
// necessarily construct a new path
return true;
}
}
void AiCombat::buildNewPath(const MWWorld::Ptr& actor, const MWWorld::Ptr& target)
{
ESM::Pathgrid::Point newPathTarget = PathFinder::MakePathgridPoint(target.getRefData().getPosition());
//construct new path only if target has moved away more than on [targetPosThreshold]
if (doesPathNeedRecalc(newPathTarget, actor.getCell()->getCell()))
{
ESM::Pathgrid::Point start(PathFinder::MakePathgridPoint(actor.getRefData().getPosition()));
mPathFinder.buildSyncedPath(start, newPathTarget, actor.getCell(), false);
}
}
int AiCombat::getTypeId() const
{
return TypeIdCombat;
}
unsigned int AiCombat::getPriority() const
{
return 1;
}
MWWorld::Ptr AiCombat::getTarget() const
{
return MWBase::Environment::get().getWorld()->searchPtrViaActorId(mTargetActorId);
}
AiCombat *MWMechanics::AiCombat::clone() const
{
return new AiCombat(*this);
}
void AiCombat::writeState(ESM::AiSequence::AiSequence &sequence) const
{
std::auto_ptr<ESM::AiSequence::AiCombat> combat(new ESM::AiSequence::AiCombat());
combat->mTargetActorId = mTargetActorId;
ESM::AiSequence::AiPackageContainer package;
package.mType = ESM::AiSequence::Ai_Combat;
package.mPackage = combat.release();
sequence.mPackages.push_back(package);
}
void AiCombatStorage::startCombatMove(bool isNpc, bool isDistantCombat, float distToTarget, float rangeAttack)
{
if (mMovement.mPosition[0] || mMovement.mPosition[1])
{
mTimerCombatMove = 0.1f + 0.1f * Misc::Rng::rollClosedProbability();
mCombatMove = true;
}
// only NPCs are smart enough to use dodge movements
else if (isNpc && (!isDistantCombat || (distToTarget < rangeAttack / 2)))
{
//apply sideway movement (kind of dodging) with some probability
if (Misc::Rng::rollClosedProbability() < 0.25)
{
mMovement.mPosition[0] = Misc::Rng::rollProbability() < 0.5 ? 1.0f : -1.0f;
mTimerCombatMove = 0.05f + 0.15f * Misc::Rng::rollClosedProbability();
mCombatMove = true;
}
}
if (isDistantCombat && distToTarget < rangeAttack / 4)
{
mMovement.mPosition[1] = -1;
}
}
void AiCombatStorage::updateCombatMove(float duration)
{
if (mCombatMove)
{
mTimerCombatMove -= duration;
if (mTimerCombatMove <= 0)
{
stopCombatMove();
}
}
}
void AiCombatStorage::stopCombatMove()
{
mTimerCombatMove = 0;
mMovement.mPosition[1] = mMovement.mPosition[0] = 0;
mCombatMove = false;
}
void AiCombatStorage::startAttackIfReady(const MWWorld::Ptr& actor, CharacterController& characterController,
const ESM::Weapon* weapon, bool distantCombat)
{
if (mReadyToAttack && characterController.readyToStartAttack())
{
if (mAttackCooldown <= 0)
{
mAttack = true; // attack starts just now
characterController.setAttackingOrSpell(true);
if (!distantCombat)
chooseBestAttack(weapon, mMovement);
mStrength = Misc::Rng::rollClosedProbability();
const MWWorld::ESMStore &store = MWBase::Environment::get().getWorld()->getStore();
float baseDelay = store.get<ESM::GameSetting>().find("fCombatDelayCreature")->getFloat();
if (actor.getClass().isNpc())
{
baseDelay = store.get<ESM::GameSetting>().find("fCombatDelayNPC")->getFloat();
//say a provoking combat phrase
int chance = store.get<ESM::GameSetting>().find("iVoiceAttackOdds")->getInt();
if (Misc::Rng::roll0to99() < chance)
{
MWBase::Environment::get().getDialogueManager()->say(actor, "attack");
}
}
mAttackCooldown = std::min(baseDelay + 0.01 * Misc::Rng::roll0to99(), baseDelay + 0.9);
}
else
mAttackCooldown -= REACTION_INTERVAL;
}
}
void AiCombatStorage::updateAttack(CharacterController& characterController)
{
if (mAttack && (characterController.getAttackStrength() >= mStrength || characterController.readyToPrepareAttack()))
{
mAttack = false;
}
characterController.setAttackingOrSpell(mAttack);
}
void AiCombatStorage::stopAttack()
{
mMovement.mPosition[0] = 0;
mMovement.mPosition[1] = 0;
mMovement.mPosition[2] = 0;
mReadyToAttack = false;
mAttack = false;
}
}
namespace
{
ESM::Weapon::AttackType chooseBestAttack(const ESM::Weapon* weapon, MWMechanics::Movement &movement)
{
ESM::Weapon::AttackType attackType;
if (weapon == NULL)
{
//hand-to-hand deal equal damage for each type
float roll = Misc::Rng::rollClosedProbability();
if(roll <= 0.333f) //side punch
{
movement.mPosition[0] = Misc::Rng::rollClosedProbability() ? 1.0f : -1.0f;
movement.mPosition[1] = 0;
attackType = ESM::Weapon::AT_Slash;
}
else if(roll <= 0.666f) //forward punch
{
movement.mPosition[1] = 1;
attackType = ESM::Weapon::AT_Thrust;
}
else
{
movement.mPosition[1] = movement.mPosition[0] = 0;
attackType = ESM::Weapon::AT_Chop;
}
}
else
{
//the more damage attackType deals the more probability it has
int slash = (weapon->mData.mSlash[0] + weapon->mData.mSlash[1])/2;
int chop = (weapon->mData.mChop[0] + weapon->mData.mChop[1])/2;
int thrust = (weapon->mData.mThrust[0] + weapon->mData.mThrust[1])/2;
float roll = Misc::Rng::rollClosedProbability() * (slash + chop + thrust);
if(roll <= slash)
{
movement.mPosition[0] = (Misc::Rng::rollClosedProbability() < 0.5f) ? 1.0f : -1.0f;
movement.mPosition[1] = 0;
attackType = ESM::Weapon::AT_Slash;
}
else if(roll <= (slash + thrust))
{
movement.mPosition[1] = 1;
attackType = ESM::Weapon::AT_Thrust;
}
else
{
movement.mPosition[1] = movement.mPosition[0] = 0;
attackType = ESM::Weapon::AT_Chop;
}
}
return attackType;
}
osg::Vec3f AimDirToMovingTarget(const MWWorld::Ptr& actor, const MWWorld::Ptr& target, const osg::Vec3f& vLastTargetPos,
float duration, int weapType, float strength)
{
float projSpeed;
// get projectile speed (depending on weapon type)
if (weapType == ESM::Weapon::MarksmanThrown)
{
static float fThrownWeaponMinSpeed =
MWBase::Environment::get().getWorld()->getStore().get<ESM::GameSetting>().find("fThrownWeaponMinSpeed")->getFloat();
static float fThrownWeaponMaxSpeed =
MWBase::Environment::get().getWorld()->getStore().get<ESM::GameSetting>().find("fThrownWeaponMaxSpeed")->getFloat();
projSpeed =
fThrownWeaponMinSpeed + (fThrownWeaponMaxSpeed - fThrownWeaponMinSpeed) * strength;
}
else
{
static float fProjectileMinSpeed =
MWBase::Environment::get().getWorld()->getStore().get<ESM::GameSetting>().find("fProjectileMinSpeed")->getFloat();
static float fProjectileMaxSpeed =
MWBase::Environment::get().getWorld()->getStore().get<ESM::GameSetting>().find("fProjectileMaxSpeed")->getFloat();
projSpeed =
fProjectileMinSpeed + (fProjectileMaxSpeed - fProjectileMinSpeed) * strength;
}
// idea: perpendicular to dir to target speed components of target move vector and projectile vector should be the same
osg::Vec3f vTargetPos = target.getRefData().getPosition().asVec3();
osg::Vec3f vDirToTarget = MWBase::Environment::get().getWorld()->aimToTarget(actor, target);
float distToTarget = vDirToTarget.length();
osg::Vec3f vTargetMoveDir = vTargetPos - vLastTargetPos;
vTargetMoveDir /= duration; // |vTargetMoveDir| is target real speed in units/sec now
osg::Vec3f vPerpToDir = vDirToTarget ^ osg::Vec3f(0,0,1); // cross product
vPerpToDir.normalize();
osg::Vec3f vDirToTargetNormalized = vDirToTarget;
vDirToTargetNormalized.normalize();
// dot product
float velPerp = vTargetMoveDir * vPerpToDir;
float velDir = vTargetMoveDir * vDirToTargetNormalized;
// time to collision between target and projectile
float t_collision;
float projVelDirSquared = projSpeed * projSpeed - velPerp * velPerp;
osg::Vec3f vTargetMoveDirNormalized = vTargetMoveDir;
vTargetMoveDirNormalized.normalize();
float projDistDiff = vDirToTarget * vTargetMoveDirNormalized; // dot product
projDistDiff = std::sqrt(distToTarget * distToTarget - projDistDiff * projDistDiff);
if (projVelDirSquared > 0)
t_collision = projDistDiff / (std::sqrt(projVelDirSquared) - velDir);
else t_collision = 0; // speed of projectile is not enough to reach moving target
return vDirToTarget + vTargetMoveDir * t_collision;
}
}