use the orientation parameter of g3_draw_bitmap

[btb/d2x.git] / main / aipath.c

/*
THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/

/*
 *
 * AI path forming stuff.
 *
 */

#ifdef HAVE_CONFIG_H
#include <conf.h>
#endif

#include <stdio.h>              //      for printf()
#include <stdlib.h>             // for d_rand() and qsort()
#include <string.h>             // for memset()

#include "inferno.h"
#include "mono.h"
#include "3d.h"
#include "dxxerror.h"
#ifdef EDITOR
#include "editor/editor.h"
#endif


#define PARALLAX        0               //      If !0, then special debugging for Parallax eyes enabled.

//      Length in segments of avoidance path
#define AVOID_SEG_LENGTH        7

#ifdef NDEBUG
#define PATH_VALIDATION 0
#else
#define PATH_VALIDATION 1
#endif

void validate_all_paths(void);
void ai_path_set_orient_and_vel(object *objp, vms_vector* goal_point, int player_visibility, vms_vector *vec_to_player);
void maybe_ai_path_garbage_collect(void);
void ai_path_garbage_collect(void);
#if PATH_VALIDATION
int validate_path(int debug_flag, point_seg* psegs, int num_points);
#endif

//      ------------------------------------------------------------------------
void create_random_xlate(sbyte *xt)
{
        int     i;

        for (i=0; i<MAX_SIDES_PER_SEGMENT; i++)
                xt[i] = i;

        for (i=0; i<MAX_SIDES_PER_SEGMENT; i++) {
                int     j = (d_rand()*MAX_SIDES_PER_SEGMENT)/(D_RAND_MAX+1);
                sbyte temp_byte;
                Assert((j >= 0) && (j < MAX_SIDES_PER_SEGMENT));

                temp_byte = xt[j];
                xt[j] = xt[i];
                xt[i] = temp_byte;
        }

}

//      -----------------------------------------------------------------------------------------------------------
//      Insert the point at the center of the side connecting two segments between the two points.
// This is messy because we must insert into the list.  The simplest (and not too slow) way to do this is to start
// at the end of the list and go backwards.
void insert_center_points(point_seg *psegs, int *num_points)
{
        int     i, j, last_point;
        int     count=*num_points;

        last_point = *num_points-1;

        for (i=last_point; i>0; i--) {
                int                     connect_side, temp_segnum;
                vms_vector      center_point, new_point;

                psegs[2*i] = psegs[i];
                connect_side = find_connect_side(&Segments[psegs[i].segnum], &Segments[psegs[i-1].segnum]);
                Assert(connect_side != -1);     //      Impossible!  These two segments must be connected, they were created by create_path_points (which was created by mk!)
                if (connect_side == -1)                 //      Try to blow past the assert, this should at least prevent a hang.
                        connect_side = 0;
                compute_center_point_on_side(&center_point, &Segments[psegs[i-1].segnum], connect_side);
                vm_vec_sub(&new_point, &psegs[i-1].point, &center_point);
                new_point.x /= 16;
                new_point.y /= 16;
                new_point.z /= 16;
                vm_vec_sub(&psegs[2*i-1].point, &center_point, &new_point);
                temp_segnum = find_point_seg(&psegs[2*i-1].point, psegs[2*i].segnum);
                if (temp_segnum == -1) {
                        mprintf((1, "Warning: point not in ANY segment in aipath.c/insert_center_points.\n"));
                        psegs[2*i-1].point = center_point;
                        find_point_seg(&psegs[2*i-1].point, psegs[2*i].segnum);
                }

                psegs[2*i-1].segnum = psegs[2*i].segnum;
                count++;
        }

        //      Now, remove unnecessary center points.
        //      A center point is unnecessary if it is close to the line between the two adjacent points.
        //      MK, OPTIMIZE!  Can get away with about half the math since every vector gets computed twice.
        for (i=1; i<count-1; i+=2) {
                vms_vector      temp1, temp2;
                fix                     dot;

                dot = vm_vec_dot(vm_vec_sub(&temp1, &psegs[i].point, &psegs[i-1].point), vm_vec_sub(&temp2, &psegs[i+1].point, &psegs[i].point));

                if (dot * 9/8 > fixmul(vm_vec_mag(&temp1), vm_vec_mag(&temp2)))
                        psegs[i].segnum = -1;

        }

        //      Now, scan for points with segnum == -1
        j = 0;
        for (i=0; i<count; i++)
                if (psegs[i].segnum != -1)
                        psegs[j++] = psegs[i];

        *num_points = j;
}

#ifdef EDITOR
int     Safety_flag_override = 0;
int     Random_flag_override = 0;
int     Ai_path_debug=0;
#endif

//      -----------------------------------------------------------------------------------------------------------
//      Move points halfway to outside of segment.
void move_towards_outside(point_seg *psegs, int *num_points, object *objp, int rand_flag)
{
        int     i;
        point_seg       new_psegs[200];

        Assert(*num_points < 200);

        for (i=1; i<*num_points-1; i++) {
                int                     new_segnum;
                fix                     segment_size;
                int                     segnum;
                vms_vector      a, b, c, d, e;
                vms_vector      goal_pos;
                int                     count;
                int                     temp_segnum;

                // -- psegs[i].segnum = find_point_seg(&psegs[i].point, psegs[i].segnum);
                temp_segnum = find_point_seg(&psegs[i].point, psegs[i].segnum);
                Assert(temp_segnum != -1);
                psegs[i].segnum = temp_segnum;
                segnum = psegs[i].segnum;

                vm_vec_sub(&a, &psegs[i].point, &psegs[i-1].point);
                vm_vec_sub(&b, &psegs[i+1].point, &psegs[i].point);
                vm_vec_sub(&c, &psegs[i+1].point, &psegs[i-1].point);
                //      I don't think we can use quick version here and this is _very_ rarely called. --MK, 07/03/95
                vm_vec_normalize_quick(&a);
                vm_vec_normalize_quick(&b);
                if (abs(vm_vec_dot(&a, &b)) > 3*F1_0/4 ) {
                        if (abs(a.z) < F1_0/2) {
                                if (rand_flag) {
                                        e.x = (d_rand()-16384)/2;
                                        e.y = (d_rand()-16384)/2;
                                        e.z = abs(e.x) + abs(e.y) + 1;
                                        vm_vec_normalize_quick(&e);
                                } else {
                                        e.x = 0;
                                        e.y = 0;
                                        e.z = F1_0;
                                }
                        } else {
                                if (rand_flag) {
                                        e.y = (d_rand()-16384)/2;
                                        e.z = (d_rand()-16384)/2;
                                        e.x = abs(e.y) + abs(e.z) + 1;
                                        vm_vec_normalize_quick(&e);
                                } else {
                                        e.x = F1_0;
                                        e.y = 0;
                                        e.z = 0;
                                }
                        }
                } else {
                        vm_vec_cross(&d, &a, &b);
                        vm_vec_cross(&e, &c, &d);
                        vm_vec_normalize_quick(&e);
                }

if (vm_vec_mag_quick(&e) < F1_0/2)
        Int3();

//mprintf((0, "(%i) Moving to side: %6.3f %6.3f %6.3f\n", i, f2fl(e.x), f2fl(e.y), f2fl(e.z)));

                segment_size = vm_vec_dist_quick(&Vertices[Segments[segnum].verts[0]], &Vertices[Segments[segnum].verts[6]]);
                if (segment_size > F1_0*40)
                        segment_size = F1_0*40;

                vm_vec_scale_add(&goal_pos, &psegs[i].point, &e, segment_size/4);

                count = 3;
                while (count) {
                        fvi_query       fq;
                        fvi_info                hit_data;
                        int                     hit_type;
        
                        fq.p0                                           = &psegs[i].point;
                        fq.startseg                             = psegs[i].segnum;
                        fq.p1                                           = &goal_pos;
                        fq.rad                                  = objp->size;
                        fq.thisobjnum       = OBJECT_NUMBER(objp);
                        fq.ignore_obj_list      = NULL;
                        fq.flags                                        = 0;
        
                        hit_type = find_vector_intersection(&fq, &hit_data);
        
                        if (hit_type == HIT_NONE)
                                count = 0;
                        else {
                                if ((count == 3) && (hit_type == HIT_BAD_P0))
                                        Int3();
                                goal_pos.x = (fq.p0->x + hit_data.hit_pnt.x)/2;
                                goal_pos.y = (fq.p0->y + hit_data.hit_pnt.y)/2;
                                goal_pos.z = (fq.p0->z + hit_data.hit_pnt.z)/2;
                                count--;
                                if (count == 0) {       //      Couldn't move towards outside, that's ok, sometimes things can't be moved.
                                        goal_pos = psegs[i].point;
                                }
                        }
                }

                //      Only move towards outside if remained inside segment.
                new_segnum = find_point_seg(&goal_pos, psegs[i].segnum);
                if (new_segnum == psegs[i].segnum) {
                        new_psegs[i].point = goal_pos;
                        new_psegs[i].segnum = new_segnum;
                } else {
                        new_psegs[i].point = psegs[i].point;
                        new_psegs[i].segnum = psegs[i].segnum;
                }

        }

        for (i=1; i<*num_points-1; i++)
                psegs[i] = new_psegs[i];
}


//      -----------------------------------------------------------------------------------------------------------
//      Create a path from objp->pos to the center of end_seg.
//      Return a list of (segment_num, point_locations) at psegs
//      Return number of points in *num_points.
//      if max_depth == -1, then there is no maximum depth.
//      If unable to create path, return -1, else return 0.
//      If random_flag !0, then introduce randomness into path by looking at sides in random order.  This means
//      that a path between two segments won't always be the same, unless it is unique.
//      If safety_flag is set, then additional points are added to "make sure" that points are reachable.  I would
//      like to say that it ensures that the object can move between the points, but that would require knowing what
//      the object is (which isn't passed, right?) and making fvi calls (slow, right?).  So, consider it the more_or_less_safe_flag.
//      If end_seg == -2, then end seg will never be found and this routine will drop out due to depth (probably called by create_n_segment_path).
int create_path_points(object *objp, int start_seg, int end_seg, point_seg *psegs, short *num_points, int max_depth, int random_flag, int safety_flag, int avoid_seg)
{
        int             cur_seg;
        int             sidenum;
        int             qtail = 0, qhead = 0;
        int             i;
        sbyte   visited[MAX_SEGMENTS];
        seg_seg seg_queue[MAX_SEGMENTS];
        short           depth[MAX_SEGMENTS];
        int             cur_depth;
        sbyte   random_xlate[MAX_SIDES_PER_SEGMENT];
        point_seg       *original_psegs = psegs;
        int             l_num_points;

// -- mprintf((0, "cpp: frame = %4i obj %3i, psegs = %5i\n", FrameCount, OBJECT_NUMBER(objp), POINT_SEG_NUMBER(psegs)));
#if PATH_VALIDATION
        validate_all_paths();
#endif

if ((objp->type == OBJ_ROBOT) && (objp->ctype.ai_info.behavior == AIB_RUN_FROM)) {
        random_flag = 1;
        avoid_seg = ConsoleObject->segnum;
        // Int3();
}

        if (max_depth == -1)
                max_depth = MAX_PATH_LENGTH;

        l_num_points = 0;
//random_flag = Random_flag_override; //!! debug!!
//safety_flag = Safety_flag_override; //!! debug!!

//      for (i=0; i<=Highest_segment_index; i++) {
//              visited[i] = 0;
//              depth[i] = 0;
//      }
        memset(visited, 0, sizeof(visited[0])*(Highest_segment_index+1));
        memset(depth, 0, sizeof(depth[0])*(Highest_segment_index+1));

        //      If there is a segment we're not allowed to visit, mark it.
        if (avoid_seg != -1) {
                Assert(avoid_seg <= Highest_segment_index);
                if ((start_seg != avoid_seg) && (end_seg != avoid_seg)) {
                        visited[avoid_seg] = 1;
                        depth[avoid_seg] = 0;
                } else
                        ; // -- mprintf((0, "Start/End/Avoid = %i %i %i\n", start_seg, end_seg, avoid_seg));
        }

        if (random_flag)
                create_random_xlate(random_xlate);

        cur_seg = start_seg;
        visited[cur_seg] = 1;
        cur_depth = 0;

        while (cur_seg != end_seg) {
                segment *segp = &Segments[cur_seg];

                if (random_flag)
                        if (d_rand() < 8192)
                                create_random_xlate(random_xlate);

                // mprintf((0, "\n"));
                for (sidenum = 0; sidenum < MAX_SIDES_PER_SEGMENT; sidenum++) {

                        int     snum = sidenum;

                        if (random_flag)
                                snum = random_xlate[sidenum];

                        if (IS_CHILD(segp->children[snum]) && ((WALL_IS_DOORWAY(segp, snum) & WID_FLY_FLAG) || (ai_door_is_openable(objp, segp, snum)))) {
                                int                     this_seg = segp->children[snum];
                                Assert(this_seg != -1);
                                if (((cur_seg == avoid_seg) || (this_seg == avoid_seg)) && (ConsoleObject->segnum == avoid_seg)) {
                                        vms_vector      center_point;

                                        fvi_query       fq;
                                        fvi_info                hit_data;
                                        int                     hit_type;
        
                                        compute_center_point_on_side(&center_point, segp, snum);

                                        fq.p0                                           = &objp->pos;
                                        fq.startseg                             = objp->segnum;
                                        fq.p1                                           = &center_point;
                                        fq.rad                                  = objp->size;
                                        fq.thisobjnum       = OBJECT_NUMBER(objp);
                                        fq.ignore_obj_list      = NULL;
                                        fq.flags                                        = 0;

                                        hit_type = find_vector_intersection(&fq, &hit_data);
                                        if (hit_type != HIT_NONE) {
                                                // -- mprintf((0, "hit_type = %i, object = %i\n", hit_type, hit_data.hit_object));
                                                goto dont_add;
                                        }
                                }

                                if (!visited[this_seg]) {
                                        seg_queue[qtail].start = cur_seg;
                                        seg_queue[qtail].end = this_seg;
                                        visited[this_seg] = 1;
                                        depth[qtail++] = cur_depth+1;
                                        if (depth[qtail-1] == max_depth) {
                                                // mprintf((0, "\ndepth == max_depth == %i\n", max_depth));
                                                end_seg = seg_queue[qtail-1].end;
                                                goto cpp_done1;
                                        }       // end if (depth[...
                                }       // end if (!visited...
                        }       // if (WALL_IS_DOORWAY(...
dont_add: ;
                }       //      for (sidenum...

                if (qhead >= qtail) {
                        //      Couldn't get to goal, return a path as far as we got, which probably acceptable to the unparticular caller.
                        end_seg = seg_queue[qtail-1].end;
                        break;
                }

                cur_seg = seg_queue[qhead].end;
                cur_depth = depth[qhead];
                qhead++;

cpp_done1: ;
        }       //      while (cur_seg ...

        //      Set qtail to the segment which ends at the goal.
        while (seg_queue[--qtail].end != end_seg)
                if (qtail < 0) {
                        // mprintf((0, "\nNo path!\n"));
                        // printf("UNABLE TO FORM PATH");
                        // Int3();
                        *num_points = l_num_points;
                        return -1;
                }

        #ifdef EDITOR
        // -- N_selected_segs = 0;
        #endif
//printf("Object #%3i, start: %3i ", OBJECT_NUMBER(objp), POINT_SEG_NUMBER(psegs));
        while (qtail >= 0) {
                int     parent_seg, this_seg;

                this_seg = seg_queue[qtail].end;
                parent_seg = seg_queue[qtail].start;
                Assert((this_seg >= 0) && (this_seg <= Highest_segment_index));
                psegs->segnum = this_seg;
//printf("%3i ", this_seg);
                compute_segment_center(&psegs->point,&Segments[this_seg]);
                psegs++;
                l_num_points++;
                #ifdef EDITOR
                // -- Selected_segs[N_selected_segs++] = this_seg;
                #endif

                if (parent_seg == start_seg)
                        break;

                while (seg_queue[--qtail].end != parent_seg)
                        Assert(qtail >= 0);
        }

        Assert((start_seg >= 0) && (start_seg <= Highest_segment_index));
        psegs->segnum = start_seg;
//printf("%3i\n", start_seg);
        compute_segment_center(&psegs->point,&Segments[start_seg]);
        psegs++;
        l_num_points++;

#if PATH_VALIDATION
        validate_path(1, original_psegs, l_num_points);
#endif

        //      Now, reverse point_segs in place.
        for (i=0; i< l_num_points/2; i++) {
                point_seg               temp_point_seg = *(original_psegs + i);
                *(original_psegs + i) = *(original_psegs + l_num_points - i - 1);
                *(original_psegs + l_num_points - i - 1) = temp_point_seg;
        }
#if PATH_VALIDATION
        validate_path(2, original_psegs, l_num_points);
#endif

        //      Now, if safety_flag set, then insert the point at the center of the side connecting two segments
        //      between the two points.  This is messy because we must insert into the list.  The simplest (and not too slow)
        //      way to do this is to start at the end of the list and go backwards.
        if (safety_flag) {
                if (POINT_SEG_NUMBER(psegs) + l_num_points + 2 > MAX_POINT_SEGS) {
                        //      Ouch!  Cannot insert center points in path.  So return unsafe path.
//                      Int3(); // Contact Mike:  This is impossible.
//                      force_dump_ai_objects_all("Error in create_path_points");
                        mprintf((0, "Resetting all paths because of safety_flag.\n"));
                        ai_reset_all_paths();
                        *num_points = l_num_points;
                        return -1;
                } else {
                        // int  old_num_points = l_num_points;
                        insert_center_points(original_psegs, &l_num_points);
                        // mprintf((0, "Saved %i/%i points.\n", 2*old_num_points - l_num_points - 1, old_num_points-1));
                }
        }

#if PATH_VALIDATION
        validate_path(3, original_psegs, l_num_points);
#endif

// -- MK, 10/30/95 -- This code causes apparent discontinuities in the path, moving a point
//      into a new segment.  It is not necessarily bad, but it makes it hard to track down actual
//      discontinuity problems.
        if (objp->type == OBJ_ROBOT)
                if (Robot_info[objp->id].companion)
                        move_towards_outside(original_psegs, &l_num_points, objp, 0);

#if PATH_VALIDATION
        validate_path(4, original_psegs, l_num_points);
#endif

        *num_points = l_num_points;
        return 0;
}

int     Last_buddy_polish_path_frame;

//      -------------------------------------------------------------------------------------------------------
//      polish_path
//      Takes an existing path and makes it nicer.
//      Drops as many leading points as possible still maintaining direct accessibility
//      from current position to first point.
//      Will not shorten path to fewer than 3 points.
//      Returns number of points.
//      Starting position in psegs doesn't change.
//      Changed, MK, 10/18/95.  I think this was causing robots to get hung up on walls.
//                              Only drop up to the first three points.
int polish_path(object *objp, point_seg *psegs, int num_points)
{
        int     i, first_point=0;

        if (num_points <= 4)
                return num_points;

        //      Prevent the buddy from polishing his path twice in one frame, which can cause him to get hung up.  Pretty ugly, huh?
        if (Robot_info[objp->id].companion)
        {
                if (FrameCount == Last_buddy_polish_path_frame)
                        return num_points;
                else
                        Last_buddy_polish_path_frame = FrameCount;
        }

        // -- MK: 10/18/95: for (i=0; i<num_points-3; i++) {
        for (i=0; i<2; i++) {
                fvi_query       fq;
                fvi_info                hit_data;
                int                     hit_type;
        
                fq.p0                                           = &objp->pos;
                fq.startseg                             = objp->segnum;
                fq.p1                                           = &psegs[i].point;
                fq.rad                                  = objp->size;
                fq.thisobjnum       = OBJECT_NUMBER(objp);
                fq.ignore_obj_list      = NULL;
                fq.flags                                        = 0;

                hit_type = find_vector_intersection(&fq, &hit_data);
        
                if (hit_type == HIT_NONE)
                        first_point = i+1;
                else
                        break;          
        }

        if (first_point) {
                //      Scrunch down all the psegs.
                for (i=first_point; i<num_points; i++)
                        psegs[i-first_point] = psegs[i];
        }

        return num_points - first_point;
}

#ifndef NDEBUG
//      -------------------------------------------------------------------------------------------------------
//      Make sure that there are connections between all segments on path.
//      Note that if path has been optimized, connections may not be direct, so this function is useless, or worse.
//      Return true if valid, else return false.
int validate_path(int debug_flag, point_seg *psegs, int num_points)
{
#if PATH_VALIDATION
        int             i, curseg;

        curseg = psegs->segnum;
        if ((curseg < 0) || (curseg > Highest_segment_index)) {
                mprintf((0, "Path beginning at index %i, length=%i is bogus!\n", POINT_SEG_NUMBER(psegs), num_points));
                Int3();         //      Contact Mike: Debug trap for elusive, nasty bug.
                return 0;
        }

if (debug_flag == 999)
        mprintf((0, "That's curious...\n"));

if (num_points == 0)
        return 1;

// printf("(%i) Validating path at psegs=%i, num_points=%i, segments = %3i ", debug_flag, POINT_SEG_NUMBER(psegs), num_points, psegs[0].segnum);
        for (i=1; i<num_points; i++) {
                int     sidenum;
                int     nextseg = psegs[i].segnum;

                if ((nextseg < 0) || (nextseg > Highest_segment_index)) {
                        mprintf((0, "Path beginning at index %i, length=%i is bogus!\n", POINT_SEG_NUMBER(psegs), num_points));
                        Int3();         //      Contact Mike: Debug trap for elusive, nasty bug.
                        return 0;
                }

// printf("%3i ", nextseg);
                if (curseg != nextseg) {
                        for (sidenum=0; sidenum<MAX_SIDES_PER_SEGMENT; sidenum++)
                                if (Segments[curseg].children[sidenum] == nextseg)
                                        break;

                        // Assert(sidenum != MAX_SIDES_PER_SEGMENT);    //      Hey, created path is not contiguous, why!?
                        if (sidenum == MAX_SIDES_PER_SEGMENT) {
                                mprintf((0, "Path beginning at index %i, length=%i is bogus!\n", POINT_SEG_NUMBER(psegs), num_points));
                                // printf("BOGUS");
                                Int3();
                                return 0;
                        }
                        curseg = nextseg;
                }
        }
//printf("\n");
#endif
        return 1;

}
#endif

#ifndef NDEBUG
//      -----------------------------------------------------------------------------------------------------------
void validate_all_paths(void)
{

#if PATH_VALIDATION
        int     i;

        for (i=0; i<=Highest_object_index; i++) {
                if (Objects[i].type == OBJ_ROBOT) {
                        object          *objp = &Objects[i];
                        ai_static       *aip = &objp->ctype.ai_info;
                        //ai_local              *ailp = &Ai_local_info[i];

                        if (objp->control_type == CT_AI) {
                                if ((aip->hide_index != -1) && (aip->path_length > 0))
                                        if (!validate_path(4, &Point_segs[aip->hide_index], aip->path_length)) {
                                                Int3(); //      This path is bogus!  Who corrupted it!  Danger! Danger!
                                                                        //      Contact Mike, he caused this mess.
                                                //force_dump_ai_objects_all("Error in validate_all_paths");
                                                aip->path_length=0;     //      This allows people to resume without harm...
                                        }
                        }
                }
        }
#endif

}
#endif

// -- //        -------------------------------------------------------------------------------------------------------
// -- //        Creates a path from the objects current segment (objp->segnum) to the specified segment for the object to
// -- //        hide in Ai_local_info[objnum].goal_segment.
// -- //        Sets    objp->ctype.ai_info.hide_index,         a pointer into Point_segs, the first point_seg of the path.
// -- //                        objp->ctype.ai_info.path_length,                length of path
// -- //                        Point_segs_free_ptr                             global pointer into Point_segs array
// -- void create_path(object *objp)
// -- {
// --   ai_static       *aip = &objp->ctype.ai_info;
// --   ai_local    *ailp = &Ai_local_info[OBJECT_NUMBER(objp)];
// --   int                     start_seg, end_seg;
// --
// --   start_seg = objp->segnum;
// --   end_seg = ailp->goal_segment;
// --
// --   if (end_seg == -1)
// --           create_n_segment_path(objp, 3, -1);
// --
// --   if (end_seg == -1) {
// --           ; //mprintf((0, "Object %i, hide_segment = -1, not creating path.\n", OBJECT_NUMBER(objp)));
// --   } else {
// --           create_path_points(objp, start_seg, end_seg, Point_segs_free_ptr, &aip->path_length, -1, 0, 0, -1);
// --           aip->hide_index = POINT_SEG_NUMBER(Point_segs_free_ptr);
// --           aip->cur_path_index = 0;
// -- #if PATH_VALIDATION
// --           validate_path(5, Point_segs_free_ptr, aip->path_length);
// -- #endif
// --           Point_segs_free_ptr += aip->path_length;
// --           if (POINT_SEG_NUMBER(Point_segs_free_ptr) + MAX_PATH_LENGTH*2 > MAX_POINT_SEGS) {
// --                   //Int3();       //      Contact Mike: This is curious, though not deadly. /eip++;g
// --                   //force_dump_ai_objects_all("Error in create_path");
// --                   ai_reset_all_paths();
// --           }
// --           aip->PATH_DIR = 1;              //      Initialize to moving forward.
// --           aip->SUBMODE = AISM_HIDING;             //      Pretend we are hiding, so we sit here until bothered.
// --   }
// --
// --   maybe_ai_path_garbage_collect();
// --
// -- }

//      -------------------------------------------------------------------------------------------------------
//      Creates a path from the objects current segment (objp->segnum) to the specified segment for the object to
//      hide in Ai_local_info[objnum].goal_segment.
//      Sets    objp->ctype.ai_info.hide_index,         a pointer into Point_segs, the first point_seg of the path.
//                      objp->ctype.ai_info.path_length,                length of path
//                      Point_segs_free_ptr                             global pointer into Point_segs array
//      Change, 10/07/95: Used to create path to ConsoleObject->pos.  Now creates path to Believed_player_pos.
void create_path_to_player(object *objp, int max_length, int safety_flag)
{
        ai_static       *aip = &objp->ctype.ai_info;
        ai_local    *ailp = &Ai_local_info[OBJECT_NUMBER(objp)];
        int                     start_seg, end_seg;

//mprintf((0, "Creating path to player.\n"));
        if (max_length == -1)
                max_length = MAX_DEPTH_TO_SEARCH_FOR_PLAYER;

        ailp->time_player_seen = GameTime;                      //      Prevent from resetting path quickly.
        ailp->goal_segment = Believed_player_seg;

        start_seg = objp->segnum;
        end_seg = ailp->goal_segment;

        // mprintf((0, "Creating path for object #%i, from segment #%i to #%i\n", OBJECT_NUMBER(objp), start_seg, end_seg));

        if (end_seg == -1) {
                ; //mprintf((0, "Object %i, hide_segment = -1, not creating path.\n", OBJECT_NUMBER(objp)));
        } else {
                create_path_points(objp, start_seg, end_seg, Point_segs_free_ptr, &aip->path_length, max_length, 1, safety_flag, -1);
                aip->path_length = polish_path(objp, Point_segs_free_ptr, aip->path_length);
                aip->hide_index = POINT_SEG_NUMBER(Point_segs_free_ptr);
                aip->cur_path_index = 0;
                Point_segs_free_ptr += aip->path_length;
                if (POINT_SEG_NUMBER(Point_segs_free_ptr) + MAX_PATH_LENGTH*2 > MAX_POINT_SEGS) {
                        //Int3();       //      Contact Mike: This is stupid.  Should call maybe_ai_garbage_collect before the add.
                        //force_dump_ai_objects_all("Error in create_path_to_player");
                        ai_reset_all_paths();
                        return;
                }
//              Assert(POINT_SEG_NUMBER(Point_segs_free_ptr) + MAX_PATH_LENGTH*2 < MAX_POINT_SEGS);
                aip->PATH_DIR = 1;              //      Initialize to moving forward.
                // -- UNUSED! aip->SUBMODE = AISM_GOHIDE;               //      This forces immediate movement.
                ailp->mode = AIM_FOLLOW_PATH;
                ailp->player_awareness_type = 0;                //      If robot too aware of player, will set mode to chase
                // mprintf((0, "Created %i segment path to player.\n", aip->path_length));
        }

        maybe_ai_path_garbage_collect();

}

//      -------------------------------------------------------------------------------------------------------
//      Creates a path from the object's current segment (objp->segnum) to segment goalseg.
void create_path_to_segment(object *objp, int goalseg, int max_length, int safety_flag)
{
        ai_static       *aip = &objp->ctype.ai_info;
        ai_local    *ailp = &Ai_local_info[OBJECT_NUMBER(objp)];
        int                     start_seg, end_seg;

        if (max_length == -1)
                max_length = MAX_DEPTH_TO_SEARCH_FOR_PLAYER;

        ailp->time_player_seen = GameTime;                      //      Prevent from resetting path quickly.
        ailp->goal_segment = goalseg;

        start_seg = objp->segnum;
        end_seg = ailp->goal_segment;

        if (end_seg == -1) {
                ;
        } else {
                create_path_points(objp, start_seg, end_seg, Point_segs_free_ptr, &aip->path_length, max_length, 1, safety_flag, -1);
                aip->hide_index = POINT_SEG_NUMBER(Point_segs_free_ptr);
                aip->cur_path_index = 0;
                Point_segs_free_ptr += aip->path_length;
                if (POINT_SEG_NUMBER(Point_segs_free_ptr) + MAX_PATH_LENGTH*2 > MAX_POINT_SEGS) {
                        ai_reset_all_paths();
                        return;
                }

                aip->PATH_DIR = 1;              //      Initialize to moving forward.
                // -- UNUSED! aip->SUBMODE = AISM_GOHIDE;               //      This forces immediate movement.
                ailp->player_awareness_type = 0;                //      If robot too aware of player, will set mode to chase
        }

        maybe_ai_path_garbage_collect();

}

//      -------------------------------------------------------------------------------------------------------
//      Creates a path from the objects current segment (objp->segnum) to the specified segment for the object to
//      hide in Ai_local_info[objnum].goal_segment
//      Sets    objp->ctype.ai_info.hide_index,         a pointer into Point_segs, the first point_seg of the path.
//                      objp->ctype.ai_info.path_length,                length of path
//                      Point_segs_free_ptr                             global pointer into Point_segs array
void create_path_to_station(object *objp, int max_length)
{
        ai_static       *aip = &objp->ctype.ai_info;
        ai_local    *ailp = &Ai_local_info[OBJECT_NUMBER(objp)];
        int                     start_seg, end_seg;

        if (max_length == -1)
                max_length = MAX_DEPTH_TO_SEARCH_FOR_PLAYER;

        ailp->time_player_seen = GameTime;                      //      Prevent from resetting path quickly.

        start_seg = objp->segnum;
        end_seg = aip->hide_segment;

        //1001: mprintf((0, "Back to station for object #%i, from segment #%i to #%i\n", OBJECT_NUMBER(objp), start_seg, end_seg));

        if (end_seg == -1) {
                ; //mprintf((0, "Object %i, hide_segment = -1, not creating path.\n", OBJECT_NUMBER(objp)));
        } else {
                create_path_points(objp, start_seg, end_seg, Point_segs_free_ptr, &aip->path_length, max_length, 1, 1, -1);
                aip->path_length = polish_path(objp, Point_segs_free_ptr, aip->path_length);
                aip->hide_index = POINT_SEG_NUMBER(Point_segs_free_ptr);
                aip->cur_path_index = 0;

                Point_segs_free_ptr += aip->path_length;
                if (POINT_SEG_NUMBER(Point_segs_free_ptr) + MAX_PATH_LENGTH*2 > MAX_POINT_SEGS) {
                        //Int3();       //      Contact Mike: Stupid.
                        //force_dump_ai_objects_all("Error in create_path_to_station");
                        ai_reset_all_paths();
                        return;
                }
//              Assert(POINT_SEG_NUMBER(Point_segs_free_ptr) + MAX_PATH_LENGTH*2 < MAX_POINT_SEGS);
                aip->PATH_DIR = 1;              //      Initialize to moving forward.
                // aip->SUBMODE = AISM_GOHIDE;          //      This forces immediate movement.
                ailp->mode = AIM_FOLLOW_PATH;
                ailp->player_awareness_type = 0;
        }


        maybe_ai_path_garbage_collect();

}


//      -------------------------------------------------------------------------------------------------------
//      Create a path of length path_length for an object, stuffing info in ai_info field.
void create_n_segment_path(object *objp, int path_length, int avoid_seg)
{
        ai_static       *aip=&objp->ctype.ai_info;
        ai_local    *ailp = &Ai_local_info[OBJECT_NUMBER(objp)];

//mprintf((0, "Creating %i segment path.\n", path_length));

        if (create_path_points(objp, objp->segnum, -2, Point_segs_free_ptr, &aip->path_length, path_length, 1, 0, avoid_seg) == -1) {
                Point_segs_free_ptr += aip->path_length;
                while ((create_path_points(objp, objp->segnum, -2, Point_segs_free_ptr, &aip->path_length, --path_length, 1, 0, -1) == -1)) {
                        //mprintf((0, "R"));
                        Assert(path_length);
                }
        }

        aip->hide_index = POINT_SEG_NUMBER(Point_segs_free_ptr);
        aip->cur_path_index = 0;
#if PATH_VALIDATION
        validate_path(8, Point_segs_free_ptr, aip->path_length);
#endif
        Point_segs_free_ptr += aip->path_length;
        if (POINT_SEG_NUMBER(Point_segs_free_ptr) + MAX_PATH_LENGTH*2 > MAX_POINT_SEGS) {
                //Int3();       //      Contact Mike: This is curious, though not deadly. /eip++;g
                //force_dump_ai_objects_all("Error in crete_n_segment_path 2");
                ai_reset_all_paths();
        }

        aip->PATH_DIR = 1;              //      Initialize to moving forward.
        // -- UNUSED! aip->SUBMODE = -1;                //      Don't know what this means.
        ailp->mode = AIM_FOLLOW_PATH;

        //      If this robot is visible (player_visibility is not available) and it's running away, move towards outside with
        //      randomness to prevent a stream of bots from going away down the center of a corridor.
        if (Ai_local_info[OBJECT_NUMBER(objp)].previous_visibility) {
                if (aip->path_length) {
                        int     t_num_points = aip->path_length;
                        move_towards_outside(&Point_segs[aip->hide_index], &t_num_points, objp, 1);
                        aip->path_length = t_num_points;
                }
        }
        //mprintf((0, "\n"));

        maybe_ai_path_garbage_collect();

}

//      -------------------------------------------------------------------------------------------------------
void create_n_segment_path_to_door(object *objp, int path_length, int avoid_seg)
{
        create_n_segment_path(objp, path_length, avoid_seg);
}

extern int Connected_segment_distance;

#define Int3_if(cond) if (!cond) Int3();

//      ----------------------------------------------------------------------------------------------------
void move_object_to_goal(object *objp, vms_vector *goal_point, int goal_seg)
{
        ai_static       *aip = &objp->ctype.ai_info;
        int                     segnum;

        if (aip->path_length < 2)
                return;

        Assert(objp->segnum != -1);

        // mprintf((0, "[%i -> %i]\n", OBJECT_NUMBER(objp), goal_seg));

#ifndef NDEBUG
        if (objp->segnum != goal_seg)
                if (find_connect_side(&Segments[objp->segnum], &Segments[goal_seg]) == -1) {
                        fix     dist;
                        dist = find_connected_distance(&objp->pos, objp->segnum, goal_point, goal_seg, 30, WID_FLY_FLAG);
                        if (Connected_segment_distance > 2) {   //      This global is set in find_connected_distance
                                // -- Int3();
                                mprintf((1, "Warning: Object %i hopped across %i segments, a distance of %7.3f.\n", OBJECT_NUMBER(objp), Connected_segment_distance, f2fl(dist)));
                        }
                }
#endif

        Assert(aip->path_length >= 2);

        if (aip->cur_path_index <= 0) {
                if (aip->behavior == AIB_STATION) {
                        // mprintf((0, "Object #%i, creating path back to station.\n", OBJECT_NUMBER(objp)));
                        create_path_to_station(objp, 15);
                        return;
                }
                aip->cur_path_index = 1;
                aip->PATH_DIR = 1;
        } else if (aip->cur_path_index >= aip->path_length - 1) {
                if (aip->behavior == AIB_STATION) {
                        // mprintf((0, "Object #%i, creating path back to station.\n", OBJECT_NUMBER(objp)));
                        create_path_to_station(objp, 15);
                        if (aip->path_length == 0) {
                                ai_local *ailp = &Ai_local_info[OBJECT_NUMBER(objp)];
                                ailp->mode = AIM_STILL;
                        }
                        return;
                }
                Assert(aip->path_length != 0);
                aip->cur_path_index = aip->path_length-2;
                aip->PATH_DIR = -1;
        } else
                aip->cur_path_index += aip->PATH_DIR;

        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));

        objp->pos = *goal_point;
        segnum = find_object_seg(objp);
        if (segnum != goal_seg)
                mprintf((1, "Object #%i goal supposed to be in segment #%i, but in segment #%i\n", OBJECT_NUMBER(objp), goal_seg, segnum));

        if (segnum == -1) {
                Int3(); //      Oops, object is not in any segment.
                                        // Contact Mike: This is impossible.
                //      Hack, move object to center of segment it used to be in.
                compute_segment_center(&objp->pos, &Segments[objp->segnum]);
        } else
                obj_relink(OBJECT_NUMBER(objp), segnum);
}

// -- too much work -- //       ----------------------------------------------------------------------------------------------------------
// -- too much work -- //       Return true if the object the companion wants to kill is reachable.
// -- too much work -- int attack_kill_object(object *objp)
// -- too much work -- {
// -- too much work --  object          *kill_objp;
// -- too much work --  fvi_info                hit_data;
// -- too much work --  int                     fate;
// -- too much work --  fvi_query       fq;
// -- too much work --
// -- too much work --  if (Escort_kill_object == -1)
// -- too much work --          return 0;
// -- too much work --
// -- too much work --  kill_objp = &Objects[Escort_kill_object];
// -- too much work --
// -- too much work --  fq.p0                                           = &objp->pos;
// -- too much work --  fq.startseg                             = objp->segnum;
// -- too much work --  fq.p1                                           = &kill_objp->pos;
// -- too much work --  fq.rad                                  = objp->size;
// -- too much work --  fq.thisobjnum       = OBJECT_NUMBER(objp);
// -- too much work --  fq.ignore_obj_list      = NULL;
// -- too much work --  fq.flags                                        = 0;
// -- too much work --
// -- too much work --  fate = find_vector_intersection(&fq,&hit_data);
// -- too much work --
// -- too much work --  if (fate == HIT_NONE)
// -- too much work --          return 1;
// -- too much work --  else
// -- too much work --          return 0;
// -- too much work -- }

//      ----------------------------------------------------------------------------------------------------------
//      Optimization: If current velocity will take robot near goal, don't change velocity
void ai_follow_path(object *objp, int player_visibility, int previous_visibility, vms_vector *vec_to_player)
{
        ai_static               *aip = &objp->ctype.ai_info;

        vms_vector      goal_point, new_goal_point;
        fix                     dist_to_goal;
        robot_info      *robptr = &Robot_info[objp->id];
        int                     forced_break, original_dir, original_index;
        fix                     dist_to_player;
        int                     goal_seg;
        ai_local    *ailp = &Ai_local_info[OBJECT_NUMBER(objp)];
        fix                     threshold_distance;


// mprintf((0, "Obj %i, dist=%6.1f index=%i len=%i seg=%i pos = %6.1f %6.1f %6.1f.\n", OBJECT_NUMBER(objp), f2fl(vm_vec_dist_quick(&objp->pos, &ConsoleObject->pos)), aip->cur_path_index, aip->path_length, objp->segnum, f2fl(objp->pos.x), f2fl(objp->pos.y), f2

        if ((aip->hide_index == -1) || (aip->path_length == 0))
        {
                if (ailp->mode == AIM_RUN_FROM_OBJECT) {
                        create_n_segment_path(objp, 5, -1);
                        //--Int3_if((aip->path_length != 0));
                        ailp->mode = AIM_RUN_FROM_OBJECT;
                } else {
                        // -- mprintf((0, "Object %i creating path for no apparent reason.\n", OBJECT_NUMBER(objp)));
                        create_n_segment_path(objp, 5, -1);
                        //--Int3_if((aip->path_length != 0));
                }
        }

        if ((aip->hide_index + aip->path_length > POINT_SEG_NUMBER(Point_segs_free_ptr)) && (aip->path_length>0)) {
                Int3(); //      Contact Mike: Bad.  Path goes into what is believed to be free space.
                //      This is debugging code.  Figure out why garbage collection
                //      didn't compress this object's path information.
                ai_path_garbage_collect();
                //force_dump_ai_objects_all("Error in ai_follow_path");
                ai_reset_all_paths();
        }

        if (aip->path_length < 2) {
                if ((aip->behavior == AIB_SNIPE) || (ailp->mode == AIM_RUN_FROM_OBJECT)) {
                        if (ConsoleObject->segnum == objp->segnum) {
                                create_n_segment_path(objp, AVOID_SEG_LENGTH, -1);                      //      Can't avoid segment player is in, robot is already in it! (That's what the -1 is for)
                                //--Int3_if((aip->path_length != 0));
                        } else {
                                create_n_segment_path(objp, AVOID_SEG_LENGTH, ConsoleObject->segnum);
                                //--Int3_if((aip->path_length != 0));
                        }
                        if (aip->behavior == AIB_SNIPE) {
                                if (robptr->thief)
                                        ailp->mode = AIM_THIEF_ATTACK;  //      It gets bashed in create_n_segment_path
                                else
                                        ailp->mode = AIM_SNIPE_FIRE;    //      It gets bashed in create_n_segment_path
                        } else {
                                ailp->mode = AIM_RUN_FROM_OBJECT;       //      It gets bashed in create_n_segment_path
                        }
                } else if (robptr->companion == 0) {
                        ailp->mode = AIM_STILL;
                        aip->path_length = 0;
                        return;
                }
        }

        //--Int3_if(((aip->PATH_DIR == -1) || (aip->PATH_DIR == 1)));
        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));

        goal_point = Point_segs[aip->hide_index + aip->cur_path_index].point;
        goal_seg = Point_segs[aip->hide_index + aip->cur_path_index].segnum;
        dist_to_goal = vm_vec_dist_quick(&goal_point, &objp->pos);

        if (Player_is_dead)
                dist_to_player = vm_vec_dist_quick(&objp->pos, &Viewer->pos);
        else
                dist_to_player = vm_vec_dist_quick(&objp->pos, &ConsoleObject->pos);

        //      Efficiency hack: If far away from player, move in big quantized jumps.
        if (!(player_visibility || previous_visibility) && (dist_to_player > F1_0*200) && !(Game_mode & GM_MULTI)) {
                if (dist_to_goal < F1_0*2) {
                        move_object_to_goal(objp, &goal_point, goal_seg);
                        return;
                } else {
                        robot_info      *robptr = &Robot_info[objp->id];
                        fix     cur_speed = robptr->max_speed[Difficulty_level]/2;
                        fix     distance_travellable = fixmul(FrameTime, cur_speed);

                        // int  connect_side = find_connect_side(objp->segnum, goal_seg);
                        //      Only move to goal if allowed to fly through the side.
                        //      Buddy-bot can create paths he can't fly, waiting for player.
                        // -- bah, this isn't good enough, buddy will fail to get through any door! if (WALL_IS_DOORWAY(&Segments[objp->segnum], connect_side) & WID_FLY_FLAG) {
                        if (!Robot_info[objp->id].companion && !Robot_info[objp->id].thief) {
                                if (distance_travellable >= dist_to_goal) {
                                        move_object_to_goal(objp, &goal_point, goal_seg);
                                } else {
                                        fix     prob = fixdiv(distance_travellable, dist_to_goal);
        
                                        int     rand_num = d_rand();
                                        if ( (rand_num >> 1) < prob) {
                                                move_object_to_goal(objp, &goal_point, goal_seg);
                                        }
                                }
                                return;
                        }
                }

        }

        //      If running from player, only run until can't be seen.
        if (ailp->mode == AIM_RUN_FROM_OBJECT) {
                if ((player_visibility == 0) && (ailp->player_awareness_type == 0)) {
                        fix     vel_scale;

                        vel_scale = F1_0 - FrameTime/2;
                        if (vel_scale < F1_0/2)
                                vel_scale = F1_0/2;

                        vm_vec_scale(&objp->mtype.phys_info.velocity, vel_scale);

                        return;
                } else if (!(FrameCount ^ ((OBJECT_NUMBER(objp)) & 0x07))) { // Done 1/8 frames.
                        //      If player on path (beyond point robot is now at), then create a new path.
                        point_seg       *curpsp = &Point_segs[aip->hide_index];
                        int                     player_segnum = ConsoleObject->segnum;
                        int                     i;

                        //      This is probably being done every frame, which is wasteful.
                        for (i=aip->cur_path_index; i<aip->path_length; i++) {
                                if (curpsp[i].segnum == player_segnum) {
                                        if (player_segnum != objp->segnum) {
                                                create_n_segment_path(objp, AVOID_SEG_LENGTH, player_segnum);
                                        } else {
                                                create_n_segment_path(objp, AVOID_SEG_LENGTH, -1);
                                        }
                                        Assert(aip->path_length != 0);
                                        ailp->mode = AIM_RUN_FROM_OBJECT;       //      It gets bashed in create_n_segment_path
                                        break;
                                }
                        }
                        if (player_visibility) {
                                ailp->player_awareness_type = 1;
                                ailp->player_awareness_time = F1_0;
                        }
                }
        }

        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));

        if (aip->cur_path_index < 0) {
                aip->cur_path_index = 0;
        } else if (aip->cur_path_index >= aip->path_length) {
                if (ailp->mode == AIM_RUN_FROM_OBJECT) {
                        create_n_segment_path(objp, AVOID_SEG_LENGTH, ConsoleObject->segnum);
                        ailp->mode = AIM_RUN_FROM_OBJECT;       //      It gets bashed in create_n_segment_path
                        Assert(aip->path_length != 0);
                } else {
                        aip->cur_path_index = aip->path_length-1;
                }
        }

        goal_point = Point_segs[aip->hide_index + aip->cur_path_index].point;

        //      If near goal, pick another goal point.
        forced_break = 0;               //      Gets set for short paths.
        original_dir = aip->PATH_DIR;
        original_index = aip->cur_path_index;
        threshold_distance = fixmul(vm_vec_mag_quick(&objp->mtype.phys_info.velocity), FrameTime)*2 + F1_0*2;

        new_goal_point = Point_segs[aip->hide_index + aip->cur_path_index].point;

        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));

        while ((dist_to_goal < threshold_distance) && !forced_break) {

                //      Advance to next point on path.
                aip->cur_path_index += aip->PATH_DIR;

                //      See if next point wraps past end of path (in either direction), and if so, deal with it based on mode.
                if ((aip->cur_path_index >= aip->path_length) || (aip->cur_path_index < 0)) {

                        //mprintf((0, "Object %i reached end of the line!\n", OBJECT_NUMBER(objp)));
                        //      If mode = hiding, then stay here until get bonked or hit by player.
                        // --   if (ailp->mode == AIM_BEHIND) {
                        // --           ailp->mode = AIM_STILL;
                        // --           return;         // Stay here until bonked or hit by player.
                        // --   } else

                        //      Buddy bot.  If he's in mode to get away from player and at end of line,
                        //      if player visible, then make a new path, else just return.
                        if (robptr->companion) {
                                if (Escort_special_goal == ESCORT_GOAL_SCRAM)
                                {
                                        if (player_visibility) {
                                                create_n_segment_path(objp, 16 + d_rand() * 16, -1);
                                                aip->path_length = polish_path(objp, &Point_segs[aip->hide_index], aip->path_length);
                                                Assert(aip->path_length != 0);
                                                // -- mprintf((0, "Buddy: Creating new path!\n"));
                                                ailp->mode = AIM_WANDER;        //      Special buddy mode.
                                                //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
                                                return;
                                        } else {
                                                ailp->mode = AIM_WANDER;        //      Special buddy mode.
                                                vm_vec_zero(&objp->mtype.phys_info.velocity);
                                                vm_vec_zero(&objp->mtype.phys_info.rotvel);
                                                // -- mprintf((0, "Buddy: I'm hidden!\n"));
                                                //!!Assert((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length));
                                                return;
                                        }
                                }
                        }

                        if (aip->behavior == AIB_FOLLOW) {
                                // mprintf((0, "AIB_FOLLOW: Making new path.\n"));
                                create_n_segment_path(objp, 10, ConsoleObject->segnum);
                                //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
                        } else if (aip->behavior == AIB_STATION) {
                                // mprintf((0, "Object %i reached end of line, creating path back to station.\n", OBJECT_NUMBER(objp)));
                                create_path_to_station(objp, 15);
                                if ((aip->hide_segment != Point_segs[aip->hide_index+aip->path_length-1].segnum) || (aip->path_length == 0)) {
                                        ailp->mode = AIM_STILL;
                                } else {
                                        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
                                }
                                return;
                        } else if (ailp->mode == AIM_FOLLOW_PATH) {
                                create_path_to_player(objp, 10, 1);
                                if (aip->hide_segment != Point_segs[aip->hide_index+aip->path_length-1].segnum) {
                                        ailp->mode = AIM_STILL;
                                        return;
                                } else {
                                        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
                                }
                        } else if (ailp->mode == AIM_RUN_FROM_OBJECT) {
                                create_n_segment_path(objp, AVOID_SEG_LENGTH, ConsoleObject->segnum);
                                ailp->mode = AIM_RUN_FROM_OBJECT;       //      It gets bashed in create_n_segment_path
                                if (aip->path_length < 1) {
                                        create_n_segment_path(objp, AVOID_SEG_LENGTH, ConsoleObject->segnum);
                                        ailp->mode = AIM_RUN_FROM_OBJECT;       //      It gets bashed in create_n_segment_path
                                        if (aip->path_length < 1) {
                                                aip->behavior = AIB_NORMAL;
                                                ailp->mode = AIM_STILL;
                                                return;
                                        }
                                }
                                //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
                        } else {
                                //      Reached end of the line.  First see if opposite end point is reachable, and if so, go there.
                                //      If not, turn around.
                                int                     opposite_end_index;
                                vms_vector      *opposite_end_point;
                                fvi_info                hit_data;
                                int                     fate;
                                fvi_query       fq;

                                // See which end we're nearer and look at the opposite end point.
                                if (abs(aip->cur_path_index - aip->path_length) < aip->cur_path_index) {
                                        //      Nearer to far end (ie, index not 0), so try to reach 0.
                                        opposite_end_index = 0;
                                } else {
                                        //      Nearer to 0 end, so try to reach far end.
                                        opposite_end_index = aip->path_length-1;
                                }

                                //--Int3_if(((opposite_end_index >= 0) && (opposite_end_index < aip->path_length)));

                                opposite_end_point = &Point_segs[aip->hide_index + opposite_end_index].point;

                                fq.p0                                           = &objp->pos;
                                fq.startseg                             = objp->segnum;
                                fq.p1                                           = opposite_end_point;
                                fq.rad                                  = objp->size;
                                fq.thisobjnum       = OBJECT_NUMBER(objp);
                                fq.ignore_obj_list      = NULL;
                                fq.flags                                        = 0;                            //what about trans walls???

                                fate = find_vector_intersection(&fq,&hit_data);

                                if (fate != HIT_WALL) {
                                        //      We can be circular!  Do it!
                                        //      Path direction is unchanged.
                                        aip->cur_path_index = opposite_end_index;
                                } else {
                                        aip->PATH_DIR = -aip->PATH_DIR;
                                        aip->cur_path_index += aip->PATH_DIR;
                                }
                                //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
                        }
                        break;
                } else {
                        new_goal_point = Point_segs[aip->hide_index + aip->cur_path_index].point;
                        goal_point = new_goal_point;
                        dist_to_goal = vm_vec_dist_quick(&goal_point, &objp->pos);
                        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
                }

                //      If went all the way around to original point, in same direction, then get out of here!
                if ((aip->cur_path_index == original_index) && (aip->PATH_DIR == original_dir)) {
                        create_path_to_player(objp, 3, 1);
                        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
                        forced_break = 1;
                }
                //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
        }       //      end while

        //      Set velocity (objp->mtype.phys_info.velocity) and orientation (objp->orient) for this object.
        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));
        ai_path_set_orient_and_vel(objp, &goal_point, player_visibility, vec_to_player);
        //--Int3_if(((aip->cur_path_index >= 0) && (aip->cur_path_index < aip->path_length)));

}

typedef struct {
        short   path_start, objnum;
} obj_path;

int path_index_compare(obj_path *i1, obj_path *i2)
{
        if (i1->path_start < i2->path_start)
                return -1;
        else if (i1->path_start == i2->path_start)
                return 0;
        else
                return 1;
}

//      ----------------------------------------------------------------------------------------------------------
//      Set orientation matrix and velocity for objp based on its desire to get to a point.
void ai_path_set_orient_and_vel(object *objp, vms_vector *goal_point, int player_visibility, vms_vector *vec_to_player)
{
        vms_vector      cur_vel = objp->mtype.phys_info.velocity;
        vms_vector      norm_cur_vel;
        vms_vector      norm_vec_to_goal;
        vms_vector      cur_pos = objp->pos;
        vms_vector      norm_fvec;
        fix                     speed_scale;
        fix                     dot;
        robot_info      *robptr = &Robot_info[objp->id];
        fix                     max_speed;

        //      If evading player, use highest difficulty level speed, plus something based on diff level
        max_speed = robptr->max_speed[Difficulty_level];
        if ((Ai_local_info[OBJECT_NUMBER(objp)].mode == AIM_RUN_FROM_OBJECT) || (objp->ctype.ai_info.behavior == AIB_SNIPE))
                max_speed = max_speed*3/2;

        vm_vec_sub(&norm_vec_to_goal, goal_point, &cur_pos);
        vm_vec_normalize_quick(&norm_vec_to_goal);

        norm_cur_vel = cur_vel;
        vm_vec_normalize_quick(&norm_cur_vel);

        norm_fvec = objp->orient.fvec;
        vm_vec_normalize_quick(&norm_fvec);

        dot = vm_vec_dot(&norm_vec_to_goal, &norm_fvec);

        //      If very close to facing opposite desired vector, perturb vector
        if (dot < -15*F1_0/16) {
                //mprintf((0, "Facing away from goal, abruptly turning\n"));
                norm_cur_vel = norm_vec_to_goal;
        } else {
                norm_cur_vel.x += norm_vec_to_goal.x/2;
                norm_cur_vel.y += norm_vec_to_goal.y/2;
                norm_cur_vel.z += norm_vec_to_goal.z/2;
        }

        vm_vec_normalize_quick(&norm_cur_vel);

        //      Set speed based on this robot type's maximum allowed speed and how hard it is turning.
        //      How hard it is turning is based on the dot product of (vector to goal) and (current velocity vector)
        //      Note that since 3*F1_0/4 is added to dot product, it is possible for the robot to back up.

        //      Set speed and orientation.
        if (dot < 0)
                dot /= -4;

        //      If in snipe mode, can move fast even if not facing that direction.
        if (objp->ctype.ai_info.behavior == AIB_SNIPE)
                if (dot < F1_0/2)
                        dot = (dot + F1_0)/2;

        speed_scale = fixmul(max_speed, dot);
        vm_vec_scale(&norm_cur_vel, speed_scale);
        objp->mtype.phys_info.velocity = norm_cur_vel;

        if ((Ai_local_info[OBJECT_NUMBER(objp)].mode == AIM_RUN_FROM_OBJECT) || (robptr->companion == 1) || (objp->ctype.ai_info.behavior == AIB_SNIPE)) {
                if (Ai_local_info[OBJECT_NUMBER(objp)].mode == AIM_SNIPE_RETREAT_BACKWARDS) {
                        if ((player_visibility) && (vec_to_player != NULL))
                                norm_vec_to_goal = *vec_to_player;
                        else
                                vm_vec_negate(&norm_vec_to_goal);
                }
                ai_turn_towards_vector(&norm_vec_to_goal, objp, robptr->turn_time[NDL-1]/2);
        } else
                ai_turn_towards_vector(&norm_vec_to_goal, objp, robptr->turn_time[Difficulty_level]);

}

int     Last_frame_garbage_collected = 0;

//      ----------------------------------------------------------------------------------------------------------
//      Garbage colledion -- Free all unused records in Point_segs and compress all paths.
void ai_path_garbage_collect(void)
{
        int     free_path_index = 0;
        int     num_path_objects = 0;
        int     objnum;
        int     objind;
        obj_path                object_list[MAX_OBJECTS];

#ifndef NDEBUG
        force_dump_ai_objects_all("***** Start ai_path_garbage_collect *****");
#endif

        // -- mprintf((0, "Garbage collection frame %i, last frame %i!  Old free index = %i ", FrameCount, Last_frame_garbage_collected, POINT_SEG_NUMBER(Point_segs_free_ptr)));

        Last_frame_garbage_collected = FrameCount;

#if PATH_VALIDATION
        validate_all_paths();
#endif
        //      Create a list of objects which have paths of length 1 or more.
        for (objnum=0; objnum <= Highest_object_index; objnum++) {
                object  *objp = &Objects[objnum];

                if ((objp->type == OBJ_ROBOT) && ((objp->control_type == CT_AI) || (objp->control_type == CT_MORPH))) {
                        ai_static       *aip = &objp->ctype.ai_info;

                        if (aip->path_length) {
                                object_list[num_path_objects].path_start = aip->hide_index;
                                object_list[num_path_objects++].objnum = objnum;
                        }
                }
        }

        qsort(object_list, num_path_objects, sizeof(object_list[0]),
                        (int (*)(void const *,void const *))path_index_compare);

        for (objind=0; objind < num_path_objects; objind++) {
                object          *objp;
                ai_static       *aip;
                int                     i;
                int                     old_index;

                objnum = object_list[objind].objnum;
                objp = &Objects[objnum];
                aip = &objp->ctype.ai_info;
                old_index = aip->hide_index;

                aip->hide_index = free_path_index;
                for (i=0; i<aip->path_length; i++)
                        Point_segs[free_path_index++] = Point_segs[old_index++];
        }

        Point_segs_free_ptr = &Point_segs[free_path_index];

        // mprintf((0, "new = %i\n", free_path_index));
//printf("After garbage collection, free index = %i\n", POINT_SEG_NUMBER(Point_segs_free_ptr));
#ifndef NDEBUG
        {
        int i;

        force_dump_ai_objects_all("***** Finish ai_path_garbage_collect *****");

        for (i=0; i<=Highest_object_index; i++) {
                ai_static       *aip = &Objects[i].ctype.ai_info;

                if ((Objects[i].type == OBJ_ROBOT) && (Objects[i].control_type == CT_AI))
                        if ((aip->hide_index + aip->path_length > POINT_SEG_NUMBER(Point_segs_free_ptr)) && (aip->path_length>0))
                                Int3();         //      Contact Mike: Debug trap for nasty, elusive bug.
        }

        validate_all_paths();
        }
#endif

}

//      -----------------------------------------------------------------------------
//      Do garbage collection if not been done for awhile, or things getting really critical.
void maybe_ai_path_garbage_collect(void)
{
        if (POINT_SEG_NUMBER(Point_segs_free_ptr) > MAX_POINT_SEGS - MAX_PATH_LENGTH) {
                if (Last_frame_garbage_collected+1 >= FrameCount) {
                        //      This is kind of bad.  Garbage collected last frame or this frame.
                        //      Just destroy all paths.  Too bad for the robots.  They are memory wasteful.
                        ai_reset_all_paths();
                        mprintf((1, "Warning: Resetting all paths.  Point_segs buffer nearly exhausted.\n"));
                } else {
                        //      We are really close to full, but didn't just garbage collect, so maybe this is recoverable.
                        mprintf((1, "Warning: Almost full garbage collection being performed: "));
                        ai_path_garbage_collect();
                        mprintf((1, "Free records = %i/%i\n", MAX_POINT_SEGS - (POINT_SEG_NUMBER(Point_segs_free_ptr)), MAX_POINT_SEGS));
                }
        } else if (POINT_SEG_NUMBER(Point_segs_free_ptr) > 3*MAX_POINT_SEGS/4) {
                if (Last_frame_garbage_collected + 16 < FrameCount) {
                        ai_path_garbage_collect();
                }
        } else if (POINT_SEG_NUMBER(Point_segs_free_ptr) > MAX_POINT_SEGS/2) {
                if (Last_frame_garbage_collected + 256 < FrameCount) {
                        ai_path_garbage_collect();
                }
        }
}

//      -----------------------------------------------------------------------------
//      Reset all paths.  Do garbage collection.
//      Should be called at the start of each level.
void ai_reset_all_paths(void)
{
        int     i;

        for (i=0; i<=Highest_object_index; i++)
                if (Objects[i].control_type == CT_AI) {
                        Objects[i].ctype.ai_info.hide_index = -1;
                        Objects[i].ctype.ai_info.path_length = 0;
                }

        ai_path_garbage_collect();

}

//      ---------------------------------------------------------------------------------------------------------
//      Probably called because a robot bashed a wall, getting a bunch of retries.
//      Try to resume path.
void attempt_to_resume_path(object *objp)
{
        //int             objnum = OBJECT_NUMBER(objp);
        ai_static               *aip = &objp->ctype.ai_info;
//      int                             goal_segnum, object_segnum,
        int                             abs_index, new_path_index;

        // mprintf((0, "Object %i trying to resume path at index %i\n", OBJECT_NUMBER(objp), aip->cur_path_index));

        if ((aip->behavior == AIB_STATION) && (Robot_info[objp->id].companion != 1))
                if (d_rand() > 8192) {
                        ai_local *ailp = &Ai_local_info[OBJECT_NUMBER(objp)];

                        aip->hide_segment = objp->segnum;
//Int3();
                        ailp->mode = AIM_STILL;
                        mprintf((1, "Note: Bashing hide segment of robot %i to current segment because he's lost.\n", OBJECT_NUMBER(objp)));
                }

//      object_segnum = objp->segnum;
        abs_index = aip->hide_index+aip->cur_path_index;
//      goal_segnum = Point_segs[abs_index].segnum;

//      if (object_segnum == goal_segnum)
//              mprintf((0, "Very peculiar, goal segnum = object's segnum = %i.\n", goal_segnum));

        new_path_index = aip->cur_path_index - aip->PATH_DIR;

        if ((new_path_index >= 0) && (new_path_index < aip->path_length)) {
                // mprintf((0, "Trying path index of %i\n", new_path_index));
                aip->cur_path_index = new_path_index;
        } else {
                //      At end of line and have nowhere to go.
                // mprintf((0, "At end of line and can't get to goal.  Creating new path.  Frame %i\n", FrameCount));
                move_towards_segment_center(objp);
                create_path_to_station(objp, 15);
        }

}

//      ----------------------------------------------------------------------------------------------------------
//                                      DEBUG FUNCTIONS FOLLOW
//      ----------------------------------------------------------------------------------------------------------

#ifdef EDITOR
int     Test_size = 1000;

void test_create_path_many(void)
{
        point_seg       point_segs[200];
        short                   num_points;

        int                     i;

        for (i=0; i<Test_size; i++) {
                Cursegp = &Segments[(d_rand() * (Highest_segment_index + 1)) / D_RAND_MAX];
                Markedsegp = &Segments[(d_rand() * (Highest_segment_index + 1)) / D_RAND_MAX];
                create_path_points(&Objects[0], SEGMENT_NUMBER(Cursegp), SEGMENT_NUMBER(Markedsegp), point_segs, &num_points, -1, 0, 0, -1);
        }

}

void test_create_path(void)
{
        point_seg       point_segs[200];
        short                   num_points;

        create_path_points(&Objects[0], SEGMENT_NUMBER(Cursegp), SEGMENT_NUMBER(Markedsegp), point_segs, &num_points, -1, 0, 0, -1);

}

void show_path(int start_seg, int end_seg, point_seg *psp, short length)
{
        printf("[%3i:%3i (%3i):] ", start_seg, end_seg, length);

        while (length--)
                printf("%3i ", psp[length].segnum);

        printf("\n");
}

//      For all segments in mine, create paths to all segments in mine, print results.
void test_create_all_paths(void)
{
        int     start_seg, end_seg;
        short   resultant_length;

        Point_segs_free_ptr = Point_segs;

        for (start_seg=0; start_seg<=Highest_segment_index-1; start_seg++) {
                // -- mprintf((0, "."));
                if (Segments[start_seg].segnum != -1) {
                        for (end_seg=start_seg+1; end_seg<=Highest_segment_index; end_seg++) {
                                if (Segments[end_seg].segnum != -1) {
                                        create_path_points(&Objects[0], start_seg, end_seg, Point_segs_free_ptr, &resultant_length, -1, 0, 0, -1);
                                        show_path(start_seg, end_seg, Point_segs_free_ptr, resultant_length);
                                }
                        }
                }
        }
}

//--anchor--int Num_anchors;
//--anchor--int Anchor_distance = 3;
//--anchor--int End_distance = 1;
//--anchor--int Anchors[MAX_SEGMENTS];

//--anchor--int get_nearest_anchor_distance(int segnum)
//--anchor--{
//--anchor--    short   resultant_length, minimum_length;
//--anchor--    int     anchor_index;
//--anchor--
//--anchor--    minimum_length = 16383;
//--anchor--
//--anchor--    for (anchor_index=0; anchor_index<Num_anchors; anchor_index++) {
//--anchor--            create_path_points(&Objects[0], segnum, Anchors[anchor_index], Point_segs_free_ptr, &resultant_length, -1, 0, 0, -1);
//--anchor--            if (resultant_length != 0)
//--anchor--                    if (resultant_length < minimum_length)
//--anchor--                            minimum_length = resultant_length;
//--anchor--    }
//--anchor--
//--anchor--    return minimum_length;
//--anchor--
//--anchor--}
//--anchor--
//--anchor--void create_new_anchor(int segnum)
//--anchor--{
//--anchor--    Anchors[Num_anchors++] = segnum;
//--anchor--}
//--anchor--
//--anchor--//  A set of anchors is within N units of all segments in the graph.
//--anchor--//  Anchor_distance = how close anchors can be.
//--anchor--//  End_distance = how close you can be to the end.
//--anchor--void test_create_all_anchors(void)
//--anchor--{
//--anchor--    int     nearest_anchor_distance;
//--anchor--    int     segnum,i;
//--anchor--
//--anchor--    Num_anchors = 0;
//--anchor--
//--anchor--    for (segnum=0; segnum<=Highest_segment_index; segnum++) {
//--anchor--            if (Segments[segnum].segnum != -1) {
//--anchor--                    nearest_anchor_distance = get_nearest_anchor_distance(segnum);
//--anchor--                    if (nearest_anchor_distance > Anchor_distance)
//--anchor--                            create_new_anchor(segnum);
//--anchor--            }
//--anchor--    }
//--anchor--
//--anchor--    //      Set selected segs.
//--anchor--    for (i=0; i<Num_anchors; i++)
//--anchor--            Selected_segs[i] = Anchors[i];
//--anchor--    N_selected_segs = Num_anchors;
//--anchor--
//--anchor--}
//--anchor--
//--anchor--int Test_path_length = 5;
//--anchor--
//--anchor--void test_create_n_segment_path(void)
//--anchor--{
//--anchor--    point_seg       point_segs[200];
//--anchor--    short                   num_points;
//--anchor--
//--anchor--    create_path_points(&Objects[0], SEGMENT_NUMBER(Cursegp), -2, point_segs, &num_points, Test_path_length, 0, 0, -1);
//--anchor--}

short   Player_path_length=0;
int     Player_hide_index=-1;
int     Player_cur_path_index=0;
int     Player_following_path_flag=0;

//      ------------------------------------------------------------------------------------------------------------------
//      Set orientation matrix and velocity for objp based on its desire to get to a point.
void player_path_set_orient_and_vel(object *objp, vms_vector *goal_point)
{
        vms_vector      cur_vel = objp->mtype.phys_info.velocity;
        vms_vector      norm_cur_vel;
        vms_vector      norm_vec_to_goal;
        vms_vector      cur_pos = objp->pos;
        vms_vector      norm_fvec;
        fix                     speed_scale;
        fix                     dot;
        fix                     max_speed;

        max_speed = Robot_info[objp->id].max_speed[Difficulty_level];

        vm_vec_sub(&norm_vec_to_goal, goal_point, &cur_pos);
        vm_vec_normalize_quick(&norm_vec_to_goal);

        norm_cur_vel = cur_vel;
        vm_vec_normalize_quick(&norm_cur_vel);

        norm_fvec = objp->orient.fvec;
        vm_vec_normalize_quick(&norm_fvec);

        dot = vm_vec_dot(&norm_vec_to_goal, &norm_fvec);
        if (Ai_local_info[OBJECT_NUMBER(objp)].mode == AIM_SNIPE_RETREAT_BACKWARDS) {
                dot = -dot;
        }

        //      If very close to facing opposite desired vector, perturb vector
        if (dot < -15*F1_0/16) {
                //mprintf((0, "Facing away from goal, abruptly turning\n"));
                norm_cur_vel = norm_vec_to_goal;
        } else {
                norm_cur_vel.x += norm_vec_to_goal.x/2;
                norm_cur_vel.y += norm_vec_to_goal.y/2;
                norm_cur_vel.z += norm_vec_to_goal.z/2;
        }

        vm_vec_normalize_quick(&norm_cur_vel);

        //      Set speed based on this robot type's maximum allowed speed and how hard it is turning.
        //      How hard it is turning is based on the dot product of (vector to goal) and (current velocity vector)
        //      Note that since 3*F1_0/4 is added to dot product, it is possible for the robot to back up.

        //      Set speed and orientation.
        if (dot < 0)
                dot /= 4;

        speed_scale = fixmul(max_speed, dot);
        vm_vec_scale(&norm_cur_vel, speed_scale);
        objp->mtype.phys_info.velocity = norm_cur_vel;
        ai_turn_towards_vector(&norm_vec_to_goal, objp, F1_0);

}

//      ----------------------------------------------------------------------------------------------------------
//      Optimization: If current velocity will take robot near goal, don't change velocity
void player_follow_path(object *objp)
{
        vms_vector      goal_point;
        fix                     dist_to_goal;
        int                     count, forced_break, original_index;
        int                     goal_seg;
        fix                     threshold_distance;

        if (!Player_following_path_flag)
                return;

        if (Player_hide_index == -1)
                return;

        if (Player_path_length < 2)
                return;

        goal_point = Point_segs[Player_hide_index + Player_cur_path_index].point;
        goal_seg = Point_segs[Player_hide_index + Player_cur_path_index].segnum;
        Assert((goal_seg >= 0) && (goal_seg <= Highest_segment_index));
        dist_to_goal = vm_vec_dist_quick(&goal_point, &objp->pos);

        if (Player_cur_path_index < 0)
                Player_cur_path_index = 0;
        else if (Player_cur_path_index >= Player_path_length)
                Player_cur_path_index = Player_path_length-1;

        goal_point = Point_segs[Player_hide_index + Player_cur_path_index].point;

        count=0;

        //      If near goal, pick another goal point.
        forced_break = 0;               //      Gets set for short paths.
        //original_dir = 1;
        original_index = Player_cur_path_index;
        threshold_distance = fixmul(vm_vec_mag_quick(&objp->mtype.phys_info.velocity), FrameTime)*2 + F1_0*2;

        while ((dist_to_goal < threshold_distance) && !forced_break) {

// --           if (count > 1)
// --                   mprintf((0, "."));

                //      ----- Debug stuff -----
                if (count++ > 20) {
                        mprintf((1,"Problem following path for player.  Aborting.\n"));
                        break;
                }

                //      Advance to next point on path.
                Player_cur_path_index += 1;

                //      See if next point wraps past end of path (in either direction), and if so, deal with it based on mode.
                if ((Player_cur_path_index >= Player_path_length) || (Player_cur_path_index < 0)) {
                        Player_following_path_flag = 0;
                        forced_break = 1;
                }

                //      If went all the way around to original point, in same direction, then get out of here!
                if (Player_cur_path_index == original_index) {
                        mprintf((0, "Forcing break because player path wrapped, count = %i.\n", count));
                        Player_following_path_flag = 0;
                        forced_break = 1;
                }

                goal_point = Point_segs[Player_hide_index + Player_cur_path_index].point;
                dist_to_goal = vm_vec_dist_quick(&goal_point, &objp->pos);

        }       //      end while

        //      Set velocity (objp->mtype.phys_info.velocity) and orientation (objp->orient) for this object.
        player_path_set_orient_and_vel(objp, &goal_point);

}


//      ------------------------------------------------------------------------------------------------------------------
//      Create path for player from current segment to goal segment.
void create_player_path_to_segment(int segnum)
{
        object          *objp = ConsoleObject;

        Player_path_length=0;
        Player_hide_index=-1;
        Player_cur_path_index=0;
        Player_following_path_flag=0;

        if (create_path_points(objp, objp->segnum, segnum, Point_segs_free_ptr, &Player_path_length, 100, 0, 0, -1) == -1)
                mprintf((0, "Unable to form path of length %i for myself\n", 100));

        Player_following_path_flag = 1;

        Player_hide_index = POINT_SEG_NUMBER(Point_segs_free_ptr);
        Player_cur_path_index = 0;
        Point_segs_free_ptr += Player_path_length;
        if (POINT_SEG_NUMBER(Point_segs_free_ptr) + MAX_PATH_LENGTH*2 > MAX_POINT_SEGS) {
                //Int3();       //      Contact Mike: This is curious, though not deadly. /eip++;g
                ai_reset_all_paths();
        }

}

int     Player_goal_segment = -1;

void check_create_player_path(void)
{
        if (Player_goal_segment != -1)
                create_player_path_to_segment(Player_goal_segment);

        Player_goal_segment = -1;
}

#endif

//      ----------------------------------------------------------------------------------------------------------
//                                      DEBUG FUNCTIONS ENDED
//      ----------------------------------------------------------------------------------------------------------