00001 /*****************************************************************************/ 00002 /* */ 00003 /* (triangle.h) */ 00004 /* */ 00005 /* Include file for programs that call Triangle. */ 00006 /* */ 00007 /* Accompanies Triangle Version 1.6 */ 00008 /* July 28, 2005 */ 00009 /* */ 00010 /* Copyright 1996, 2005 */ 00011 /* Jonathan Richard Shewchuk */ 00012 /* 2360 Woolsey #H */ 00013 /* Berkeley, California 94705-1927 */ 00014 /* jrs@cs.berkeley.edu */ 00015 /* */ 00016 /* Modified by Andreas Geiger, 2011 */ 00017 /*****************************************************************************/ 00018 00019 /*****************************************************************************/ 00020 /* */ 00021 /* How to call Triangle from another program */ 00022 /* */ 00023 /* */ 00024 /* If you haven't read Triangle's instructions (run "triangle -h" to read */ 00025 /* them), you won't understand what follows. */ 00026 /* */ 00027 /* Triangle must be compiled into an object file (triangle.o) with the */ 00028 /* TRILIBRARY symbol defined (generally by using the -DTRILIBRARY compiler */ 00029 /* switch). The makefile included with Triangle will do this for you if */ 00030 /* you run "make trilibrary". The resulting object file can be called via */ 00031 /* the procedure triangulate(). */ 00032 /* */ 00033 /* If the size of the object file is important to you, you may wish to */ 00034 /* generate a reduced version of triangle.o. The REDUCED symbol gets rid */ 00035 /* of all features that are primarily of research interest. Specifically, */ 00036 /* the -DREDUCED switch eliminates Triangle's -i, -F, -s, and -C switches. */ 00037 /* The CDT_ONLY symbol gets rid of all meshing algorithms above and beyond */ 00038 /* constrained Delaunay triangulation. Specifically, the -DCDT_ONLY switch */ 00039 /* eliminates Triangle's -r, -q, -a, -u, -D, -Y, -S, and -s switches. */ 00040 /* */ 00041 /* IMPORTANT: These definitions (TRILIBRARY, REDUCED, CDT_ONLY) must be */ 00042 /* made in the makefile or in triangle.c itself. Putting these definitions */ 00043 /* in this file (triangle.h) will not create the desired effect. */ 00044 /* */ 00045 /* */ 00046 /* The calling convention for triangulate() follows. */ 00047 /* */ 00048 /* void triangulate(triswitches, in, out, vorout) */ 00049 /* char *triswitches; */ 00050 /* struct triangulateio *in; */ 00051 /* struct triangulateio *out; */ 00052 /* struct triangulateio *vorout; */ 00053 /* */ 00054 /* `triswitches' is a string containing the command line switches you wish */ 00055 /* to invoke. No initial dash is required. Some suggestions: */ 00056 /* */ 00057 /* - You'll probably find it convenient to use the `z' switch so that */ 00058 /* points (and other items) are numbered from zero. This simplifies */ 00059 /* indexing, because the first item of any type always starts at index */ 00060 /* [0] of the corresponding array, whether that item's number is zero or */ 00061 /* one. */ 00062 /* - You'll probably want to use the `Q' (quiet) switch in your final code, */ 00063 /* but you can take advantage of Triangle's printed output (including the */ 00064 /* `V' switch) while debugging. */ 00065 /* - If you are not using the `q', `a', `u', `D', `j', or `s' switches, */ 00066 /* then the output points will be identical to the input points, except */ 00067 /* possibly for the boundary markers. If you don't need the boundary */ 00068 /* markers, you should use the `N' (no nodes output) switch to save */ 00069 /* memory. (If you do need boundary markers, but need to save memory, a */ 00070 /* good nasty trick is to set out->pointlist equal to in->pointlist */ 00071 /* before calling triangulate(), so that Triangle overwrites the input */ 00072 /* points with identical copies.) */ 00073 /* - The `I' (no iteration numbers) and `g' (.off file output) switches */ 00074 /* have no effect when Triangle is compiled with TRILIBRARY defined. */ 00075 /* */ 00076 /* `in', `out', and `vorout' are descriptions of the input, the output, */ 00077 /* and the Voronoi output. If the `v' (Voronoi output) switch is not used, */ 00078 /* `vorout' may be NULL. `in' and `out' may never be NULL. */ 00079 /* */ 00080 /* Certain fields of the input and output structures must be initialized, */ 00081 /* as described below. */ 00082 /* */ 00083 /*****************************************************************************/ 00084 00085 /*****************************************************************************/ 00086 /* */ 00087 /* The `triangulateio' structure. */ 00088 /* */ 00089 /* Used to pass data into and out of the triangulate() procedure. */ 00090 /* */ 00091 /* */ 00092 /* Arrays are used to store points, triangles, markers, and so forth. In */ 00093 /* all cases, the first item in any array is stored starting at index [0]. */ 00094 /* However, that item is item number `1' unless the `z' switch is used, in */ 00095 /* which case it is item number `0'. Hence, you may find it easier to */ 00096 /* index points (and triangles in the neighbor list) if you use the `z' */ 00097 /* switch. Unless, of course, you're calling Triangle from a Fortran */ 00098 /* program. */ 00099 /* */ 00100 /* Description of fields (except the `numberof' fields, which are obvious): */ 00101 /* */ 00102 /* `pointlist': An array of point coordinates. The first point's x */ 00103 /* coordinate is at index [0] and its y coordinate at index [1], followed */ 00104 /* by the coordinates of the remaining points. Each point occupies two */ 00105 /* REALs. */ 00106 /* `pointattributelist': An array of point attributes. Each point's */ 00107 /* attributes occupy `numberofpointattributes' REALs. */ 00108 /* `pointmarkerlist': An array of point markers; one int per point. */ 00109 /* */ 00110 /* `trianglelist': An array of triangle corners. The first triangle's */ 00111 /* first corner is at index [0], followed by its other two corners in */ 00112 /* counterclockwise order, followed by any other nodes if the triangle */ 00113 /* represents a nonlinear element. Each triangle occupies */ 00114 /* `numberofcorners' ints. */ 00115 /* `triangleattributelist': An array of triangle attributes. Each */ 00116 /* triangle's attributes occupy `numberoftriangleattributes' REALs. */ 00117 /* `trianglearealist': An array of triangle area constraints; one REAL per */ 00118 /* triangle. Input only. */ 00119 /* `neighborlist': An array of triangle neighbors; three ints per */ 00120 /* triangle. Output only. */ 00121 /* */ 00122 /* `segmentlist': An array of segment endpoints. The first segment's */ 00123 /* endpoints are at indices [0] and [1], followed by the remaining */ 00124 /* segments. Two ints per segment. */ 00125 /* `segmentmarkerlist': An array of segment markers; one int per segment. */ 00126 /* */ 00127 /* `holelist': An array of holes. The first hole's x and y coordinates */ 00128 /* are at indices [0] and [1], followed by the remaining holes. Two */ 00129 /* REALs per hole. Input only, although the pointer is copied to the */ 00130 /* output structure for your convenience. */ 00131 /* */ 00132 /* `regionlist': An array of regional attributes and area constraints. */ 00133 /* The first constraint's x and y coordinates are at indices [0] and [1], */ 00134 /* followed by the regional attribute at index [2], followed by the */ 00135 /* maximum area at index [3], followed by the remaining area constraints. */ 00136 /* Four REALs per area constraint. Note that each regional attribute is */ 00137 /* used only if you select the `A' switch, and each area constraint is */ 00138 /* used only if you select the `a' switch (with no number following), but */ 00139 /* omitting one of these switches does not change the memory layout. */ 00140 /* Input only, although the pointer is copied to the output structure for */ 00141 /* your convenience. */ 00142 /* */ 00143 /* `edgelist': An array of edge endpoints. The first edge's endpoints are */ 00144 /* at indices [0] and [1], followed by the remaining edges. Two ints per */ 00145 /* edge. Output only. */ 00146 /* `edgemarkerlist': An array of edge markers; one int per edge. Output */ 00147 /* only. */ 00148 /* `normlist': An array of normal vectors, used for infinite rays in */ 00149 /* Voronoi diagrams. The first normal vector's x and y magnitudes are */ 00150 /* at indices [0] and [1], followed by the remaining vectors. For each */ 00151 /* finite edge in a Voronoi diagram, the normal vector written is the */ 00152 /* zero vector. Two REALs per edge. Output only. */ 00153 /* */ 00154 /* */ 00155 /* Any input fields that Triangle will examine must be initialized. */ 00156 /* Furthermore, for each output array that Triangle will write to, you */ 00157 /* must either provide space by setting the appropriate pointer to point */ 00158 /* to the space you want the data written to, or you must initialize the */ 00159 /* pointer to NULL, which tells Triangle to allocate space for the results. */ 00160 /* The latter option is preferable, because Triangle always knows exactly */ 00161 /* how much space to allocate. The former option is provided mainly for */ 00162 /* people who need to call Triangle from Fortran code, though it also makes */ 00163 /* possible some nasty space-saving tricks, like writing the output to the */ 00164 /* same arrays as the input. */ 00165 /* */ 00166 /* Triangle will not free() any input or output arrays, including those it */ 00167 /* allocates itself; that's up to you. You should free arrays allocated by */ 00168 /* Triangle by calling the trifree() procedure defined below. (By default, */ 00169 /* trifree() just calls the standard free() library procedure, but */ 00170 /* applications that call triangulate() may replace trimalloc() and */ 00171 /* trifree() in triangle.c to use specialized memory allocators.) */ 00172 /* */ 00173 /* Here's a guide to help you decide which fields you must initialize */ 00174 /* before you call triangulate(). */ 00175 /* */ 00176 /* `in': */ 00177 /* */ 00178 /* - `pointlist' must always point to a list of points; `numberofpoints' */ 00179 /* and `numberofpointattributes' must be properly set. */ 00180 /* `pointmarkerlist' must either be set to NULL (in which case all */ 00181 /* markers default to zero), or must point to a list of markers. If */ 00182 /* `numberofpointattributes' is not zero, `pointattributelist' must */ 00183 /* point to a list of point attributes. */ 00184 /* - If the `r' switch is used, `trianglelist' must point to a list of */ 00185 /* triangles, and `numberoftriangles', `numberofcorners', and */ 00186 /* `numberoftriangleattributes' must be properly set. If */ 00187 /* `numberoftriangleattributes' is not zero, `triangleattributelist' */ 00188 /* must point to a list of triangle attributes. If the `a' switch is */ 00189 /* used (with no number following), `trianglearealist' must point to a */ 00190 /* list of triangle area constraints. `neighborlist' may be ignored. */ 00191 /* - If the `p' switch is used, `segmentlist' must point to a list of */ 00192 /* segments, `numberofsegments' must be properly set, and */ 00193 /* `segmentmarkerlist' must either be set to NULL (in which case all */ 00194 /* markers default to zero), or must point to a list of markers. */ 00195 /* - If the `p' switch is used without the `r' switch, then */ 00196 /* `numberofholes' and `numberofregions' must be properly set. If */ 00197 /* `numberofholes' is not zero, `holelist' must point to a list of */ 00198 /* holes. If `numberofregions' is not zero, `regionlist' must point to */ 00199 /* a list of region constraints. */ 00200 /* - If the `p' switch is used, `holelist', `numberofholes', */ 00201 /* `regionlist', and `numberofregions' is copied to `out'. (You can */ 00202 /* nonetheless get away with not initializing them if the `r' switch is */ 00203 /* used.) */ 00204 /* - `edgelist', `edgemarkerlist', `normlist', and `numberofedges' may be */ 00205 /* ignored. */ 00206 /* */ 00207 /* `out': */ 00208 /* */ 00209 /* - `pointlist' must be initialized (NULL or pointing to memory) unless */ 00210 /* the `N' switch is used. `pointmarkerlist' must be initialized */ 00211 /* unless the `N' or `B' switch is used. If `N' is not used and */ 00212 /* `in->numberofpointattributes' is not zero, `pointattributelist' must */ 00213 /* be initialized. */ 00214 /* - `trianglelist' must be initialized unless the `E' switch is used. */ 00215 /* `neighborlist' must be initialized if the `n' switch is used. If */ 00216 /* the `E' switch is not used and (`in->numberofelementattributes' is */ 00217 /* not zero or the `A' switch is used), `elementattributelist' must be */ 00218 /* initialized. `trianglearealist' may be ignored. */ 00219 /* - `segmentlist' must be initialized if the `p' or `c' switch is used, */ 00220 /* and the `P' switch is not used. `segmentmarkerlist' must also be */ 00221 /* initialized under these circumstances unless the `B' switch is used. */ 00222 /* - `edgelist' must be initialized if the `e' switch is used. */ 00223 /* `edgemarkerlist' must be initialized if the `e' switch is used and */ 00224 /* the `B' switch is not. */ 00225 /* - `holelist', `regionlist', `normlist', and all scalars may be ignored.*/ 00226 /* */ 00227 /* `vorout' (only needed if `v' switch is used): */ 00228 /* */ 00229 /* - `pointlist' must be initialized. If `in->numberofpointattributes' */ 00230 /* is not zero, `pointattributelist' must be initialized. */ 00231 /* `pointmarkerlist' may be ignored. */ 00232 /* - `edgelist' and `normlist' must both be initialized. */ 00233 /* `edgemarkerlist' may be ignored. */ 00234 /* - Everything else may be ignored. */ 00235 /* */ 00236 /* After a call to triangulate(), the valid fields of `out' and `vorout' */ 00237 /* will depend, in an obvious way, on the choice of switches used. Note */ 00238 /* that when the `p' switch is used, the pointers `holelist' and */ 00239 /* `regionlist' are copied from `in' to `out', but no new space is */ 00240 /* allocated; be careful that you don't free() the same array twice. On */ 00241 /* the other hand, Triangle will never copy the `pointlist' pointer (or any */ 00242 /* others); new space is allocated for `out->pointlist', or if the `N' */ 00243 /* switch is used, `out->pointlist' remains uninitialized. */ 00244 /* */ 00245 /* All of the meaningful `numberof' fields will be properly set; for */ 00246 /* instance, `numberofedges' will represent the number of edges in the */ 00247 /* triangulation whether or not the edges were written. If segments are */ 00248 /* not used, `numberofsegments' will indicate the number of boundary edges. */ 00249 /* */ 00250 /*****************************************************************************/ 00251 00252 struct triangulateio { 00253 float *pointlist; /* In / out */ 00254 float *pointattributelist; /* In / out */ 00255 int *pointmarkerlist; /* In / out */ 00256 int numberofpoints; /* In / out */ 00257 int numberofpointattributes; /* In / out */ 00258 00259 int *trianglelist; /* In / out */ 00260 float *triangleattributelist; /* In / out */ 00261 float *trianglearealist; /* In only */ 00262 int *neighborlist; /* Out only */ 00263 int numberoftriangles; /* In / out */ 00264 int numberofcorners; /* In / out */ 00265 int numberoftriangleattributes; /* In / out */ 00266 00267 int *segmentlist; /* In / out */ 00268 int *segmentmarkerlist; /* In / out */ 00269 int numberofsegments; /* In / out */ 00270 00271 float *holelist; /* In / pointer to array copied out */ 00272 int numberofholes; /* In / copied out */ 00273 00274 float *regionlist; /* In / pointer to array copied out */ 00275 int numberofregions; /* In / copied out */ 00276 00277 int *edgelist; /* Out only */ 00278 int *edgemarkerlist; /* Not used with Voronoi diagram; out only */ 00279 float *normlist; /* Used only with Voronoi diagram; out only */ 00280 int numberofedges; /* Out only */ 00281 }; 00282 00283 void triangulate(char *,triangulateio *,triangulateio *,triangulateio *); 00284 void trifree(int *memptr); 00285