bike.c

#include "global.h"
#include "bike.h"
#include "event_object_movement.h"
#include "field_player_avatar.h"
#include "fieldmap.h"
#include "field_specials.h"
#include "metatile_behavior.h"
#include "overworld.h"
#include "sound.h"
#include "constants/map_types.h"
#include "constants/songs.h"

// this file's functions
static void MovePlayerOnMachBike(u8, u16, u16);
static u8 GetMachBikeTransition(u8 *);
static void MachBikeTransition_FaceDirection(u8);
static void MachBikeTransition_TurnDirection(u8);
static void MachBikeTransition_TrySpeedUp(u8);
static void MachBikeTransition_TrySlowDown(u8);
static void MovePlayerOnAcroBike(u8, u16, u16);
static u8 CheckMovementInputAcroBike(u8 *, u16, u16);
static u8 AcroBikeHandleInputNormal(u8 *, u16, u16);
static u8 AcroBikeHandleInputTurning(u8 *, u16, u16);
static u8 AcroBikeHandleInputWheelieStanding(u8 *, u16, u16);
static u8 AcroBikeHandleInputBunnyHop(u8 *, u16, u16);
static u8 AcroBikeHandleInputWheelieMoving(u8 *, u16, u16);
static u8 AcroBikeHandleInputSidewaysJump(u8 *, u16, u16);
static u8 AcroBikeHandleInputTurnJump(u8 *, u16, u16);
static void AcroBikeTransition_FaceDirection(u8);
static void AcroBikeTransition_TurnDirection(u8);
static void AcroBikeTransition_Moving(u8);
static void AcroBikeTransition_NormalToWheelie(u8);
static void AcroBikeTransition_WheelieToNormal(u8);
static void AcroBikeTransition_WheelieIdle(u8);
static void AcroBikeTransition_WheelieHoppingStanding(u8);
static void AcroBikeTransition_WheelieHoppingMoving(u8);
static void AcroBikeTransition_SideJump(u8);
static void AcroBikeTransition_TurnJump(u8);
static void AcroBikeTransition_WheelieMoving(u8);
static void AcroBikeTransition_WheelieRisingMoving(u8);
static void AcroBikeTransition_WheelieLoweringMoving(u8);
static void AcroBike_TryHistoryUpdate(u16, u16);
static u8 AcroBike_GetJumpDirection(void);
static void Bike_UpdateDirTimerHistory(u8);
static void Bike_UpdateABStartSelectHistory(u8);
static u8 Bike_DPadToDirection(u16);
static u8 GetBikeCollision(u8);
static u8 GetBikeCollisionAt(struct ObjectEvent *, s16, s16, u8, u8);
static bool8 IsRunningDisallowedByMetatile(u8);
static void Bike_TryAdvanceCyclingRoadCollisions();
static u8 CanBikeFaceDirOnMetatile(u8, u8);
static bool8 WillPlayerCollideWithCollision(u8, u8);
static void Bike_SetBikeStill(void);

// const rom data

/*
    A bike transition is a type of callback for the bike that actually
    modifies the bicycle's direction or momentum or otherwise movement.
    Alternatively, a bike may also have input handlers which process the
    bike transition to call: the acro bike has input handlers while the mach
    bike does not. This is because the Acro needs to know the button inputs
    for its complex tricks and actions.
*/

static void (*const sMachBikeTransitions[])(u8) =
{
    MachBikeTransition_FaceDirection, // Face vs Turn: Face has no anim while Turn does. Turn checks for collision because if you turn right as opposed to face right, if there is a wall there, turn will make a bonk sound effect while face will not.
    MachBikeTransition_TurnDirection,
    MachBikeTransition_TrySpeedUp,
    MachBikeTransition_TrySlowDown,
};

// bikeFrameCounter is input which is represented by sMachBikeSpeeds in order
static void (*const sMachBikeSpeedCallbacks[])(u8) =
{
    PlayerWalkNormal,
    PlayerWalkFast,
    PlayerWalkFaster,
};

static void (*const sAcroBikeTransitions[])(u8) =
{
    AcroBikeTransition_FaceDirection,
    AcroBikeTransition_TurnDirection,
    AcroBikeTransition_Moving,
    AcroBikeTransition_NormalToWheelie,
    AcroBikeTransition_WheelieToNormal,
    AcroBikeTransition_WheelieIdle,
    AcroBikeTransition_WheelieHoppingStanding,
    AcroBikeTransition_WheelieHoppingMoving,
    AcroBikeTransition_SideJump,
    AcroBikeTransition_TurnJump,
    AcroBikeTransition_WheelieMoving,
    AcroBikeTransition_WheelieRisingMoving,
    AcroBikeTransition_WheelieLoweringMoving,
};

static u8 (*const sAcroBikeInputHandlers[])(u8 *, u16, u16) =
{
    AcroBikeHandleInputNormal,
    AcroBikeHandleInputTurning,
    AcroBikeHandleInputWheelieStanding,
    AcroBikeHandleInputBunnyHop,
    AcroBikeHandleInputWheelieMoving,
    AcroBikeHandleInputSidewaysJump,
    AcroBikeHandleInputTurnJump,
};

// used with bikeFrameCounter from mach bike
static const u16 sMachBikeSpeeds[] = {PLAYER_SPEED_NORMAL, PLAYER_SPEED_FAST, PLAYER_SPEED_FASTEST};

// this is a list of timers to compare against later, terminated with 0. the only timer being compared against is 4 frames in this list.
static const u8 sAcroBikeJumpTimerList[] = {4, 0};

// this is a list of history inputs to do in order to do the check to retrieve a jump direction for acro bike. it seems to be an extensible list, so its possible that Game Freak may have intended for the Acro Bike to have more complex tricks at some point. The final list only has the acro jump.
static const struct BikeHistoryInputInfo sAcroBikeTricksList[] =
{
    // the 0xF is a mask performed with each byte of the array in order to perform the check on only the last entry of the history list, otherwise the check wouldn't work as there can be 0xF0 as opposed to 0x0F.
    {DIR_SOUTH, B_BUTTON, 0xF, 0xF, sAcroBikeJumpTimerList, sAcroBikeJumpTimerList, DIR_SOUTH},
    {DIR_NORTH, B_BUTTON, 0xF, 0xF, sAcroBikeJumpTimerList, sAcroBikeJumpTimerList, DIR_NORTH},
    {DIR_WEST, B_BUTTON, 0xF, 0xF, sAcroBikeJumpTimerList, sAcroBikeJumpTimerList, DIR_WEST},
    {DIR_EAST, B_BUTTON, 0xF, 0xF, sAcroBikeJumpTimerList, sAcroBikeJumpTimerList, DIR_EAST},
};

// code
void MovePlayerOnBike(u8 direction, u16 newKeys, u16 heldKeys)
{
    if (gPlayerAvatar.flags & PLAYER_AVATAR_FLAG_MACH_BIKE)
        MovePlayerOnMachBike(direction, newKeys, heldKeys);
    else
        MovePlayerOnAcroBike(direction, newKeys, heldKeys);
}

static void MovePlayerOnMachBike(u8 direction, u16 newKeys, u16 heldKeys)
{
    sMachBikeTransitions[GetMachBikeTransition(&direction)](direction);
}

// dirTraveling is a variable that is 0 when the player is standing still.
static u8 GetMachBikeTransition(u8 *dirTraveling)
{
    // if the dir updated before this function, get the relevent new direction to check later.
    u8 direction = GetPlayerMovementDirection();

    // is the player standing still?
    if (*dirTraveling == 0)
    {
        *dirTraveling = direction; // update the direction, since below we either faced a direction or we started moving.
        if (gPlayerAvatar.bikeSpeed == PLAYER_SPEED_STANDING)
        {
            gPlayerAvatar.runningState = NOT_MOVING;
            return MACH_TRANS_FACE_DIRECTION;
        }
        gPlayerAvatar.runningState = MOVING;
        return MACH_TRANS_START_MOVING;
    }

    // we need to check if the last traveled direction changed from the new direction as well as ensuring that we dont update the state while the player is moving: see the else check.
    if (*dirTraveling != direction && gPlayerAvatar.runningState != MOVING)
    {
        if (gPlayerAvatar.bikeSpeed != PLAYER_SPEED_STANDING)
        {
            *dirTraveling = direction; // implement the new direction
            gPlayerAvatar.runningState = MOVING;
            return MACH_TRANS_START_MOVING;
        }
        // if you didnt start moving but your dir was different, do a turn direction instead.
        gPlayerAvatar.runningState = TURN_DIRECTION;
        return MACH_TRANS_TURN_DIRECTION;
    }
    else // the player is either going in the current direction and hasnt changed or their state is currently moving.
    {
        gPlayerAvatar.runningState = MOVING;
        return MACH_TRANS_KEEP_MOVING;
    }
}

// the difference between face direction and turn direction is that one changes direction while the other does the animation of turning as well as changing direction.
static void MachBikeTransition_FaceDirection(u8 direction)
{
    PlayerFaceDirection(direction);
    Bike_SetBikeStill();
}

static void MachBikeTransition_TurnDirection(u8 direction)
{
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior))
    {
        PlayerTurnInPlace(direction);
        Bike_SetBikeStill();
    }
    else
    {
        MachBikeTransition_FaceDirection(playerObjEvent->facingDirection);
    }
}

static void MachBikeTransition_TrySpeedUp(u8 direction)
{
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];
    u8 collision;

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == FALSE)
    {
        // we cannot go forward, so either slow down or, if we are stopped, idle face direction.
        if (gPlayerAvatar.bikeSpeed)
            MachBikeTransition_TrySlowDown(playerObjEvent->movementDirection);
        else
            MachBikeTransition_FaceDirection(playerObjEvent->movementDirection);
    }
    else
    {
        collision = GetBikeCollision(direction);
        if (collision > 0 && collision < COLLISION_VERTICAL_RAIL)
        {
            // we hit a solid object, but check to see if its a ledge and then jump.
            if (collision == COLLISION_LEDGE_JUMP)
            {
                PlayerJumpLedge(direction);
            }
            else
            {
                // we hit a solid object that is not a ledge, so perform the collision.
                Bike_SetBikeStill();
                if (collision == COLLISION_OBJECT_EVENT && IsPlayerCollidingWithFarawayIslandMew(direction))
                    PlayerOnBikeCollideWithFarawayIslandMew(direction);
                else if (collision < COLLISION_STOP_SURFING || collision > COLLISION_ROTATING_GATE)
                    PlayerOnBikeCollide(direction);
            }
        }
        else
        {
            // we did not hit anything that can slow us down, so perform the advancement callback depending on the bikeFrameCounter and try to increase the mach bike's speed.
            sMachBikeSpeedCallbacks[gPlayerAvatar.bikeFrameCounter](direction);
            gPlayerAvatar.bikeSpeed = gPlayerAvatar.bikeFrameCounter + (gPlayerAvatar.bikeFrameCounter >> 1); // same as dividing by 2, but compiler is insistent on >> 1
            if (gPlayerAvatar.bikeFrameCounter < 2) // do not go faster than the last element in the mach bike array
                gPlayerAvatar.bikeFrameCounter++;
        }
    }
}

static void MachBikeTransition_TrySlowDown(u8 direction)
{
    u8 collision;

    if (gPlayerAvatar.bikeSpeed != PLAYER_SPEED_STANDING)
        gPlayerAvatar.bikeFrameCounter = --gPlayerAvatar.bikeSpeed;

    collision = GetBikeCollision(direction);

    if (collision > 0 && collision < COLLISION_VERTICAL_RAIL)
    {
        if (collision == COLLISION_LEDGE_JUMP)
        {
            PlayerJumpLedge(direction);
        }
        else
        {
            Bike_SetBikeStill();
            if (collision == COLLISION_OBJECT_EVENT && IsPlayerCollidingWithFarawayIslandMew(direction))
                PlayerOnBikeCollideWithFarawayIslandMew(direction);
            else if (collision < COLLISION_STOP_SURFING || collision > COLLISION_ROTATING_GATE)
                PlayerOnBikeCollide(direction);
        }
    }
    else
    {
        sMachBikeSpeedCallbacks[gPlayerAvatar.bikeFrameCounter](direction);
    }
}

// the acro bike requires the input handler to be executed before the transition can.
static void MovePlayerOnAcroBike(u8 newDirection, u16 newKeys, u16 heldKeys)
{
    sAcroBikeTransitions[CheckMovementInputAcroBike(&newDirection, newKeys, heldKeys)](newDirection);
}

static u8 CheckMovementInputAcroBike(u8 *newDirection, u16 newKeys, u16 heldKeys)
{
    return sAcroBikeInputHandlers[gPlayerAvatar.acroBikeState](newDirection, newKeys, heldKeys);
}

static u8 AcroBikeHandleInputNormal(u8 *newDirection, u16 newKeys, u16 heldKeys)
{
    u8 direction = GetPlayerMovementDirection();

    gPlayerAvatar.bikeFrameCounter = 0;
    if (*newDirection == DIR_NONE)
    {
        if (newKeys & B_BUTTON)
        {
            //We're standing still with the B button held.
            //Do a wheelie.
            *newDirection = direction;
            gPlayerAvatar.runningState = NOT_MOVING;
            gPlayerAvatar.acroBikeState = ACRO_STATE_WHEELIE_STANDING;
            return ACRO_TRANS_NORMAL_TO_WHEELIE;
        }
        else
        {
            *newDirection = direction;
            gPlayerAvatar.runningState = NOT_MOVING;
            return ACRO_TRANS_FACE_DIRECTION;
        }
    }
    if (*newDirection == direction && (heldKeys & B_BUTTON) && gPlayerAvatar.bikeSpeed == PLAYER_SPEED_STANDING)
    {
        gPlayerAvatar.bikeSpeed++;
        gPlayerAvatar.acroBikeState = ACRO_STATE_WHEELIE_MOVING;
        return ACRO_TRANS_WHEELIE_RISING_MOVING;
    }
    if (*newDirection != direction && gPlayerAvatar.runningState != MOVING)
    {
        gPlayerAvatar.acroBikeState = ACRO_STATE_TURNING;
        gPlayerAvatar.newDirBackup = *newDirection;
        gPlayerAvatar.runningState = NOT_MOVING;
        return CheckMovementInputAcroBike(newDirection, newKeys, heldKeys);
    }
    gPlayerAvatar.runningState = MOVING;
    return ACRO_TRANS_MOVING;
}

static u8 AcroBikeHandleInputTurning(u8 *newDirection, u16 newKeys, u16 heldKeys)
{
    u8 direction;

    *newDirection = gPlayerAvatar.newDirBackup;
    gPlayerAvatar.bikeFrameCounter++;

    // Wait 6 frames before actually changing direction
    if (gPlayerAvatar.bikeFrameCounter > 6) // ... because it takes 6 frames to advance 1 tile.
    {
        gPlayerAvatar.runningState = TURN_DIRECTION;
        gPlayerAvatar.acroBikeState = ACRO_STATE_NORMAL;
        Bike_SetBikeStill();
        return ACRO_TRANS_TURN_DIRECTION;
    }
    direction = GetPlayerMovementDirection();
    if (*newDirection == AcroBike_GetJumpDirection())
    {
        Bike_SetBikeStill(); // Bike_SetBikeStill sets speed to standing, but the next line immediately overrides it. could have just reset acroBikeState to 0 here instead of wasting a jump.
        gPlayerAvatar.bikeSpeed = PLAYER_SPEED_NORMAL;
        if (*newDirection == GetOppositeDirection(direction))
        {
            // do a turn jump.
            // no need to update runningState, didnt move.
            gPlayerAvatar.acroBikeState = ACRO_STATE_TURN_JUMP;
            return ACRO_TRANS_TURN_JUMP;
        }
        else
        {
            // do a sideways jump.
            gPlayerAvatar.runningState = MOVING; // we need to move, set state to moving.
            gPlayerAvatar.acroBikeState = ACRO_STATE_SIDE_JUMP;
            return ACRO_TRANS_SIDE_JUMP;
        }
    }
    *newDirection = direction;
    return ACRO_TRANS_FACE_DIRECTION;
}

static u8 AcroBikeHandleInputWheelieStanding(u8 *newDirection, u16 newKeys, u16 heldKeys)
{
    u8 direction;
    struct ObjectEvent *playerObjEvent;

    direction = GetPlayerMovementDirection();
    playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];
    gPlayerAvatar.runningState = NOT_MOVING;

    if (heldKeys & B_BUTTON)
    {
        gPlayerAvatar.bikeFrameCounter++;
    }
    else
    {
        // B button was released.
        gPlayerAvatar.bikeFrameCounter = 0;
        if (!MetatileBehavior_IsBumpySlope(playerObjEvent->currentMetatileBehavior))
        {
            // Go back to normal on flat ground
            *newDirection = direction;
            gPlayerAvatar.acroBikeState = ACRO_STATE_NORMAL;
            Bike_SetBikeStill();
            return ACRO_TRANS_WHEELIE_TO_NORMAL;
        }
    }
    if (gPlayerAvatar.bikeFrameCounter >= 40)
    {
        *newDirection = direction;
        gPlayerAvatar.acroBikeState = ACRO_STATE_BUNNY_HOP;
        Bike_SetBikeStill();
        return ACRO_TRANS_WHEELIE_HOPPING_STANDING;
    }
    if (*newDirection == direction)
    {
        gPlayerAvatar.runningState = MOVING;
        gPlayerAvatar.acroBikeState = ACRO_STATE_WHEELIE_MOVING;
        Bike_SetBikeStill();
        return ACRO_TRANS_WHEELIE_MOVING;
    }
    if (*newDirection == 0)
    {
        *newDirection = direction;
        return ACRO_TRANS_WHEELIE_IDLE;
    }
    gPlayerAvatar.runningState = TURN_DIRECTION;
    return ACRO_TRANS_WHEELIE_IDLE;
}

static u8 AcroBikeHandleInputBunnyHop(u8 *newDirection, u16 newKeys, u16 heldKeys)
{
    u8 direction;
    struct ObjectEvent *playerObjEvent;

    direction = GetPlayerMovementDirection();
    playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];
    if (!(heldKeys & B_BUTTON))
    {
        // B button was released
        Bike_SetBikeStill();
        if (MetatileBehavior_IsBumpySlope(playerObjEvent->currentMetatileBehavior))
        {
            // even though B was released, dont undo the wheelie on the bumpy slope.
            gPlayerAvatar.acroBikeState = ACRO_STATE_WHEELIE_STANDING;
            return CheckMovementInputAcroBike(newDirection, newKeys, heldKeys);
        }
        else
        {
            // .. otherwise, go back to normal on flat ground
            *newDirection = direction;
            gPlayerAvatar.runningState = NOT_MOVING;
            gPlayerAvatar.acroBikeState = ACRO_STATE_NORMAL;
            return ACRO_TRANS_WHEELIE_TO_NORMAL;
        }
    }

    // B Button is still held

    if (*newDirection == DIR_NONE)
    {
        // we did not move, so keep hopping in place without moving.
        *newDirection = direction;
        gPlayerAvatar.runningState = NOT_MOVING;
        return ACRO_TRANS_WHEELIE_HOPPING_STANDING;
    }
    if (*newDirection != direction && gPlayerAvatar.runningState != MOVING)
    {
        // we changed direction, so turn but do not move hop.
        gPlayerAvatar.runningState = TURN_DIRECTION;
        return ACRO_TRANS_WHEELIE_HOPPING_STANDING;
    }
    // otherwise, we started moving while hopping
    gPlayerAvatar.runningState = MOVING;
    return ACRO_TRANS_WHEELIE_HOPPING_MOVING;
}

static u8 AcroBikeHandleInputWheelieMoving(u8 *newDirection, u16 newKeys, u16 heldKeys)
{
    u8 direction;
    struct ObjectEvent *playerObjEvent;

    direction = GetPlayerFacingDirection();
    playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];
    if (!(heldKeys & B_BUTTON))
    {
        // we were moving on a wheelie, but we let go while moving. reset bike still status
        Bike_SetBikeStill();
        if (!MetatileBehavior_IsBumpySlope(playerObjEvent->currentMetatileBehavior))
        {
            // we let go of B and arent on a bumpy slope, set state to normal because now we need to handle this
            gPlayerAvatar.acroBikeState = ACRO_STATE_NORMAL;
            if (*newDirection == DIR_NONE)
            {
                // we stopped moving but are turning, still try to lower the wheelie in place.
                *newDirection = direction;
                gPlayerAvatar.runningState = NOT_MOVING;
                return ACRO_TRANS_WHEELIE_TO_NORMAL;
            }
            if (*newDirection != direction && gPlayerAvatar.runningState != MOVING)
            {
                // we did not turn while lowering wheelie, so do so without turning.
                gPlayerAvatar.runningState = NOT_MOVING;
                return ACRO_TRANS_WHEELIE_TO_NORMAL;
            }
            // if we are moving while lowering wheelie, put the acro into a lowering state while moving.
            gPlayerAvatar.runningState = MOVING;
            return ACRO_TRANS_WHEELIE_LOWERING_MOVING;
        }
        // please do not undo the wheelie on a bumpy slope
        gPlayerAvatar.acroBikeState = ACRO_STATE_WHEELIE_STANDING;
        return CheckMovementInputAcroBike(newDirection, newKeys, heldKeys);
    }
    // we are still holding B.
    if (*newDirection == DIR_NONE)
    {
        // idle the wheelie in place because we're holding B without moving.
        *newDirection = direction;
        gPlayerAvatar.acroBikeState = ACRO_STATE_WHEELIE_STANDING;
        gPlayerAvatar.runningState = NOT_MOVING;
        Bike_SetBikeStill();
        return ACRO_TRANS_WHEELIE_IDLE;
    }
    if (direction != *newDirection && gPlayerAvatar.runningState != MOVING)
    {
        gPlayerAvatar.runningState = NOT_MOVING;
        return ACRO_TRANS_WHEELIE_IDLE;
    }
    gPlayerAvatar.runningState = MOVING;
    return ACRO_TRANS_WHEELIE_MOVING;
}

static u8 AcroBikeHandleInputSidewaysJump(u8 *ptr, u16 newKeys, u16 heldKeys)
{
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    playerObjEvent->facingDirectionLocked = 0;
    SetObjectEventDirection(playerObjEvent, playerObjEvent->facingDirection);
    gPlayerAvatar.acroBikeState = ACRO_STATE_NORMAL;
    return CheckMovementInputAcroBike(ptr, newKeys, heldKeys);
}

static u8 AcroBikeHandleInputTurnJump(u8 *ptr, u16 newKeys, u16 heldKeys)
{
    gPlayerAvatar.acroBikeState = ACRO_STATE_NORMAL;
    return CheckMovementInputAcroBike(ptr, newKeys, heldKeys);
}

static void AcroBikeTransition_FaceDirection(u8 direction)
{
    PlayerFaceDirection(direction);
}

static void AcroBikeTransition_TurnDirection(u8 direction)
{
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
        direction = playerObjEvent->movementDirection;
    PlayerFaceDirection(direction);
}

static void AcroBikeTransition_Moving(u8 direction)
{
    u8 collision;
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
    {
        AcroBikeTransition_FaceDirection(playerObjEvent->movementDirection);
        return;
    }
    collision = GetBikeCollision(direction);
    if (collision > 0 && collision < COLLISION_VERTICAL_RAIL)
    {
        if (collision == COLLISION_LEDGE_JUMP)
            PlayerJumpLedge(direction);
        else if (collision == COLLISION_OBJECT_EVENT && IsPlayerCollidingWithFarawayIslandMew(direction))
            PlayerOnBikeCollideWithFarawayIslandMew(direction);
        else if (collision < COLLISION_STOP_SURFING || collision > COLLISION_ROTATING_GATE)
            PlayerOnBikeCollide(direction);
    }
    else
    {
        PlayerRideWaterCurrent(direction);
    }
}

static void AcroBikeTransition_NormalToWheelie(u8 direction)
{
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
        direction = playerObjEvent->movementDirection;
    PlayerStartWheelie(direction);
}

static void AcroBikeTransition_WheelieToNormal(u8 direction)
{
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
        direction = playerObjEvent->movementDirection;
    PlayerEndWheelie(direction);
}

static void AcroBikeTransition_WheelieIdle(u8 direction)
{
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
        direction = playerObjEvent->movementDirection;
    PlayerIdleWheelie(direction);
}

static void AcroBikeTransition_WheelieHoppingStanding(u8 direction)
{
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
        direction = playerObjEvent->movementDirection;
    PlayerStandingHoppingWheelie(direction);
}

static void AcroBikeTransition_WheelieHoppingMoving(u8 direction)
{
    u8 collision;
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
    {
        AcroBikeTransition_WheelieHoppingStanding(playerObjEvent->movementDirection);
        return;
    }
    collision = GetBikeCollision(direction);
    if (collision && collision != COLLISION_WHEELIE_HOP)
    {
        if (collision == COLLISION_LEDGE_JUMP)
        {
            PlayerLedgeHoppingWheelie(direction);
            return;
        }
        if (collision >= COLLISION_STOP_SURFING && collision <= COLLISION_ROTATING_GATE)
        {
            return;
        }
        if (collision < COLLISION_VERTICAL_RAIL)
        {
            AcroBikeTransition_WheelieHoppingStanding(direction);
            return;
        }
    }
    PlayerMovingHoppingWheelie(direction);
}

static void AcroBikeTransition_SideJump(u8 direction)
{
    u8 collision;
    struct ObjectEvent *playerObjEvent;

    collision = GetBikeCollision(direction);
    if (collision)
    {
        if (collision == COLLISION_PUSHED_BOULDER)
            return;
        if (collision < COLLISION_ISOLATED_VERTICAL_RAIL)
        {
            AcroBikeTransition_TurnDirection(direction);
            return;
        }
        if (WillPlayerCollideWithCollision(collision, direction) == FALSE)
        {
            AcroBikeTransition_TurnDirection(direction);
            return;
        }
    }
    playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];
    PlaySE(SE_BIKE_HOP);
    playerObjEvent->facingDirectionLocked = 1;
    PlayerSetAnimId(GetJumpMovementAction(direction), COPY_MOVE_WALK);
}

static void AcroBikeTransition_TurnJump(u8 direction)
{
    PlayerAcroTurnJump(direction);
}

static void AcroBikeTransition_WheelieMoving(u8 direction)
{
    u8 collision;
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
    {
        PlayerIdleWheelie(playerObjEvent->movementDirection);
        return;
    }
    collision = GetBikeCollision(direction);
    if (collision > 0 && collision < COLLISION_VERTICAL_RAIL)
    {
        if (collision == COLLISION_LEDGE_JUMP)
        {
            PlayerLedgeHoppingWheelie(direction);
        }
        else if (collision == COLLISION_WHEELIE_HOP)
        {
            PlayerIdleWheelie(direction);
        }
        else if (collision < COLLISION_STOP_SURFING)
        {
            if (MetatileBehavior_IsBumpySlope(playerObjEvent->currentMetatileBehavior))
                PlayerIdleWheelie(direction);
            else
                PlayerWheelieInPlace(direction);  //hit wall?
        }
        return;
    }
    PlayerWheelieMove(direction);
    gPlayerAvatar.runningState = MOVING;
}

static void AcroBikeTransition_WheelieRisingMoving(u8 direction)
{
    u8 collision;
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
    {
        PlayerStartWheelie(playerObjEvent->movementDirection);
        return;
    }
    collision = GetBikeCollision(direction);
    if (collision > 0 && collision < COLLISION_VERTICAL_RAIL)
    {
        if (collision == COLLISION_LEDGE_JUMP)
        {
            PlayerLedgeHoppingWheelie(direction);
        }
        else if (collision == COLLISION_WHEELIE_HOP)
        {
            PlayerIdleWheelie(direction);
        }
        else if (collision < COLLISION_STOP_SURFING)
        {
            if (MetatileBehavior_IsBumpySlope(playerObjEvent->currentMetatileBehavior))
                PlayerIdleWheelie(direction);
            else
                PlayerWheelieInPlace(direction);  //hit wall?
        }
        return;
    }
    PlayerPopWheelieWhileMoving(direction);
    gPlayerAvatar.runningState = MOVING;
}

static void AcroBikeTransition_WheelieLoweringMoving(u8 direction)
{
    u8 collision;
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];

    if (CanBikeFaceDirOnMetatile(direction, playerObjEvent->currentMetatileBehavior) == 0)
    {
        PlayerEndWheelie(playerObjEvent->movementDirection);
        return;
    }
    collision = GetBikeCollision(direction);
    if (collision > 0 && collision < COLLISION_VERTICAL_RAIL)
    {
        if (collision == COLLISION_LEDGE_JUMP)
            PlayerJumpLedge(direction);
        else if (collision < COLLISION_STOP_SURFING || collision > COLLISION_ROTATING_GATE)
            PlayerEndWheelie(direction);
        return;
    }
    PlayerEndWheelieWhileMoving(direction);
}

void Bike_TryAcroBikeHistoryUpdate(u16 newKeys, u16 heldKeys)
{
    if (gPlayerAvatar.flags & PLAYER_AVATAR_FLAG_ACRO_BIKE)
        AcroBike_TryHistoryUpdate(newKeys, heldKeys);
}

static void AcroBike_TryHistoryUpdate(u16 newKeys, u16 heldKeys) // newKeys is unused
{
    u8 direction = Bike_DPadToDirection(heldKeys);

    if (direction == (gPlayerAvatar.directionHistory & 0xF))
    {
        // increment the timer for direction history since last input.
        if (gPlayerAvatar.dirTimerHistory[0] < 0xFF)
            gPlayerAvatar.dirTimerHistory[0]++;
    }
    else
    {
        Bike_UpdateDirTimerHistory(direction);
        gPlayerAvatar.bikeSpeed = PLAYER_SPEED_STANDING;
    }

    direction = heldKeys & (A_BUTTON | B_BUTTON | SELECT_BUTTON | START_BUTTON); // directions is reused for some reason.
    if (direction == (gPlayerAvatar.abStartSelectHistory & 0xF))
    {
        if (gPlayerAvatar.abStartSelectTimerHistory[0] < 0xFF)
            gPlayerAvatar.abStartSelectTimerHistory[0]++;
    }
    else
    {
        Bike_UpdateABStartSelectHistory(direction);
        gPlayerAvatar.bikeSpeed = PLAYER_SPEED_STANDING;
    }
}

static bool8 HasPlayerInputTakenLongerThanList(const u8 *dirTimerList, const u8 *abStartSelectTimerList)
{
    u8 i;

    for (i = 0; dirTimerList[i] != 0; i++)
    {
        if (gPlayerAvatar.dirTimerHistory[i] > dirTimerList[i])
            return FALSE;
    }
    for (i = 0; abStartSelectTimerList[i] != 0; i++)
    {
        if (gPlayerAvatar.abStartSelectTimerHistory[i] > abStartSelectTimerList[i])
            return FALSE;
    }
    return TRUE;
}

static u8 AcroBike_GetJumpDirection(void)
{
    u32 i;

    for (i = 0; i < ARRAY_COUNT(sAcroBikeTricksList); i++)
    {
        const struct BikeHistoryInputInfo *historyInputInfo = &sAcroBikeTricksList[i];
        u32 dirHistory = gPlayerAvatar.directionHistory;
        u32 abStartSelectHistory = gPlayerAvatar.abStartSelectHistory;

        dirHistory &= historyInputInfo->dirHistoryMask;
        abStartSelectHistory &= historyInputInfo->abStartSelectHistoryMask;
        if (dirHistory == historyInputInfo->dirHistoryMatch && abStartSelectHistory == historyInputInfo->abStartSelectHistoryMatch && HasPlayerInputTakenLongerThanList(historyInputInfo->dirTimerHistoryList, historyInputInfo->abStartSelectHistoryList))
            return historyInputInfo->direction;
    }
    return 0;
}

static void Bike_UpdateDirTimerHistory(u8 dir)
{
    u8 i;

    gPlayerAvatar.directionHistory = (gPlayerAvatar.directionHistory << 4) | (dir & 0xF);

    for (i = ARRAY_COUNT(gPlayerAvatar.dirTimerHistory) - 1; i != 0; i--)
        gPlayerAvatar.dirTimerHistory[i] = gPlayerAvatar.dirTimerHistory[i - 1];
    gPlayerAvatar.dirTimerHistory[0] = 1;
}

static void Bike_UpdateABStartSelectHistory(u8 input)
{
    u8 i;

    gPlayerAvatar.abStartSelectHistory = (gPlayerAvatar.abStartSelectHistory << 4) | (input & 0xF);

    for (i = ARRAY_COUNT(gPlayerAvatar.abStartSelectTimerHistory) - 1; i != 0; i--)
        gPlayerAvatar.abStartSelectTimerHistory[i] = gPlayerAvatar.abStartSelectTimerHistory[i - 1];
    gPlayerAvatar.abStartSelectTimerHistory[0] = 1;
}

static u8 Bike_DPadToDirection(u16 heldKeys)
{
    if (heldKeys & DPAD_UP)
        return DIR_NORTH;
    if (heldKeys & DPAD_DOWN)
        return DIR_SOUTH;
    if (heldKeys & DPAD_LEFT)
        return DIR_WEST;
    if (heldKeys & DPAD_RIGHT)
        return DIR_EAST;
    return DIR_NONE;
}

static u8 GetBikeCollision(u8 direction)
{
    u8 metatileBehavior;
    struct ObjectEvent *playerObjEvent = &gObjectEvents[gPlayerAvatar.objectEventId];
    s16 x = playerObjEvent->currentCoords.x;
    s16 y = playerObjEvent->currentCoords.y;
    MoveCoords(direction, &x, &y);
    metatileBehavior = MapGridGetMetatileBehaviorAt(x, y);
    return GetBikeCollisionAt(playerObjEvent, x, y, direction, metatileBehavior);
}

static u8 GetBikeCollisionAt(struct ObjectEvent *objectEvent, s16 x, s16 y, u8 direction, u8 metatileBehavior)
{
    u8 collision = CheckForObjectEventCollision(objectEvent, x, y, direction, metatileBehavior);

    if (collision > COLLISION_OBJECT_EVENT)
        return collision;

    if (collision == COLLISION_NONE && IsRunningDisallowedByMetatile(metatileBehavior))
        collision = COLLISION_IMPASSABLE;

    if (collision)
        Bike_TryAdvanceCyclingRoadCollisions();

    return collision;
}

bool8 RS_IsRunningDisallowed(u8 tile)
{
    if (IsRunningDisallowedByMetatile(tile) != FALSE || gMapHeader.mapType == MAP_TYPE_INDOOR)
        return TRUE;
    else
        return FALSE;
}

static bool8 IsRunningDisallowedByMetatile(u8 tile)
{
    if (MetatileBehavior_IsRunningDisallowed(tile))
        return TRUE;
    if (MetatileBehavior_IsFortreeBridge(tile) && (PlayerGetElevation() & 1) == 0)
        return TRUE;
    return FALSE;
}

static void Bike_TryAdvanceCyclingRoadCollisions(void)
{
    if (gBikeCyclingChallenge != FALSE && gBikeCollisions < 100)
        gBikeCollisions++;
}

static bool8 CanBikeFaceDirOnMetatile(u8 direction, u8 tile)
{
    if (direction == DIR_EAST || direction == DIR_WEST)
    {
        // Bike cannot face east or west on a vertical rail
        if (MetatileBehavior_IsIsolatedVerticalRail(tile)
         || MetatileBehavior_IsVerticalRail(tile))
            return FALSE;
    }
    else
    {
        // Bike cannot face north or south on a horizontal rail
        if (MetatileBehavior_IsIsolatedHorizontalRail(tile)
         || MetatileBehavior_IsHorizontalRail(tile))
            return FALSE;
    }
    return TRUE;
}

static bool8 WillPlayerCollideWithCollision(u8 newTileCollision, u8 direction)
{
    if (direction == DIR_NORTH || direction == DIR_SOUTH)
    {
        if (newTileCollision == COLLISION_ISOLATED_VERTICAL_RAIL || newTileCollision == COLLISION_VERTICAL_RAIL)
            return FALSE;
    }
    else if (newTileCollision == COLLISION_ISOLATED_HORIZONTAL_RAIL || newTileCollision == COLLISION_HORIZONTAL_RAIL)
    {
        return FALSE;
    }

    return TRUE;
}

bool8 IsBikingDisallowedByPlayer(void)
{
    s16 x, y;
    u8 tileBehavior;

    if (!(gPlayerAvatar.flags & (PLAYER_AVATAR_FLAG_SURFING | PLAYER_AVATAR_FLAG_UNDERWATER)))
    {
        PlayerGetDestCoords(&x, &y);
        tileBehavior = MapGridGetMetatileBehaviorAt(x, y);
        if (!IsRunningDisallowedByMetatile(tileBehavior))
            return FALSE;
    }
    return TRUE;
}

bool8 IsPlayerNotUsingAcroBikeOnBumpySlope(void)
{
    if (TestPlayerAvatarFlags(PLAYER_AVATAR_FLAG_ACRO_BIKE)
        && MetatileBehavior_IsBumpySlope(gObjectEvents[gPlayerAvatar.objectEventId].currentMetatileBehavior))
        return FALSE;
    else
        return TRUE;
}

void GetOnOffBike(u8 transitionFlags)
{
    gUnusedBikeCameraAheadPanback = FALSE;

    if (gPlayerAvatar.flags & (PLAYER_AVATAR_FLAG_MACH_BIKE | PLAYER_AVATAR_FLAG_ACRO_BIKE))
    {
        SetPlayerAvatarTransitionFlags(PLAYER_AVATAR_FLAG_ON_FOOT);
        Overworld_ClearSavedMusic();
        Overworld_PlaySpecialMapMusic();
    }
    else
    {
        SetPlayerAvatarTransitionFlags(transitionFlags);
        Overworld_SetSavedMusic(MUS_CYCLING);
        Overworld_ChangeMusicTo(MUS_CYCLING);
    }
}

void BikeClearState(int newDirHistory, int newAbStartHistory)
{
    u8 i;

    gPlayerAvatar.acroBikeState = ACRO_STATE_NORMAL;
    gPlayerAvatar.newDirBackup = DIR_NONE;
    gPlayerAvatar.bikeFrameCounter = 0;
    gPlayerAvatar.bikeSpeed = PLAYER_SPEED_STANDING;
    gPlayerAvatar.directionHistory = newDirHistory;
    gPlayerAvatar.abStartSelectHistory = newAbStartHistory;

    for (i = 0; i < ARRAY_COUNT(gPlayerAvatar.dirTimerHistory); i++)
        gPlayerAvatar.dirTimerHistory[i] = 0;

    for (i = 0; i < ARRAY_COUNT(gPlayerAvatar.abStartSelectTimerHistory); i++)
        gPlayerAvatar.abStartSelectTimerHistory[i] = 0;
}

void Bike_UpdateBikeCounterSpeed(u8 counter)
{
    gPlayerAvatar.bikeFrameCounter = counter;
    gPlayerAvatar.bikeSpeed = gPlayerAvatar.bikeFrameCounter + (gPlayerAvatar.bikeFrameCounter >> 1); // lazy way of multiplying by 1.5.
}

static void Bike_SetBikeStill(void)
{
    gPlayerAvatar.bikeFrameCounter = 0;
    gPlayerAvatar.bikeSpeed = PLAYER_SPEED_STANDING;
}

s16 GetPlayerSpeed(void)
{
    // because the player pressed a direction, it won't ever return a speed of 0 since this function returns the player's current speed.
    s16 machSpeeds[3];

    memcpy(machSpeeds, sMachBikeSpeeds, sizeof(machSpeeds));

    if (gPlayerAvatar.flags & PLAYER_AVATAR_FLAG_MACH_BIKE)
        return machSpeeds[gPlayerAvatar.bikeFrameCounter];
    else if (gPlayerAvatar.flags & PLAYER_AVATAR_FLAG_ACRO_BIKE)
        return PLAYER_SPEED_FASTER;
    else if (gPlayerAvatar.flags & (PLAYER_AVATAR_FLAG_SURFING | PLAYER_AVATAR_FLAG_DASH))
        return PLAYER_SPEED_FAST;
    else
        return PLAYER_SPEED_NORMAL;
}

void Bike_HandleBumpySlopeJump(void)
{
    s16 x, y;
    u8 tileBehavior;

    if (gPlayerAvatar.flags & PLAYER_AVATAR_FLAG_ACRO_BIKE)
    {
        PlayerGetDestCoords(&x, &y);
        tileBehavior = MapGridGetMetatileBehaviorAt(x, y);
        if (MetatileBehavior_IsBumpySlope(tileBehavior))
        {
            gPlayerAvatar.acroBikeState = ACRO_STATE_WHEELIE_STANDING;
            PlayerUseAcroBikeOnBumpySlope(GetPlayerMovementDirection());
        }
    }
}

bool32 IsRunningDisallowed(u8 metatile)
{
    if (!gMapHeader.allowRunning || IsRunningDisallowedByMetatile(metatile) == TRUE)
        return TRUE;
    else
        return FALSE;
}