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Reference Guide
triangle.h
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1 #ifndef TRIANGLE_H
2 #define TRIANGLE_H
3 
4 /*****************************************************************************/
5 /* */
6 /* (triangle.h) */
7 /* */
8 /* Include file for programs that call Triangle. */
9 /* */
10 /* Accompanies Triangle Version 1.6 */
11 /* July 28, 2005 */
12 /* */
13 /* Copyright 1996, 2005 */
14 /* Jonathan Richard Shewchuk */
15 /* 2360 Woolsey #H */
16 /* Berkeley, California 94705-1927 */
17 /* jrs@cs.berkeley.edu */
18 /* */
19 /*****************************************************************************/
20 
21 /*****************************************************************************/
22 /* */
23 /* How to call Triangle from another program */
24 /* */
25 /* */
26 /* If you haven't read Triangle's instructions (run "triangle -h" to read */
27 /* them), you won't understand what follows. */
28 /* */
29 /* Triangle must be compiled into an object file (triangle.o) with the */
30 /* TRILIBRARY symbol defined (generally by using the -DTRILIBRARY compiler */
31 /* switch). The makefile included with Triangle will do this for you if */
32 /* you run "make trilibrary". The resulting object file can be called via */
33 /* the procedure triangulate(). */
34 /* */
35 /* If the size of the object file is important to you, you may wish to */
36 /* generate a reduced version of triangle.o. The REDUCED symbol gets rid */
37 /* of all features that are primarily of research interest. Specifically, */
38 /* the -DREDUCED switch eliminates Triangle's -i, -F, -s, and -C switches. */
39 /* The CDT_ONLY symbol gets rid of all meshing algorithms above and beyond */
40 /* constrained Delaunay triangulation. Specifically, the -DCDT_ONLY switch */
41 /* eliminates Triangle's -r, -q, -a, -u, -D, -Y, -S, and -s switches. */
42 /* */
43 /* IMPORTANT: These definitions (TRILIBRARY, REDUCED, CDT_ONLY) must be */
44 /* made in the makefile or in triangle.c itself. Putting these definitions */
45 /* in this file (triangle.h) will not create the desired effect. */
46 /* */
47 /* */
48 /* The calling convention for triangulate() follows. */
49 /* */
50 /* void triangulate(triswitches, in, out, vorout) */
51 /* char *triswitches; */
52 /* struct triangulateio *in; */
53 /* struct triangulateio *out; */
54 /* struct triangulateio *vorout; */
55 /* */
56 /* `triswitches' is a string containing the command line switches you wish */
57 /* to invoke. No initial dash is required. Some suggestions: */
58 /* */
59 /* - You'll probably find it convenient to use the `z' switch so that */
60 /* points (and other items) are numbered from zero. This simplifies */
61 /* indexing, because the first item of any type always starts at index */
62 /* [0] of the corresponding array, whether that item's number is zero or */
63 /* one. */
64 /* - You'll probably want to use the `Q' (quiet) switch in your final code, */
65 /* but you can take advantage of Triangle's printed output (including the */
66 /* `V' switch) while debugging. */
67 /* - If you are not using the `q', `a', `u', `D', `j', or `s' switches, */
68 /* then the output points will be identical to the input points, except */
69 /* possibly for the boundary markers. If you don't need the boundary */
70 /* markers, you should use the `N' (no nodes output) switch to save */
71 /* memory. (If you do need boundary markers, but need to save memory, a */
72 /* good nasty trick is to set out->pointlist equal to in->pointlist */
73 /* before calling triangulate(), so that Triangle overwrites the input */
74 /* points with identical copies.) */
75 /* - The `I' (no iteration numbers) and `g' (.off file output) switches */
76 /* have no effect when Triangle is compiled with TRILIBRARY defined. */
77 /* */
78 /* `in', `out', and `vorout' are descriptions of the input, the output, */
79 /* and the Voronoi output. If the `v' (Voronoi output) switch is not used, */
80 /* `vorout' may be NULL. `in' and `out' may never be NULL. */
81 /* */
82 /* Certain fields of the input and output structures must be initialized, */
83 /* as described below. */
84 /* */
85 /*****************************************************************************/
86 
87 /*****************************************************************************/
88 /* */
89 /* The `triangulateio' structure. */
90 /* */
91 /* Used to pass data into and out of the triangulate() procedure. */
92 /* */
93 /* */
94 /* Arrays are used to store points, triangles, markers, and so forth. In */
95 /* all cases, the first item in any array is stored starting at index [0]. */
96 /* However, that item is item number `1' unless the `z' switch is used, in */
97 /* which case it is item number `0'. Hence, you may find it easier to */
98 /* index points (and triangles in the neighbor list) if you use the `z' */
99 /* switch. Unless, of course, you're calling Triangle from a Fortran */
100 /* program. */
101 /* */
102 /* Description of fields (except the `numberof' fields, which are obvious): */
103 /* */
104 /* `pointlist': An array of point coordinates. The first point's x */
105 /* coordinate is at index [0] and its y coordinate at index [1], followed */
106 /* by the coordinates of the remaining points. Each point occupies two */
107 /* REALs. */
108 /* `pointattributelist': An array of point attributes. Each point's */
109 /* attributes occupy `numberofpointattributes' REALs. */
110 /* `pointmarkerlist': An array of point markers; one int per point. */
111 /* */
112 /* `trianglelist': An array of triangle corners. The first triangle's */
113 /* first corner is at index [0], followed by its other two corners in */
114 /* counterclockwise order, followed by any other nodes if the triangle */
115 /* represents a nonlinear element. Each triangle occupies */
116 /* `numberofcorners' ints. */
117 /* `triangleattributelist': An array of triangle attributes. Each */
118 /* triangle's attributes occupy `numberoftriangleattributes' REALs. */
119 /* `trianglearealist': An array of triangle area constraints; one REAL per */
120 /* triangle. Input only. */
121 /* `neighborlist': An array of triangle neighbors; three ints per */
122 /* triangle. Output only. */
123 /* */
124 /* `segmentlist': An array of segment endpoints. The first segment's */
125 /* endpoints are at indices [0] and [1], followed by the remaining */
126 /* segments. Two ints per segment. */
127 /* `segmentmarkerlist': An array of segment markers; one int per segment. */
128 /* */
129 /* `holelist': An array of holes. The first hole's x and y coordinates */
130 /* are at indices [0] and [1], followed by the remaining holes. Two */
131 /* REALs per hole. Input only, although the pointer is copied to the */
132 /* output structure for your convenience. */
133 /* */
134 /* `regionlist': An array of regional attributes and area constraints. */
135 /* The first constraint's x and y coordinates are at indices [0] and [1], */
136 /* followed by the regional attribute at index [2], followed by the */
137 /* maximum area at index [3], followed by the remaining area constraints. */
138 /* Four REALs per area constraint. Note that each regional attribute is */
139 /* used only if you select the `A' switch, and each area constraint is */
140 /* used only if you select the `a' switch (with no number following), but */
141 /* omitting one of these switches does not change the memory layout. */
142 /* Input only, although the pointer is copied to the output structure for */
143 /* your convenience. */
144 /* */
145 /* `edgelist': An array of edge endpoints. The first edge's endpoints are */
146 /* at indices [0] and [1], followed by the remaining edges. Two ints per */
147 /* edge. Output only. */
148 /* `edgemarkerlist': An array of edge markers; one int per edge. Output */
149 /* only. */
150 /* `normlist': An array of normal vectors, used for infinite rays in */
151 /* Voronoi diagrams. The first normal vector's x and y magnitudes are */
152 /* at indices [0] and [1], followed by the remaining vectors. For each */
153 /* finite edge in a Voronoi diagram, the normal vector written is the */
154 /* zero vector. Two REALs per edge. Output only. */
155 /* */
156 /* */
157 /* Any input fields that Triangle will examine must be initialized. */
158 /* Furthermore, for each output array that Triangle will write to, you */
159 /* must either provide space by setting the appropriate pointer to point */
160 /* to the space you want the data written to, or you must initialize the */
161 /* pointer to NULL, which tells Triangle to allocate space for the results. */
162 /* The latter option is preferable, because Triangle always knows exactly */
163 /* how much space to allocate. The former option is provided mainly for */
164 /* people who need to call Triangle from Fortran code, though it also makes */
165 /* possible some nasty space-saving tricks, like writing the output to the */
166 /* same arrays as the input. */
167 /* */
168 /* Triangle will not free() any input or output arrays, including those it */
169 /* allocates itself; that's up to you. You should free arrays allocated by */
170 /* Triangle by calling the trifree() procedure defined below. (By default, */
171 /* trifree() just calls the standard free() library procedure, but */
172 /* applications that call triangulate() may replace trimalloc() and */
173 /* trifree() in triangle.c to use specialized memory allocators.) */
174 /* */
175 /* Here's a guide to help you decide which fields you must initialize */
176 /* before you call triangulate(). */
177 /* */
178 /* `in': */
179 /* */
180 /* - `pointlist' must always point to a list of points; `numberofpoints' */
181 /* and `numberofpointattributes' must be properly set. */
182 /* `pointmarkerlist' must either be set to NULL (in which case all */
183 /* markers default to zero), or must point to a list of markers. If */
184 /* `numberofpointattributes' is not zero, `pointattributelist' must */
185 /* point to a list of point attributes. */
186 /* - If the `r' switch is used, `trianglelist' must point to a list of */
187 /* triangles, and `numberoftriangles', `numberofcorners', and */
188 /* `numberoftriangleattributes' must be properly set. If */
189 /* `numberoftriangleattributes' is not zero, `triangleattributelist' */
190 /* must point to a list of triangle attributes. If the `a' switch is */
191 /* used (with no number following), `trianglearealist' must point to a */
192 /* list of triangle area constraints. `neighborlist' may be ignored. */
193 /* - If the `p' switch is used, `segmentlist' must point to a list of */
194 /* segments, `numberofsegments' must be properly set, and */
195 /* `segmentmarkerlist' must either be set to NULL (in which case all */
196 /* markers default to zero), or must point to a list of markers. */
197 /* - If the `p' switch is used without the `r' switch, then */
198 /* `numberofholes' and `numberofregions' must be properly set. If */
199 /* `numberofholes' is not zero, `holelist' must point to a list of */
200 /* holes. If `numberofregions' is not zero, `regionlist' must point to */
201 /* a list of region constraints. */
202 /* - If the `p' switch is used, `holelist', `numberofholes', */
203 /* `regionlist', and `numberofregions' is copied to `out'. (You can */
204 /* nonetheless get away with not initializing them if the `r' switch is */
205 /* used.) */
206 /* - `edgelist', `edgemarkerlist', `normlist', and `numberofedges' may be */
207 /* ignored. */
208 /* */
209 /* `out': */
210 /* */
211 /* - `pointlist' must be initialized (NULL or pointing to memory) unless */
212 /* the `N' switch is used. `pointmarkerlist' must be initialized */
213 /* unless the `N' or `B' switch is used. If `N' is not used and */
214 /* `in->numberofpointattributes' is not zero, `pointattributelist' must */
215 /* be initialized. */
216 /* - `trianglelist' must be initialized unless the `E' switch is used. */
217 /* `neighborlist' must be initialized if the `n' switch is used. If */
218 /* the `E' switch is not used and (`in->numberofelementattributes' is */
219 /* not zero or the `A' switch is used), `elementattributelist' must be */
220 /* initialized. `trianglearealist' may be ignored. */
221 /* - `segmentlist' must be initialized if the `p' or `c' switch is used, */
222 /* and the `P' switch is not used. `segmentmarkerlist' must also be */
223 /* initialized under these circumstances unless the `B' switch is used. */
224 /* - `edgelist' must be initialized if the `e' switch is used. */
225 /* `edgemarkerlist' must be initialized if the `e' switch is used and */
226 /* the `B' switch is not. */
227 /* - `holelist', `regionlist', `normlist', and all scalars may be ignored.*/
228 /* */
229 /* `vorout' (only needed if `v' switch is used): */
230 /* */
231 /* - `pointlist' must be initialized. If `in->numberofpointattributes' */
232 /* is not zero, `pointattributelist' must be initialized. */
233 /* `pointmarkerlist' may be ignored. */
234 /* - `edgelist' and `normlist' must both be initialized. */
235 /* `edgemarkerlist' may be ignored. */
236 /* - Everything else may be ignored. */
237 /* */
238 /* After a call to triangulate(), the valid fields of `out' and `vorout' */
239 /* will depend, in an obvious way, on the choice of switches used. Note */
240 /* that when the `p' switch is used, the pointers `holelist' and */
241 /* `regionlist' are copied from `in' to `out', but no new space is */
242 /* allocated; be careful that you don't free() the same array twice. On */
243 /* the other hand, Triangle will never copy the `pointlist' pointer (or any */
244 /* others); new space is allocated for `out->pointlist', or if the `N' */
245 /* switch is used, `out->pointlist' remains uninitialized. */
246 /* */
247 /* All of the meaningful `numberof' fields will be properly set; for */
248 /* instance, `numberofedges' will represent the number of edges in the */
249 /* triangulation whether or not the edges were written. If segments are */
250 /* not used, `numberofsegments' will indicate the number of boundary edges. */
251 /* */
252 /*****************************************************************************/
253 
254 #ifdef __cplusplus
255 extern "C" {
256 #endif
257 
258 /* For single precision (which will save some memory and reduce paging), */
259 /* define the symbol SINGLE by using the -DSINGLE compiler switch or by */
260 /* writing "#define SINGLE" below. */
261 /* */
262 /* For double precision (which will allow you to refine meshes to a smaller */
263 /* edge length), leave SINGLE undefined. */
264 /* */
265 /* Double precision uses more memory, but improves the resolution of the */
266 /* meshes you can generate with Triangle. It also reduces the likelihood */
267 /* of a floating exception due to overflow. Finally, it is much faster */
268 /* than single precision on 64-bit architectures like the DEC Alpha. I */
269 /* recommend double precision unless you want to generate a mesh for which */
270 /* you do not have enough memory. */
271 
272 /* #define SINGLE */
273 
274 #ifdef SINGLE
275 #define REAL float
276 #else /* not SINGLE */
277 #define REAL double
278 #endif /* not SINGLE */
279 
280 #define ANSI_DECLARATORS
281 
282 /* The next line is used to outsmart some very stupid compilers. If your */
283 /* compiler is smarter, feel free to replace the "int" with "void". */
284 /* Not that it matters. */
285 
286 #define VOID void
287 
288 struct triangulateio {
289  REAL *pointlist; /* In / out */
290  REAL *pointattributelist; /* In / out */
291  int *pointmarkerlist; /* In / out */
292  int numberofpoints; /* In / out */
293  int numberofpointattributes; /* In / out */
294 
295  int *trianglelist; /* In / out */
296  REAL *triangleattributelist; /* In / out */
297  REAL *trianglearealist; /* In only */
298  int *neighborlist; /* Out only */
299  int numberoftriangles; /* In / out */
300  int numberofcorners; /* In / out */
301  int numberoftriangleattributes; /* In / out */
302 
303  int *segmentlist; /* In / out */
304  int *segmentmarkerlist; /* In / out */
305  int numberofsegments; /* In / out */
306 
307  REAL *holelist; /* In / pointer to array copied out */
308  int numberofholes; /* In / copied out */
309 
310  REAL *regionlist; /* In / pointer to array copied out */
311  int numberofregions; /* In / copied out */
312 
313  int *edgelist; /* Out only */
314  int *edgemarkerlist; /* Not used with Voronoi diagram; out only */
315  REAL *normlist; /* Used only with Voronoi diagram; out only */
316  int numberofedges; /* Out only */
317 };
318 
319 #ifdef ANSI_DECLARATORS
320 void triangulate(char *, struct triangulateio *, struct triangulateio *,
321  struct triangulateio *);
322 void trifree(VOID *memptr);
323 #else /* not ANSI_DECLARATORS */
324 void triangulate();
325 void trifree();
326 #endif /* not ANSI_DECLARATORS */
327 
328 #ifdef __cplusplus
329 }
330 #endif
331 
332 #endif /* not TRIANGLE_H */
triangulateio::holelist
REAL * holelist
Definition: triangle.h:307
triangulateio::edgelist
int * edgelist
Definition: triangle.h:313
triangulateio::edgemarkerlist
int * edgemarkerlist
Definition: triangle.h:314
triangulateio::trianglelist
int * trianglelist
Definition: triangle.h:295
triangulateio::numberofsegments
int numberofsegments
Definition: triangle.h:305
triangulateio::pointmarkerlist
int * pointmarkerlist
Definition: triangle.h:291
triangulateio::numberofregions
int numberofregions
Definition: triangle.h:311
triangulate
void triangulate(char *, struct triangulateio *, struct triangulateio *, struct triangulateio *)
Definition: triangle.c:15651
REAL
#define REAL
Definition: triangle.h:277
trifree
void trifree(VOID *memptr)
Definition: triangle.c:1414
triangulateio::neighborlist
int * neighborlist
Definition: triangle.h:298
triangulateio::numberoftriangleattributes
int numberoftriangleattributes
Definition: triangle.h:301
triangulateio::pointattributelist
REAL * pointattributelist
Definition: triangle.h:290
triangulateio::numberofcorners
int numberofcorners
Definition: triangle.h:300
triangulateio::normlist
REAL * normlist
Definition: triangle.h:315
VOID
#define VOID
Definition: triangle.h:286
triangulateio::triangleattributelist
REAL * triangleattributelist
Definition: triangle.h:296
triangulateio::numberofpoints
int numberofpoints
Definition: triangle.h:292
triangulateio::segmentlist
int * segmentlist
Definition: triangle.h:303
triangulateio::numberofedges
int numberofedges
Definition: triangle.h:316
triangulateio::regionlist
REAL * regionlist
Definition: triangle.h:310
triangulateio::trianglearealist
REAL * trianglearealist
Definition: triangle.h:297
triangulateio::segmentmarkerlist
int * segmentmarkerlist
Definition: triangle.h:304
triangulateio::pointlist
REAL * pointlist
Definition: triangle.h:289
triangulateio::numberofpointattributes
int numberofpointattributes
Definition: triangle.h:293
triangulateio::numberofholes
int numberofholes
Definition: triangle.h:308
triangulateio::numberoftriangles
int numberoftriangles
Definition: triangle.h:299