main/fvi.c

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