motion.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * Based on the original sources
 *   Faery Tale II -- The Halls of the Dead
 *   (c) 1993-1996 The Wyrmkeep Entertainment Co.
 */

#ifndef SAGA2_MOTION_H
#define SAGA2_MOTION_H

#include "saga2/actor.h"

namespace Saga2 {

class PathRequest;
struct StandingTileInfo;

extern const StaticTilePoint dirTable[];
extern const StaticTilePoint incDirTable[];


const int   kGravity         = 2;
const int   kWalkSpeed       = 4;
const int   kSlowWalkSpeed   = 2;
const int   kRunSpeed        = 8;
const int   kWalkSpeedDiag   = 3;
const int   kRunSpeedDiag    = 6;
const int   kAngleThresh     = 24;

enum MotionThreadReturnValues {
    kMotionInterrupted,              //  MotionTask has been rudely
    //  interrupted and recycled for a new
    //  motion.

    kMotionStarted,                  //  The actor started moving.
    kMotionCompleted,                //  The actor motion completed
    //  successfully.
    kMotionWalkBlocked               //  The walk motion failed.
};

enum {
    kMoveWait            = (1 << 0),
    kMoveRun             = (1 << 1)
};

/* ===================================================================== *
   Utility Motion Functions
 * ===================================================================== */

void setObjectSurface(GameObject *obj, StandingTileInfo &sti);

/* ===================================================================== *
   Motion Task Class
 * ===================================================================== */

//  This class handles the movement of objects. It includes things like
//  thrown rocks, cast spells, and actors walking.
//
//  Since most things in the game aren't moving at a given point, the
//  variables for simulating motion don't need to always be present.

//  Also need to handle explosion on impact for projectiles
//  Or other special action.
//      an object can hit a regular surface
//      can hit a trip plate
//      can hit another object
//      can hit an actor
//
//      can damage actor
//      can break
//      can set off trap
//      can explode

class MotionTask {
    friend class    MotionTaskList;
    friend class    PathRequest;
    friend class    DestinationPathRequest;
    friend class    WanderPathRequest;
    friend class    Actor;
    friend void     RequestPath(MotionTask *mTask, int16 smartness);
    friend void     RequestWanderPath(MotionTask *mTask, int16 smartness);
    friend void     abortPathFind(MotionTask *mTask);

    GameObject      *_object;                // the object to move
    TilePoint       _velocity;               // object velocity for ballistic flight
    TilePoint       _immediateLocation,      // where we are trying to get to
                    _finalTarget;            // where we eventually want to get to
    int16           _tetherMinU,
                    _tetherMinV,
                    _tetherMaxU,
                    _tetherMaxV;
    uint8           _motionType,             // thrown or shot.
                    _prevMotionType;         // motion type before interruption

    ThreadID        _thread;                 // SAGA thread to wake up when
    // motion is done

    uint16          _flags;                  // various flags

    enum motionFlags {
        kMfPathFind        = (1 << 0),         // walk is using path finding
        kMfFinalPath       = (1 << 1),         // current path is final
        kMfInWater         = (1 << 2),         // handle motion as in water
        kMfReset           = (1 << 3),         // target has been reset
        kMfBlocked         = (1 << 4),         // target was blocked
        kMfRequestRun      = (1 << 5),         // caller has requested running
        kMfWandering       = (1 << 6),         // wander
        kMfTethered        = (1 << 7),         // stay within tether
        kMfNextAnim        = (1 << 8),         // update animation for this frame
        kMfTurnDelay       = (1 << 9),         // Delay While Turning
        kMfTAGTarg         = (1 << 10),        // The target is not an object but a TAG
        kMfLocTarg         = (1 << 11),        // The target is not an object but a TAG
        kMfAgitated        = (1 << 12),        // Walking around blockage
        kMfAgitatable      = (1 << 13),        // Will agitate when blocked
        kMfOnStairs        = (1 << 14),        // actor is climbing stairs
        kMfPrivledged      = (1 << 15)         // don't let AI interrupt this
    };

    Direction       _direction;              // direction of movement
    TilePoint       _pathList[16];         // intermediate motion targets
    int16           _pathCount,              // number of points in path
                    _pathIndex,              // number of points so far
                    _runCount;               // used for run requests.
    PathRequest     *_pathFindTask;          // request to find the path
    int16           _steps,                  // number of steps in ballistic motion
                    _uFrac,                  // remainder in U direction
                    _vFrac,                  // remainder in V direction
                    _uErrorTerm,             // used to adjust for rounding errors
                    _vErrorTerm;             // used to adjust for rounding errors

    //  Data used in combat motion
    uint8           _combatMotionType;       // combat sub motion type

    // Spell casting stuff
    GameObject      *_targetObj;             // target of attack or defense (object)
    ActiveItem      *_targetTAG;             // target of attack or defense (TAG)
    Location        _targetLoc;              // target of attack or defense (Location)
    SkillProto      *_spellObj;              // spell being cast

    union {
        int16           actionCounter;      // counter used in some motion
        int16           moveCount;          // counter used when moving mergeable objects around
    };

    enum defenseMotionFlags {
        kDfBlocking    = (1 << 0)             // actor is blocking an attack
    };

    union {
        //  Object interaction stuff
        struct {
            GameObject      *directObject,  // object directly being acted
                            // upon.
                            *indirectObject;    // object idirectly being acted
            // upon.
            Actor           *enactor;
            ActiveItem      *TAI;           // TAI involved in interation
        } _o;

        //  Defensive motion stuff
        struct {
            Actor           *attacker;      // attacking actor
            GameObject      *defensiveObj;  // shield or parrying weapon
            uint8           defenseFlags;   // various combat flags
        } _d;
    };

public:
    //  Combat specific motion sub-types
    enum TwoHandedSwingTypes {
        kTwoHandedSwingHigh,
        kTwoHandedSwingLow,
        kTwoHandedSwingLeftHigh,
        kTwoHandedSwingLeftLow,
        kTwoHandedSwingRightHigh,
        kTwoHandedSwingRightLow
    };

    enum OneHandedSwingTypes {
        kOneHandedSwingHigh,
        kOneHandedSwingLow,
        kOneHandedThrust
    };

    enum OneHandedParryTypes {
        kOneHandedParryHigh,
        kOneHandedParryLow
    };

private:

    enum motionTypes {
        kMotionTypeNone,                     // no motion

        kMotionTypeThrown,                   // thrown in an arc
        kMotionTypeShot,                     // shot in very shallow arc w/ cheat
        kMotionTypeFall,                     // fall from a height
        kMotionTypeWalk,                     // walk to a point
        kMotionTypeStagger,                  // stagger to a point
        kMotionTypeClimbUp,                  // climb up ladder to a point
        kMotionTypeClimbDown,                // climb dowb ladder
        kMotionTypeTalk,                     // talk and gesture
        kMotionTypeLand,                     // land after falling
        kMotionTypeLandBadly,                // land badly after falling
        kMotionTypeJump,                     // get ready for jump
        kMotionTypeTurn,                     // Turn Object
        kMotionTypeGive,                     // Extend arm to give object
        kMotionTypeRise,                     // Rise slowly in water
        kMotionTypeHit,                      // For simple animations

        //  Immobile motions
        kMotionTypeWait,                     // Don't move, simply eat some time
        kMotionTypeUseObject,                // Use an object
        kMotionTypeUseObjectOnObject,        // Use one object on another
        kMotionTypeUseObjectOnTAI,           // Use an object on a TAI
        kMotionTypeUseObjectOnLocation,      // Use an object on a TilePoint
        kMotionTypeUseTAI,                   // Use a TAI
        kMotionTypeDropObject,               // Drop an object at a location
        kMotionTypeDropObjectOnObject,       // Drop one object on another
        kMotionTypeDropObjectOnTAI,          // Drop an object on a TAI

        //  Offensive combat actions
        kMotionTypeTwoHandedSwing,           // swing two-handed weapon
        kMotionTypeOneHandedSwing,           // swing one-handed weapon
        kMotionTypeFireBow,                  // fire bow
        kMotionTypeCastSpell,                // cast spell
        kMotionTypeUseWand,                  // cast spell with wand

        //  Defensive combat actions
        kMotionTypeTwoHandedParry,           // parry with two-handed weapon
        kMotionTypeOneHandedParry,           // parry with one-handed weapon
        kMotionTypeShieldParry,              // parry with shield
        kMotionTypeDodge,                    // dodge blow

        //  Other combat actions
        kMotionTypeAcceptHit,                // show effect of hit
        kMotionTypeFallDown,                 // be knocked off feet
        kMotionTypeDie                       // self-explanatory

    };

    void read(Common::InSaveFile *in);

    //  Return the number of bytes needed to archive this MotionTask
    int32 archiveSize();

    void write(Common::MemoryWriteStreamDynamic *out);

    // motion task is finished.
    void remove(int16 returnVal = kMotionInterrupted);

    TilePoint getImmediateTarget();      // determine immediate target
    // location

    //  Routines to handle updating of specific motion types
    void turnAction() {
        Actor   *a = (Actor *)_object;

        if (_flags & kMfReset) {
            a->setAction(kActionStand, 0);
            _flags &= ~kMfReset;
        }

        if (a->_currentFacing != _direction)
            a->turn(_direction);
        else
            remove(kMotionCompleted);
    }

    void ballisticAction();
    void walkAction();
    void giveAction();

    void upLadderAction();
    void downLadderAction();

    //  Set up specified animation and run through the frames
    void genericAnimationAction(uint8 actionType);

    //  Offensive combat actions
    void twoHandedSwingAction();
    void oneHandedSwingAction();
    void fireBowAction();
    void castSpellAction();
    void useWandAction();

    //  Defensive combat actions
    void twoHandedParryAction();
    void oneHandedParryAction();
    void shieldParryAction();
    void dodgeAction();

    //  Other combat actions
    void acceptHitAction();
    void fallDownAction();

    //  Generic offensive melee code.  Called by twoHandedSwingAction()
    //  and oneHandedSwingAction
    void offensiveMeleeAction();

    //  Generic magic weapon code.  Called by useWandAction() and
    //  useStaffAction()
    void useMagicWeaponAction();

    //  Generic defensive melee code.  Called by twoHandedParryAction(),
    //  oneHandedParryAction() and shieldParryAction().
    void defensiveMeleeAction();

    //  Retrieve the next waypoint from the path list.
    bool nextWayPoint();
    bool checkWalk(int16, int16, int16, TilePoint &);

    //  Determine the velocity for a ballistic motion
    void calcVelocity(const TilePoint &vector, int16 turns);

public:

    //  Functions to create a new motion task. If the game object is
    //  an actor, then it will cancel any existing motion task
    static void throwObject(GameObject &obj, const TilePoint &velocity);
    static void throwObjectTo(GameObject &obj, const TilePoint &where);
    static void shootObject(
        GameObject  &obj,
        Actor       &doer,
        GameObject  &target,
        int16       speed);
    static void walkTo(
        Actor           &obj,
        const TilePoint &target,
        bool            run = false,
        bool            canAgitate = true);
    static void walkTo(
        ThreadID        th,
        Actor           &obj,
        const TilePoint &target,
        bool            run = false,
        bool            canAgitate = true);
    static void walkToDirect(
        Actor           &obj,
        const TilePoint &target,
        bool            run = false,
        bool            canAgitate = true);
    static void walkToDirect(
        ThreadID        th,
        Actor           &obj,
        const TilePoint &target,
        bool            run = false,
        bool            canAgitate = true);
    static void wander(Actor &obj, bool run = false);
    static void tetheredWander(Actor &obj, const TileRegion &tether, bool run = false);
//  static void runTo( GameObject &obj, const TilePoint &target );
    static void staggerTo(Actor &obj, const TilePoint &target);
    static void upLadder(Actor &obj);
    static void downLadder(Actor &obj);
    static void talk(Actor &obj);
    static void jump(Actor &obj);
    static void turn(Actor &obj, Direction dir);
    static void turn(ThreadID th, Actor &obj, Direction dir);
    static void turnTowards(Actor &obj, const TilePoint &where);
    static void turnTowards(ThreadID th, Actor &obj, const TilePoint &where);
    static void give(Actor &obj, Actor &givee);
    static void give(ThreadID th, Actor &obj, Actor &givee);

    // Imobile motions
    static void wait(Actor &a);
    static void useObject(Actor &a, GameObject &dObj);
    static void useObjectOnObject(
        Actor       &a,
        GameObject  &dObj,
        GameObject  &target);
    static void useObjectOnTAI(
        Actor       &a,
        GameObject  &dObj,
        ActiveItem  &target);
    static void useObjectOnLocation(
        Actor           &a,
        GameObject      &dObj,
        const Location &target);
    static void useTAI(Actor &a, ActiveItem &dTAI);
    static void dropObject(
        Actor           &a,
        GameObject      &dObj,
        const Location  &loc,
        int16           num = 1);

    static void dropObjectOnObject(
        Actor       &a,
        GameObject  &dObj,
        GameObject  &target,
        int16       num = 1);

    static void dropObjectOnTAI(
        Actor           &a,
        GameObject      &dObj,
        ActiveItem      &target,
        const Location  &loc);

    //  Offensive combat actions
    static void twoHandedSwing(Actor &obj, GameObject &target);
    static void oneHandedSwing(Actor &obj, GameObject &target);
    static void fireBow(Actor &obj, GameObject &target);
    static void castSpell(Actor &obj, SkillProto &spell, GameObject &target);
    static void castSpell(Actor &obj, SkillProto &spell, Location &target);
    static void castSpell(Actor &obj, SkillProto &spell, ActiveItem &target);
    static void useWand(Actor &obj, GameObject &target);

    //  Defensive combat actions
    static void twoHandedParry(
        Actor       &obj,
        GameObject  &weapon,
        Actor       &opponent);
    static void oneHandedParry(
        Actor       &obj,
        GameObject  &weapon,
        Actor       &opponent);
    static void shieldParry(
        Actor       &obj,
        GameObject  &shield,
        Actor       &opponent);
    static void dodge(Actor &obj, Actor &opponent);

    //  Other combat actions
    static void acceptHit(Actor &obj, Actor &opponent);
    static void fallDown(Actor &obj, Actor &opponent);
    static void die(Actor &obj);

    static void updatePositions();

    int16 testCollision(GameObject &obstacle);

    bool freeFall(TilePoint &newPos, StandingTileInfo &sti);

    //  Determine if the motion task is a walk motion
    bool isWalk();

    //  Determine if the motion task is walking to a destination
    bool isWalkToDest() {
        return isWalk() && !(_flags & kMfWandering);
    }

    //  Determine if the motion task is a wandering motion
    bool isWander() {
        return isWalk() && (_flags & kMfWandering);
    }

    //  Determine if the motion task is tethered
    bool isTethered() {
        return isWander() && (_flags & kMfTethered);
    }

    bool isRunning() {
        return (_flags & kMfRequestRun) && _runCount == 0;
    }

    bool isTurn() {
        return _motionType == kMotionTypeTurn;
    }

    //  Return the wandering tether region
    TileRegion getTether();

    //  Return the final target location
    TilePoint getTarget() {
        return _finalTarget;
    }

    //  Update to a new final target
    void changeTarget(const TilePoint &newPos, bool run = false);
    void changeDirectTarget(const TilePoint &newPos, bool run = false);
    void finishWalk();                   // stop walking
    void finishTurn() {
        if (isTurn()) remove();
    }
    void finishTalking();                    // stop talking motion

    //  Determine if this MotionTask is a reflexive motion
    bool isReflex();

    //  Determine if this MotionTask is a defensive motion
    bool isDefense();

    //  End the defensive motion task
    void finishDefense() {
        if (isDefense()) remove();
    }

    //  Determine if this MotionTask is an offensive motion
    bool isAttack();

    //  Determine if this MotionTask is an offensive melee motion
    bool isMeleeAttack();

    //  Compute the number of frames before the actual strike in an
    //  offensive melee motion
    uint16 framesUntilStrike();

    //  End the offensive motion
    void finishAttack() {
        if (isAttack()) remove();
    }

    //  Returns a pointer to the blocking object if it applicable to
    //  this motion task
    GameObject *blockingObject(Actor *thisAttacker);

    //  Determine if this motion is a dodge motion
    bool isDodging(Actor *thisAttacker) {
        return _motionType == kMotionTypeDodge && thisAttacker == _d.attacker;
    }

    static void initMotionTasks();

    bool isPrivledged() {
        return _flags & kMfPrivledged;
    }
};

class MotionTaskList {
    friend class    MotionTask;

    Common::List<MotionTask *> _list;
    Common::List<MotionTask *>::iterator _nextMT;

public:
    //  Default constructor
    MotionTaskList();

    MotionTaskList(Common::SeekableReadStream *stream);

    void read(Common::InSaveFile *in);

    //  Return the number of bytes needed to archive the motion tasks
    //  in a buffer
    int32 archiveSize();

    void write(Common::MemoryWriteStreamDynamic *out);

    //  Cleanup the motion tasks
    void cleanup();

    MotionTask *newTask(GameObject *obj);    // get new motion task
};

/* ===================================================================== *
    MotionTask inline member functions
 * ===================================================================== */

inline void MotionTask::walkTo(
    ThreadID        th,
    Actor           &actor,
    const TilePoint &target,
    bool            run,
    bool            canAgitate) {
    walkTo(actor, target, run, canAgitate);
    if (actor._moveTask != NULL)
        actor._moveTask->_thread = th;
}

inline void MotionTask::walkToDirect(
    ThreadID        th,
    Actor           &actor,
    const TilePoint &target,
    bool            run,
    bool            canAgitate) {
    walkToDirect(actor, target, run, canAgitate);
    if (actor._moveTask != NULL)
        actor._moveTask->_thread = th;
}

inline void MotionTask::turn(ThreadID th, Actor &actor, Direction dir) {
    turn(actor, dir);
    if (actor._moveTask != NULL)
        actor._moveTask->_thread = th;
}

inline void MotionTask::turnTowards(
    ThreadID        th,
    Actor           &actor,
    const TilePoint &where) {
    turnTowards(actor, where);
    if (actor._moveTask != NULL)
        actor._moveTask->_thread = th;
}

inline void MotionTask::give(ThreadID th, Actor &actor, Actor &givee) {
    give(actor, givee);
    if (actor._moveTask != NULL)
        actor._moveTask->_thread = th;
}

/* ===================================================================== *
   Utility functions
 * ===================================================================== */

//  Initiate ladder climbing
bool checkLadder(Actor *a, const TilePoint &tp);

void pauseInterruptableMotions();
void resumeInterruptableMotions();

/* ===================================================================== *
   MotionTask list management functions
 * ===================================================================== */

//  Initialize the motion task list
void initMotionTasks();

void saveMotionTasks(Common::OutSaveFile *out);
void loadMotionTasks(Common::InSaveFile *in, int32 chunkSize);

//  Cleanup the motion task list
void cleanupMotionTasks();

} // end of namespace Saga2

#endif