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triangle.h
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triangle.h
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/*****************************************************************************/
/* */
/* (triangle.h) */
/* */
/* Include file for programs that call Triangle. */
/* */
/* Accompanies Triangle Version 1.6 */
/* July 28, 2005 */
/* */
/* Copyright 1996, 2005 */
/* Jonathan Richard Shewchuk */
/* 2360 Woolsey #H */
/* Berkeley, California 94705-1927 */
/* [email protected] */
/* */
/*****************************************************************************/
/*****************************************************************************/
/* */
/* 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 (generally 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, -u, -D, -Y, -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 (triangle.h) 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', `a', `u', `D', `j', or `s' 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 at 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. You should free arrays allocated by */
/* Triangle by calling the trifree() procedure defined below. (By default, */
/* trifree() just calls the standard free() library procedure, but */
/* applications that call triangulate() may replace trimalloc() and */
/* trifree() in triangle.c to use specialized memory allocators.) */
/* */
/* 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. */
/* */
/*****************************************************************************/
#ifdef __cplusplus
extern "C" {
#endif
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 */
};
void triangulate(char *, struct triangulateio *, struct triangulateio *,
struct triangulateio *);
void trifree(VOID *memptr);
#ifdef __cplusplus
}
#endif