quiver.h

   1 /* A rational number */
   2 struct rational {
   3         /* Numerator */
   4         int_fast8_t p;
   5
   6         /* Denominator */
   7         uint_fast8_t q;
   8 };
   9
  10 /* The structure for a vertex */
  11 struct vertex {
  12         /* A textual identifier for this vertex */
  13         const char *name;
  14
  15         /* Whether this vertex is `fat' or not. Expected to be 1, 2, or 3. */
  16         uint_fast8_t fatness;
  17
  18         /* Drawing data: coordinates in `internal coordinates */
  19         int x;
  20         int y;
  21 };
  22
  23 /* The cluster algebra structure */
  24 struct quiver {
  25         /* How many vertices there actually are in the quiver */
  26         size_t v_num;
  27
  28         /* How many vertices we have allocated memory for */
  29         size_t v_len;
  30
  31         /* Vertices */
  32         struct vertex *v;
  33
  34         /* Edges */
  35         struct rational *e;
  36 };
  37
  38 /* Add an arrow of weight a/b from i -> j, affecting e(i,j) and e(j,i) */
  39 int
  40 quiver_add_to_edge(struct quiver *q, size_t i, size_t j, int_fast8_t a,
  41                    uint_fast8_t b, const char **out_errstr);
  42
  43 /* Add a vertex with a name and weight */
  44 int
  45 quiver_add_vertex(struct quiver *q, size_t *out_i, const char *name,
  46                   uint_fast16_t fatness, int x, int y, const char **out_errstr);
  47
  48 /* Mutate the quiver at vertex k */
  49 int
  50 quiver_mutate(struct quiver *q, size_t k, const char **out_errstr);