#include "system.h"

#include "prototyp.h"

#include "stratdef.h"

#include "bh_types.h"

#include "track.h"

#include "psndplat.h"

#include <math.h>

#include <assert.h>

extern void MulQuat(QUAT *q1, QUAT *q2, QUAT *output);

extern void QNormalise(QUAT*);

extern int QDot(QUAT *, QUAT *);

static void TrackSlerp(TRACK_SECTION_DATA* tsd,int lerp,MATRIXCH* output_mat)

{

    int sclp,sclq;

    QUAT* input1 = &tsd->quat_start;

    QUAT* input2 = &tsd->quat_end;

    QUAT output;

    if(lerp < 0)

        lerp=0;

    else if(lerp > 65536)

        lerp = 65536;

    /* First check for special case. */

    if (tsd->omega == 2048)

    {

        int t1,t2;

        output.quatx=-input1->quaty;

        output.quaty=input1->quatx;

        output.quatz=-input1->quatw;

        output.quatw=input1->quatz;

        t1 = MUL_FIXED((ONE_FIXED-lerp),1024);

        sclp = GetSin(t1);

        t2 = MUL_FIXED(lerp,1024);

        sclq = GetSin(t2);

        output.quatx = (MUL_FIXED(input1->quatx,sclp))+(MUL_FIXED(output.quatx,sclq));

        output.quaty = (MUL_FIXED(input1->quaty,sclp))+(MUL_FIXED(output.quaty,sclq));

        output.quatz = (MUL_FIXED(input1->quatz,sclp))+(MUL_FIXED(output.quatz,sclq));

        output.quatw = (MUL_FIXED(input1->quatw,sclp))+(MUL_FIXED(output.quatw,sclq));

    }

    else

    {

        if ( !tsd->omega && !tsd->oneoversinomega)

        {

            sclp = ONE_FIXED-lerp;

            sclq = lerp;

        }

        else

        {

            int t1,t2;

            t1 = MUL_FIXED((ONE_FIXED-lerp),tsd->omega);

            t2 = GetSin(t1);

            sclp = MUL_FIXED(t2,tsd->oneoversinomega);

            t1 = MUL_FIXED(lerp,tsd->omega);

            t2 = GetSin(t1);

            sclq = MUL_FIXED(t2,tsd->oneoversinomega);

        }

        output.quatx = (MUL_FIXED(input1->quatx,sclp))+(MUL_FIXED(input2->quatx,sclq));

        output.quaty = (MUL_FIXED(input1->quaty,sclp))+(MUL_FIXED(input2->quaty,sclq));

        output.quatz = (MUL_FIXED(input1->quatz,sclp))+(MUL_FIXED(input2->quatz,sclq));

        output.quatw = (MUL_FIXED(input1->quatw,sclp))+(MUL_FIXED(input2->quatw,sclq));

    }

    QNormalise(&output);

    QuatToMat(&output,output_mat);

}

void Start_Track_Sound(TRACK_SOUND* ts, VECTORCH * location)

{

    SOUND3DDATA s3d;

    assert(ts);

    ts->playing = 1;

    if((ts->activ_no != SOUND_NOACTIVEINDEX) || (SID_NOSOUND == ts->sound_number))

        return;

    if(ts->loop)

    {

        //make sure track is close enough to be heard

        int dist = VectorDistance(&PlayerStatus.DisplayBlock->ObWorld, location);

        if(dist > ts->outer_range)

            return;

    }

    s3d.position = *location;

    s3d.inner_range = ts->inner_range;

    s3d.outer_range = ts->outer_range;

    s3d.velocity.vx = 0;

    s3d.velocity.vy = 0;

    s3d.velocity.vz = 0;

    Sound_Play ((SOUNDINDEX)ts->sound_number, (ts->loop ? "nvpel" : "nvpe"), &s3d, ts->max_volume, ts->pitch,
&ts->activ_no);

    //printf("Playing track sound \t%s\n", GameSounds[ts->sound_number].wavName);

}

void Stop_Track_Sound(TRACK_SOUND* ts)

{

    assert(ts);

    ts->playing = 0;

    if(ts->activ_no != SOUND_NOACTIVEINDEX)

        Sound_Stop(ts->activ_no);

}

void Update_Track_Sound(TRACK_SOUND* ts, VECTORCH * location)

{

    assert(ts);

    if(ts->playing)

    {

        if(ts->loop)

        {

            //check to see if sound is close enough to player

            int dist = VectorDistance(&PlayerStatus.DisplayBlock->ObWorld, location);

            if(dist > ts->outer_range)

            {

                //stop playing the sound for the moment

                if(ts->activ_no != SOUND_NOACTIVEINDEX)

                    Sound_Stop(ts->activ_no);

            }

            else

            {

                if(ts->activ_no == SOUND_NOACTIVEINDEX)

                {

                    //restart the sound

                    Start_Track_Sound(ts,location);

                }

                else

                {

                    //update the sound's location

                    SOUND3DDATA s3d;

                    s3d.position = *location;

                    s3d.inner_range = ts->inner_range;

                    s3d.outer_range = ts->outer_range;

                    s3d.velocity.vx = 0;

                    s3d.velocity.vy = 0;

                    s3d.velocity.vz = 0;

                    Sound_UpdateNew3d (ts->activ_no, &s3d);

                }

            }

        }

        else

        {

            if(ts->activ_no == SOUND_NOACTIVEINDEX)

            {

                //sound has stopped playing.

                ts->playing = 0;

            }

        }

    }

}

static void SmoothTrackPosition(TRACK_SECTION_DATA* trackPtr, int u, VECTORCH *outputPositionPtr)

{

    int u2 = MUL_FIXED(u, u);

    int u3 = MUL_FIXED(u2, u);

     {

        int a = (-trackPtr->pivot_0.vx+3*trackPtr->pivot_1.vx-3*trackPtr->pivot_2.vx+trackPtr->pivot_3.vx);

        int b = (2*trackPtr->pivot_0.vx-5*trackPtr->pivot_1.vx+4*trackPtr->pivot_2.vx-trackPtr->pivot_3.vx);

        int c = (-1*trackPtr->pivot_0.vx+trackPtr->pivot_2.vx);

        outputPositionPtr->vx = (MUL_FIXED(a,u3)+MUL_FIXED(b,u2)+MUL_FIXED(c,u))/2+trackPtr->pivot_1.vx;

    }

     {

        int a = (-trackPtr->pivot_0.vy+3*trackPtr->pivot_1.vy-3*trackPtr->pivot_2.vy+trackPtr->pivot_3.vy);

        int b = (2*trackPtr->pivot_0.vy-5*trackPtr->pivot_1.vy+4*trackPtr->pivot_2.vy-trackPtr->pivot_3.vy);

        int c = (-1*trackPtr->pivot_0.vy+trackPtr->pivot_2.vy);

        outputPositionPtr->vy = (MUL_FIXED(a,u3)+MUL_FIXED(b,u2)+MUL_FIXED(c,u))/2+trackPtr->pivot_1.vy;

    }

     {

        int a = (-trackPtr->pivot_0.vz+3*trackPtr->pivot_1.vz-3*trackPtr->pivot_2.vz+trackPtr->pivot_3.vz);

        int b = (2*trackPtr->pivot_0.vz-5*trackPtr->pivot_1.vz+4*trackPtr->pivot_2.vz-trackPtr->pivot_3.vz);

        int c = (-1*trackPtr->pivot_0.vz+trackPtr->pivot_2.vz);

        outputPositionPtr->vz = (MUL_FIXED(a,u3)+MUL_FIXED(b,u2)+MUL_FIXED(c,u))/2+trackPtr->pivot_1.vz;

    }

}

static void BasicSlerp(QUAT *input1,QUAT *input2,QUAT *output,int lerp)

{

    int sclp,sclq;

    int omega, sinom;

    int cosom = QDot(input1, input2);

    if (cosom > 0)

    {

        *output = *input2;

    }

    else

    {

        output->quatx =- input2->quatx;

        output->quaty =- input2->quaty;

        output->quatz =- input2->quatz;

        output->quatw =- input2->quatw;

        cosom =- cosom;

    }

    if(cosom < 65500)

    {

        omega = ArcCos(cosom);

        sinom = GetSin(omega);

        /* healthy paranoia */

        assert(sinom != 0);

        sclp = DIV_FIXED ( GetSin ( MUL_FIXED((ONE_FIXED-lerp),omega) ), sinom );

        sclq = DIV_FIXED ( GetSin ( MUL_FIXED(lerp, omega) ), sinom );

    }

    else

    {

        sclp = ONE_FIXED-lerp;

        sclq = lerp;

    }

    output->quatx = (MUL_FIXED(input1->quatx,sclp))+(MUL_FIXED(output->quatx,sclq));

    output->quaty = (MUL_FIXED(input1->quaty,sclp))+(MUL_FIXED(output->quaty,sclq));

    output->quatz = (MUL_FIXED(input1->quatz,sclp))+(MUL_FIXED(output->quatz,sclq));

    output->quatw = (MUL_FIXED(input1->quatw,sclp))+(MUL_FIXED(output->quatw,sclq));

      QNormalise(output);

}

static void SmoothTrackOrientation(TRACK_SECTION_DATA* trackPtr, int lerp, MATRIXCH* outputMatrixPtr)

{

    QUAT q1,q2,q3;

    if(lerp < 0)

        lerp = 0;

    else if(lerp > 65536)

        lerp = 65536;

      BasicSlerp(&trackPtr->quat_start,&trackPtr->quat_end, &q1, lerp);

     BasicSlerp(&trackPtr->quat_start_control,&trackPtr->quat_end_control, &q2, lerp);

     lerp = MUL_FIXED(ONE_FIXED-lerp,2*lerp);

    if(lerp < 0)

        lerp = 0;

    else if(lerp > 65536)

        lerp = 65536;

      BasicSlerp(&q1, &q2, &q3, lerp);

    QuatToMat(&q3,outputMatrixPtr);

}

void Update_Track_Position_Only(TRACK_CONTROLLER* tc)

{

    assert(tc);

    assert(tc->sbptr);

    assert(tc->sections);

    DYNAMICSBLOCK* dynptr = tc->sbptr->DynPtr;

    assert(dynptr);

    TRACK_SECTION_DATA* cur_tsd = &tc->sections[tc->current_section];

    //adjust timer until time lies within a section

    while(tc->timer>cur_tsd->time_for_section || tc->timer < 0)

    {

        if(tc->timer>cur_tsd->time_for_section)

        {

            tc->timer -= cur_tsd->time_for_section;

            if(tc->current_section == (tc->num_sections-1) && !tc->loop)

            {

                if(tc->loop_backandforth)

                {

                    //turn around

                    tc->reverse = 1;

                    tc->timer = cur_tsd->time_for_section-tc->timer;

                }

                else

                {

                    //reached end of track

                    tc->timer = cur_tsd->time_for_section;

                    tc->playing = 0;

                    tc->reverse = 1; 

                }

            }

            else

            {

                tc->current_section++;

                if(tc->current_section == tc->num_sections)

                    tc->current_section=0;

                cur_tsd = &tc->sections[tc->current_section];

            }

        }

        else

        {

            if(!tc->current_section && !tc->loop)

            {

                if(tc->loop_backandforth)

                {

                    //turn around

                    tc->reverse = 0;

                    tc->timer = -tc->timer;

                }

                else

                {

                    //reached end of track

                      tc->timer = 0;

                      tc->playing = 0;

                      tc->reverse = 0; 

                }

            }

            else

            {

                tc->current_section--;

                if(tc->current_section < 0)

                    tc->current_section = tc->num_sections-1;

                cur_tsd = &tc->sections[tc->current_section];

                tc->timer += cur_tsd->time_for_section;

            }

        }

    }

    // now work out the object position at this time

    /* KJL 14:47:44 24/03/98 - check for smoothing; if you've

    less than 3 points then smoothing is a bit pointless */

    if (tc->use_smoothing && tc->num_sections >= 3)

    {

        int lerp = MUL_FIXED(tc->timer,cur_tsd->oneovertime);

        SmoothTrackOrientation(cur_tsd, lerp, &dynptr->OrientMat);

        SmoothTrackPosition(cur_tsd, lerp, &dynptr->Position);

    }

    else

    {

        if(tc->no_rotation)

        {

            int lerp = MUL_FIXED(tc->timer, cur_tsd->oneovertime);

            VECTORCH pivot_pos = cur_tsd->pivot_start;

            pivot_pos.vx += MUL_FIXED(cur_tsd->pivot_travel.vx, lerp);

            pivot_pos.vy += MUL_FIXED(cur_tsd->pivot_travel.vy, lerp);

            pivot_pos.vz += MUL_FIXED(cur_tsd->pivot_travel.vz, lerp);

            dynptr->Position = pivot_pos;

        }

        else

        {

            int lerp = MUL_FIXED(tc->timer,cur_tsd->oneovertime);

            MATRIXCH orient;

            VECTORCH pivot_pos = cur_tsd->pivot_start;

            VECTORCH object_pos = cur_tsd->object_offset;

              TrackSlerp(cur_tsd,lerp,&orient);

            pivot_pos.vx += MUL_FIXED(cur_tsd->pivot_travel.vx,lerp);

            pivot_pos.vy += MUL_FIXED(cur_tsd->pivot_travel.vy,lerp);

            pivot_pos.vz += MUL_FIXED(cur_tsd->pivot_travel.vz,lerp);

            RotateVector(&object_pos, &orient);

            object_pos.vx += pivot_pos.vx;

            object_pos.vy += pivot_pos.vy;

            object_pos.vz += pivot_pos.vz;

            dynptr->OrientMat = orient;

            dynptr->Position = object_pos;

        }

    }

}

void Update_Track_Position(TRACK_CONTROLLER* tc)

{

    assert(tc);

    if(!tc->playing)

        return;

    assert(tc->sbptr);

    assert(tc->sections);

    DYNAMICSBLOCK* dynptr = tc->sbptr->DynPtr;

    assert(dynptr);

    if(tc->playing_start_sound)

    {

        Update_Track_Sound(tc->start_sound,&dynptr->Position);

        if(tc->start_sound->playing)

            return;

        tc->playing_start_sound = 0;

        if(tc->sound)

            Start_Track_Sound(tc->sound,&tc->sbptr->DynPtr->Position);

    }

    //update timer and current section number

    if(tc->reverse)

        tc->timer -= tc->use_speed_mult ? MUL_FIXED(NormalFrameTime, tc->speed_mult) : NormalFrameTime;

    else

        tc->timer += tc->use_speed_mult ? MUL_FIXED(NormalFrameTime, tc->speed_mult) : NormalFrameTime;

    Update_Track_Position_Only(tc);

    if(tc->sound)

    {

        if(tc->playing)

        {

            Update_Track_Sound(tc->sound, &dynptr->Position);

        }

        else

        {

            Stop_Track_Sound(tc->sound);

            if(tc->end_sound)

                Start_Track_Sound(tc->end_sound,&tc->sbptr->DynPtr->Position);

        }

    }

}

static void LnQuat(QUAT *q)

{

    float theta;

       float m,x,y,z;

       x = q->quatx;

       y = q->quaty;

       z = q->quatz;

    if (x == 0 && y == 0 && z == 0)

    {

        q->quatw = 0;

        q->quatx = 0;    

        q->quaty = 0;

        q->quatz = 0;

        return;

    }

       {

           double cosine = (q->quatw/65536.0);

        if (cosine > 1.0)

            cosine = 1.0;

        else if (cosine < -1.0)

            cosine = -1.0;

        theta = (float)acos(cosine);

    }

    m = (65536.0/sqrt((x*x) + (y*y) + (z*z)) );

    x *= m;

    y *= m;

    z *= m;

    q->quatw = 0;

    q->quatx = (int)(x*theta);    

    q->quaty = (int)(y*theta);

    q->quatz = (int)(z*theta);

}

static void ExpPurelyImaginaryQuat(QUAT *q)

{

    float x,y,z;

    int theta;

    x = q->quatx;

    y = q->quaty;

       z = q->quatz;

    if (x != 0||y != 0||z != 0)

    {

        float m = sqrt((x*x) + (y*y) + (z*z));

        x /= m;

        y /= m;

        z /= m;

        theta = (int)((m / 16.0) / 6.28318530718);

        q->quatx = (int)(x*(float)GetSin(theta));    

        q->quaty = (int)(y*(float)GetSin(theta));    

        q->quatz = (int)(z*(float)GetSin(theta));    

        q->quatw = GetCos(theta);

    }

    else

    {

        q->quatx = 0;    

        q->quaty = 0;    

        q->quatz = 0;    

        q->quatw = ONE_FIXED;

    }

    QNormalise(q);

}

static void MakeControlQuat(QUAT *control, QUAT *q0, QUAT *q1, QUAT *q2)

{

    QUAT a;

    QUAT b,c;

    a.quatx = -q1->quatx;

    a.quaty = -q1->quaty;

    a.quatz = -q1->quatz;

    a.quatw = q1->quatw;

    MulQuat(&a,q2, &b);

    MulQuat(&a,q0, &c);

    LnQuat(&b);

    LnQuat(&c);

    a.quatx = -(b.quatx+c.quatx)/4;

    a.quaty = -(b.quaty+c.quaty)/4;

    a.quatz = -(b.quatz+c.quatz)/4;

    ExpPurelyImaginaryQuat(&a);

    MulQuat(q1,&a, control);

}

/*KJL*******************************************************************

*                                                                      *

* Smooth track system - this code overlays cubic splines over the lerp *

* and slerp code used by the original track system                     *

*                                                                      *

*******************************************************************KJL*/

static void Preprocess_Smooth_Track_Controller(TRACK_CONTROLLER* tc)

{

    int i;

    assert(tc->sections);

    for(i=0;i < tc->num_sections; i++)

    {

        TRACK_SECTION_DATA* tsd = &tc->sections[i];

        tsd->oneovertime = DIV_FIXED(ONE_FIXED,tsd->time_for_section);

        if (!i)

        {

            tsd->quat_prev = tsd->quat_start;

            tsd->pivot_0 = tsd->pivot_start;

            tsd->pivot_1 = tsd->pivot_start;

            tsd->pivot_2 = tc->sections[1].pivot_start;

            tsd->pivot_3 = tc->sections[2].pivot_start;

        }

        else if (i == tc->num_sections-1)

        {

            tsd->quat_prev = tc->sections[i-1].quat_start;

            tsd->pivot_0 = tc->sections[i-1].pivot_1;

            tsd->pivot_1 = tsd->pivot_start;

            tsd->pivot_2 = tsd->pivot_1;

            tsd->pivot_2.vx += tsd->pivot_travel.vx;

            tsd->pivot_2.vy += tsd->pivot_travel.vy;

            tsd->pivot_2.vz += tsd->pivot_travel.vz;

            tsd->pivot_3 = tsd->pivot_2;

        }

        else if (i == tc->num_sections-2)

        {

            tsd->quat_prev = tc->sections[i-1].quat_start;

            tsd->pivot_0 = tc->sections[i-1].pivot_1;

            tsd->pivot_1 = tsd->pivot_start;

            tsd->pivot_2 = tc->sections[i+1].pivot_start;

            tsd->pivot_3 = tsd->pivot_2;

            tsd->pivot_3.vx += tc->sections[i+1].pivot_travel.vx;

            tsd->pivot_3.vy += tc->sections[i+1].pivot_travel.vy;

            tsd->pivot_3.vz += tc->sections[i+1].pivot_travel.vz;

        }

        else

        {

            tsd->quat_prev = tc->sections[i-1].quat_start;

            tsd->pivot_0 = tc->sections[i-1].pivot_start;

            tsd->pivot_1 = tsd->pivot_start;

            tsd->pivot_2 = tc->sections[i+1].pivot_start;

            tsd->pivot_3 = tc->sections[i+2].pivot_start;

        }

    }

    for(i=0; i < tc->num_sections; i++)

    {

        TRACK_SECTION_DATA* tsd = &tc->sections[i];

        if (QDot(&tsd->quat_prev,&tsd->quat_start)<0)

        {

            tsd->quat_start.quatx =- tsd->quat_start.quatx;

            tsd->quat_start.quaty =- tsd->quat_start.quaty;

            tsd->quat_start.quatz =- tsd->quat_start.quatz;

            tsd->quat_start.quatw =- tsd->quat_start.quatw;

        }

        if (QDot(&tsd->quat_start,&tsd->quat_end)<0)

        {

            tsd->quat_end.quatx =- tsd->quat_end.quatx;

            tsd->quat_end.quaty =- tsd->quat_end.quaty;

            tsd->quat_end.quatz =- tsd->quat_end.quatz;

            tsd->quat_end.quatw =- tsd->quat_end.quatw;

        }

        MakeControlQuat ( &(tsd->quat_start_control), &(tsd->quat_prev), &(tsd->quat_start), &(tsd->quat_end) );

    }

    for(i=0; i < tc->num_sections-1; i++)

    {

        tc->sections[i].quat_end_control =  tc->sections[i+1].quat_start_control;

    }

    tc->sections[tc->num_sections-1].quat_end_control =  tc->sections[tc->num_sections-1].quat_end;

}

void Preprocess_Track_Controller(TRACK_CONTROLLER* tc)

{

    int i;

    assert(tc->sections);

    /* KJL 14:47:44 24/03/98 - check for smoothing; if you've

    less than 3 points then smoothing is a bit pointless */

    if (tc->use_smoothing && tc->num_sections >= 3)

    {

        Preprocess_Smooth_Track_Controller(tc);

        return;

    }

    for(i=0; i < tc->num_sections; i++)

    {

        TRACK_SECTION_DATA* tsd = &tc->sections[i];

        tsd->oneovertime = DIV_FIXED(ONE_FIXED,tsd->time_for_section);

        if(!tc->no_rotation)

        {

            int sinom;

            int cosom = QDot(&tsd->quat_start,&tsd->quat_end);

            if (cosom < 0)

            {

                tsd->quat_end.quatx =- tsd->quat_end.quatx;

                tsd->quat_end.quaty =- tsd->quat_end.quaty;

                tsd->quat_end.quatz =- tsd->quat_end.quatz;

                tsd->quat_end.quatw =- tsd->quat_end.quatw;

                cosom = -cosom;

            }

            tsd->omega = ArcCos(cosom);

            sinom = GetSin(tsd->omega);

            if (sinom)

            {

                tsd->oneoversinomega = DIV_FIXED(ONE_FIXED,sinom);

            }

            else

            {

                tsd->omega = 0;

                tsd->oneoversinomega = 0;

            }

        }

    }

}

void Start_Track_Playing(TRACK_CONTROLLER* tc)

{

    assert(tc);

    assert(tc->sbptr);

    assert(tc->sbptr->DynPtr);

    if(tc->playing)

        return;

    tc->playing = 1;

    if(tc->start_sound)

    {

        tc->playing_start_sound = 1;

        Start_Track_Sound(tc->start_sound,&tc->sbptr->DynPtr->Position);

    }

    else if(tc->sound)

    {

        Start_Track_Sound(tc->sound,&tc->sbptr->DynPtr->Position);

    }

}

void Stop_Track_Playing(TRACK_CONTROLLER* tc)

{

    assert(tc);

    assert(tc->sbptr);

    assert(tc->sbptr->DynPtr);

    if(!tc->playing)

        return;

    tc->playing = 0;

    tc->playing_start_sound = 0;

    if(tc->sound)

        Stop_Track_Sound(tc->sound);

    if(tc->start_sound)

        Stop_Track_Sound(tc->sound);

    if(tc->end_sound)

        Start_Track_Sound(tc->end_sound,&tc->sbptr->DynPtr->Position);

}

void Reset_Track(TRACK_CONTROLLER* tc)

{

    assert(tc);

    if(tc->sound)

        Stop_Track_Sound(tc->sound);

    if(tc->start_sound)

        Stop_Track_Sound(tc->start_sound);

    if(tc->end_sound)

        Stop_Track_Sound(tc->end_sound);

    tc->timer = tc->initial_state_timer;

    tc->playing = tc->initial_state_playing;

    tc->reverse = tc->initial_state_reverse;

    tc->current_section = 0;    

    if(tc->playing && tc->sound)

        tc->sound->playing = 1;

}

/*--------------------**

** Loading and Saving **

**--------------------*/

#include "savegame.h"

typedef struct track_save_block

{

    SAVE_BLOCK_HEADER header;

    int timer;

    int speed_mult;

    int current_section;

    unsigned int playing:1;

    unsigned int reverse:1;

    unsigned int no_rotation:1;

    unsigned int use_speed_mult:1;

    unsigned int start_sound_playing:1;

    unsigned int mid_sound_playing:1;

    unsigned int end_sound_playing:1;

} TRACK_SAVE_BLOCK;

//defines for load/save macros

#define SAVELOAD_BLOCK block

#define SAVELOAD_BEHAV tc

void LoadTrackPosition(SAVE_BLOCK_HEADER* header,TRACK_CONTROLLER* tc)

{

    TRACK_SAVE_BLOCK* block = (TRACK_SAVE_BLOCK*)header;

    if(!header || !tc)

        return;

    //check the size of the save block

    if(header->size != sizeof(*block))

        return;

    //start copying stuff

    COPYELEMENT_LOAD(timer)

    COPYELEMENT_LOAD(speed_mult)

    COPYELEMENT_LOAD(current_section)

    COPYELEMENT_LOAD(playing)

    COPYELEMENT_LOAD(reverse)

    COPYELEMENT_LOAD(no_rotation)

    COPYELEMENT_LOAD(use_speed_mult)

    Update_Track_Position_Only(tc);

    if(tc->start_sound)

        tc->start_sound->playing = block->start_sound_playing;

    if(tc->sound)

        tc->sound->playing = block->mid_sound_playing;

    if(tc->end_sound)

        tc->end_sound->playing = block->end_sound_playing;

    if(tc->start_sound)

        Load_SoundState(&tc->start_sound->activ_no);

    if(tc->sound)

        Load_SoundState(&tc->sound->activ_no);

    if(tc->end_sound)

        Load_SoundState(&tc->end_sound->activ_no);

}

void SaveTrackPosition(TRACK_CONTROLLER* tc)

{

    TRACK_SAVE_BLOCK* block;

    if(!tc)

        return;

    GET_SAVE_BLOCK_POINTER(block);

    //fill in header

    block->header.type = SaveBlock_Track;

    block->header.size = sizeof(*block);

    //start copying stuff

    COPYELEMENT_SAVE(timer)

    COPYELEMENT_SAVE(speed_mult)

    COPYELEMENT_SAVE(current_section)

    COPYELEMENT_SAVE(playing)

    COPYELEMENT_SAVE(reverse)

    COPYELEMENT_SAVE(no_rotation)

    COPYELEMENT_SAVE(use_speed_mult)

    if(tc->start_sound)

    {

        block->start_sound_playing = tc->start_sound->playing;

    }

    else

    {

        block->start_sound_playing = 0;

    }

    if(tc->sound)

    {

        block->mid_sound_playing = tc->sound->playing;

    }

    else

    {

        block->mid_sound_playing = 0;

    }

    if(tc->end_sound)

    {

        block->end_sound_playing = tc->end_sound->playing;

    }

    else

    {

        block->end_sound_playing = 0;

    }                           

    if(tc->start_sound)

        Save_SoundState(&tc->start_sound->activ_no);

    if(tc->sound)

        Save_SoundState(&tc->sound->activ_no);

    if(tc->end_sound)

        Save_SoundState(&tc->end_sound->activ_no);

}