main/fvi.c

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