| 1 |
/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
| 2 |
|
| 3 |
#ifndef lint |
| 4 |
static char SCCSid[] = "$SunId$ SGI"; |
| 5 |
#endif |
| 6 |
|
| 7 |
/* |
| 8 |
* sm_stree.c |
| 9 |
* An stree (spherical quadtree) is defined by an octahedron in |
| 10 |
* canonical form,and a world center point. Each face of the |
| 11 |
* octahedron is adaptively subdivided as a planar triangular quadtree. |
| 12 |
* World space geometry is projected onto the quadtree faces from the |
| 13 |
* sphere center. |
| 14 |
*/ |
| 15 |
#include "standard.h" |
| 16 |
#include "sm_list.h" |
| 17 |
#include "sm_flag.h" |
| 18 |
#include "sm_geom.h" |
| 19 |
#include "sm_qtree.h" |
| 20 |
#include "sm_stree.h" |
| 21 |
|
| 22 |
|
| 23 |
#ifdef TEST_DRIVER |
| 24 |
extern FVECT Pick_point[500],Pick_v0[500],Pick_v1[500],Pick_v2[500]; |
| 25 |
extern int Pick_cnt; |
| 26 |
#endif |
| 27 |
/* octahedron coordinates */ |
| 28 |
FVECT stDefault_base[6] = { {1.,0.,0.},{0.,1.,0.}, {0.,0.,1.}, |
| 29 |
{-1.,0.,0.},{0.,-1.,0.},{0.,0.,-1.}}; |
| 30 |
/* octahedron triangle vertices */ |
| 31 |
int stBase_verts[8][3] = { {0,1,2},{3,1,2},{0,4,2},{3,4,2}, |
| 32 |
{0,1,5},{3,1,5},{0,4,5},{3,4,5}}; |
| 33 |
/* octahedron triangle nbrs ; nbr i is the face opposite vertex i*/ |
| 34 |
int stBase_nbrs[8][3] = { {1,2,4},{0,3,5},{3,0,6},{2,1,7}, |
| 35 |
{5,6,0},{4,7,1},{7,4,2},{6,5,3}}; |
| 36 |
int stRoot_indices[8][3] = {{1,1,1},{-1,1,1},{1,-1,1},{-1,-1,1}, |
| 37 |
{1,1,-1},{-1,1,-1},{1,-1,-1},{-1,-1,-1}}; |
| 38 |
/* |
| 39 |
+z y -z y |
| 40 |
| | |
| 41 |
1 | 0 5 | 4 |
| 42 |
______|______ x _______|______ x |
| 43 |
3 | 2 7 | 6 |
| 44 |
| | |
| 45 |
|
| 46 |
Nbrs |
| 47 |
+z y -z y |
| 48 |
/0|1\ /1|0\ |
| 49 |
5 / | \ 4 / | \ |
| 50 |
/(1)|(0)\ 1 /(5)|(4)\ 0 |
| 51 |
/ | \ / | \ |
| 52 |
/2 1|0 2\ /2 0|1 2\ |
| 53 |
/------|------\x /------|------\x |
| 54 |
\0 1|2 0/ \0 2|2 1/ |
| 55 |
\ | / \ | / |
| 56 |
7\ (3)|(2) / 6 3 \ (7)|(6) / 2 |
| 57 |
\ | / \ | / |
| 58 |
\ 2|1 / \ 1|0 / |
| 59 |
*/ |
| 60 |
|
| 61 |
|
| 62 |
stInit(st) |
| 63 |
STREE *st; |
| 64 |
{ |
| 65 |
int i,j; |
| 66 |
|
| 67 |
qtDone(); |
| 68 |
|
| 69 |
ST_TOP_QT(st) = qtAlloc(); |
| 70 |
ST_BOTTOM_QT(st) = qtAlloc(); |
| 71 |
/* Clear the children */ |
| 72 |
|
| 73 |
QT_CLEAR_CHILDREN(ST_TOP_QT(st)); |
| 74 |
QT_CLEAR_CHILDREN(ST_BOTTOM_QT(st)); |
| 75 |
} |
| 76 |
|
| 77 |
stFree(st) |
| 78 |
STREE *st; |
| 79 |
{ |
| 80 |
qtDone(); |
| 81 |
free(st); |
| 82 |
} |
| 83 |
|
| 84 |
/* Allocates a stree structure and creates octahedron base */ |
| 85 |
STREE |
| 86 |
*stAlloc(st) |
| 87 |
STREE *st; |
| 88 |
{ |
| 89 |
int i,m; |
| 90 |
FVECT v0,v1,v2; |
| 91 |
FVECT n; |
| 92 |
|
| 93 |
if(!st) |
| 94 |
if(!(st = (STREE *)malloc(sizeof(STREE)))) |
| 95 |
error(SYSTEM,"stAlloc(): Unable to allocate memory\n"); |
| 96 |
|
| 97 |
/* Allocate the top and bottom quadtree root nodes */ |
| 98 |
stInit(st); |
| 99 |
|
| 100 |
return(st); |
| 101 |
} |
| 102 |
|
| 103 |
#define BARY_INT(v,b) if((v)>2.0) (b) = MAXBCOORD;else \ |
| 104 |
if((v)<-2.0) (b)=-MAXBCOORD;else (b)=(BCOORD)((v)*MAXBCOORD2); |
| 105 |
|
| 106 |
vert_to_qt_frame(root,v,b) |
| 107 |
int root; |
| 108 |
FVECT v; |
| 109 |
BCOORD b[3]; |
| 110 |
{ |
| 111 |
int i; |
| 112 |
double scale; |
| 113 |
double d0,d1,d2; |
| 114 |
|
| 115 |
if(STR_NTH_INDEX(root,0)==-1) |
| 116 |
d0 = -v[0]; |
| 117 |
else |
| 118 |
d0 = v[0]; |
| 119 |
if(STR_NTH_INDEX(root,1)==-1) |
| 120 |
d1 = -v[1]; |
| 121 |
else |
| 122 |
d1 = v[1]; |
| 123 |
if(STR_NTH_INDEX(root,2)==-1) |
| 124 |
d2 = -v[2]; |
| 125 |
else |
| 126 |
d2 = v[2]; |
| 127 |
|
| 128 |
/* Plane is now x+y+z = 1 - intersection of pt ray is qtv/den */ |
| 129 |
scale = 1.0/ (d0 + d1 + d2); |
| 130 |
d0 *= scale; |
| 131 |
d1 *= scale; |
| 132 |
d2 *= scale; |
| 133 |
|
| 134 |
BARY_INT(d0,b[0]) |
| 135 |
BARY_INT(d1,b[1]) |
| 136 |
BARY_INT(d2,b[2]) |
| 137 |
} |
| 138 |
|
| 139 |
|
| 140 |
|
| 141 |
|
| 142 |
ray_to_qt_frame(root,v,dir,b,db) |
| 143 |
int root; |
| 144 |
FVECT v,dir; |
| 145 |
BCOORD b[3],db[3]; |
| 146 |
{ |
| 147 |
int i; |
| 148 |
double scale; |
| 149 |
double d0,d1,d2; |
| 150 |
double dir0,dir1,dir2; |
| 151 |
|
| 152 |
if(STR_NTH_INDEX(root,0)==-1) |
| 153 |
{ |
| 154 |
d0 = -v[0]; |
| 155 |
dir0 = -dir[0]; |
| 156 |
} |
| 157 |
else |
| 158 |
{ |
| 159 |
d0 = v[0]; |
| 160 |
dir0 = dir[0]; |
| 161 |
} |
| 162 |
if(STR_NTH_INDEX(root,1)==-1) |
| 163 |
{ |
| 164 |
d1 = -v[1]; |
| 165 |
dir1 = -dir[1]; |
| 166 |
} |
| 167 |
else |
| 168 |
{ |
| 169 |
d1 = v[1]; |
| 170 |
dir1 = dir[1]; |
| 171 |
} |
| 172 |
if(STR_NTH_INDEX(root,2)==-1) |
| 173 |
{ |
| 174 |
d2 = -v[2]; |
| 175 |
dir2 = -dir[2]; |
| 176 |
} |
| 177 |
else |
| 178 |
{ |
| 179 |
d2 = v[2]; |
| 180 |
dir2 = dir[2]; |
| 181 |
} |
| 182 |
/* Plane is now x+y+z = 1 - intersection of pt ray is qtv/den */ |
| 183 |
scale = 1.0/ (d0 + d1 + d2); |
| 184 |
d0 *= scale; |
| 185 |
d1 *= scale; |
| 186 |
d2 *= scale; |
| 187 |
|
| 188 |
/* Calculate intersection point of orig+dir: This calculation is done |
| 189 |
after the origin is projected into the plane in order to constrain |
| 190 |
the projection( i.e. the size of the projection of the unit direction |
| 191 |
vector translated to the origin depends on how close |
| 192 |
the origin is to the view center |
| 193 |
*/ |
| 194 |
/* Must divide by at least root2 to insure that projection will fit |
| 195 |
int [-2,2] bounds: assumed length is 1: therefore greatest projection |
| 196 |
from endpoint of triangle is at 45 degrees or projected length of root2 |
| 197 |
*/ |
| 198 |
dir0 = d0 + dir0*0.5; |
| 199 |
dir1 = d1 + dir1*0.5; |
| 200 |
dir2 = d2 + dir2*0.5; |
| 201 |
|
| 202 |
scale = 1.0/ (dir0 + dir1 + dir2); |
| 203 |
dir0 *= scale; |
| 204 |
dir1 *= scale; |
| 205 |
dir2 *= scale; |
| 206 |
|
| 207 |
BARY_INT(d0,b[0]) |
| 208 |
BARY_INT(d1,b[1]) |
| 209 |
BARY_INT(d2,b[2]) |
| 210 |
BARY_INT(dir0,db[0]) |
| 211 |
BARY_INT(dir1,db[1]) |
| 212 |
BARY_INT(dir2,db[2]) |
| 213 |
|
| 214 |
db[0] -= b[0]; |
| 215 |
db[1] -= b[1]; |
| 216 |
db[2] -= b[2]; |
| 217 |
} |
| 218 |
|
| 219 |
qt_frame_to_vert(root,b,v) |
| 220 |
int root; |
| 221 |
BCOORD b[3]; |
| 222 |
FVECT v; |
| 223 |
{ |
| 224 |
int i; |
| 225 |
double d0,d1,d2; |
| 226 |
|
| 227 |
d0 = b[0]/(double)MAXBCOORD2; |
| 228 |
d1 = b[1]/(double)MAXBCOORD2; |
| 229 |
d2 = b[2]/(double)MAXBCOORD2; |
| 230 |
|
| 231 |
if(STR_NTH_INDEX(root,0)==-1) |
| 232 |
v[0] = -d0; |
| 233 |
else |
| 234 |
v[0] = d0; |
| 235 |
if(STR_NTH_INDEX(root,1)==-1) |
| 236 |
v[1] = -d1; |
| 237 |
else |
| 238 |
v[1] = d1; |
| 239 |
if(STR_NTH_INDEX(root,2)==-1) |
| 240 |
v[2] = -d2; |
| 241 |
else |
| 242 |
v[2] = d2; |
| 243 |
} |
| 244 |
|
| 245 |
|
| 246 |
/* Return quadtree leaf node containing point 'p'*/ |
| 247 |
QUADTREE |
| 248 |
stPoint_locate(st,p) |
| 249 |
STREE *st; |
| 250 |
FVECT p; |
| 251 |
{ |
| 252 |
QUADTREE qt; |
| 253 |
BCOORD bcoordi[3]; |
| 254 |
int i; |
| 255 |
|
| 256 |
/* Find root quadtree that contains p */ |
| 257 |
i = stLocate_root(p); |
| 258 |
qt = ST_ROOT_QT(st,i); |
| 259 |
|
| 260 |
/* Will return lowest level triangle containing point: It the |
| 261 |
point is on an edge or vertex: will return first associated |
| 262 |
triangle encountered in the child traversal- the others can |
| 263 |
be derived using triangle adjacency information |
| 264 |
*/ |
| 265 |
if(QT_IS_TREE(qt)) |
| 266 |
{ |
| 267 |
vert_to_qt_frame(i,p,bcoordi); |
| 268 |
i = bary_child(bcoordi); |
| 269 |
return(qtLocate(QT_NTH_CHILD(qt,i),bcoordi)); |
| 270 |
} |
| 271 |
else |
| 272 |
return(qt); |
| 273 |
} |
| 274 |
|
| 275 |
static unsigned int nbr_b[8][3] ={{2,4,16},{1,8,32},{8,1,64},{4,2,128}, |
| 276 |
{32,64,1},{16,128,2},{128,16,4},{64,32,8}}; |
| 277 |
unsigned int |
| 278 |
stTri_cells(st,v) |
| 279 |
STREE *st; |
| 280 |
FVECT v[3]; |
| 281 |
{ |
| 282 |
unsigned int cells,cross; |
| 283 |
unsigned int vcell[3]; |
| 284 |
double t0,t1; |
| 285 |
int i,inext; |
| 286 |
|
| 287 |
/* First find base cells that tri vertices are in (0-7)*/ |
| 288 |
vcell[0] = stLocate_root(v[0]); |
| 289 |
vcell[1] = stLocate_root(v[1]); |
| 290 |
vcell[2] = stLocate_root(v[2]); |
| 291 |
|
| 292 |
/* If all in same cell- return that bit only */ |
| 293 |
if(vcell[0] == vcell[1] && vcell[1] == vcell[2]) |
| 294 |
return( 1 << vcell[0]); |
| 295 |
|
| 296 |
cells = 0; |
| 297 |
for(i=0;i<3; i++) |
| 298 |
{ |
| 299 |
if(i==2) |
| 300 |
inext = 0; |
| 301 |
else |
| 302 |
inext = i+1; |
| 303 |
/* Mark cell containing initial vertex */ |
| 304 |
cells |= 1 << vcell[i]; |
| 305 |
|
| 306 |
/* Take the exclusive or: will have bits set where edge crosses axis=0*/ |
| 307 |
cross = vcell[i] ^ vcell[inext]; |
| 308 |
/* If crosses 2 planes: then have 2 options for edge crossing-pick closest |
| 309 |
otherwise just hits two*/ |
| 310 |
/* Neighbors are zyx */ |
| 311 |
switch(cross){ |
| 312 |
case 3: /* crosses x=0 and y=0 */ |
| 313 |
t0 = -v[i][0]/(v[inext][0]-v[i][0]); |
| 314 |
t1 = -v[i][1]/(v[inext][1]-v[i][1]); |
| 315 |
if(t0==t1) |
| 316 |
break; |
| 317 |
else if(t0 < t1) |
| 318 |
cells |= nbr_b[vcell[i]][0]; |
| 319 |
else |
| 320 |
cells |= nbr_b[vcell[i]][1]; |
| 321 |
break; |
| 322 |
case 5: /* crosses x=0 and z=0 */ |
| 323 |
t0 = -v[i][0]/(v[inext][0]-v[i][0]); |
| 324 |
t1 = -v[i][2]/(v[inext][2]-v[i][2]); |
| 325 |
if(t0==t1) |
| 326 |
break; |
| 327 |
else if(t0 < t1) |
| 328 |
cells |= nbr_b[vcell[i]][0]; |
| 329 |
else |
| 330 |
cells |=nbr_b[vcell[i]][2]; |
| 331 |
|
| 332 |
break; |
| 333 |
case 6:/* crosses z=0 and y=0 */ |
| 334 |
t0 = -v[i][2]/(v[inext][2]-v[i][2]); |
| 335 |
t1 = -v[i][1]/(v[inext][1]-v[i][1]); |
| 336 |
if(t0==t1) |
| 337 |
break; |
| 338 |
else if(t0 < t1) |
| 339 |
{ |
| 340 |
cells |= nbr_b[vcell[i]][2]; |
| 341 |
} |
| 342 |
else |
| 343 |
{ |
| 344 |
cells |=nbr_b[vcell[i]][1]; |
| 345 |
} |
| 346 |
break; |
| 347 |
case 7: |
| 348 |
error(CONSISTENCY," Insert:Edge shouldnt be able to span 3 cells"); |
| 349 |
break; |
| 350 |
} |
| 351 |
} |
| 352 |
return(cells); |
| 353 |
} |
| 354 |
|
| 355 |
|
| 356 |
stRoot_trace_ray(qt,root,orig,dir,nextptr,func,f) |
| 357 |
QUADTREE qt; |
| 358 |
int root; |
| 359 |
FVECT orig,dir; |
| 360 |
int *nextptr; |
| 361 |
FUNC func; |
| 362 |
int *f; |
| 363 |
{ |
| 364 |
double br[3]; |
| 365 |
BCOORD bi[3],dbi[3]; |
| 366 |
|
| 367 |
/* Project the origin onto the root node plane */ |
| 368 |
/* Find the intersection point of the origin */ |
| 369 |
ray_to_qt_frame(root,orig,dir,bi,dbi); |
| 370 |
|
| 371 |
/* trace the ray starting with this node */ |
| 372 |
qtTrace_ray(qt,bi,dbi[0],dbi[1],dbi[2],nextptr,0,0,func,f); |
| 373 |
if(!QT_FLAG_IS_DONE(*f)) |
| 374 |
qt_frame_to_vert(root,bi,orig); |
| 375 |
|
| 376 |
} |
| 377 |
|
| 378 |
/* Trace ray 'orig-dir' through stree and apply 'func(qtptr,f,argptr)' at each |
| 379 |
node that it intersects |
| 380 |
*/ |
| 381 |
int |
| 382 |
stTrace_ray(st,orig,dir,func) |
| 383 |
STREE *st; |
| 384 |
FVECT orig,dir; |
| 385 |
FUNC func; |
| 386 |
{ |
| 387 |
int next,last,i,f=0; |
| 388 |
QUADTREE qt; |
| 389 |
FVECT o,n,v; |
| 390 |
double pd,t,d; |
| 391 |
|
| 392 |
VCOPY(o,orig); |
| 393 |
#ifdef TEST_DRIVER |
| 394 |
Pick_cnt=0; |
| 395 |
#endif; |
| 396 |
/* Find the qt node that o falls in */ |
| 397 |
i = stLocate_root(o); |
| 398 |
qt = ST_ROOT_QT(st,i); |
| 399 |
|
| 400 |
stRoot_trace_ray(qt,i,o,dir,&next,func,&f); |
| 401 |
|
| 402 |
if(QT_FLAG_IS_DONE(f)) |
| 403 |
return(TRUE); |
| 404 |
/* |
| 405 |
d = DOT(orig,dir)/sqrt(DOT(orig,orig)); |
| 406 |
VSUM(v,orig,dir,-d); |
| 407 |
*/ |
| 408 |
/* Crossed over to next cell: id = nbr */ |
| 409 |
while(1) |
| 410 |
{ |
| 411 |
/* test if ray crosses plane between this quadtree triangle and |
| 412 |
its neighbor- if it does then find intersection point with |
| 413 |
ray and plane- this is the new origin |
| 414 |
*/ |
| 415 |
if(next == INVALID) |
| 416 |
return(FALSE); |
| 417 |
/* |
| 418 |
if(DOT(o,v) < 0.0) |
| 419 |
return(FALSE); |
| 420 |
*/ |
| 421 |
i = stBase_nbrs[i][next]; |
| 422 |
qt = ST_ROOT_QT(st,i); |
| 423 |
stRoot_trace_ray(qt,i,o,dir,&next,func,&f); |
| 424 |
if(QT_FLAG_IS_DONE(f)) |
| 425 |
return(TRUE); |
| 426 |
} |
| 427 |
} |
| 428 |
|
| 429 |
|
| 430 |
stVisit_poly(st,verts,l,root,func,n) |
| 431 |
STREE *st; |
| 432 |
FVECT *verts; |
| 433 |
LIST *l; |
| 434 |
unsigned int root; |
| 435 |
FUNC func; |
| 436 |
int n; |
| 437 |
{ |
| 438 |
int id0,id1,id2; |
| 439 |
FVECT tri[3]; |
| 440 |
|
| 441 |
id0 = pop_list(&l); |
| 442 |
id1 = pop_list(&l); |
| 443 |
while(l) |
| 444 |
{ |
| 445 |
id2 = pop_list(&l); |
| 446 |
VCOPY(tri[0],verts[id0]); |
| 447 |
VCOPY(tri[1],verts[id1]); |
| 448 |
VCOPY(tri[2],verts[id2]); |
| 449 |
stRoot_visit_tri(st,root,tri,func,n); |
| 450 |
id1 = id2; |
| 451 |
} |
| 452 |
} |
| 453 |
|
| 454 |
stVisit_clip(st,i,verts,vcnt,l,cell,func,n) |
| 455 |
STREE *st; |
| 456 |
int i; |
| 457 |
FVECT *verts; |
| 458 |
int *vcnt; |
| 459 |
LIST *l; |
| 460 |
unsigned int cell; |
| 461 |
FUNC func; |
| 462 |
int n; |
| 463 |
{ |
| 464 |
|
| 465 |
LIST *labove,*lbelow,*endb,*enda; |
| 466 |
int last = -1; |
| 467 |
int id,last_id; |
| 468 |
int first,first_id; |
| 469 |
unsigned int cellb; |
| 470 |
|
| 471 |
labove = lbelow = NULL; |
| 472 |
enda = endb = NULL; |
| 473 |
while(l) |
| 474 |
{ |
| 475 |
id = pop_list(&l); |
| 476 |
if(ZERO(verts[id][i])) |
| 477 |
{ |
| 478 |
if(last==-1) |
| 479 |
{/* add below and above */ |
| 480 |
first = 2; |
| 481 |
first_id= id; |
| 482 |
} |
| 483 |
lbelow=add_data(lbelow,id,&endb); |
| 484 |
labove=add_data(labove,id,&enda); |
| 485 |
last_id = id; |
| 486 |
last = 2; |
| 487 |
continue; |
| 488 |
} |
| 489 |
if(verts[id][i] < 0) |
| 490 |
{ |
| 491 |
if(last != 1) |
| 492 |
{ |
| 493 |
lbelow=add_data(lbelow,id,&endb); |
| 494 |
if(last==-1) |
| 495 |
{ |
| 496 |
first = 0; |
| 497 |
first_id = id; |
| 498 |
} |
| 499 |
last_id = id; |
| 500 |
last = 0; |
| 501 |
continue; |
| 502 |
} |
| 503 |
/* intersect_edges */ |
| 504 |
intersect_edge_coord_plane(verts[last_id],verts[id],i,verts[*vcnt]); |
| 505 |
/*newpoint goes to above and below*/ |
| 506 |
lbelow=add_data(lbelow,*vcnt,&endb); |
| 507 |
lbelow=add_data(lbelow,id,&endb); |
| 508 |
labove=add_data(labove,*vcnt,&enda); |
| 509 |
last = 0; |
| 510 |
last_id = id; |
| 511 |
(*vcnt)++; |
| 512 |
} |
| 513 |
else |
| 514 |
{ |
| 515 |
if(last != 0) |
| 516 |
{ |
| 517 |
labove=add_data(labove,id,&enda); |
| 518 |
if(last==-1) |
| 519 |
{ |
| 520 |
first = 1; |
| 521 |
first_id = id; |
| 522 |
} |
| 523 |
last_id = id; |
| 524 |
last = 1; |
| 525 |
continue; |
| 526 |
} |
| 527 |
/* intersect_edges */ |
| 528 |
/*newpoint goes to above and below*/ |
| 529 |
intersect_edge_coord_plane(verts[last_id],verts[id],i,verts[*vcnt]); |
| 530 |
lbelow=add_data(lbelow,*vcnt,&endb); |
| 531 |
labove=add_data(labove,*vcnt,&enda); |
| 532 |
labove=add_data(labove,id,&enda); |
| 533 |
last_id = id; |
| 534 |
(*vcnt)++; |
| 535 |
last = 1; |
| 536 |
} |
| 537 |
} |
| 538 |
if(first != 2 && first != last) |
| 539 |
{ |
| 540 |
intersect_edge_coord_plane(verts[id],verts[first_id],i,verts[*vcnt]); |
| 541 |
/*newpoint goes to above and below*/ |
| 542 |
lbelow=add_data(lbelow,*vcnt,&endb); |
| 543 |
labove=add_data(labove,*vcnt,&enda); |
| 544 |
(*vcnt)++; |
| 545 |
|
| 546 |
} |
| 547 |
if(i==2) |
| 548 |
{ |
| 549 |
if(lbelow) |
| 550 |
{ |
| 551 |
if(LIST_NEXT(lbelow) && LIST_NEXT(LIST_NEXT(lbelow))) |
| 552 |
{ |
| 553 |
cellb = cell | (1 << i); |
| 554 |
stVisit_poly(st,verts,lbelow,cellb,func,n); |
| 555 |
} |
| 556 |
else |
| 557 |
free_list(lbelow); |
| 558 |
} |
| 559 |
if(labove) |
| 560 |
{ |
| 561 |
if(LIST_NEXT(labove) && LIST_NEXT(LIST_NEXT(labove))) |
| 562 |
stVisit_poly(st,verts,labove,cell,func,n); |
| 563 |
else |
| 564 |
free_list(labove); |
| 565 |
} |
| 566 |
} |
| 567 |
else |
| 568 |
{ |
| 569 |
if(lbelow) |
| 570 |
{ |
| 571 |
if(LIST_NEXT(lbelow) && LIST_NEXT(LIST_NEXT(lbelow))) |
| 572 |
{ |
| 573 |
cellb = cell | (1 << i); |
| 574 |
stVisit_clip(st,i+1,verts,vcnt,lbelow,cellb,func,n); |
| 575 |
} |
| 576 |
else |
| 577 |
free_list(lbelow); |
| 578 |
} |
| 579 |
if(labove) |
| 580 |
{ |
| 581 |
if(LIST_NEXT(labove) && LIST_NEXT(LIST_NEXT(labove))) |
| 582 |
stVisit_clip(st,i+1,verts,vcnt,labove,cell,func,n); |
| 583 |
else |
| 584 |
free_list(labove); |
| 585 |
} |
| 586 |
} |
| 587 |
|
| 588 |
} |
| 589 |
|
| 590 |
stVisit(st,tri,func,n) |
| 591 |
STREE *st; |
| 592 |
FVECT tri[3]; |
| 593 |
FUNC func; |
| 594 |
int n; |
| 595 |
{ |
| 596 |
int r0,r1,r2; |
| 597 |
LIST *l; |
| 598 |
|
| 599 |
r0 = stLocate_root(tri[0]); |
| 600 |
r1 = stLocate_root(tri[1]); |
| 601 |
r2 = stLocate_root(tri[2]); |
| 602 |
if(r0 == r1 && r1==r2) |
| 603 |
stRoot_visit_tri(st,r0,tri,func,n); |
| 604 |
else |
| 605 |
{ |
| 606 |
FVECT verts[ST_CLIP_VERTS]; |
| 607 |
int cnt; |
| 608 |
|
| 609 |
VCOPY(verts[0],tri[0]); |
| 610 |
VCOPY(verts[1],tri[1]); |
| 611 |
VCOPY(verts[2],tri[2]); |
| 612 |
|
| 613 |
l = add_data(NULL,0,NULL); |
| 614 |
l = add_data(l,1,NULL); |
| 615 |
l = add_data(l,2,NULL); |
| 616 |
cnt = 3; |
| 617 |
stVisit_clip(st,0,verts,&cnt,l,0,func,n); |
| 618 |
} |
| 619 |
} |
| 620 |
|
| 621 |
|
| 622 |
/* New Insertion code!!! */ |
| 623 |
|
| 624 |
|
| 625 |
BCOORD qtRoot[3][3] = { {MAXBCOORD2,0,0},{0,MAXBCOORD2,0},{0,0,MAXBCOORD2}}; |
| 626 |
|
| 627 |
|
| 628 |
convert_tri_to_frame(root,tri,b0,b1,b2,db10,db21,db02) |
| 629 |
int root; |
| 630 |
FVECT tri[3]; |
| 631 |
BCOORD b0[3],b1[3],b2[3]; |
| 632 |
BCOORD db10[3],db21[3],db02[3]; |
| 633 |
{ |
| 634 |
/* Project the vertex into the qtree plane */ |
| 635 |
vert_to_qt_frame(root,tri[0],b0); |
| 636 |
vert_to_qt_frame(root,tri[1],b1); |
| 637 |
vert_to_qt_frame(root,tri[2],b2); |
| 638 |
|
| 639 |
/* calculate triangle edge differences in new frame */ |
| 640 |
db10[0] = b1[0] - b0[0]; db10[1] = b1[1] - b0[1]; db10[2] = b1[2] - b0[2]; |
| 641 |
db21[0] = b2[0] - b1[0]; db21[1] = b2[1] - b1[1]; db21[2] = b2[2] - b1[2]; |
| 642 |
db02[0] = b0[0] - b2[0]; db02[1] = b0[1] - b2[1]; db02[2] = b0[2] - b2[2]; |
| 643 |
} |
| 644 |
|
| 645 |
|
| 646 |
QUADTREE |
| 647 |
stRoot_insert_tri(st,root,tri,f) |
| 648 |
STREE *st; |
| 649 |
int root; |
| 650 |
FVECT tri[3]; |
| 651 |
FUNC f; |
| 652 |
{ |
| 653 |
BCOORD b0[3],b1[3],b2[3]; |
| 654 |
BCOORD db10[3],db21[3],db02[3]; |
| 655 |
unsigned int s0,s1,s2,sq0,sq1,sq2; |
| 656 |
QUADTREE qt; |
| 657 |
|
| 658 |
/* Map the triangle vertices into the canonical barycentric frame */ |
| 659 |
convert_tri_to_frame(root,tri,b0,b1,b2,db10,db21,db02); |
| 660 |
|
| 661 |
/* Calculate initial sidedness info */ |
| 662 |
SIDES_GTR(b0,b1,b2,s0,s1,s2,qtRoot[1][0],qtRoot[0][1],qtRoot[0][2]); |
| 663 |
SIDES_GTR(b0,b1,b2,sq0,sq1,sq2,qtRoot[0][0],qtRoot[1][1],qtRoot[2][2]); |
| 664 |
|
| 665 |
qt = ST_ROOT_QT(st,root); |
| 666 |
/* Visit cells that triangle intersects */ |
| 667 |
qt = qtInsert_tri(root,qt,qtRoot[0],qtRoot[1],qtRoot[2], |
| 668 |
b0,b1,b2,db10,db21,db02,MAXBCOORD2 >> 1,s0,s1,s2, sq0,sq1,sq2,f,0); |
| 669 |
|
| 670 |
return(qt); |
| 671 |
} |
| 672 |
|
| 673 |
stRoot_visit_tri(st,root,tri,f,n) |
| 674 |
STREE *st; |
| 675 |
int root; |
| 676 |
FVECT tri[3]; |
| 677 |
FUNC f; |
| 678 |
int n; |
| 679 |
{ |
| 680 |
BCOORD b0[3],b1[3],b2[3]; |
| 681 |
BCOORD db10[3],db21[3],db02[3]; |
| 682 |
unsigned int s0,s1,s2,sq0,sq1,sq2; |
| 683 |
QUADTREE qt; |
| 684 |
|
| 685 |
/* Map the triangle vertices into the canonical barycentric frame */ |
| 686 |
convert_tri_to_frame(root,tri,b0,b1,b2,db10,db21,db02); |
| 687 |
|
| 688 |
/* Calculate initial sidedness info */ |
| 689 |
SIDES_GTR(b0,b1,b2,s0,s1,s2,qtRoot[1][0],qtRoot[0][1],qtRoot[0][2]); |
| 690 |
SIDES_GTR(b0,b1,b2,sq0,sq1,sq2,qtRoot[0][0],qtRoot[1][1],qtRoot[2][2]); |
| 691 |
|
| 692 |
qt = ST_ROOT_QT(st,root); |
| 693 |
QT_SET_FLAG(ST_QT(st,root)); |
| 694 |
/* Visit cells that triangle intersects */ |
| 695 |
qtVisit_tri(root,qt,qtRoot[0],qtRoot[1],qtRoot[2], |
| 696 |
b0,b1,b2,db10,db21,db02,MAXBCOORD2 >> 1,s0,s1,s2, sq0,sq1,sq2,f,n); |
| 697 |
|
| 698 |
} |
| 699 |
|
| 700 |
stInsert_tri(st,tri,f) |
| 701 |
STREE *st; |
| 702 |
FVECT tri[3]; |
| 703 |
FUNC f; |
| 704 |
{ |
| 705 |
unsigned int cells,which; |
| 706 |
int root; |
| 707 |
|
| 708 |
|
| 709 |
/* calculate entry/exit points of edges through the cells */ |
| 710 |
cells = stTri_cells(st,tri); |
| 711 |
|
| 712 |
/* For each cell that quadtree intersects: Map the triangle vertices into |
| 713 |
the canonical barycentric frame of (1,0,0), (0,1,0),(0,0,1). Insert |
| 714 |
by first doing a trivial reject on the interior nodes, and then a |
| 715 |
tri/tri intersection at the leaf nodes. |
| 716 |
*/ |
| 717 |
for(root=0,which=1; root < ST_NUM_ROOT_NODES; root++,which <<= 1) |
| 718 |
{ |
| 719 |
/* For each of the quadtree roots: check if marked as intersecting tri*/ |
| 720 |
if(cells & which) |
| 721 |
/* Visit tri cells */ |
| 722 |
ST_ROOT_QT(st,root) = stRoot_insert_tri(st,root,tri,f); |
| 723 |
} |
| 724 |
} |
| 725 |
|
| 726 |
stInsert_samp(st,p,f) |
| 727 |
STREE *st; |
| 728 |
FVECT p; |
| 729 |
FUNC f; |
| 730 |
{ |
| 731 |
|
| 732 |
QUADTREE qt; |
| 733 |
BCOORD bcoordi[3]; |
| 734 |
int i,done; |
| 735 |
|
| 736 |
/* Find root quadtree that contains p */ |
| 737 |
i = stLocate_root(p); |
| 738 |
qt = ST_ROOT_QT(st,i); |
| 739 |
|
| 740 |
/* Will return lowest level triangle containing point: It the |
| 741 |
point is on an edge or vertex: will return first associated |
| 742 |
triangle encountered in the child traversal- the others can |
| 743 |
be derived using triangle adjacency information |
| 744 |
*/ |
| 745 |
vert_to_qt_frame(i,p,bcoordi); |
| 746 |
ST_ROOT_QT(st,i) = qtInsert_point(i,qt,EMPTY,qtRoot[0],qtRoot[1], |
| 747 |
qtRoot[2],bcoordi,MAXBCOORD2>>1,f,0,&done); |
| 748 |
|
| 749 |
} |
| 750 |
|
| 751 |
|
| 752 |
|
| 753 |
|
| 754 |
|
| 755 |
|
| 756 |
|
| 757 |
|
| 758 |
|
| 759 |
|
