示例#1
0
//	-----------------------------------------------------------------------------------------------------------
//Simulate a physics object for this frame
void do_physics_sim(object *obj)
{
	int ignore_obj_list[MAX_IGNORE_OBJS],n_ignore_objs;
	int iseg;
	int try_again;
	int fate=0;
	vms_vector frame_vec;			//movement in this frame
	vms_vector new_pos,ipos;		//position after this frame
	int count=0;
	int objnum;
	int WallHitSeg, WallHitSide;
	fvi_info hit_info;
	fvi_query fq;
	vms_vector save_pos;
	int save_seg;
	fix drag;
	fix sim_time;
	vms_vector start_pos;
	int obj_stopped=0;
	fix moved_time; 			//how long objected moved before hit something
	physics_info *pi;
	int orig_segnum = obj->segnum;
	fix PhysTime = (FrameTime<F1_0/30?F1_0/30:FrameTime);

	Assert(obj->movement_type == MT_PHYSICS);

#ifndef NDEBUG
	if (Dont_move_ai_objects)
		if (obj->control_type == CT_AI)
			return;
#endif

	pi = &obj->mtype.phys_info;

	do_physics_sim_rot(obj);

	if (!(pi->velocity.x || pi->velocity.y || pi->velocity.z || pi->thrust.x || pi->thrust.y || pi->thrust.z))
		return;

	objnum = obj-Objects;

	n_phys_segs = 0;

	/* As this engine was not designed for that high FPS as we intend, we use F1_0/30 max. for sim_time to ensure
	   scaling and dot products stay accurate and reliable. The object position intended for this frame will be scaled down later,
	   after the main collision-loop is done.
	   This won't make collision results be equal in all FPS settings, but hopefully more accurate, the higher our FPS are.
	*/
	sim_time = PhysTime; //FrameTime;

	//debug_obj = obj;

#ifdef EXTRA_DEBUG
	//check for correct object segment 
        if(!get_seg_masks(&obj->pos,obj->segnum,0,__FILE__,__LINE__).centermask==0) {
		//Int3();  Removed by Rob 10/5/94
		if (!update_object_seg(obj)) {
			if (!(Game_mode & GM_MULTI))
				Int3();
			compute_segment_center(&obj->pos,&Segments[obj->segnum]);
			obj->pos.x += objnum;
		}
	}
#endif

	start_pos = obj->pos;

	n_ignore_objs = 0;

	Assert(obj->mtype.phys_info.brakes==0);		//brakes not used anymore?

		//if uses thrust, cannot have zero drag
        Assert(!(obj->mtype.phys_info.flags&PF_USES_THRUST) || obj->mtype.phys_info.drag!=0);

	//do thrust & drag
	// NOTE: this always must be dependent on FrameTime, if sim_time differs!
	if ((drag = obj->mtype.phys_info.drag) != 0) {

		int count;
		vms_vector accel;
		fix r,k,have_accel;

		count = FrameTime / FT;
		r = FrameTime % FT;
		k = fixdiv(r,FT);

		if (obj->mtype.phys_info.flags & PF_USES_THRUST) {

			vm_vec_copy_scale(&accel,&obj->mtype.phys_info.thrust,fixdiv(f1_0,obj->mtype.phys_info.mass));
			have_accel = (accel.x || accel.y || accel.z);

			while (count--) {
				if (have_accel)
					vm_vec_add2(&obj->mtype.phys_info.velocity,&accel);

				vm_vec_scale(&obj->mtype.phys_info.velocity,f1_0-drag);
			}

			//do linear scale on remaining bit of time

			vm_vec_scale_add2(&obj->mtype.phys_info.velocity,&accel,k);
			if (drag)
				vm_vec_scale(&obj->mtype.phys_info.velocity,f1_0-fixmul(k,drag));
		}
		else if (drag)
		{
			fix total_drag=f1_0;

			while (count--)
				total_drag = fixmul(total_drag,f1_0-drag);

			//do linear scale on remaining bit of time

			total_drag = fixmul(total_drag,f1_0-fixmul(k,drag));

			vm_vec_scale(&obj->mtype.phys_info.velocity,total_drag);
		}
	}

	do {
		try_again = 0;

		//Move the object
		vm_vec_copy_scale(&frame_vec, &obj->mtype.phys_info.velocity, sim_time);

		if ( (frame_vec.x==0) && (frame_vec.y==0) && (frame_vec.z==0) )	
			break;

		count++;

		//	If retry count is getting large, then we are trying to do something stupid.
		if (count > 8) break; // in original code this was 3 for all non-player objects. still leave us some limit in case fvi goes apeshit.

		vm_vec_add(&new_pos,&obj->pos,&frame_vec);

		ignore_obj_list[n_ignore_objs] = -1;

		fq.p0						= &obj->pos;
		fq.startseg				= obj->segnum;
		fq.p1						= &new_pos;
		fq.rad					= obj->size;
		fq.thisobjnum			= objnum;
		fq.ignore_obj_list	= ignore_obj_list;
		fq.flags					= FQ_CHECK_OBJS;

		if (obj->type == OBJ_WEAPON)
			fq.flags |= FQ_TRANSPOINT;

		if (obj->type == OBJ_PLAYER)
			fq.flags |= FQ_GET_SEGLIST;

		fate = find_vector_intersection(&fq,&hit_info);
		//	Matt: Mike's hack.
		if (fate == HIT_OBJECT) {
			object	*objp = &Objects[hit_info.hit_object];

			if (((objp->type == OBJ_WEAPON) && (objp->id == PROXIMITY_ID)) || objp->type == OBJ_POWERUP) // do not increase count for powerups since they *should* not change our movement
				count--;
		}

#ifndef NDEBUG
		if (fate == HIT_BAD_P0) {
			Int3();
		}
#endif

		if (obj->type == OBJ_PLAYER) {
			int i;

			if (n_phys_segs && phys_seglist[n_phys_segs-1]==hit_info.seglist[0])
				n_phys_segs--;

			for (i=0;(i<hit_info.n_segs) && (n_phys_segs<MAX_FVI_SEGS-1);  )
				phys_seglist[n_phys_segs++] = hit_info.seglist[i++];
		}

		ipos = hit_info.hit_pnt;
		iseg = hit_info.hit_seg;
		WallHitSide = hit_info.hit_side;
		WallHitSeg = hit_info.hit_side_seg;

		if (iseg==-1) {		//some sort of horrible error
			if (obj->type == OBJ_WEAPON)
				obj->flags |= OF_SHOULD_BE_DEAD;
			break;
		}

		Assert(!((fate==HIT_WALL) && ((WallHitSeg == -1) || (WallHitSeg > Highest_segment_index))));

		//if(!get_seg_masks(&hit_info.hit_pnt,hit_info.hit_seg,0).centermask==0)
		//	Int3();

		save_pos = obj->pos;			//save the object's position
		save_seg = obj->segnum;

		// update object's position and segment number
		obj->pos = ipos;

		if ( iseg != obj->segnum )
			obj_relink(objnum, iseg );

		//if start point not in segment, move object to center of segment
                if (get_seg_masks(&obj->pos,obj->segnum,0,__FILE__,__LINE__).centermask!=0) {
			int n;

			if ((n=find_object_seg(obj))==-1) {
				//Int3();
				if (obj->type==OBJ_PLAYER && (n=find_point_seg(&obj->last_pos,obj->segnum))!=-1) {
					obj->pos = obj->last_pos;
					obj_relink(objnum, n );
				}
				else {
					compute_segment_center(&obj->pos,&Segments[obj->segnum]);
					obj->pos.x += objnum;
				}
				if (obj->type == OBJ_WEAPON)
					obj->flags |= OF_SHOULD_BE_DEAD;
			}
			return;
		}

		//calulate new sim time
		{
			//vms_vector moved_vec;
			vms_vector moved_vec_n;
			fix attempted_dist,actual_dist;

			actual_dist = vm_vec_normalized_dir(&moved_vec_n,&obj->pos,&save_pos);

			if (fate==HIT_WALL && vm_vec_dot(&moved_vec_n,&frame_vec) < 0) {		//moved backwards

				//don't change position or sim_time

				obj->pos = save_pos;
		
				//iseg = obj->segnum;		//don't change segment

				obj_relink(objnum, save_seg );

				moved_time = 0;
			}
			else {
				fix old_sim_time;

				attempted_dist = vm_vec_mag(&frame_vec);

				old_sim_time = sim_time;

				sim_time = fixmuldiv(sim_time,attempted_dist-actual_dist,attempted_dist);

				moved_time = old_sim_time - sim_time;

				if (sim_time < 0 || sim_time>old_sim_time) {
					sim_time = old_sim_time;
					//WHY DOES THIS HAPPEN??

					moved_time = 0;
				}
			}
		}


		switch( fate )		{

			case HIT_WALL:		{
				vms_vector moved_v;
				fix hit_speed=0, wall_part=0;

				// Find hit speed	

				vm_vec_sub(&moved_v,&obj->pos,&save_pos);

				wall_part = vm_vec_dot(&moved_v,&hit_info.hit_wallnorm);

				if ((wall_part != 0 && moved_time>0 && (hit_speed=-fixdiv(wall_part,moved_time))>0) || obj->type == OBJ_WEAPON || obj->type == OBJ_DEBRIS)
					collide_object_with_wall( obj, hit_speed, WallHitSeg, WallHitSide, &hit_info.hit_pnt );
				if (obj->type == OBJ_PLAYER)
					scrape_player_on_wall(obj, WallHitSeg, WallHitSide, &hit_info.hit_pnt );

				Assert( WallHitSeg > -1 );				
				Assert( WallHitSide > -1 );				

				if ( !(obj->flags&OF_SHOULD_BE_DEAD) )	{


					Assert(! (obj->mtype.phys_info.flags & PF_STICK && obj->mtype.phys_info.flags & PF_BOUNCE));	//can't be bounce and stick

					if (obj->mtype.phys_info.flags & PF_STICK) {		//stop moving

						add_stuck_object(obj, WallHitSeg, WallHitSide);

						vm_vec_zero(&obj->mtype.phys_info.velocity);
						obj_stopped = 1;
						try_again = 0;
					}
					else {					// Slide object along wall

						//We're constrained by wall, so subtract wall part from 
						//velocity vector

						wall_part = vm_vec_dot(&hit_info.hit_wallnorm,&obj->mtype.phys_info.velocity);

						// if wall_part, make sure the value is sane enough to get usable velocity computed
						if (wall_part < 0 && wall_part > -f1_0) wall_part = -f1_0;
						if (wall_part > 0 && wall_part < f1_0) wall_part = f1_0;

						if (obj->mtype.phys_info.flags & PF_BOUNCE)		//bounce off wall
							wall_part *= 2;	//Subtract out wall part twice to achieve bounce

						vm_vec_scale_add2(&obj->mtype.phys_info.velocity,&hit_info.hit_wallnorm,-wall_part);

						try_again = 1;
					}
				}

				break;
			}

			case HIT_OBJECT:		{
				vms_vector old_vel;

				// Mark the hit object so that on a retry the fvi code
				// ignores this object.

				Assert(hit_info.hit_object != -1);
				//	Calculcate the hit point between the two objects.
				{	vms_vector	*ppos0, *ppos1, pos_hit;
					fix			size0, size1;
					ppos0 = &Objects[hit_info.hit_object].pos;
					ppos1 = &obj->pos;
					size0 = Objects[hit_info.hit_object].size;
					size1 = obj->size;
					Assert(size0+size1 != 0);	// Error, both sizes are 0, so how did they collide, anyway?!?
					//vm_vec_scale(vm_vec_sub(&pos_hit, ppos1, ppos0), fixdiv(size0, size0 + size1));
					//vm_vec_add2(&pos_hit, ppos0);
					vm_vec_sub(&pos_hit, ppos1, ppos0);
					vm_vec_scale_add(&pos_hit,ppos0,&pos_hit,fixdiv(size0, size0 + size1));

					old_vel = obj->mtype.phys_info.velocity;

					collide_two_objects( obj, &Objects[hit_info.hit_object], &pos_hit);

				}

				// Let object continue its movement
				if ( !(obj->flags&OF_SHOULD_BE_DEAD)  )	{
					//obj->pos = save_pos;

					if (obj->mtype.phys_info.flags&PF_PERSISTENT || (old_vel.x == obj->mtype.phys_info.velocity.x && old_vel.y == obj->mtype.phys_info.velocity.y && old_vel.z == obj->mtype.phys_info.velocity.z)) {
						//if (Objects[hit_info.hit_object].type == OBJ_POWERUP)
							ignore_obj_list[n_ignore_objs++] = hit_info.hit_object;
						try_again = 1;
					}
				}

				break;
			}	
			case HIT_NONE:		
				break;

#ifndef NDEBUG
			case HIT_BAD_P0:
				Int3();		// Unexpected collision type: start point not in specified segment.
				break;
			default:
				// Unknown collision type returned from find_vector_intersection!!
				Int3();
				break;
#endif
		}
	} while ( try_again );

	//	Pass retry count info to AI.
	if (obj->control_type == CT_AI) {
		if (count > 0) {
			Ai_local_info[objnum].retry_count = count-1;
			Total_retries += count-1;
			Total_sims++;
		}
	}

	// As sim_time may not base on FrameTime, scale actual object position to get accurate movement
	if (PhysTime/FrameTime > 0)
	{
		vms_vector md;
		vm_vec_sub(&md, &obj->pos, &start_pos);
		vm_vec_scale(&md, F1_0/((float)PhysTime/FrameTime));
		vm_vec_add(&obj->pos,&start_pos, &md);
		//check for and update correct object segment
		if(!get_seg_masks(&obj->pos, obj->segnum, 0, __FILE__, __LINE__).centermask == 0)
		{
			if (!update_object_seg(obj)) {
				if (!(Game_mode & GM_MULTI))
					Int3();
				compute_segment_center(&obj->pos,&Segments[obj->segnum]);
				obj->pos.x += objnum;
			}
		}
	}

	// After collision with objects and walls, set velocity from actual movement
	if (!obj_stopped
		&& ((obj->type == OBJ_PLAYER) || (obj->type == OBJ_ROBOT) || (obj->type == OBJ_DEBRIS)) 
		&& ((fate == HIT_WALL) || (fate == HIT_OBJECT) || (fate == HIT_BAD_P0))
		)
	{	
		vms_vector moved_vec;
		vm_vec_sub(&moved_vec,&obj->pos,&start_pos);
		vm_vec_copy_scale(&obj->mtype.phys_info.velocity,&moved_vec,fixdiv(f1_0,FrameTime));
	}

	fix_illegal_wall_intersection(obj, &start_pos);

	//Assert(check_point_in_seg(&obj->pos,obj->segnum,0).centermask==0);

	//if (obj->control_type == CT_FLYING)
	if (obj->mtype.phys_info.flags & PF_LEVELLING)
		do_physics_align_object( obj );


	//hack to keep player from going through closed doors
	if (obj->type==OBJ_PLAYER && obj->segnum!=orig_segnum && (!cheats.ghostphysics) ) {
		int sidenum;

		sidenum = find_connect_side(&Segments[obj->segnum],&Segments[orig_segnum]);

		if (sidenum != -1) {

			if (! (WALL_IS_DOORWAY(&Segments[orig_segnum],sidenum) & WID_FLY_FLAG)) {
				side *s;
				int vertnum,num_faces,i;
				fix dist;
				int vertex_list[6];

				//bump object back

				s = &Segments[orig_segnum].sides[sidenum];

                                create_abs_vertex_lists( &num_faces, vertex_list, orig_segnum, sidenum, __FILE__,__LINE__);

				//let's pretend this wall is not triangulated
				vertnum = vertex_list[0];
				for (i=1;i<4;i++)
					if (vertex_list[i] < vertnum)
						vertnum = vertex_list[i];

#ifdef COMPACT_SEGS
					{
						vms_vector _vn;
						get_side_normal(&Segments[orig_segnum], sidenum, 0, &_vn );
						dist = vm_dist_to_plane(&start_pos, &_vn, &Vertices[vertnum]);
						vm_vec_scale_add(&obj->pos,&start_pos,&_vn,obj->size-dist);
					}
#else
					dist = vm_dist_to_plane(&start_pos, &s->normals[0], &Vertices[vertnum]);
					vm_vec_scale_add(&obj->pos,&start_pos,&s->normals[0],obj->size-dist);
#endif
				update_object_seg(obj);

			}
		}
	}

//--WE ALWYS WANT THIS IN, MATT AND MIKE DECISION ON 12/10/94, TWO MONTHS AFTER FINAL 	#ifndef NDEBUG
	//if end point not in segment, move object to last pos, or segment center
        if (get_seg_masks(&obj->pos,obj->segnum,0,__FILE__,__LINE__).centermask!=0) {
		if (find_object_seg(obj)==-1) {
			int n;

			//Int3();
			if (obj->type==OBJ_PLAYER && (n=find_point_seg(&obj->last_pos,obj->segnum))!=-1) {
				obj->pos = obj->last_pos;
				obj_relink(objnum, n );
			}
			else {
				compute_segment_center(&obj->pos,&Segments[obj->segnum]);
				obj->pos.x += objnum;
			}
			if (obj->type == OBJ_WEAPON)
				obj->flags |= OF_SHOULD_BE_DEAD;
		}
	}
//--WE ALWYS WANT THIS IN, MATT AND MIKE DECISION ON 12/10/94, TWO MONTHS AFTER FINAL 	#endif
}
示例#2
0
//	-----------------------------------------------------------------------------------------------------------
//Simulate a physics object for this frame
do_physics_sim(object *obj)
{
	int ignore_obj_list[MAX_IGNORE_OBJS],n_ignore_objs;
	int iseg;
	int try_again;
	int fate;
	vms_vector frame_vec;			//movement in this frame
	vms_vector new_pos,ipos;		//position after this frame
	int count=0;
	int objnum;
	int WallHitSeg, WallHitSide;
	fvi_info hit_info;
	fvi_query fq;
	vms_vector save_pos;
	int save_seg;
	fix drag;
	fix sim_time;
	vms_vector start_pos;
	int obj_stopped=0;
	fix moved_time;			//how long objected moved before hit something
	vms_vector save_p0,save_p1;
	physics_info *pi;
	int orig_segnum = obj->segnum;

	Assert(obj->type != OBJ_NONE);
	Assert(obj->movement_type == MT_PHYSICS);

#ifndef NDEBUG
if (Dont_move_ai_objects)
	if (obj->control_type == CT_AI)
		return;
#endif

	pi = &obj->mtype.phys_info;

	do_physics_sim_rot(obj);

	if (!(pi->velocity.x || pi->velocity.y || pi->velocity.z || pi->thrust.x || pi->thrust.y || pi->thrust.z))
		return;

	objnum = obj-Objects;

	n_phys_segs = 0;

	disable_new_fvi_stuff = (obj->type != OBJ_PLAYER);

	sim_time = FrameTime;

//debug_obj = obj;

	#ifdef EXTRA_DEBUG
	if (obj == debug_obj) {
		printf("object %d:\n  start pos = %x %x %x\n",objnum,XYZ(&obj->pos));
		printf("  thrust = %x %x %x\n",XYZ(&obj->mtype.phys_info.thrust));
		printf("  sim_time = %x\n",sim_time);
	}

	//check for correct object segment 
	if(!get_seg_masks(&obj->pos,obj->segnum,0).centermask==0) {
		#ifndef NDEBUG
		mprintf((0,"Warning: object %d not in given seg!\n",objnum));
		#endif
		//Int3();  Removed by Rob 10/5/94
		if (!update_object_seg(obj)) {
			#ifndef NDEBUG
			mprintf((0,"Warning: can't find seg for object %d - moving\n",objnum));
			#endif
			if (!(Game_mode & GM_MULTI))
				Int3();
			compute_segment_center(&obj->pos,&Segments[obj->segnum]);
			obj->pos.x += objnum;
		}
	}
	#endif

	start_pos = obj->pos;

	n_ignore_objs = 0;

	Assert(obj->mtype.phys_info.brakes==0);		//brakes not used anymore?

		//if uses thrust, cannot have zero drag
	Assert(!(obj->mtype.phys_info.flags&PF_USES_THRUST) || obj->mtype.phys_info.drag!=0);

//mprintf((0,"thrust=%x  speed=%x\n",vm_vec_mag(&obj->mtype.phys_info.thrust),vm_vec_mag(&obj->mtype.phys_info.velocity)));

	//do thrust & drag
	
	if ((drag = obj->mtype.phys_info.drag) != 0) {

		int count;
		vms_vector accel;
		fix r,k;

		count = sim_time / FT;
		r = sim_time % FT;
		k = fixdiv(r,FT);

		if (obj->mtype.phys_info.flags & PF_USES_THRUST) {

			vm_vec_copy_scale(&accel,&obj->mtype.phys_info.thrust,fixdiv(f1_0,obj->mtype.phys_info.mass));

			while (count--) {

				vm_vec_add2(&obj->mtype.phys_info.velocity,&accel);

				vm_vec_scale(&obj->mtype.phys_info.velocity,f1_0-drag);
			}

			//do linear scale on remaining bit of time

			vm_vec_scale_add2(&obj->mtype.phys_info.velocity,&accel,k);

			vm_vec_scale(&obj->mtype.phys_info.velocity,f1_0-fixmul(k,drag));
		}
		else {
			fix total_drag=f1_0;

			while (count--)
				total_drag = fixmul(total_drag,f1_0-drag);

			//do linear scale on remaining bit of time

			total_drag = fixmul(total_drag,f1_0-fixmul(k,drag));

			vm_vec_scale(&obj->mtype.phys_info.velocity,total_drag);
		}
	}

	#ifdef EXTRA_DEBUG
	if (obj == debug_obj)
		printf("  velocity = %x %x %x\n",XYZ(&obj->mtype.phys_info.velocity));
	#endif

	do {
		try_again = 0;

		//Move the object
		vm_vec_copy_scale(&frame_vec, &obj->mtype.phys_info.velocity, sim_time);

		#ifdef EXTRA_DEBUG
		if (obj == debug_obj)
			printf("  pass %d, frame_vec = %x %x %x\n",count,XYZ(&frame_vec));
		#endif

		if ( (frame_vec.x==0) && (frame_vec.y==0) && (frame_vec.z==0) )	
			break;

		count++;

		//	If retry count is getting large, then we are trying to do something stupid.
		if ( count > 3) 	{
			if (obj->type == OBJ_PLAYER) {
				if (count > 8)
					break;
			} else
				break;
		}

		vm_vec_add(&new_pos,&obj->pos,&frame_vec);

		#ifdef EXTRA_DEBUG
		if (obj == debug_obj)
			printf("   desired_pos  = %x %x %x\n",XYZ(&new_pos));
		#endif

		ignore_obj_list[n_ignore_objs] = -1;

		#ifdef EXTRA_DEBUG
		if (obj == debug_obj) {
			printf("   FVI parms: p0 = %8x %8x %8x, segnum=%x, size=%x\n",XYZ(&obj->pos),obj->segnum,obj->size);
			printf("              p1 = %8x %8x %8x\n",XYZ(&new_pos));
		}
		#endif

		fq.p0						= &obj->pos;
		fq.startseg				= obj->segnum;
		fq.p1						= &new_pos;
		fq.rad					= obj->size;
		fq.thisobjnum			= objnum;
		fq.ignore_obj_list	= ignore_obj_list;
		fq.flags					= FQ_CHECK_OBJS;

		if (obj->type == OBJ_WEAPON)
			fq.flags |= FQ_TRANSPOINT;

		if (obj->type == OBJ_PLAYER)
			fq.flags |= FQ_GET_SEGLIST;

//@@			if (get_seg_masks(&obj->pos,obj->segnum,0).centermask!=0)
//@@				Int3();

save_p0 = *fq.p0;
save_p1 = *fq.p1;


		fate = find_vector_intersection(&fq,&hit_info);
		//	Matt: Mike's hack.
		if (fate == HIT_OBJECT) {
			object	*objp = &Objects[hit_info.hit_object];

			if ((objp->type == OBJ_WEAPON) && (objp->id == PROXIMITY_ID))
				count--;
		}

		#ifndef NDEBUG
		if (fate == HIT_BAD_P0) {
			mprintf((0,"Warning: Bad p0 in physics!  Object = %i, type = %i [%s]\n", obj-Objects, obj->type, Object_type_names[obj->type]));
			Int3();
		}
		#endif

		if (obj->type == OBJ_PLAYER) {
			int i;

			if (n_phys_segs && phys_seglist[n_phys_segs-1]==hit_info.seglist[0])
				n_phys_segs--;

			for (i=0;(i<hit_info.n_segs) && (n_phys_segs<MAX_FVI_SEGS-1);  )
				phys_seglist[n_phys_segs++] = hit_info.seglist[i++];
		}

		#ifdef EXTRA_DEBUG
		if (obj == debug_obj)
			printf("   fate  = %d, hit_pnt = %8x %8x %8x\n",fate,XYZ(&hit_info.hit_pnt));;
		#endif

		ipos = hit_info.hit_pnt;
		iseg = hit_info.hit_seg;
		WallHitSide = hit_info.hit_side;
		WallHitSeg = hit_info.hit_side_seg;

		if (iseg==-1) {		//some sort of horrible error
			#ifndef NDEBUG
			mprintf((1,"iseg==-1 in physics!  Object = %i, type = %i (%s)\n", obj-Objects, obj->type, Object_type_names[obj->type]));
			#endif
			//Int3();
			//compute_segment_center(&ipos,&Segments[obj->segnum]);
			//ipos.x += objnum;
			//iseg = obj->segnum;
			//fate = HIT_NONE;
			if (obj->type == OBJ_WEAPON)
				obj->flags |= OF_SHOULD_BE_DEAD;
			break;
		}

		Assert(!((fate==HIT_WALL) && ((WallHitSeg == -1) || (WallHitSeg > Highest_segment_index))));

		//if(!get_seg_masks(&hit_info.hit_pnt,hit_info.hit_seg,0).centermask==0)
		//	Int3();

		save_pos = obj->pos;			//save the object's position
		save_seg = obj->segnum;

		// update object's position and segment number
		obj->pos = ipos;

		#ifdef EXTRA_DEBUG
		if (obj == debug_obj)
			printf("   new pos = %x %x %x\n",XYZ(&obj->pos));
		#endif

		if ( iseg != obj->segnum )
			obj_relink(objnum, iseg );

		//if start point not in segment, move object to center of segment
		if (get_seg_masks(&obj->pos,obj->segnum,0).centermask!=0) {
			int n;

			if ((n=find_object_seg(obj))==-1) {
				//Int3();
				if (obj->type==OBJ_PLAYER && (n=find_point_seg(&obj->last_pos,obj->segnum))!=-1) {
					obj->pos = obj->last_pos;
					obj_relink(objnum, n );
				}
				else {
					compute_segment_center(&obj->pos,&Segments[obj->segnum]);
					obj->pos.x += objnum;
				}
				if (obj->type == OBJ_WEAPON)
					obj->flags |= OF_SHOULD_BE_DEAD;
			}
			return;
		}

		//calulate new sim time
		{
			//vms_vector moved_vec;
			vms_vector moved_vec_n;
			fix attempted_dist,actual_dist;

			actual_dist = vm_vec_normalized_dir(&moved_vec_n,&obj->pos,&save_pos);

			if (fate==HIT_WALL && vm_vec_dot(&moved_vec_n,&frame_vec) < 0) {		//moved backwards

				//don't change position or sim_time

//*******					mprintf((0,"Obj %d moved backwards\n",obj-Objects));

				#ifdef EXTRA_DEBUG
				if (obj == debug_obj)
					printf("   Warning: moved backwards!\n");
				#endif

				obj->pos = save_pos;
		
				//iseg = obj->segnum;		//don't change segment

				obj_relink(objnum, save_seg );

				moved_time = 0;
			}
			else {
				fix old_sim_time;

				//if (obj == debug_obj)
				//	printf("   moved_vec = %x %x %x\n",XYZ(&moved_vec));
			
				attempted_dist = vm_vec_mag(&frame_vec);

				old_sim_time = sim_time;

				sim_time = fixmuldiv(sim_time,attempted_dist-actual_dist,attempted_dist);

				moved_time = old_sim_time - sim_time;

				if (sim_time < 0 || sim_time>old_sim_time) {
					#ifndef NDEBUG
					mprintf((0,"Bogus sim_time = %x, old = %x\n",sim_time,old_sim_time));
					if (obj == debug_obj)
						printf("   Bogus sim_time = %x, old = %x, attempted_dist = %x, actual_dist = %x\n",sim_time,old_sim_time,attempted_dist,actual_dist);
					//Int3(); Removed by Rob
					#endif
					sim_time = old_sim_time;
					//WHY DOES THIS HAPPEN??

					moved_time = 0;
				}
			}

			#ifdef EXTRA_DEBUG
			if (obj == debug_obj)
				printf("   new sim_time = %x\n",sim_time);
			#endif

		}


		switch( fate )		{

			case HIT_WALL:		{
				vms_vector moved_v;
				//@@fix total_d,moved_d;
				fix hit_speed,wall_part;
	
				// Find hit speed	

				vm_vec_sub(&moved_v,&obj->pos,&save_pos);

				wall_part = vm_vec_dot(&moved_v,&hit_info.hit_wallnorm);

				if (wall_part != 0 && moved_time>0 && (hit_speed=-fixdiv(wall_part,moved_time))>0)
					collide_object_with_wall( obj, hit_speed, WallHitSeg, WallHitSide, &hit_info.hit_pnt );
				else
					scrape_object_on_wall(obj, WallHitSeg, WallHitSide, &hit_info.hit_pnt );

				Assert( WallHitSeg > -1 );				
				Assert( WallHitSide > -1 );				

				if ( !(obj->flags&OF_SHOULD_BE_DEAD) )	{


					Assert(! (obj->mtype.phys_info.flags & PF_STICK && obj->mtype.phys_info.flags & PF_BOUNCE));	//can't be bounce and stick

					if (obj->mtype.phys_info.flags & PF_STICK) {		//stop moving

						// mprintf((0, "Object %i stuck at %i:%i\n", obj-Objects, WallHitSeg, WallHitSide));
						add_stuck_object(obj, WallHitSeg, WallHitSide);

						vm_vec_zero(&obj->mtype.phys_info.velocity);
						obj_stopped = 1;
						try_again = 0;
					}
					else {					// Slide object along wall

						//We're constrained by wall, so subtract wall part from 
						//velocity vector

						wall_part = vm_vec_dot(&hit_info.hit_wallnorm,&obj->mtype.phys_info.velocity);

						if (obj->mtype.phys_info.flags & PF_BOUNCE)		//bounce off wall
							wall_part *= 2;	//Subtract out wall part twice to achieve bounce

						vm_vec_scale_add2(&obj->mtype.phys_info.velocity,&hit_info.hit_wallnorm,-wall_part);

						#ifdef EXTRA_DEBUG
						if (obj == debug_obj) {
							printf("   sliding - wall_norm %x %x %x\n",wall_part,XYZ(&hit_info.hit_wallnorm));
							printf("   wall_part %x, new velocity = %x %x %x\n",wall_part,XYZ(&obj->mtype.phys_info.velocity));
						}
						#endif

						try_again = 1;
					}
				}
				break;
			}

			case HIT_OBJECT:		{
				vms_vector old_vel;

				// Mark the hit object so that on a retry the fvi code
				// ignores this object.

				Assert(hit_info.hit_object != -1);

				//	Calculcate the hit point between the two objects.
				{	vms_vector	*ppos0, *ppos1, pos_hit;
					fix			size0, size1;
					ppos0 = &Objects[hit_info.hit_object].pos;
					ppos1 = &obj->pos;
					size0 = Objects[hit_info.hit_object].size;
					size1 = obj->size;
					Assert(size0+size1 != 0);	// Error, both sizes are 0, so how did they collide, anyway?!?
					//vm_vec_scale(vm_vec_sub(&pos_hit, ppos1, ppos0), fixdiv(size0, size0 + size1));
					//vm_vec_add2(&pos_hit, ppos0);
					vm_vec_sub(&pos_hit, ppos1, ppos0);
					vm_vec_scale_add(&pos_hit,ppos0,&pos_hit,fixdiv(size0, size0 + size1));

					old_vel = obj->mtype.phys_info.velocity;

					collide_two_objects( obj, &Objects[hit_info.hit_object], &pos_hit);

				}

				// Let object continue its movement
				if ( !(obj->flags&OF_SHOULD_BE_DEAD)  )	{
					//obj->pos = save_pos;

					if (obj->mtype.phys_info.flags&PF_PERSISTENT || (old_vel.x == obj->mtype.phys_info.velocity.x && old_vel.y == obj->mtype.phys_info.velocity.y && old_vel.z == obj->mtype.phys_info.velocity.z)) {
						//if (Objects[hit_info.hit_object].type == OBJ_POWERUP)
							ignore_obj_list[n_ignore_objs++] = hit_info.hit_object;
						try_again = 1;
					}
				}

				break;
			}	
			case HIT_NONE:		
				break;

			#ifndef NDEBUG
			case HIT_BAD_P0:
				Int3();		// Unexpected collision type: start point not in specified segment.
				mprintf((0,"Warning: Bad p0 in physics!!!\n"));
				break;
			default:
				// Unknown collision type returned from find_vector_intersection!!
				Int3();
				break;
			#endif
		}

	} while ( try_again );

	//	Pass retry count info to AI.
	if (obj->control_type == CT_AI) {
		if (count > 0) {
			Ai_local_info[objnum].retry_count = count-1;
			Total_retries += count-1;
			Total_sims++;
		}
	}

	if (! obj_stopped)	{	//Set velocity from actual movement
		vms_vector moved_vec;
		vm_vec_sub(&moved_vec,&obj->pos,&start_pos);
		vm_vec_copy_scale(&obj->mtype.phys_info.velocity,&moved_vec,fixdiv(f1_0,FrameTime));

		#ifdef BUMP_HACK
		if (obj==ConsoleObject && (obj->mtype.phys_info.velocity.x==0 && obj->mtype.phys_info.velocity.y==0 && obj->mtype.phys_info.velocity.z==0) &&
			  !(obj->mtype.phys_info.thrust.x==0 && obj->mtype.phys_info.thrust.y==0 && obj->mtype.phys_info.thrust.z==0)) {
			vms_vector center,bump_vec;

			//bump player a little towards center of segment to unstick

			compute_segment_center(&center,&Segments[obj->segnum]);
			vm_vec_normalized_dir_quick(&bump_vec,&center,&obj->pos);
			vm_vec_scale_add2(&obj->pos,&bump_vec,obj->size/5);
		}
		#endif
	}

	//Assert(check_point_in_seg(&obj->pos,obj->segnum,0).centermask==0);

	//if (obj->control_type == CT_FLYING)
	if (obj->mtype.phys_info.flags & PF_LEVELLING)
		do_physics_align_object( obj );


	//hack to keep player from going through closed doors
	if (obj->type==OBJ_PLAYER && obj->segnum!=orig_segnum && (Physics_cheat_flag!=0xBADA55) ) {
		int sidenum;

		sidenum = find_connect_side(&Segments[obj->segnum],&Segments[orig_segnum]);

		if (sidenum != -1) {

			if (! (WALL_IS_DOORWAY(&Segments[orig_segnum],sidenum) & WID_FLY_FLAG)) {
				side *s;
				int vertnum,num_faces,i;
				fix dist;
				int vertex_list[6];

				//bump object back

				s = &Segments[orig_segnum].sides[sidenum];

				create_abs_vertex_lists( &num_faces, vertex_list, orig_segnum, sidenum);

				//let's pretend this wall is not triangulated
				vertnum = vertex_list[0];
				for (i=1;i<4;i++)
					if (vertex_list[i] < vertnum)
						vertnum = vertex_list[i];

				#ifdef COMPACT_SEGS
					{
					vms_vector _vn;
					get_side_normal(&Segments[orig_segnum], sidenum, 0, &_vn );
					dist = vm_dist_to_plane(&start_pos, &_vn, &Vertices[vertnum]);
					vm_vec_scale_add(&obj->pos,&start_pos,&_vn,obj->size-dist);
					}
				#else
					dist = vm_dist_to_plane(&start_pos, &s->normals[0], &Vertices[vertnum]);
					vm_vec_scale_add(&obj->pos,&start_pos,&s->normals[0],obj->size-dist);
				#endif
				update_object_seg(obj);

			}
		}
	}

//--WE ALWYS WANT THIS IN, MATT AND MIKE DECISION ON 12/10/94, TWO MONTHS AFTER FINAL 	#ifndef NDEBUG
	//if end point not in segment, move object to last pos, or segment center
	if (get_seg_masks(&obj->pos,obj->segnum,0).centermask!=0) {
		if (find_object_seg(obj)==-1) {
			int n;

			//Int3();
			if (obj->type==OBJ_PLAYER && (n=find_point_seg(&obj->last_pos,obj->segnum))!=-1) {
				obj->pos = obj->last_pos;
				obj_relink(objnum, n );
			}
			else {
				compute_segment_center(&obj->pos,&Segments[obj->segnum]);
				obj->pos.x += objnum;
			}
			if (obj->type == OBJ_WEAPON)
				obj->flags |= OF_SHOULD_BE_DEAD;
		}
	}
//--WE ALWYS WANT THIS IN, MATT AND MIKE DECISION ON 12/10/94, TWO MONTHS AFTER FINAL 	#endif


}