/*****************************************************************************/ /* */ /* (triangle.h) */ /* */ /* Include file for programs that call Triangle. */ /* */ /* Accompanies Triangle Version 1.3 */ /* July 19, 1996 */ /* */ /* Copyright 1996 */ /* Jonathan Richard Shewchuk */ /* School of Computer Science */ /* Carnegie Mellon University */ /* 5000 Forbes Avenue */ /* Pittsburgh, Pennsylvania 15213-3891 */ /* jrs@cs.cmu.edu */ /* */ /*****************************************************************************/ /*****************************************************************************/ /* */ /* How to call Triangle from another program */ /* */ /* */ /* If you haven't read Triangle's instructions (run "triangle -h" to read */ /* them), you won't understand what follows. */ /* */ /* Triangle must be compiled into an object file (triangle.o) with the */ /* TRILIBRARY symbol defined (preferably by using the -DTRILIBRARY compiler */ /* switch). The makefile included with Triangle will do this for you if */ /* you run "make trilibrary". The resulting object file can be called via */ /* the procedure triangulate(). */ /* */ /* If the size of the object file is important to you, you may wish to */ /* generate a reduced version of triangle.o. The REDUCED symbol gets rid */ /* of all features that are primarily of research interest. Specifically, */ /* the -DREDUCED switch eliminates Triangle's -i, -F, -s, and -C switches. */ /* The CDT_ONLY symbol gets rid of all meshing algorithms above and beyond */ /* constrained Delaunay triangulation. Specifically, the -DCDT_ONLY switch */ /* eliminates Triangle's -r, -q, -a, -S, and -s switches. */ /* */ /* IMPORTANT: These definitions (TRILIBRARY, REDUCED, CDT_ONLY) must be */ /* made in the makefile or in triangle.c itself. Putting these definitions */ /* in this file will not create the desired effect. */ /* */ /* */ /* The calling convention for triangulate() follows. */ /* */ /* void triangulate(triswitches, in, out, vorout) */ /* char *triswitches; */ /* struct triangulateio *in; */ /* struct triangulateio *out; */ /* struct triangulateio *vorout; */ /* */ /* `triswitches' is a string containing the command line switches you wish */ /* to invoke. No initial dash is required. Some suggestions: */ /* */ /* - You'll probably find it convenient to use the `z' switch so that */ /* points (and other items) are numbered from zero. This simplifies */ /* indexing, because the first item of any type always starts at index */ /* [0] of the corresponding array, whether that item's number is zero or */ /* one. */ /* - You'll probably want to use the `Q' (quiet) switch in your final code, */ /* but you can take advantage of Triangle's printed output (including the */ /* `V' switch) while debugging. */ /* - If you are not using the `q' or `a' switches, then the output points */ /* will be identical to the input points, except possibly for the */ /* boundary markers. If you don't need the boundary markers, you should */ /* use the `N' (no nodes output) switch to save memory. (If you do need */ /* boundary markers, but need to save memory, a good nasty trick is to */ /* set out->pointlist equal to in->pointlist before calling triangulate(),*/ /* so that Triangle overwrites the input points with identical copies.) */ /* - The `I' (no iteration numbers) and `g' (.off file output) switches */ /* have no effect when Triangle is compiled with TRILIBRARY defined. */ /* */ /* `in', `out', and `vorout' are descriptions of the input, the output, */ /* and the Voronoi output. If the `v' (Voronoi output) switch is not used, */ /* `vorout' may be NULL. `in' and `out' may never be NULL. */ /* */ /* Certain fields of the input and output structures must be initialized, */ /* as described below. */ /* */ /*****************************************************************************/ /*****************************************************************************/ /* */ /* The `triangulateio' structure. */ /* */ /* Used to pass data into and out of the triangulate() procedure. */ /* */ /* */ /* Arrays are used to store points, triangles, markers, and so forth. In */ /* all cases, the first item in any array is stored starting at index [0]. */ /* However, that item is item number `1' unless the `z' switch is used, in */ /* which case it is item number `0'. Hence, you may find it easier to */ /* index points (and triangles in the neighbor list) if you use the `z' */ /* switch. Unless, of course, you're calling Triangle from a Fortran */ /* program. */ /* */ /* Description of fields (except the `numberof' fields, which are obvious): */ /* */ /* `pointlist': An array of point coordinates. The first point's x */ /* coordinate is at index [0] and its y coordinate at index [1], followed */ /* by the coordinates of the remaining points. Each point occupies two */ /* REALs. */ /* `pointattributelist': An array of point attributes. Each point's */ /* attributes occupy `numberofpointattributes' REALs. */ /* `pointmarkerlist': An array of point markers; one int per point. */ /* */ /* `trianglelist': An array of triangle corners. The first triangle's */ /* first corner is at index [0], followed by its other two corners in */ /* counterclockwise order, followed by any other nodes if the triangle */ /* represents a nonlinear element. Each triangle occupies */ /* `numberofcorners' ints. */ /* `triangleattributelist': An array of triangle attributes. Each */ /* triangle's attributes occupy `numberoftriangleattributes' REALs. */ /* `trianglearealist': An array of triangle area constraints; one REAL per */ /* triangle. Input only. */ /* `neighborlist': An array of triangle neighbors; three ints per */ /* triangle. Output only. */ /* */ /* `segmentlist': An array of segment endpoints. The first segment's */ /* endpoints are at indices [0] and [1], followed by the remaining */ /* segments. Two ints per segment. */ /* `segmentmarkerlist': An array of segment markers; one int per segment. */ /* */ /* `holelist': An array of holes. The first hole's x and y coordinates */ /* are at indices [0] and [1], followed by the remaining holes. Two */ /* REALs per hole. Input only, although the pointer is copied to the */ /* output structure for your convenience. */ /* */ /* `regionlist': An array of regional attributes and area constraints. */ /* The first constraint's x and y coordinates are at indices [0] and [1], */ /* followed by the regional attribute and index [2], followed by the */ /* maximum area at index [3], followed by the remaining area constraints. */ /* Four REALs per area constraint. Note that each regional attribute is */ /* used only if you select the `A' switch, and each area constraint is */ /* used only if you select the `a' switch (with no number following), but */ /* omitting one of these switches does not change the memory layout. */ /* Input only, although the pointer is copied to the output structure for */ /* your convenience. */ /* */ /* `edgelist': An array of edge endpoints. The first edge's endpoints are */ /* at indices [0] and [1], followed by the remaining edges. Two ints per */ /* edge. Output only. */ /* `edgemarkerlist': An array of edge markers; one int per edge. Output */ /* only. */ /* `normlist': An array of normal vectors, used for infinite rays in */ /* Voronoi diagrams. The first normal vector's x and y magnitudes are */ /* at indices [0] and [1], followed by the remaining vectors. For each */ /* finite edge in a Voronoi diagram, the normal vector written is the */ /* zero vector. Two REALs per edge. Output only. */ /* */ /* */ /* Any input fields that Triangle will examine must be initialized. */ /* Furthermore, for each output array that Triangle will write to, you */ /* must either provide space by setting the appropriate pointer to point */ /* to the space you want the data written to, or you must initialize the */ /* pointer to NULL, which tells Triangle to allocate space for the results. */ /* The latter option is preferable, because Triangle always knows exactly */ /* how much space to allocate. The former option is provided mainly for */ /* people who need to call Triangle from Fortran code, though it also makes */ /* possible some nasty space-saving tricks, like writing the output to the */ /* same arrays as the input. */ /* */ /* Triangle will not free() any input or output arrays, including those it */ /* allocates itself; that's up to you. */ /* */ /* Here's a guide to help you decide which fields you must initialize */ /* before you call triangulate(). */ /* */ /* `in': */ /* */ /* - `pointlist' must always point to a list of points; `numberofpoints' */ /* and `numberofpointattributes' must be properly set. */ /* `pointmarkerlist' must either be set to NULL (in which case all */ /* markers default to zero), or must point to a list of markers. If */ /* `numberofpointattributes' is not zero, `pointattributelist' must */ /* point to a list of point attributes. */ /* - If the `r' switch is used, `trianglelist' must point to a list of */ /* triangles, and `numberoftriangles', `numberofcorners', and */ /* `numberoftriangleattributes' must be properly set. If */ /* `numberoftriangleattributes' is not zero, `triangleattributelist' */ /* must point to a list of triangle attributes. If the `a' switch is */ /* used (with no number following), `trianglearealist' must point to a */ /* list of triangle area constraints. `neighborlist' may be ignored. */ /* - If the `p' switch is used, `segmentlist' must point to a list of */ /* segments, `numberofsegments' must be properly set, and */ /* `segmentmarkerlist' must either be set to NULL (in which case all */ /* markers default to zero), or must point to a list of markers. */ /* - If the `p' switch is used without the `r' switch, then */ /* `numberofholes' and `numberofregions' must be properly set. If */ /* `numberofholes' is not zero, `holelist' must point to a list of */ /* holes. If `numberofregions' is not zero, `regionlist' must point to */ /* a list of region constraints. */ /* - If the `p' switch is used, `holelist', `numberofholes', */ /* `regionlist', and `numberofregions' is copied to `out'. (You can */ /* nonetheless get away with not initializing them if the `r' switch is */ /* used.) */ /* - `edgelist', `edgemarkerlist', `normlist', and `numberofedges' may be */ /* ignored. */ /* */ /* `out': */ /* */ /* - `pointlist' must be initialized (NULL or pointing to memory) unless */ /* the `N' switch is used. `pointmarkerlist' must be initialized */ /* unless the `N' or `B' switch is used. If `N' is not used and */ /* `in->numberofpointattributes' is not zero, `pointattributelist' must */ /* be initialized. */ /* - `trianglelist' must be initialized unless the `E' switch is used. */ /* `neighborlist' must be initialized if the `n' switch is used. If */ /* the `E' switch is not used and (`in->numberofelementattributes' is */ /* not zero or the `A' switch is used), `elementattributelist' must be */ /* initialized. `trianglearealist' may be ignored. */ /* - `segmentlist' must be initialized if the `p' or `c' switch is used, */ /* and the `P' switch is not used. `segmentmarkerlist' must also be */ /* initialized under these circumstances unless the `B' switch is used. */ /* - `edgelist' must be initialized if the `e' switch is used. */ /* `edgemarkerlist' must be initialized if the `e' switch is used and */ /* the `B' switch is not. */ /* - `holelist', `regionlist', `normlist', and all scalars may be ignored.*/ /* */ /* `vorout' (only needed if `v' switch is used): */ /* */ /* - `pointlist' must be initialized. If `in->numberofpointattributes' */ /* is not zero, `pointattributelist' must be initialized. */ /* `pointmarkerlist' may be ignored. */ /* - `edgelist' and `normlist' must both be initialized. */ /* `edgemarkerlist' may be ignored. */ /* - Everything else may be ignored. */ /* */ /* After a call to triangulate(), the valid fields of `out' and `vorout' */ /* will depend, in an obvious way, on the choice of switches used. Note */ /* that when the `p' switch is used, the pointers `holelist' and */ /* `regionlist' are copied from `in' to `out', but no new space is */ /* allocated; be careful that you don't free() the same array twice. On */ /* the other hand, Triangle will never copy the `pointlist' pointer (or any */ /* others); new space is allocated for `out->pointlist', or if the `N' */ /* switch is used, `out->pointlist' remains uninitialized. */ /* */ /* All of the meaningful `numberof' fields will be properly set; for */ /* instance, `numberofedges' will represent the number of edges in the */ /* triangulation whether or not the edges were written. If segments are */ /* not used, `numberofsegments' will indicate the number of boundary edges. */ /* */ /*****************************************************************************/ /* CLO: 3/21/99 - this could be done as a compile flag, but I always want this defined and I don't want to sprinkle extra stuff throughout the Makefile system if I don't have to. */ #define ANSI_DECLARATORS 1 struct triangulateio { REAL *pointlist; /* In / out */ REAL *pointattributelist; /* In / out */ int *pointmarkerlist; /* In / out */ int numberofpoints; /* In / out */ int numberofpointattributes; /* In / out */ int *trianglelist; /* In / out */ REAL *triangleattributelist; /* In / out */ REAL *trianglearealist; /* In only */ int *neighborlist; /* Out only */ int numberoftriangles; /* In / out */ int numberofcorners; /* In / out */ int numberoftriangleattributes; /* In / out */ int *segmentlist; /* In / out */ int *segmentmarkerlist; /* In / out */ int numberofsegments; /* In / out */ REAL *holelist; /* In / pointer to array copied out */ int numberofholes; /* In / copied out */ REAL *regionlist; /* In / pointer to array copied out */ int numberofregions; /* In / copied out */ int *edgelist; /* Out only */ int *edgemarkerlist; /* Not used with Voronoi diagram; out only */ REAL *normlist; /* Used only with Voronoi diagram; out only */ int numberofedges; /* Out only */ }; #ifdef ANSI_DECLARATORS void triangulate(char *, struct triangulateio *, struct triangulateio *, struct triangulateio *); #else /* not ANSI_DECLARATORS */ void triangulate(); #endif /* not ANSI_DECLARATORS */