added -udp documentation from d1x
[btb/d2x.git] / main / fvi.c
1 /* $Id: fvi.c,v 1.4 2004-05-21 00:02:34 btb Exp $ */
2 /*
3 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
4 SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
5 END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
6 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
7 IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
8 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
9 FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
10 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
11 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
12 COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
13 */
14
15 /*
16  *
17  * New home for find_vector_intersection()
18  *
19  * Old Log:
20  * Revision 1.7  1995/10/21  23:52:18  allender
21  * #ifdef'ed out stack debug stuff
22  *
23  * Revision 1.6  1995/10/10  12:07:42  allender
24  * add forgotten ;
25  *
26  * Revision 1.5  1995/10/10  11:47:27  allender
27  * put in stack space check
28  *
29  * Revision 1.4  1995/08/23  21:34:08  allender
30  * fix mcc compiler warning
31  *
32  * Revision 1.3  1995/08/14  14:35:18  allender
33  * changed transparency to 0
34  *
35  * Revision 1.2  1995/07/05  16:50:51  allender
36  * transparency/kitchen change
37  *
38  * Revision 1.1  1995/05/16  15:24:59  allender
39  * Initial revision
40  *
41  * Revision 2.3  1995/03/24  14:49:04  john
42  * Added cheat for player to go thru walls.
43  *
44  * Revision 2.2  1995/03/21  17:58:32  john
45  * Fixed bug with normals..
46  *
47  *
48  * Revision 2.1  1995/03/20  18:15:37  john
49  * Added code to not store the normals in the segment structure.
50  *
51  * Revision 2.0  1995/02/27  11:27:41  john
52  * New version 2.0, which has no anonymous unions, builds with
53  * Watcom 10.0, and doesn't require parsing BITMAPS.TBL.
54  *
55  * Revision 1.49  1995/02/22  14:45:47  allender
56  * remove anonymous unions from object structure
57  *
58  * Revision 1.48  1995/02/22  13:24:50  john
59  * Removed the vecmat anonymous unions.
60  *
61  * Revision 1.47  1995/02/07  16:17:26  matt
62  * Disabled all robot-robot collisions except those involving two green
63  * guys.  Used to do collisions if either robot was green guy.
64  *
65  * Revision 1.46  1995/02/02  14:07:53  matt
66  * Fixed confusion about which segment you are touching when you're
67  * touching a wall.  This manifested itself in spurious lava burns.
68  *
69  * Revision 1.45  1995/02/02  13:45:53  matt
70  * Made a bunch of lint-inspired changes
71  *
72  * Revision 1.44  1995/01/24  12:10:17  matt
73  * Fudged collisions for player/player, and player weapon/other player in
74  * coop games.
75  *
76  * Revision 1.43  1995/01/14  19:16:45  john
77  * First version of new bitmap paging code.
78  *
79  * Revision 1.42  1994/12/15  12:22:40  matt
80  * Small change which may or may not help
81  *
82  * Revision 1.41  1994/12/14  11:45:51  matt
83  * Fixed (hopefully) little bug with invalid segnum
84  *
85  * Revision 1.40  1994/12/13  17:12:01  matt
86  * Increased edge tolerance a bunch more
87  *
88  * Revision 1.39  1994/12/13  14:37:59  matt
89  * Fixed another stupid little bug
90  *
91  * Revision 1.38  1994/12/13  13:25:44  matt
92  * Increased tolerance massively to avoid catching on corners
93  *
94  * Revision 1.37  1994/12/13  12:02:20  matt
95  * Fixed small bug
96  *
97  * Revision 1.36  1994/12/13  11:17:35  matt
98  * Lots of changes to hopefully fix objects leaving the mine.  Note that
99  * this code should be considered somewhat experimental - one problem I
100  * know about is that you can get stuck on edges more easily than before.
101  * There may be other problems I don't know about yet.
102  *
103  * Revision 1.35  1994/12/12  01:20:57  matt
104  * Added hack in object-object collisions that treats claw guys as
105  * if they have 3/4 of their actual radius.
106  *
107  * Revision 1.34  1994/12/04  22:48:39  matt
108  * Physics & FVI now only build seglist for player objects, and they
109  * responsilby deal with buffer full conditions
110  *
111  * Revision 1.33  1994/12/04  22:07:05  matt
112  * Added better handing of buffer full condition
113  *
114  * Revision 1.32  1994/12/01  21:06:33  matt
115  * Several important changes:
116  *  (1) Checking against triangulated sides has been standardized a bit
117  *  (2) Code has been added to de-triangulate some sides
118  *  (3) BIG ONE: the tolerance for checking a point against a plane has
119  *      been drastically relaxed
120  *
121  *
122  * Revision 1.31  1994/11/27  23:15:03  matt
123  * Made changes for new mprintf calling convention
124  *
125  * Revision 1.30  1994/11/19  15:20:30  mike
126  * rip out unused code and data
127  *
128  * Revision 1.29  1994/11/16  12:18:17  mike
129  * hack for green_guy:green_guy collision detection.
130  *
131  * Revision 1.28  1994/11/10  13:08:54  matt
132  * Added support for new run-length-encoded bitmaps
133  *
134  * Revision 1.27  1994/10/31  12:27:51  matt
135  * Added new function object_intersects_wall()
136  *
137  * Revision 1.26  1994/10/20  13:59:27  matt
138  * Added assert
139  *
140  * Revision 1.25  1994/10/09  23:51:09  matt
141  * Made find_hitpoint_uv() work with triangulated sides
142  *
143  * Revision 1.24  1994/09/25  00:39:29  matt
144  * Took out mprintf's
145  *
146  * Revision 1.23  1994/09/25  00:37:53  matt
147  * Made the 'find the point in the bitmap where something hit' system
148  * publicly accessible.
149  *
150  * Revision 1.22  1994/09/21  16:58:22  matt
151  * Fixed bug in trans wall check that was checking against verically
152  * flipped bitmap (i.e., the y coord was negative when checking).
153  *
154  * Revision 1.21  1994/09/02  11:31:40  matt
155  * Fixed object/object collisions, so you can't fly through robots anymore.
156  * Cleaned up object damage system.
157  *
158  * Revision 1.20  1994/08/26  09:42:03  matt
159  * Increased the size of a buffer
160  *
161  * Revision 1.19  1994/08/11  18:57:53  mike
162  * Convert shorts to ints for optimization.
163  *
164  * Revision 1.18  1994/08/08  21:38:24  matt
165  * Put in small optimization
166  *
167  * Revision 1.17  1994/08/08  12:21:52  yuan
168  * Fixed assert
169  *
170  * Revision 1.16  1994/08/08  11:47:04  matt
171  * Cleaned up fvi and physics a little
172  *
173  * Revision 1.15  1994/08/04  00:21:04  matt
174  * Cleaned up fvi & physics error handling; put in code to make sure objects
175  * are in correct segment; simplified segment finding for objects and points
176  *
177  * Revision 1.14  1994/08/02  19:04:26  matt
178  * Cleaned up vertex list functions
179  *
180  * Revision 1.13  1994/08/02  09:56:28  matt
181  * Put in check for bad value find_plane_line_intersection()
182  *
183  * Revision 1.12  1994/08/01  17:27:26  matt
184  * Added support for triangulated walls in trans point check
185  *
186  * Revision 1.11  1994/08/01  13:30:40  matt
187  * Made fvi() check holes in transparent walls, and changed fvi() calling
188  * parms to take all input data in query structure.
189  *
190  * Revision 1.10  1994/07/13  21:47:17  matt
191  * FVI() and physics now keep lists of segments passed through which the
192  * trigger code uses.
193  *
194  * Revision 1.9  1994/07/09  21:21:40  matt
195  * Fixed, hopefull, bugs in sphere-to-vector intersection code
196  *
197  * Revision 1.8  1994/07/08  14:26:42  matt
198  * Non-needed powerups don't get picked up now; this required changing FVI to
199  * take a list of ingore objects rather than just one ignore object.
200  *
201  * Revision 1.7  1994/07/06  20:02:37  matt
202  * Made change to match gameseg that uses lowest point number as reference
203  * point when checking against a plane
204  *
205  * Revision 1.6  1994/06/29  15:43:58  matt
206  * When computing intersection of vector and sphere, use the radii of both
207  * objects.
208  *
209  * Revision 1.5  1994/06/14  15:57:58  matt
210  * Took out asserts, and added other hacks, pending real bug fixes
211  *
212  * Revision 1.4  1994/06/13  23:10:08  matt
213  * Fixed problems with triangulated sides
214  *
215  * Revision 1.3  1994/06/09  12:11:14  matt
216  * Fixed confusing use of two variables, hit_objnum & fvi_hit_object, to
217  * keep the same information in different ways.
218  *
219  * Revision 1.2  1994/06/09  09:58:38  matt
220  * Moved find_vector_intersection() from physics.c to new file fvi.c
221  *
222  * Revision 1.1  1994/06/09  09:25:57  matt
223  * Initial revision
224  *
225  *
226  */
227
228
229 #define NEW_FVI_STUFF 1
230
231 #ifdef HAVE_CONFIG_H
232 #include <conf.h>
233 #endif
234
235 #include <stdio.h>
236 #include <stdlib.h>
237 #include <string.h>
238
239 #ifdef MACINTOSH
240 #include <Memory.h>
241 #endif
242
243 #include "pstypes.h"
244 #include "u_mem.h"
245 #include "error.h"
246 #include "mono.h"
247
248 #include "inferno.h"
249 #include "fvi.h"
250 #include "segment.h"
251 #include "object.h"
252 #include "wall.h"
253 #include "laser.h"
254 #include "rle.h"
255 #include "robot.h"
256 #include "piggy.h"
257 #include "player.h"
258
259 extern int Physics_cheat_flag;
260
261 #define face_type_num(nfaces,face_num,tri_edge) ((nfaces==1)?0:(tri_edge*2 + face_num))
262
263 #include "fvi_a.h"
264
265 //find the point on the specified plane where the line intersects
266 //returns true if point found, false if line parallel to plane
267 //new_pnt is the found point on the plane
268 //plane_pnt & plane_norm describe the plane
269 //p0 & p1 are the ends of the line
270 int find_plane_line_intersection(vms_vector *new_pnt,vms_vector *plane_pnt,vms_vector *plane_norm,vms_vector *p0,vms_vector *p1,fix rad)
271 {
272         vms_vector d,w;
273         fix num,den;
274
275         vm_vec_sub(&d,p1,p0);
276         vm_vec_sub(&w,p0,plane_pnt);
277
278         num =  vm_vec_dot(plane_norm,&w);
279         den = -vm_vec_dot(plane_norm,&d);
280
281 //Why does this assert hit so often
282 //      Assert(num > -rad);
283
284         num -= rad;                     //move point out by rad
285
286         //check for various bad values
287
288         if ( (den==0) ||                                        //moving parallel to wall, so can't hit it
289                   ((den>0) &&
290                         ( (num>den) ||                          //frac greater than one
291                      (-num>>15)>=den)) ||       //will overflow (large negative)
292                   (den<0 && num<den))           //frac greater than one
293                 return 0;
294
295 //if (num>0) {mprintf(1,"HEY! num>0 in FVI!!!"); return 0;}
296 //??    Assert(num>=0);
297 //    Assert(num >= den);
298
299         //do check for potenial overflow
300         {
301                 fix k;
302
303                 if (labs(num)/(f1_0/2) >= labs(den)) {Int3(); return 0;}
304                 k = fixdiv(num,den);
305
306                 Assert(k<=f1_0);                //should be trapped above
307
308 //              Assert(k>=0);
309                 if (oflow_check(d.x,k) || oflow_check(d.y,k) || oflow_check(d.z,k)) return 0;
310                 //Note: it is ok for k to be greater than 1, since this might mean
311                 //that an object with a non-zero radius that moved from p0 to p1
312                 //actually hit the wall on the "other side" of p0.
313         }
314
315         vm_vec_scale2(&d,num,den);
316
317         vm_vec_add(new_pnt,p0,&d);
318
319         //we should have vm_vec_scale2_add2()
320
321         return 1;
322
323 }
324
325 typedef struct vec2d {
326         fix i,j;
327 } vec2d;
328
329 //given largest componant of normal, return i & j
330 //if largest componant is negative, swap i & j
331 int ij_table[3][2] =        {
332                                                         {2,1},          //pos x biggest
333                                                         {0,2},          //pos y biggest
334                                                         {1,0},          //pos z biggest
335                                                 };
336
337 //intersection types
338 #define IT_NONE 0       //doesn't touch face at all
339 #define IT_FACE 1       //touches face
340 #define IT_EDGE 2       //touches edge of face
341 #define IT_POINT        3       //touches vertex
342
343 //see if a point in inside a face by projecting into 2d
344 uint check_point_to_face(vms_vector *checkp, side *s,int facenum,int nv,int *vertex_list)
345 {
346         vms_vector_array *checkp_array;
347         vms_vector_array norm;
348         vms_vector t;
349         int biggest;
350 ///
351         int i,j,edge;
352         uint edgemask;
353         fix check_i,check_j;
354         vms_vector_array *v0,*v1;
355
356         #ifdef COMPACT_SEGS
357                 get_side_normal(sp, s-sp->sides, facenum, (vms_vector *)&norm );
358         #else
359                 memcpy( &norm, &s->normals[facenum], sizeof(vms_vector_array));
360         #endif
361         checkp_array = (vms_vector_array *)checkp;
362
363         //now do 2d check to see if point is in side
364
365         //project polygon onto plane by finding largest component of normal
366         t.x = labs(norm.xyz[0]); t.y = labs(norm.xyz[1]); t.z = labs(norm.xyz[2]);
367
368         if (t.x > t.y) if (t.x > t.z) biggest=0; else biggest=2;
369         else if (t.y > t.z) biggest=1; else biggest=2;
370
371         if (norm.xyz[biggest] > 0) {
372                 i = ij_table[biggest][0];
373                 j = ij_table[biggest][1];
374         }
375         else {
376                 i = ij_table[biggest][1];
377                 j = ij_table[biggest][0];
378         }
379
380         //now do the 2d problem in the i,j plane
381
382         check_i = checkp_array->xyz[i];
383         check_j = checkp_array->xyz[j];
384
385         for (edge=edgemask=0;edge<nv;edge++) {
386                 vec2d edgevec,checkvec;
387                 fix d;
388
389                 v0 = (vms_vector_array *)&Vertices[vertex_list[facenum*3+edge]];
390                 v1 = (vms_vector_array *)&Vertices[vertex_list[facenum*3+((edge+1)%nv)]];
391
392                 edgevec.i = v1->xyz[i] - v0->xyz[i];
393                 edgevec.j = v1->xyz[j] - v0->xyz[j];
394
395                 checkvec.i = check_i - v0->xyz[i];
396                 checkvec.j = check_j - v0->xyz[j];
397
398                 d = fixmul(checkvec.i,edgevec.j) - fixmul(checkvec.j,edgevec.i);
399
400                 if (d < 0)                              //we are outside of triangle
401                         edgemask |= (1<<edge);
402         }
403
404         return edgemask;
405
406 }
407
408
409 //check if a sphere intersects a face
410 int check_sphere_to_face(vms_vector *pnt, side *s,int facenum,int nv,fix rad,int *vertex_list)
411 {
412         vms_vector checkp=*pnt;
413         uint edgemask;
414
415         //now do 2d check to see if point is in side
416
417         edgemask = check_point_to_face(pnt,s,facenum,nv,vertex_list);
418
419         //we've gone through all the sides, are we inside?
420
421         if (edgemask == 0)
422                 return IT_FACE;
423         else {
424                 vms_vector edgevec,checkvec;            //this time, real 3d vectors
425                 vms_vector closest_point;
426                 fix edgelen,d,dist;
427                 vms_vector *v0,*v1;
428                 int itype;
429                 int edgenum;
430
431                 //get verts for edge we're behind
432
433                 for (edgenum=0;!(edgemask&1);(edgemask>>=1),edgenum++);
434
435                 v0 = &Vertices[vertex_list[facenum*3+edgenum]];
436                 v1 = &Vertices[vertex_list[facenum*3+((edgenum+1)%nv)]];
437
438                 //check if we are touching an edge or point
439
440                 vm_vec_sub(&checkvec,&checkp,v0);
441                 edgelen = vm_vec_normalized_dir(&edgevec,v1,v0);
442                 
443                 //find point dist from planes of ends of edge
444
445                 d = vm_vec_dot(&edgevec,&checkvec);
446
447                 if (d+rad < 0) return IT_NONE;                  //too far behind start point
448
449                 if (d-rad > edgelen) return IT_NONE;    //too far part end point
450
451                 //find closest point on edge to check point
452
453                 itype = IT_POINT;
454
455                 if (d < 0) closest_point = *v0;
456                 else if (d > edgelen) closest_point = *v1;
457                 else {
458                         itype = IT_EDGE;
459
460                         //vm_vec_scale(&edgevec,d);
461                         //vm_vec_add(&closest_point,v0,&edgevec);
462
463                         vm_vec_scale_add(&closest_point,v0,&edgevec,d);
464                 }
465
466                 dist = vm_vec_dist(&checkp,&closest_point);
467
468                 if (dist <= rad)
469                         return (itype==IT_POINT)?IT_NONE:itype;
470                 else
471                         return IT_NONE;
472         }
473
474
475 }
476
477 //returns true if line intersects with face. fills in newp with intersection
478 //point on plane, whether or not line intersects side
479 //facenum determines which of four possible faces we have
480 //note: the seg parm is temporary, until the face itself has a point field
481 int check_line_to_face(vms_vector *newp,vms_vector *p0,vms_vector *p1,segment *seg,int side,int facenum,int nv,fix rad)
482 {
483         vms_vector checkp;
484         int pli;
485         struct side *s=&seg->sides[side];
486         int vertex_list[6];
487         int num_faces;
488         int vertnum;
489         vms_vector norm;
490
491         #ifdef COMPACT_SEGS
492                 get_side_normal(seg, side, facenum, &norm );
493         #else
494                 norm = seg->sides[side].normals[facenum];
495         #endif
496
497         if ((seg-Segments)==-1)
498                 Error("segnum == -1 in check_line_to_face()");
499
500         create_abs_vertex_lists(&num_faces, vertex_list, seg - Segments, side, __FILE__, __LINE__);
501
502         //use lowest point number
503         if (num_faces==2) {
504                 vertnum = min(vertex_list[0],vertex_list[2]);
505         }
506         else {
507                 int i;
508                 vertnum = vertex_list[0];
509                 for (i=1;i<4;i++)
510                         if (vertex_list[i] < vertnum)
511                                 vertnum = vertex_list[i];
512         }
513
514         pli = find_plane_line_intersection(newp,&Vertices[vertnum],&norm,p0,p1,rad);
515
516         if (!pli) return IT_NONE;
517
518         checkp = *newp;
519
520         //if rad != 0, project the point down onto the plane of the polygon
521
522         if (rad!=0)
523                 vm_vec_scale_add2(&checkp,&norm,-rad);
524
525         return check_sphere_to_face(&checkp,s,facenum,nv,rad,vertex_list);
526
527 }
528
529 //returns the value of a determinant
530 fix calc_det_value(vms_matrix *det)
531 {
532         return  fixmul(det->rvec.x,fixmul(det->uvec.y,det->fvec.z)) -
533                                 fixmul(det->rvec.x,fixmul(det->uvec.z,det->fvec.y)) -
534                                 fixmul(det->rvec.y,fixmul(det->uvec.x,det->fvec.z)) +
535                                 fixmul(det->rvec.y,fixmul(det->uvec.z,det->fvec.x)) +
536                                 fixmul(det->rvec.z,fixmul(det->uvec.x,det->fvec.y)) -
537                                 fixmul(det->rvec.z,fixmul(det->uvec.y,det->fvec.x));
538 }
539
540 //computes the parameters of closest approach of two lines
541 //fill in two parameters, t0 & t1.  returns 0 if lines are parallel, else 1
542 int check_line_to_line(fix *t1,fix *t2,vms_vector *p1,vms_vector *v1,vms_vector *p2,vms_vector *v2)
543 {
544         vms_matrix det;
545         fix d,cross_mag2;               //mag squared cross product
546
547         vm_vec_sub(&det.rvec,p2,p1);
548         vm_vec_cross(&det.fvec,v1,v2);
549         cross_mag2 = vm_vec_dot(&det.fvec,&det.fvec);
550
551         if (cross_mag2 == 0)
552                 return 0;                       //lines are parallel
553
554         det.uvec = *v2;
555         d = calc_det_value(&det);
556         if (oflow_check(d,cross_mag2))
557                 return 0;
558         else
559                 *t1 = fixdiv(d,cross_mag2);
560
561         det.uvec = *v1;
562         d = calc_det_value(&det);
563         if (oflow_check(d,cross_mag2))
564                 return 0;
565         else
566                 *t2 = fixdiv(d,cross_mag2);
567
568         return 1;               //found point
569 }
570
571 #ifdef NEW_FVI_STUFF
572 int disable_new_fvi_stuff=0;
573 #else
574 #define disable_new_fvi_stuff 1
575 #endif
576
577 //this version is for when the start and end positions both poke through
578 //the plane of a side.  In this case, we must do checks against the edge
579 //of faces
580 int special_check_line_to_face(vms_vector *newp,vms_vector *p0,vms_vector *p1,segment *seg,int side,int facenum,int nv,fix rad)
581 {
582         vms_vector move_vec;
583         fix edge_t,move_t,edge_t2,move_t2,closest_dist;
584         fix edge_len,move_len;
585         int vertex_list[6];
586         int num_faces,edgenum;
587         uint edgemask;
588         vms_vector *edge_v0,*edge_v1,edge_vec;
589         struct side *s=&seg->sides[side];
590         vms_vector closest_point_edge,closest_point_move;
591
592         if (disable_new_fvi_stuff)
593                 return check_line_to_face(newp,p0,p1,seg,side,facenum,nv,rad);
594
595         //calc some basic stuff
596
597         if ((seg-Segments)==-1)
598                 Error("segnum == -1 in special_check_line_to_face()");
599
600         create_abs_vertex_lists(&num_faces, vertex_list, seg - Segments, side, __FILE__, __LINE__);
601         vm_vec_sub(&move_vec,p1,p0);
602
603         //figure out which edge(s) to check against
604
605         edgemask = check_point_to_face(p0,s,facenum,nv,vertex_list);
606
607         if (edgemask == 0)
608                 return check_line_to_face(newp,p0,p1,seg,side,facenum,nv,rad);
609
610         for (edgenum=0;!(edgemask&1);edgemask>>=1,edgenum++);
611
612         edge_v0 = &Vertices[vertex_list[facenum*3+edgenum]];
613         edge_v1 = &Vertices[vertex_list[facenum*3+((edgenum+1)%nv)]];
614
615         vm_vec_sub(&edge_vec,edge_v1,edge_v0);
616
617         //is the start point already touching the edge?
618
619         //??
620
621         //first, find point of closest approach of vec & edge
622
623         edge_len = vm_vec_normalize(&edge_vec);
624         move_len = vm_vec_normalize(&move_vec);
625
626         check_line_to_line(&edge_t,&move_t,edge_v0,&edge_vec,p0,&move_vec);
627
628         //make sure t values are in valid range
629
630         if (move_t<0 || move_t>move_len+rad)
631                 return IT_NONE;
632
633         if (move_t > move_len)
634                 move_t2 = move_len;
635         else
636                 move_t2 = move_t;
637
638         if (edge_t < 0)         //saturate at points
639                 edge_t2 = 0;
640         else
641                 edge_t2 = edge_t;
642         
643         if (edge_t2 > edge_len)         //saturate at points
644                 edge_t2 = edge_len;
645         
646         //now, edge_t & move_t determine closest points.  calculate the points.
647
648         vm_vec_scale_add(&closest_point_edge,edge_v0,&edge_vec,edge_t2);
649         vm_vec_scale_add(&closest_point_move,p0,&move_vec,move_t2);
650
651         //find dist between closest points
652
653         closest_dist = vm_vec_dist(&closest_point_edge,&closest_point_move);
654
655         //could we hit with this dist?
656
657         //note massive tolerance here
658 //      if (closest_dist < (rad*18)/20) {               //we hit.  figure out where
659         if (closest_dist < (rad*15)/20) {               //we hit.  figure out where
660
661                 //now figure out where we hit
662
663                 vm_vec_scale_add(newp,p0,&move_vec,move_t-rad);
664
665                 return IT_EDGE;
666
667         }
668         else
669                 return IT_NONE;                 //no hit
670
671 }
672
673 //maybe this routine should just return the distance and let the caller
674 //decide it it's close enough to hit
675 //determine if and where a vector intersects with a sphere
676 //vector defined by p0,p1
677 //returns dist if intersects, and fills in intp
678 //else returns 0
679 int check_vector_to_sphere_1(vms_vector *intp,vms_vector *p0,vms_vector *p1,vms_vector *sphere_pos,fix sphere_rad)
680 {
681         vms_vector d,dn,w,closest_point;
682         fix mag_d,dist,w_dist,int_dist;
683
684         //this routine could be optimized if it's taking too much time!
685
686         vm_vec_sub(&d,p1,p0);
687         vm_vec_sub(&w,sphere_pos,p0);
688
689         mag_d = vm_vec_copy_normalize(&dn,&d);
690
691         if (mag_d == 0) {
692                 int_dist = vm_vec_mag(&w);
693                 *intp = *p0;
694                 return (int_dist<sphere_rad)?int_dist:0;
695         }
696
697         w_dist = vm_vec_dot(&dn,&w);
698
699         if (w_dist < 0)         //moving away from object
700                  return 0;
701
702         if (w_dist > mag_d+sphere_rad)
703                 return 0;               //cannot hit
704
705         vm_vec_scale_add(&closest_point,p0,&dn,w_dist);
706
707         dist = vm_vec_dist(&closest_point,sphere_pos);
708
709         if (dist < sphere_rad) {
710                 fix dist2,rad2,shorten;
711
712                 dist2 = fixmul(dist,dist);
713                 rad2 = fixmul(sphere_rad,sphere_rad);
714
715                 shorten = fix_sqrt(rad2 - dist2);
716
717                 int_dist = w_dist-shorten;
718
719                 if (int_dist > mag_d || int_dist < 0) {
720                         //past one or the other end of vector, which means we're inside
721
722                         *intp = *p0;            //don't move at all
723                         return 1;
724                 }
725
726                 vm_vec_scale_add(intp,p0,&dn,int_dist);         //calc intersection point
727
728 //              {
729 //                      fix dd = vm_vec_dist(intp,sphere_pos);
730 //                      Assert(dd == sphere_rad);
731 //                      mprintf(0,"dd=%x, rad=%x, delta=%x\n",dd,sphere_rad,dd-sphere_rad);
732 //              }
733
734
735                 return int_dist;
736         }
737         else
738                 return 0;
739 }
740
741 /*
742 //$$fix get_sphere_int_dist(vms_vector *w,fix dist,fix rad);
743 //$$
744 //$$#pragma aux get_sphere_int_dist parm [esi] [ebx] [ecx] value [eax] modify exact [eax ebx ecx edx] = \
745 //$$    "mov eax,ebx"           \
746 //$$    "imul eax"                      \
747 //$$                                                    \
748 //$$    "mov ebx,eax"           \
749 //$$   "mov eax,ecx"            \
750 //$$    "mov ecx,edx"           \
751 //$$                                                    \
752 //$$    "imul eax"                      \
753 //$$                                                    \
754 //$$    "sub eax,ebx"           \
755 //$$    "sbb edx,ecx"           \
756 //$$                                                    \
757 //$$    "call quad_sqrt"        \
758 //$$                                                    \
759 //$$    "push eax"                      \
760 //$$                                                    \
761 //$$    "push ebx"                      \
762 //$$    "push ecx"                      \
763 //$$                                                    \
764 //$$    "mov eax,[esi]" \
765 //$$    "imul eax"                      \
766 //$$    "mov ebx,eax"           \
767 //$$    "mov ecx,edx"           \
768 //$$    "mov eax,4[esi]"        \
769 //$$    "imul eax"                      \
770 //$$    "add ebx,eax"           \
771 //$$    "adc ecx,edx"           \
772 //$$    "mov eax,8[esi]"        \
773 //$$    "imul eax"                      \
774 //$$    "add eax,ebx"           \
775 //$$    "adc edx,ecx"           \
776 //$$                                                    \
777 //$$    "pop ecx"                       \
778 //$$    "pop ebx"                       \
779 //$$                                                    \
780 //$$    "sub eax,ebx"           \
781 //$$    "sbb edx,ecx"           \
782 //$$                                                    \
783 //$$    "call quad_sqrt"        \
784 //$$                                                    \
785 //$$    "pop ebx"                       \
786 //$$    "sub eax,ebx";
787 //$$
788 //$$
789 //$$//determine if and where a vector intersects with a sphere
790 //$$//vector defined by p0,p1
791 //$$//returns dist if intersects, and fills in intp. if no intersect, return 0
792 //$$fix check_vector_to_sphere_2(vms_vector *intp,vms_vector *p0,vms_vector *p1,vms_vector *sphere_pos,fix sphere_rad)
793 //$${
794 //$$    vms_vector d,w,c;
795 //$$    fix mag_d,dist,mag_c,mag_w;
796 //$$    vms_vector wn,dn;
797 //$$
798 //$$    vm_vec_sub(&d,p1,p0);
799 //$$    vm_vec_sub(&w,sphere_pos,p0);
800 //$$
801 //$$    //wn = w; mag_w = vm_vec_normalize(&wn);
802 //$$    //dn = d; mag_d = vm_vec_normalize(&dn);
803 //$$
804 //$$    mag_w = vm_vec_copy_normalize(&wn,&w);
805 //$$    mag_d = vm_vec_copy_normalize(&dn,&d);
806 //$$
807 //$$    //vm_vec_cross(&c,&w,&d);
808 //$$    vm_vec_cross(&c,&wn,&dn);
809 //$$
810 //$$    mag_c = vm_vec_mag(&c);
811 //$$    //mag_d = vm_vec_mag(&d);
812 //$$
813 //$$    //dist = fixdiv(mag_c,mag_d);
814 //$$
815 //$$dist = fixmul(mag_c,mag_w);
816 //$$
817 //$$    if (dist < sphere_rad) {        //we intersect.  find point of intersection
818 //$$            fix int_dist;                   //length of vector to intersection point
819 //$$            fix k;                                  //portion of p0p1 we want
820 //$$//@@                fix dist2,rad2,shorten,mag_w2;
821 //$$
822 //$$//@@                mag_w2 = vm_vec_dot(&w,&w);     //the square of the magnitude
823 //$$//@@                //WHAT ABOUT OVERFLOW???
824 //$$//@@                dist2 = fixmul(dist,dist);
825 //$$//@@                rad2 = fixmul(sphere_rad,sphere_rad);
826 //$$//@@                shorten = fix_sqrt(rad2 - dist2);
827 //$$//@@                int_dist = fix_sqrt(mag_w2 - dist2) - shorten;
828 //$$
829 //$$            int_dist = get_sphere_int_dist(&w,dist,sphere_rad);
830 //$$
831 //$$if (labs(int_dist) > mag_d) //I don't know why this would happen
832 //$$    if (int_dist > 0)
833 //$$            k = f1_0;
834 //$$    else
835 //$$            k = -f1_0;
836 //$$else
837 //$$            k = fixdiv(int_dist,mag_d);
838 //$$
839 //$$//          vm_vec_scale(&d,k);                     //vec from p0 to intersection point
840 //$$//          vm_vec_add(intp,p0,&d);         //intersection point
841 //$$            vm_vec_scale_add(intp,p0,&d,k); //calc new intersection point
842 //$$
843 //$$            return int_dist;
844 //$$    }
845 //$$    else
846 //$$            return 0;       //no intersection
847 //$$}
848 */
849
850 //determine if a vector intersects with an object
851 //if no intersects, returns 0, else fills in intp and returns dist
852 fix check_vector_to_object(vms_vector *intp,vms_vector *p0,vms_vector *p1,fix rad,object *obj,object *otherobj)
853 {
854         fix size = obj->size;
855
856         if (obj->type == OBJ_ROBOT && Robot_info[obj->id].attack_type)
857                 size = (size*3)/4;
858
859         //if obj is player, and bumping into other player or a weapon of another coop player, reduce radius
860         if (obj->type == OBJ_PLAYER &&
861                         ((otherobj->type == OBJ_PLAYER) ||
862                         ((Game_mode&GM_MULTI_COOP) && otherobj->type == OBJ_WEAPON && otherobj->ctype.laser_info.parent_type == OBJ_PLAYER)))
863                 size = size/2;
864
865         return check_vector_to_sphere_1(intp,p0,p1,&obj->pos,size+rad);
866
867 }
868
869
870 #define MAX_SEGS_VISITED 100
871 int n_segs_visited;
872 short segs_visited[MAX_SEGS_VISITED];
873
874 int fvi_nest_count;
875
876 //these vars are used to pass vars from fvi_sub() to find_vector_intersection()
877 int fvi_hit_object;     // object number of object hit in last find_vector_intersection call.
878 int fvi_hit_seg;                // what segment the hit point is in
879 int fvi_hit_side;               // what side was hit
880 int fvi_hit_side_seg;// what seg the hitside is in
881 vms_vector wall_norm;   //ptr to surface normal of hit wall
882 int fvi_hit_seg2;               // what segment the hit point is in
883
884 int fvi_sub(vms_vector *intp,int *ints,vms_vector *p0,int startseg,vms_vector *p1,fix rad,short thisobjnum,int *ignore_obj_list,int flags,int *seglist,int *n_segs,int entry_seg);
885
886 //What the hell is fvi_hit_seg for???
887
888 //Find out if a vector intersects with anything.
889 //Fills in hit_data, an fvi_info structure (see header file).
890 //Parms:
891 //  p0 & startseg       describe the start of the vector
892 //  p1                                  the end of the vector
893 //  rad                                         the radius of the cylinder
894 //  thisobjnum          used to prevent an object with colliding with itself
895 //  ingore_obj                  ignore collisions with this object
896 //  check_obj_flag      determines whether collisions with objects are checked
897 //Returns the hit_data->hit_type
898 int find_vector_intersection(fvi_query *fq,fvi_info *hit_data)
899 {
900         int hit_type,hit_seg,hit_seg2;
901         vms_vector hit_pnt;
902         int i;
903
904         Assert(fq->ignore_obj_list != (int *)(-1));
905         Assert((fq->startseg <= Highest_segment_index) && (fq->startseg >= 0));
906
907         fvi_hit_seg = -1;
908         fvi_hit_side = -1;
909
910         fvi_hit_object = -1;
911
912         //check to make sure start point is in seg its supposed to be in
913         //Assert(check_point_in_seg(p0,startseg,0).centermask==0);      //start point not in seg
914
915         // Viewer is not in segment as claimed, so say there is no hit.
916         if(!(get_seg_masks(fq->p0,fq->startseg,0).centermask==0)) {
917
918                 hit_data->hit_type = HIT_BAD_P0;
919                 hit_data->hit_pnt = *fq->p0;
920                 hit_data->hit_seg = fq->startseg;
921                 hit_data->hit_side = hit_data->hit_object = 0;
922                 hit_data->hit_side_seg = -1;
923
924                 return hit_data->hit_type;
925         }
926
927         segs_visited[0] = fq->startseg;
928
929         n_segs_visited=1;
930
931         fvi_nest_count = 0;
932
933         hit_seg2 = fvi_hit_seg2 = -1;
934
935         hit_type = fvi_sub(&hit_pnt,&hit_seg2,fq->p0,fq->startseg,fq->p1,fq->rad,fq->thisobjnum,fq->ignore_obj_list,fq->flags,hit_data->seglist,&hit_data->n_segs,-2);
936         //!!hit_seg = find_point_seg(&hit_pnt,fq->startseg);
937         if (hit_seg2!=-1 && !get_seg_masks(&hit_pnt,hit_seg2,0).centermask)
938                 hit_seg = hit_seg2;
939         else
940                 hit_seg = find_point_seg(&hit_pnt,fq->startseg);
941
942 //MATT: TAKE OUT THIS HACK AND FIX THE BUGS!
943         if (hit_type == HIT_WALL && hit_seg==-1)
944                 if (fvi_hit_seg2!=-1 && get_seg_masks(&hit_pnt,fvi_hit_seg2,0).centermask==0)
945                         hit_seg = fvi_hit_seg2;
946
947         if (hit_seg == -1) {
948                 int new_hit_type;
949                 int new_hit_seg2=-1;
950                 vms_vector new_hit_pnt;
951
952                 //because of code that deal with object with non-zero radius has
953                 //problems, try using zero radius and see if we hit a wall
954
955                 new_hit_type = fvi_sub(&new_hit_pnt,&new_hit_seg2,fq->p0,fq->startseg,fq->p1,0,fq->thisobjnum,fq->ignore_obj_list,fq->flags,hit_data->seglist,&hit_data->n_segs,-2);
956
957                 if (new_hit_seg2 != -1) {
958                         hit_seg = new_hit_seg2;
959                         hit_pnt = new_hit_pnt;
960                 }
961         }
962
963
964 if (hit_seg!=-1 && fq->flags&FQ_GET_SEGLIST)
965         if (hit_seg != hit_data->seglist[hit_data->n_segs-1] && hit_data->n_segs<MAX_FVI_SEGS-1)
966                 hit_data->seglist[hit_data->n_segs++] = hit_seg;
967
968 if (hit_seg!=-1 && fq->flags&FQ_GET_SEGLIST)
969         for (i=0;i<hit_data->n_segs && i<MAX_FVI_SEGS-1;i++)
970                 if (hit_data->seglist[i] == hit_seg) {
971                         hit_data->n_segs = i+1;
972                         break;
973                 }
974
975 //I'm sorry to say that sometimes the seglist isn't correct.  I did my
976 //best.  Really.
977
978
979 //{     //verify hit list
980 //
981 //      int i,ch;
982 //
983 //      Assert(hit_data->seglist[0] == startseg);
984 //
985 //      for (i=0;i<hit_data->n_segs-1;i++) {
986 //              for (ch=0;ch<6;ch++)
987 //                      if (Segments[hit_data->seglist[i]].children[ch] == hit_data->seglist[i+1])
988 //                              break;
989 //              Assert(ch<6);
990 //      }
991 //
992 //      Assert(hit_data->seglist[hit_data->n_segs-1] == hit_seg);
993 //}
994         
995
996 //MATT: PUT THESE ASSERTS BACK IN AND FIX THE BUGS!
997 //!!    Assert(hit_seg!=-1);
998 //!!    Assert(!((hit_type==HIT_WALL) && (hit_seg == -1)));
999         //When this assert happens, get Matt.  Matt:  Look at hit_seg2 &
1000         //fvi_hit_seg.  At least one of these should be set.  Why didn't
1001         //find_new_seg() find something?
1002
1003 //      Assert(fvi_hit_seg==-1 || fvi_hit_seg == hit_seg);
1004
1005         Assert(!(hit_type==HIT_OBJECT && fvi_hit_object==-1));
1006
1007         hit_data->hit_type              = hit_type;
1008         hit_data->hit_pnt               = hit_pnt;
1009         hit_data->hit_seg               = hit_seg;
1010         hit_data->hit_side              = fvi_hit_side; //looks at global
1011         hit_data->hit_side_seg  = fvi_hit_side_seg;     //looks at global
1012         hit_data->hit_object            = fvi_hit_object;       //looks at global
1013         hit_data->hit_wallnorm  = wall_norm;            //looks at global
1014
1015 //      if(hit_seg!=-1 && get_seg_masks(&hit_data->hit_pnt,hit_data->hit_seg,0).centermask!=0)
1016 //              Int3();
1017
1018         return hit_type;
1019
1020 }
1021
1022 //--unused-- fix check_dist(vms_vector *v0,vms_vector *v1)
1023 //--unused-- {
1024 //--unused--    return vm_vec_dist(v0,v1);
1025 //--unused-- }
1026
1027 int obj_in_list(int objnum,int *obj_list)
1028 {
1029         int t;
1030
1031         while ((t=*obj_list)!=-1 && t!=objnum) obj_list++;
1032
1033         return (t==objnum);
1034
1035 }
1036
1037 int check_trans_wall(vms_vector *pnt,segment *seg,int sidenum,int facenum);
1038
1039 int fvi_sub(vms_vector *intp,int *ints,vms_vector *p0,int startseg,vms_vector *p1,fix rad,short thisobjnum,int *ignore_obj_list,int flags,int *seglist,int *n_segs,int entry_seg)
1040 {
1041         segment *seg;                           //the segment we're looking at
1042         int startmask,endmask;  //mask of faces
1043         //@@int sidemask;                               //mask of sides - can be on back of face but not side
1044         int centermask;                 //where the center point is
1045         int objnum;
1046         segmasks masks;
1047         vms_vector hit_point,closest_hit_point;         //where we hit
1048         fix d,closest_d=0x7fffffff;                                     //distance to hit point
1049         int hit_type=HIT_NONE;                                                  //what sort of hit
1050         int hit_seg=-1;
1051         int hit_none_seg=-1;
1052         int hit_none_n_segs=0;
1053         int hit_none_seglist[MAX_FVI_SEGS];
1054         int cur_nest_level = fvi_nest_count;
1055
1056         //fvi_hit_object = -1;
1057
1058         if (flags&FQ_GET_SEGLIST)
1059                 *seglist = startseg;
1060         *n_segs=1;
1061
1062         seg = &Segments[startseg];
1063
1064         fvi_nest_count++;
1065
1066         //first, see if vector hit any objects in this segment
1067         if (flags & FQ_CHECK_OBJS)
1068                 for (objnum=seg->objects;objnum!=-1;objnum=Objects[objnum].next)
1069                         if (    !(Objects[objnum].flags & OF_SHOULD_BE_DEAD) &&
1070                                         !(thisobjnum == objnum ) &&
1071                                         (ignore_obj_list==NULL || !obj_in_list(objnum,ignore_obj_list)) &&
1072                                         !laser_are_related( objnum, thisobjnum ) &&
1073                                         !((thisobjnum  > -1)    &&
1074                                                 (CollisionResult[Objects[thisobjnum].type][Objects[objnum].type] == RESULT_NOTHING ) &&
1075                                                 (CollisionResult[Objects[objnum].type][Objects[thisobjnum].type] == RESULT_NOTHING ))) {
1076                                 int fudged_rad = rad;
1077
1078                                 //      If this is a powerup, don't do collision if flag FQ_IGNORE_POWERUPS is set
1079                                 if (Objects[objnum].type == OBJ_POWERUP)
1080                                         if (flags & FQ_IGNORE_POWERUPS)
1081                                                 continue;
1082
1083                                 //      If this is a robot:robot collision, only do it if both of them have attack_type != 0 (eg, green guy)
1084                                 if (Objects[thisobjnum].type == OBJ_ROBOT)
1085                                         if (Objects[objnum].type == OBJ_ROBOT)
1086                                                 // -- MK: 11/18/95, 4claws glomming together...this is easy.  -- if (!(Robot_info[Objects[objnum].id].attack_type && Robot_info[Objects[thisobjnum].id].attack_type))
1087                                                         continue;
1088
1089                                 if (Objects[thisobjnum].type == OBJ_ROBOT && Robot_info[Objects[thisobjnum].id].attack_type)
1090                                         fudged_rad = (rad*3)/4;
1091
1092                                 //if obj is player, and bumping into other player or a weapon of another coop player, reduce radius
1093                                 if (Objects[thisobjnum].type == OBJ_PLAYER &&
1094                                                 ((Objects[objnum].type == OBJ_PLAYER) ||
1095                                                 ((Game_mode&GM_MULTI_COOP) &&  Objects[objnum].type == OBJ_WEAPON && Objects[objnum].ctype.laser_info.parent_type == OBJ_PLAYER)))
1096                                         fudged_rad = rad/2;     //(rad*3)/4;
1097
1098                                 d = check_vector_to_object(&hit_point,p0,p1,fudged_rad,&Objects[objnum],&Objects[thisobjnum]);
1099
1100                                 if (d)          //we have intersection
1101                                         if (d < closest_d) {
1102                                                 fvi_hit_object = objnum;
1103                                                 Assert(fvi_hit_object!=-1);
1104                                                 closest_d = d;
1105                                                 closest_hit_point = hit_point;
1106                                                 hit_type=HIT_OBJECT;
1107                                         }
1108                         }
1109
1110         if (    (thisobjnum > -1 ) && (CollisionResult[Objects[thisobjnum].type][OBJ_WALL] == RESULT_NOTHING ) )
1111                 rad = 0;                //HACK - ignore when edges hit walls
1112
1113         //now, check segment walls
1114
1115         startmask = get_seg_masks(p0,startseg,rad).facemask;
1116
1117         masks = get_seg_masks(p1,startseg,rad);    //on back of which faces?
1118         endmask = masks.facemask;
1119         //@@sidemask = masks.sidemask;
1120         centermask = masks.centermask;
1121
1122         if (centermask==0) hit_none_seg = startseg;
1123
1124         if (endmask != 0) {                             //on the back of at least one face
1125
1126                 int side,bit,face;
1127
1128                 //for each face we are on the back of, check if intersected
1129
1130                 for (side=0,bit=1;side<6 && endmask>=bit;side++) {
1131                         int num_faces;
1132                         num_faces = get_num_faces(&seg->sides[side]);
1133
1134                         if (num_faces == 0)
1135                                 num_faces = 1;
1136
1137                         // commented out by mk on 02/13/94:: if ((num_faces=seg->sides[side].num_faces)==0) num_faces=1;
1138
1139                         for (face=0;face<2;face++,bit<<=1) {
1140
1141                                 if (endmask & bit) {            //on the back of this face
1142                                         int face_hit_type;      //in what way did we hit the face?
1143
1144
1145                                         if (seg->children[side] == entry_seg)
1146                                                 continue;               //don't go back through entry side
1147
1148                                         //did we go through this wall/door?
1149
1150                                         //#ifdef NEW_FVI_STUFF
1151                                         if (startmask & bit)            //start was also though.  Do extra check
1152                                                 face_hit_type = special_check_line_to_face( &hit_point,
1153                                                                                 p0,p1,seg,side,
1154                                                                                 face,
1155                                                                                 ((num_faces==1)?4:3),rad);
1156                                         else
1157                                         //#endif
1158                                                 //NOTE LINK TO ABOVE!!
1159                                                 face_hit_type = check_line_to_face( &hit_point,
1160                                                                                 p0,p1,seg,side,
1161                                                                                 face,
1162                                                                                 ((num_faces==1)?4:3),rad);
1163
1164         
1165                                         if (face_hit_type) {            //through this wall/door
1166                                                 int wid_flag;
1167
1168                                                 //if what we have hit is a door, check the adjoining seg
1169
1170                                                 if ( (thisobjnum == Players[Player_num].objnum) && (Physics_cheat_flag==0xBADA55) )     {
1171                                                         wid_flag = WALL_IS_DOORWAY(seg, side);
1172                                                         if (seg->children[side] >= 0 )
1173                                                                 wid_flag |= WID_FLY_FLAG;
1174                                                 } else {
1175                                                         wid_flag = WALL_IS_DOORWAY(seg, side);
1176                                                 }
1177
1178                                                 if ((wid_flag & WID_FLY_FLAG) ||
1179                                                         (((wid_flag & WID_RENDER_FLAG) && (wid_flag & WID_RENDPAST_FLAG)) &&
1180                                                                 ((flags & FQ_TRANSWALL) || (flags & FQ_TRANSPOINT && check_trans_wall(&hit_point,seg,side,face))))) {
1181
1182                                                         int newsegnum;
1183                                                         vms_vector sub_hit_point;
1184                                                         int sub_hit_type,sub_hit_seg;
1185                                                         vms_vector save_wall_norm = wall_norm;
1186                                                         int save_hit_objnum=fvi_hit_object;
1187                                                         int i;
1188
1189                                                         //do the check recursively on the next seg.
1190
1191                                                         newsegnum = seg->children[side];
1192
1193                                                         for (i=0;i<n_segs_visited && newsegnum!=segs_visited[i];i++);
1194
1195                                                         if (i==n_segs_visited) {                //haven't visited here yet
1196                                                                 int temp_seglist[MAX_FVI_SEGS],temp_n_segs;
1197                                                                 
1198                                                                 segs_visited[n_segs_visited++] = newsegnum;
1199
1200                                                                 if (n_segs_visited >= MAX_SEGS_VISITED)
1201                                                                         goto quit_looking;              //we've looked a long time, so give up
1202
1203                                                                 sub_hit_type = fvi_sub(&sub_hit_point,&sub_hit_seg,p0,newsegnum,p1,rad,thisobjnum,ignore_obj_list,flags,temp_seglist,&temp_n_segs,startseg);
1204
1205                                                                 if (sub_hit_type != HIT_NONE) {
1206
1207                                                                         d = vm_vec_dist(&sub_hit_point,p0);
1208
1209                                                                         if (d < closest_d) {
1210
1211                                                                                 closest_d = d;
1212                                                                                 closest_hit_point = sub_hit_point;
1213                                                                                 hit_type = sub_hit_type;
1214                                                                                 if (sub_hit_seg!=-1) hit_seg = sub_hit_seg;
1215
1216                                                                                 //copy seglist
1217                                                                                 if (flags&FQ_GET_SEGLIST) {
1218                                                                                         int ii;
1219                                                                                         for (ii=0;i<temp_n_segs && *n_segs<MAX_FVI_SEGS-1;)
1220                                                                                                 seglist[(*n_segs)++] = temp_seglist[ii++];
1221                                                                                 }
1222
1223                                                                                 Assert(*n_segs < MAX_FVI_SEGS);
1224                                                                         }
1225                                                                         else {
1226                                                                                 wall_norm = save_wall_norm;     //global could be trashed
1227                                                                                 fvi_hit_object = save_hit_objnum;
1228                                                                         }
1229
1230                                                                 }
1231                                                                 else {
1232                                                                         wall_norm = save_wall_norm;     //global could be trashed
1233                                                                         if (sub_hit_seg!=-1) hit_none_seg = sub_hit_seg;
1234                                                                         //copy seglist
1235                                                                         if (flags&FQ_GET_SEGLIST) {
1236                                                                                 int ii;
1237                                                                                 for (ii=0;ii<temp_n_segs && ii<MAX_FVI_SEGS-1;ii++)
1238                                                                                         hit_none_seglist[ii] = temp_seglist[ii];
1239                                                                         }
1240                                                                         hit_none_n_segs = temp_n_segs;
1241                                                                 }
1242                                                         }
1243                                                 }
1244                                                 else {          //a wall
1245                                                                                                                                 
1246                                                                 //is this the closest hit?
1247         
1248                                                                 d = vm_vec_dist(&hit_point,p0);
1249         
1250                                                                 if (d < closest_d) {
1251                                                                         closest_d = d;
1252                                                                         closest_hit_point = hit_point;
1253                                                                         hit_type = HIT_WALL;
1254                                                                         
1255                                                                         #ifdef COMPACT_SEGS
1256                                                                                 get_side_normal(seg, side, face, &wall_norm );
1257                                                                         #else
1258                                                                                 wall_norm = seg->sides[side].normals[face];     
1259                                                                         #endif
1260                                                                         
1261         
1262                                                                         if (get_seg_masks(&hit_point,startseg,rad).centermask==0)
1263                                                                                 hit_seg = startseg;             //hit in this segment
1264                                                                         else
1265                                                                                 fvi_hit_seg2 = startseg;
1266
1267                                                                         //@@else         {
1268                                                                         //@@    mprintf( 0, "Warning on line 991 in physics.c\n" );
1269                                                                         //@@    hit_seg = startseg;             //hit in this segment
1270                                                                         //@@    //Int3();
1271                                                                         //@@}
1272
1273                                                                         fvi_hit_seg = hit_seg;
1274                                                                         fvi_hit_side =  side;
1275                                                                         fvi_hit_side_seg = startseg;
1276
1277                                                                 }
1278                                                 }
1279                                         }
1280                                 }
1281                         }
1282                 }
1283         }
1284
1285 //      Assert(centermask==0 || hit_seg!=startseg);
1286
1287 //      Assert(sidemask==0);            //Error("Didn't find side we went though");
1288
1289 quit_looking:
1290         ;
1291
1292         if (hit_type == HIT_NONE) {     //didn't hit anything, return end point
1293                 int i;
1294
1295                 *intp = *p1;
1296                 *ints = hit_none_seg;
1297                 //MATT: MUST FIX THIS!!!!
1298                 //Assert(!centermask);
1299
1300                 if (hit_none_seg!=-1) {                 ///(centermask == 0)
1301                         if (flags&FQ_GET_SEGLIST)
1302                                 //copy seglist
1303                                 for (i=0;i<hit_none_n_segs && *n_segs<MAX_FVI_SEGS-1;)
1304                                         seglist[(*n_segs)++] = hit_none_seglist[i++];
1305                 }
1306                 else
1307                         if (cur_nest_level!=0)
1308                                 *n_segs=0;
1309
1310         }
1311         else {
1312                 *intp = closest_hit_point;
1313                 if (hit_seg==-1)
1314                         if (fvi_hit_seg2 != -1)
1315                                 *ints = fvi_hit_seg2;
1316                         else
1317                                 *ints = hit_none_seg;
1318                 else
1319                         *ints = hit_seg;
1320         }
1321
1322         Assert(!(hit_type==HIT_OBJECT && fvi_hit_object==-1));
1323
1324         return hit_type;
1325
1326 }
1327
1328 /*
1329 //--unused-- //compute the magnitude of a 2d vector
1330 //--unused-- fix mag2d(vec2d *v);
1331 //--unused-- #pragma aux mag2d parm [esi] value [eax] modify exact [eax ebx ecx edx] = \
1332 //--unused--    "mov    eax,[esi]"              \
1333 //--unused--    "imul   eax"                            \
1334 //--unused--    "mov    ebx,eax"                        \
1335 //--unused--    "mov    ecx,edx"                        \
1336 //--unused--    "mov    eax,4[esi]"             \
1337 //--unused--    "imul   eax"                            \
1338 //--unused--    "add    eax,ebx"                        \
1339 //--unused--    "adc    edx,ecx"                        \
1340 //--unused--    "call   quad_sqrt";
1341 */
1342
1343 //--unused-- //returns mag
1344 //--unused-- fix normalize_2d(vec2d *v)
1345 //--unused-- {
1346 //--unused--    fix mag;
1347 //--unused--
1348 //--unused--    mag = mag2d(v);
1349 //--unused--
1350 //--unused--    v->i = fixdiv(v->i,mag);
1351 //--unused--    v->j = fixdiv(v->j,mag);
1352 //--unused--
1353 //--unused--    return mag;
1354 //--unused-- }
1355
1356 #include "textures.h"
1357 #include "texmerge.h"
1358
1359 #define cross(v0,v1) (fixmul((v0)->i,(v1)->j) - fixmul((v0)->j,(v1)->i))
1360
1361 //finds the uv coords of the given point on the given seg & side
1362 //fills in u & v. if l is non-NULL fills it in also
1363 void find_hitpoint_uv(fix *u,fix *v,fix *l,vms_vector *pnt,segment *seg,int sidenum,int facenum)
1364 {
1365         vms_vector_array *pnt_array;
1366         vms_vector_array normal_array;
1367         int segnum = seg-Segments;
1368         int num_faces;
1369         int biggest,ii,jj;
1370         side *side = &seg->sides[sidenum];
1371         int vertex_list[6],vertnum_list[6];
1372         vec2d p1,vec0,vec1,checkp;      //@@,checkv;
1373         uvl uvls[3];
1374         fix k0,k1;
1375         int i;
1376
1377         //mprintf(0,"\ncheck_trans_wall  vec=%x,%x,%x\n",pnt->x,pnt->y,pnt->z);
1378
1379         //do lasers pass through illusory walls?
1380
1381         //when do I return 0 & 1 for non-transparent walls?
1382
1383         if (segnum < 0 || segnum > Highest_segment_index) {
1384                 mprintf((0,"Bad segnum (%d) in find_hitpoint_uv()\n",segnum));
1385                 *u = *v = 0;
1386                 return;
1387         }
1388
1389         if (segnum==-1)
1390                 Error("segnum == -1 in find_hitpoint_uv()");
1391
1392         create_abs_vertex_lists(&num_faces, vertex_list, segnum, sidenum, __FILE__, __LINE__);
1393         create_all_vertnum_lists(&num_faces,vertnum_list,segnum,sidenum);
1394
1395         //now the hard work.
1396
1397         //1. find what plane to project this wall onto to make it a 2d case
1398
1399         #ifdef COMPACT_SEGS
1400                 get_side_normal(seg, sidenum, facenum, (vms_vector *)&normal_array );
1401         #else
1402                 memcpy( &normal_array, &side->normals[facenum], sizeof(vms_vector_array) );
1403         #endif
1404         biggest = 0;
1405
1406         if (abs(normal_array.xyz[1]) > abs(normal_array.xyz[biggest])) biggest = 1;
1407         if (abs(normal_array.xyz[2]) > abs(normal_array.xyz[biggest])) biggest = 2;
1408
1409         if (biggest == 0) ii=1; else ii=0;
1410         if (biggest == 2) jj=1; else jj=2;
1411
1412         //2. compute u,v of intersection point
1413
1414         //vec from 1 -> 0
1415         pnt_array = (vms_vector_array *)&Vertices[vertex_list[facenum*3+1]];
1416         p1.i = pnt_array->xyz[ii];
1417         p1.j = pnt_array->xyz[jj];
1418
1419         pnt_array = (vms_vector_array *)&Vertices[vertex_list[facenum*3+0]];
1420         vec0.i = pnt_array->xyz[ii] - p1.i;
1421         vec0.j = pnt_array->xyz[jj] - p1.j;
1422
1423         //vec from 1 -> 2
1424         pnt_array = (vms_vector_array *)&Vertices[vertex_list[facenum*3+2]];
1425         vec1.i = pnt_array->xyz[ii] - p1.i;
1426         vec1.j = pnt_array->xyz[jj] - p1.j;
1427
1428         //vec from 1 -> checkpoint
1429         pnt_array = (vms_vector_array *)pnt;
1430         checkp.i = pnt_array->xyz[ii];
1431         checkp.j = pnt_array->xyz[jj];
1432
1433         //@@checkv.i = checkp.i - p1.i;
1434         //@@checkv.j = checkp.j - p1.j;
1435
1436         //mprintf(0," vec0   = %x,%x  ",vec0.i,vec0.j);
1437         //mprintf(0," vec1   = %x,%x  ",vec1.i,vec1.j);
1438         //mprintf(0," checkv = %x,%x\n",checkv.i,checkv.j);
1439
1440         k1 = -fixdiv(cross(&checkp,&vec0) + cross(&vec0,&p1),cross(&vec0,&vec1));
1441         if (abs(vec0.i) > abs(vec0.j))
1442                 k0 = fixdiv(fixmul(-k1,vec1.i) + checkp.i - p1.i,vec0.i);
1443         else
1444                 k0 = fixdiv(fixmul(-k1,vec1.j) + checkp.j - p1.j,vec0.j);
1445
1446         //mprintf(0," k0,k1  = %x,%x\n",k0,k1);
1447
1448         for (i=0;i<3;i++)
1449                 uvls[i] = side->uvls[vertnum_list[facenum*3+i]];
1450
1451         *u = uvls[1].u + fixmul( k0,uvls[0].u - uvls[1].u) + fixmul(k1,uvls[2].u - uvls[1].u);
1452         *v = uvls[1].v + fixmul( k0,uvls[0].v - uvls[1].v) + fixmul(k1,uvls[2].v - uvls[1].v);
1453
1454         if (l)
1455                 *l = uvls[1].l + fixmul( k0,uvls[0].l - uvls[1].l) + fixmul(k1,uvls[2].l - uvls[1].l);
1456
1457         //mprintf(0," u,v    = %x,%x\n",*u,*v);
1458 }
1459
1460 //check if a particular point on a wall is a transparent pixel
1461 //returns 1 if can pass though the wall, else 0
1462 int check_trans_wall(vms_vector *pnt,segment *seg,int sidenum,int facenum)
1463 {
1464         grs_bitmap *bm;
1465         side *side = &seg->sides[sidenum];
1466         int bmx,bmy;
1467         fix u,v;
1468
1469 //      Assert(WALL_IS_DOORWAY(seg,sidenum) == WID_TRANSPARENT_WALL);
1470
1471         find_hitpoint_uv(&u,&v,NULL,pnt,seg,sidenum,facenum);   //      Don't compute light value.
1472
1473         if (side->tmap_num2 != 0)       {
1474                 bm = texmerge_get_cached_bitmap( side->tmap_num, side->tmap_num2 );
1475         } else {
1476                 bm = &GameBitmaps[Textures[side->tmap_num].index];
1477                 PIGGY_PAGE_IN( Textures[side->tmap_num] );
1478         }
1479
1480         if (bm->bm_flags & BM_FLAG_RLE)
1481                 bm = rle_expand_texture(bm);
1482
1483         bmx = ((unsigned) f2i(u*bm->bm_w)) % bm->bm_w;
1484         bmy = ((unsigned) f2i(v*bm->bm_h)) % bm->bm_h;
1485
1486 //note: the line above had -v, but that was wrong, so I changed it.  if
1487 //something doesn't work, and you want to make it negative again, you
1488 //should figure out what's going on.
1489
1490         //mprintf(0," bmx,y  = %d,%d, color=%x\n",bmx,bmy,bm->bm_data[bmy*64+bmx]);
1491
1492         return (bm->bm_data[bmy*bm->bm_w+bmx] == TRANSPARENCY_COLOR);
1493 }
1494
1495 //new function for Mike
1496 //note: n_segs_visited must be set to zero before this is called
1497 int sphere_intersects_wall(vms_vector *pnt,int segnum,fix rad)
1498 {
1499         int facemask;
1500         segment *seg;
1501
1502         segs_visited[n_segs_visited++] = segnum;
1503
1504         facemask = get_seg_masks(pnt,segnum,rad).facemask;
1505
1506         seg = &Segments[segnum];
1507
1508         if (facemask != 0) {                            //on the back of at least one face
1509
1510                 int side,bit,face;
1511
1512                 //for each face we are on the back of, check if intersected
1513
1514                 for (side=0,bit=1;side<6 && facemask>=bit;side++) {
1515
1516                         for (face=0;face<2;face++,bit<<=1) {
1517
1518                                 if (facemask & bit) {            //on the back of this face
1519                                         int face_hit_type;      //in what way did we hit the face?
1520                                         int num_faces,vertex_list[6];
1521
1522                                         //did we go through this wall/door?
1523
1524                                         if ((seg-Segments)==-1)
1525                                                 Error("segnum == -1 in sphere_intersects_wall()");
1526
1527                                         create_abs_vertex_lists(&num_faces, vertex_list, seg - Segments, side, __FILE__, __LINE__);
1528
1529                                         face_hit_type = check_sphere_to_face( pnt,&seg->sides[side],
1530                                                                                 face,((num_faces==1)?4:3),rad,vertex_list);
1531
1532                                         if (face_hit_type) {            //through this wall/door
1533                                                 int child,i;
1534
1535                                                 //if what we have hit is a door, check the adjoining seg
1536
1537                                                 child = seg->children[side];
1538
1539                                                 for (i=0;i<n_segs_visited && child!=segs_visited[i];i++);
1540
1541                                                 if (i==n_segs_visited) {                //haven't visited here yet
1542
1543                                                         if (!IS_CHILD(child))
1544                                                                 return 1;
1545                                                         else {
1546
1547                                                                 if (sphere_intersects_wall(pnt,child,rad))
1548                                                                         return 1;
1549                                                         }
1550                                                 }
1551                                         }
1552                                 }
1553                         }
1554                 }
1555         }
1556
1557         return 0;
1558 }
1559
1560 //Returns true if the object is through any walls
1561 int object_intersects_wall(object *objp)
1562 {
1563         n_segs_visited = 0;
1564
1565         return sphere_intersects_wall(&objp->pos,objp->segnum,objp->size);
1566 }
1567
1568