1 |
/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
2 |
|
3 |
#ifndef lint |
4 |
static char SCCSid[] = "$SunId$ SGI"; |
5 |
#endif |
6 |
|
7 |
/* |
8 |
* sm_del.c |
9 |
*/ |
10 |
#include "standard.h" |
11 |
#include "sm_flag.h" |
12 |
#include "sm_list.h" |
13 |
#include "sm_geom.h" |
14 |
#include "sm_qtree.h" |
15 |
#include "sm_stree.h" |
16 |
#include "sm.h" |
17 |
|
18 |
static int Max_edges=200; |
19 |
static EDGE *Edges=NULL; |
20 |
static int Ecnt=0; |
21 |
|
22 |
#define remove_tri_compress remove_tri |
23 |
remove_tri(qtptr,fptr,tptr) |
24 |
QUADTREE *qtptr; |
25 |
int *fptr; |
26 |
int *tptr; |
27 |
{ |
28 |
int n; |
29 |
|
30 |
if(QT_IS_EMPTY(*qtptr)) |
31 |
return; |
32 |
if(QT_LEAF_IS_FLAG(*qtptr)) |
33 |
return; |
34 |
|
35 |
n = QT_SET_CNT(qtqueryset(*qtptr))-1; |
36 |
*qtptr = qtdelelem(*qtptr,*tptr); |
37 |
if(n == 0) |
38 |
(*fptr) |= QT_COMPRESS; |
39 |
if(!QT_FLAG_FILL_TRI(*fptr)) |
40 |
(*fptr)++; |
41 |
} |
42 |
|
43 |
|
44 |
smLocator_remove_tri(sm,t_id,v0_id,v1_id,v2_id) |
45 |
SM *sm; |
46 |
int t_id; |
47 |
int v0_id,v1_id,v2_id; |
48 |
{ |
49 |
STREE *st; |
50 |
FVECT v0,v1,v2; |
51 |
|
52 |
st = SM_LOCATOR(sm); |
53 |
|
54 |
VSUB(v0,SM_NTH_WV(sm,v0_id),SM_VIEW_CENTER(sm)); |
55 |
VSUB(v1,SM_NTH_WV(sm,v1_id),SM_VIEW_CENTER(sm)); |
56 |
VSUB(v2,SM_NTH_WV(sm,v2_id),SM_VIEW_CENTER(sm)); |
57 |
|
58 |
qtClearAllFlags(); |
59 |
|
60 |
stApply_to_tri(st,v0,v1,v2,remove_tri,remove_tri_compress,&t_id); |
61 |
|
62 |
} |
63 |
|
64 |
smFree_tri(sm,id) |
65 |
SM *sm; |
66 |
int id; |
67 |
{ |
68 |
TRI *tri; |
69 |
|
70 |
tri = SM_NTH_TRI(sm,id); |
71 |
/* Add to the free_list */ |
72 |
T_NEXT_FREE(tri) = SM_FREE_TRIS(sm); |
73 |
SM_FREE_TRIS(sm) = id; |
74 |
T_VALID_FLAG(tri) = -1; |
75 |
} |
76 |
|
77 |
/* Assumes mesh pointers have been cleaned up appropriately: just deletes from |
78 |
Point location and triangle data structure |
79 |
*/ |
80 |
smDelete_tri(sm,t_id) |
81 |
SM *sm; |
82 |
int t_id; |
83 |
{ |
84 |
|
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/* NOTE: Assumes that a new triangle adjacent to each vertex |
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has been added- before the deletion: replacing |
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the old tri- and therefore dont need to dereference any pointers |
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to id because the vertices can no longer |
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point to tri id as being the first triangle pointer |
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*/ |
91 |
if(!SM_IS_NTH_T_BASE(sm,t_id)) |
92 |
{ |
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SM_SAMPLE_TRIS(sm)--; |
94 |
if(SM_IS_NTH_T_NEW(sm,t_id)) |
95 |
smNew_tri_cnt--; |
96 |
} |
97 |
smClear_tri_flags(sm,t_id); |
98 |
|
99 |
smFree_tri(sm,t_id); |
100 |
} |
101 |
|
102 |
|
103 |
int |
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eNew_edge() |
105 |
{ |
106 |
if(!Edges) |
107 |
if(!(Edges = (EDGE *)realloc(NULL,(Max_edges+1)*sizeof(EDGE)))) |
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goto memerr; |
109 |
|
110 |
if(Ecnt >= Max_edges) |
111 |
{ |
112 |
if(Max_edges > 10000) |
113 |
error(CONSISTENCY,"Too many edges in vertex loop\n"); |
114 |
Max_edges += 100; |
115 |
if(!(Edges = (EDGE *)realloc(Edges,(Max_edges+1)*sizeof(EDGE)))) |
116 |
goto memerr; |
117 |
} |
118 |
return(++Ecnt); |
119 |
|
120 |
memerr: |
121 |
error(SYSTEM,"eNew_edge(): Unable to allocate memory"); |
122 |
} |
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|
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/* Return list of edges defining polygon formed by boundary of triangles |
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adjacent to id. Return set of triangles adjacent to id to delete in delptr |
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*/ |
127 |
LIST |
128 |
*smVertexPolygon(sm,id,delptr) |
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SM *sm; |
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int id; |
131 |
QUADTREE *delptr; |
132 |
{ |
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TRI *tri,*t_next; |
134 |
LIST *elist,*end; |
135 |
int e,t_id,v_next,t_next_id,b_id,v_id; |
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OBJECT del_set[2]; |
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|
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eClear_edges(); |
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elist = end = NULL; |
140 |
|
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/* Get the first triangle adjacent to vertex id */ |
142 |
t_id = SM_NTH_VERT(sm,id); |
143 |
tri = SM_NTH_TRI(sm,t_id); |
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|
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e = eNew_edge(); |
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/* Get the next vertex on the polygon boundary */ |
147 |
v_id = T_WHICH_V(tri,id); |
148 |
b_id = (v_id + 1)%3; |
149 |
/* Create an edge */ |
150 |
SET_E_NTH_VERT(e,0,T_NTH_V(tri,b_id)); |
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SET_E_NTH_TRI(e,0,INVALID); |
152 |
SET_E_NTH_TRI(e,1,T_NTH_NBR(tri,v_id)); |
153 |
v_next = T_NTH_V(tri,(b_id+1)%3); |
154 |
SET_E_NTH_VERT(e,1,v_next); |
155 |
elist = add_data_to_circular_list(elist,&end,e); |
156 |
t_next_id = t_id; |
157 |
t_next = tri; |
158 |
|
159 |
/* Create a set to hold all of the triangles for deletion later */ |
160 |
del_set[0] = 1; del_set[1] = t_id; |
161 |
*delptr = qtnewleaf(del_set); |
162 |
|
163 |
while((t_next_id = T_NTH_NBR(t_next,b_id)) != t_id) |
164 |
{ |
165 |
e = eNew_edge(); |
166 |
t_next = SM_NTH_TRI(sm,t_next_id); |
167 |
SET_E_NTH_VERT(e,0,v_next); |
168 |
SET_E_NTH_TRI(e,0,INVALID); |
169 |
v_id = T_WHICH_V(t_next,id); |
170 |
b_id = (v_id + 1)%3; |
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SET_E_NTH_TRI(e,1,T_NTH_NBR(t_next,v_id)); |
172 |
v_next = T_NTH_V(t_next,(b_id+1)%3); |
173 |
SET_E_NTH_VERT(e,1,v_next); |
174 |
elist = add_data_to_circular_list(elist,&end,e); |
175 |
qtaddelem(*delptr,t_next_id); |
176 |
} |
177 |
return(elist); |
178 |
} |
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|
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|
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int |
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smTriangulate_add_tri(sm,id0,id1,id2,e0,e1,e2ptr) |
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SM *sm; |
184 |
int id0,id1,id2,e0,e1,*e2ptr; |
185 |
{ |
186 |
int t_id; |
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int e2; |
188 |
|
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#ifdef DEBUG |
190 |
if(id0 == INVALID || id1==INVALID || id2==INVALID) |
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error(CONSISTENCY,"bad id- smTriangulate_add_tri()\n"); |
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#endif |
193 |
t_id = smAdd_tri(sm,id0,id1,id2); |
194 |
if(*e2ptr == 0) |
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{ |
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e2 = eNew_edge(); |
197 |
SET_E_NTH_VERT(e2,0,id2); |
198 |
SET_E_NTH_VERT(e2,1,id0); |
199 |
} |
200 |
else |
201 |
e2 = *e2ptr; |
202 |
/* set appropriate tri for each edge*/ |
203 |
SET_E_NTH_TRI(e0,0,t_id); |
204 |
SET_E_NTH_TRI(e1,0,t_id); |
205 |
SET_E_NTH_TRI(e2,0,t_id); |
206 |
|
207 |
*e2ptr = e2; |
208 |
return(t_id); |
209 |
} |
210 |
|
211 |
int |
212 |
smTriangulateConvex(sm,plist,add_ptr) |
213 |
SM *sm; |
214 |
LIST *plist,**add_ptr; |
215 |
{ |
216 |
int t_id,e_id0,e_id1,e_id2; |
217 |
int v_id0,v_id1,v_id2; |
218 |
LIST *lptr; |
219 |
|
220 |
lptr = plist; |
221 |
e_id0 = (int)LIST_DATA(lptr); |
222 |
v_id0 = E_NTH_VERT(e_id0,0); |
223 |
lptr = LIST_NEXT(lptr); |
224 |
while(LIST_NEXT(lptr) != plist) |
225 |
{ |
226 |
e_id1 = (int)LIST_DATA(lptr); |
227 |
v_id1 = E_NTH_VERT(e_id1,0); |
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v_id2 = E_NTH_VERT(e_id1,1); |
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lptr = LIST_NEXT(lptr); |
230 |
|
231 |
if(LIST_NEXT(lptr) != plist) |
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e_id2 = 0; |
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else |
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e_id2 = (int)LIST_DATA(lptr); |
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t_id = smTriangulate_add_tri(sm,v_id0,v_id1,v_id2,e_id0,e_id1,&e_id2); |
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*add_ptr = push_data(*add_ptr,t_id); |
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e_id0 = -e_id2; |
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} |
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free_list(plist); |
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return(TRUE); |
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} |
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#ifdef TEST_DRIVER |
243 |
FVECT Norm[500],B_V[500]; |
244 |
int Ncnt,Bcnt,Del=0; |
245 |
#endif |
246 |
|
247 |
|
248 |
/* Triangulate the polygon defined by plist, and generating vertex p_id. |
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Return list of added triangles in list add_ptr. Returns TRUE if |
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successful, FALSE otherwise. This is NOT a general triangulation routine, |
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assumes polygon star relative to id |
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*/ |
253 |
|
254 |
int |
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smTriangulate(sm,id,plist,add_ptr) |
256 |
SM *sm; |
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int id; |
258 |
LIST *plist,**add_ptr; |
259 |
{ |
260 |
LIST *l,*prev,*t; |
261 |
FVECT v0,v1,v2,n,p; |
262 |
int is_tri,is_convex,cut,t_id,id0,id1,id2,e2,e1,enew; |
263 |
double dp; |
264 |
|
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VSUB(p,SM_NTH_WV(sm,id),SM_VIEW_CENTER(sm)); |
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enew = 0; |
267 |
is_convex = TRUE; |
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cut = is_tri= FALSE; |
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l = prev = plist; |
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|
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/* get v0,v1 */ |
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e1 = (int)LIST_DATA(l); |
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id0 = E_NTH_VERT(e1,0); |
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id1 = E_NTH_VERT(e1,1); |
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VSUB(v0,SM_NTH_WV(sm,id0),SM_VIEW_CENTER(sm)); |
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VSUB(v1,SM_NTH_WV(sm,id1),SM_VIEW_CENTER(sm)); |
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#ifdef TEST_DRIVER |
278 |
Del = TRUE; |
279 |
VCOPY(B_V[0],v0); |
280 |
VCOPY(B_V[1],v1); |
281 |
Bcnt = 2; |
282 |
Ncnt = 0; |
283 |
#endif |
284 |
while(l) |
285 |
{ |
286 |
l = LIST_NEXT(l); |
287 |
/* Get v2 */ |
288 |
e2 = (int)LIST_DATA(l); |
289 |
id2 = E_NTH_VERT(e2,1); |
290 |
VSUB(v2,SM_NTH_WV(sm,id2),SM_VIEW_CENTER(sm)); |
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#ifdef TEST_DRIVER |
292 |
VCOPY(B_V[Bcnt++],v2); |
293 |
#endif |
294 |
if(LIST_NEXT(LIST_NEXT(l)) == prev) |
295 |
{/* Check if have a triangle */ |
296 |
is_tri = TRUE; |
297 |
break; |
298 |
} |
299 |
|
300 |
/* determine if v0-v1-v2 is convex:defined clockwise on the sphere- |
301 |
so switch orientation |
302 |
*/ |
303 |
if(convex_angle(v2,v1,v0)) |
304 |
{ |
305 |
/* test if safe to cut off v0-v1-v2 by testing if p lies outside of |
306 |
triangle v0-v1-v2: if so, because plist is the star polygon around p, |
307 |
the new edge v2-v0 cannot intersect any existing edges |
308 |
*/ |
309 |
VCROSS(n,v0,v2); |
310 |
dp = DOT(n,p); |
311 |
if(dp <= 0.0) |
312 |
{ |
313 |
/* remove edges e1,e2 and add triangle id0,id1,id2 */ |
314 |
enew = 0; |
315 |
t_id = smTriangulate_add_tri(sm,id0,id1,id2,e1,e2,&enew); |
316 |
cut = TRUE; |
317 |
*add_ptr = push_data(*add_ptr,t_id); |
318 |
/* Insert edge enew into the list, reuse prev list element */ |
319 |
LIST_NEXT(prev) = LIST_NEXT(l); |
320 |
LIST_DATA(prev) = e1 = -enew; |
321 |
/* If removing head of list- reset plist pointer */ |
322 |
if(l== plist) |
323 |
plist = prev; |
324 |
/* free list element for e2 */ |
325 |
LIST_NEXT(l)=NULL; |
326 |
free_list(l); |
327 |
l = prev; |
328 |
VCOPY(v1,v2); |
329 |
id1 = id2; |
330 |
continue; |
331 |
} |
332 |
} |
333 |
else |
334 |
is_convex = FALSE; |
335 |
VCOPY(v0,v1); |
336 |
VCOPY(v1,v2); |
337 |
id0 = id1; |
338 |
id1 = id2; |
339 |
e1 = e2; |
340 |
/* check if gone around circular list without adding any |
341 |
triangles: prevent infinite loop */ |
342 |
if(l == plist) |
343 |
{ |
344 |
if(LIST_NEXT(LIST_NEXT(l)) == prev) |
345 |
{/* Check if have a triangle */ |
346 |
is_tri = TRUE; |
347 |
break; |
348 |
} |
349 |
|
350 |
if(is_convex) |
351 |
break; |
352 |
if(!cut) |
353 |
{ |
354 |
#ifdef DEBUG |
355 |
eputs("smTriangulate():Unable to triangulate\n"); |
356 |
#endif |
357 |
free_list(l); |
358 |
while(*add_ptr) |
359 |
{ |
360 |
t_id = pop_list(add_ptr); |
361 |
smDelete_tri(sm,t_id); |
362 |
} |
363 |
return(FALSE); |
364 |
} |
365 |
cut = FALSE; |
366 |
is_convex = TRUE; |
367 |
} |
368 |
prev = l; |
369 |
} |
370 |
if(is_tri) |
371 |
{ |
372 |
l = LIST_NEXT(l); |
373 |
enew = (int)LIST_DATA(l); |
374 |
t_id = smTriangulate_add_tri(sm,id0,id1,id2,e1,e2,&enew); |
375 |
*add_ptr = push_data(*add_ptr,t_id); |
376 |
free_list(l); |
377 |
} |
378 |
else |
379 |
if(!smTriangulateConvex(sm,l,add_ptr)) |
380 |
return(FALSE); |
381 |
|
382 |
/* Set triangle adjacencies based on edge adjacencies */ |
383 |
FOR_ALL_EDGES(enew) |
384 |
{ |
385 |
id0 = E_NTH_TRI(enew,0); |
386 |
id1 = E_NTH_TRI(enew,1); |
387 |
|
388 |
e1 = (T_WHICH_V(SM_NTH_TRI(sm,id0),E_NTH_VERT(enew,0))+2)%3; |
389 |
T_NTH_NBR(SM_NTH_TRI(sm,id0),e1) = id1; |
390 |
|
391 |
e2 = (T_WHICH_V(SM_NTH_TRI(sm,id1),E_NTH_VERT(enew,1))+2)%3; |
392 |
T_NTH_NBR(SM_NTH_TRI(sm,id1),e2) = id0; |
393 |
} |
394 |
return(TRUE); |
395 |
} |
396 |
|
397 |
eIn_tri(e,t) |
398 |
int e; |
399 |
TRI *t; |
400 |
{ |
401 |
|
402 |
if(T_NTH_V(t,0)==E_NTH_VERT(e,0)) |
403 |
return(T_NTH_V(t,1)==E_NTH_VERT(e,1)||T_NTH_V(t,2)==E_NTH_VERT(e,1)); |
404 |
else |
405 |
if(T_NTH_V(t,1)==E_NTH_VERT(e,0)) |
406 |
return(T_NTH_V(t,0)==E_NTH_VERT(e,1)||T_NTH_V(t,2)==E_NTH_VERT(e,1)); |
407 |
else if(T_NTH_V(t,2)==E_NTH_VERT(e,0)) |
408 |
return(T_NTH_V(t,0)==E_NTH_VERT(e,1)||T_NTH_V(t,1)==E_NTH_VERT(e,1)); |
409 |
|
410 |
return(FALSE); |
411 |
} |
412 |
|
413 |
/* Test the new set of triangles for Delaunay condition. 'Edges' contains |
414 |
all of the new edges added. The CCW triangle assoc with each edge is |
415 |
tested against the opposite vertex of the CW triangle. If the vertex |
416 |
lies inside the circle defined by the CCW triangle- the edge is swapped |
417 |
for the opposite diagonal |
418 |
*/ |
419 |
smFixEdges(sm,add_list,delptr) |
420 |
SM *sm; |
421 |
LIST *add_list; |
422 |
QUADTREE *delptr; |
423 |
|
424 |
{ |
425 |
int e,t0_id,t1_id,e_new,e0,e1,e0_next,e1_next; |
426 |
int i,v0_id,v1_id,v2_id,p_id,t0_nid,t1_nid; |
427 |
FVECT v0,v1,v2,p,np,v; |
428 |
TRI *t0,*t1; |
429 |
|
430 |
FOR_ALL_EDGES(e) |
431 |
{ |
432 |
t0_id = E_NTH_TRI(e,0); |
433 |
t1_id = E_NTH_TRI(e,1); |
434 |
if((t0_id==INVALID) || (t1_id==INVALID)) |
435 |
{ |
436 |
#ifdef DEBUG |
437 |
error(CONSISTENCY,"smFix_edges: Unassigned edge nbr\n"); |
438 |
#endif |
439 |
} |
440 |
t0 = SM_NTH_TRI(sm,t0_id); |
441 |
t1 = SM_NTH_TRI(sm,t1_id); |
442 |
e0 = T_NTH_NBR_PTR(t1_id,t0); |
443 |
e1 = T_NTH_NBR_PTR(t0_id,t1); |
444 |
|
445 |
v0_id = E_NTH_VERT(e,0); |
446 |
v1_id = E_NTH_VERT(e,1); |
447 |
v2_id = T_NTH_V(t0,e0); |
448 |
p_id = T_NTH_V(t1,e1); |
449 |
|
450 |
smDir_in_cone(sm,v0,v0_id); |
451 |
smDir_in_cone(sm,v1,v1_id); |
452 |
smDir_in_cone(sm,v2,v2_id); |
453 |
|
454 |
VCOPY(p,SM_NTH_WV(sm,p_id)); |
455 |
VSUB(p,p,SM_VIEW_CENTER(sm)); |
456 |
if(point_in_cone(p,v0,v1,v2)) |
457 |
{ |
458 |
smTris_swap_edge(sm,t0_id,t1_id,e0,e1,&t0_nid,&t1_nid,&add_list, |
459 |
delptr); |
460 |
|
461 |
/* Adjust the triangle pointers of the remaining edges to be |
462 |
processed |
463 |
*/ |
464 |
FOR_ALL_EDGES_FROM(e,i) |
465 |
{ |
466 |
if(E_NTH_TRI(i,0)==t0_id || E_NTH_TRI(i,0)==t1_id) |
467 |
{ |
468 |
if(eIn_tri(i,SM_NTH_TRI(sm,t0_nid))) |
469 |
SET_E_NTH_TRI(i,0,t0_nid); |
470 |
else |
471 |
SET_E_NTH_TRI(i,0,t1_nid); |
472 |
} |
473 |
|
474 |
if(E_NTH_TRI(i,1)==t0_id || E_NTH_TRI(i,1)==t1_id) |
475 |
{ |
476 |
if(eIn_tri(i,SM_NTH_TRI(sm,t0_nid))) |
477 |
SET_E_NTH_TRI(i,1,t0_nid); |
478 |
else |
479 |
SET_E_NTH_TRI(i,1,t1_nid); |
480 |
} |
481 |
} |
482 |
t0_id = t0_nid; |
483 |
t1_id = t1_nid; |
484 |
e_new = eNew_edge(); |
485 |
SET_E_NTH_VERT(e_new,0,p_id); |
486 |
SET_E_NTH_VERT(e_new,1,v2_id); |
487 |
SET_E_NTH_TRI(e_new,0,t0_id); |
488 |
SET_E_NTH_TRI(e_new,1,t1_id); |
489 |
} |
490 |
} |
491 |
/* Add/Delete the appropriate triangles from the stree */ |
492 |
smUpdate_locator(sm,add_list,qtqueryset(*delptr)); |
493 |
|
494 |
} |
495 |
|
496 |
/* Remove vertex "id" from the mesh- and retriangulate the resulting |
497 |
hole: Returns TRUE if successful, FALSE otherwise. |
498 |
*/ |
499 |
int |
500 |
smRemoveVertex(sm,id) |
501 |
SM *sm; |
502 |
int id; |
503 |
{ |
504 |
LIST *b_list,*add_list; |
505 |
QUADTREE delnode=-1; |
506 |
int t_id; |
507 |
|
508 |
/* generate list of edges that form the boundary of the |
509 |
polygon formed by the triangles adjacent to vertex 'id' |
510 |
*/ |
511 |
b_list = smVertexPolygon(sm,id,&delnode); |
512 |
|
513 |
add_list = NULL; |
514 |
/* Triangulate polygonal hole */ |
515 |
if(!smTriangulate(sm,id,b_list,&add_list)) |
516 |
{ |
517 |
qtfreeleaf(delnode); |
518 |
return(FALSE); |
519 |
} |
520 |
/* Fix up new triangles to be Delaunay-delnode contains set of |
521 |
triangles to delete,add_list is the set of new triangles to add |
522 |
*/ |
523 |
smFixEdges(sm,add_list,&delnode); |
524 |
|
525 |
|
526 |
qtfreeleaf(delnode); |
527 |
return(TRUE); |
528 |
} |
529 |
|
530 |
|
531 |
|
532 |
|
533 |
|
534 |
|
535 |
|
536 |
|
537 |
|
538 |
|
539 |
|
540 |
|
541 |
|
542 |
|
543 |
|