/* See dg_spline.h */
/* Last edited on 2007-01-04 00:16:44 by stolfi */

#include <dg_tree.h>
#include <dg_spline.h>
#include <dg_locus.h>
#include <math.h>

/* INTERNAL PROTOTYPES */

/* IMPLEMENTATIONS */

void dg_tent_alloc_explicit_rep
  ( dg_dim_t d, 
    dg_degree_t g,
    dg_node_t_t *root
  )
  {
    int nCoefs = ipow(g+1, d);
    bz_Degrees gg;
    int i;
    for (i = 0; i < d; i++) { gg[i] = g; } 

    auto void do_alloc(dg_node_t_t *t);
    void do_alloc(dg_node_t_t *t)
      { if (t != NULL) 
          { double *c = (double *)notnull(malloc(nCoefs * sizeof(double))); 
            int k; 
            for (k = 0; k < nCoefs; k++) { c[k] = 0.0; }
            t->data = c;
            do_alloc(t->ch[0]);
            do_alloc(t->ch[1]); 
          }
      }
      
    do_alloc(root);
  }
  
void dg_tent_free_explicit_rep(dg_node_t_t *root)
  { if (root != NULL) 
      { if (root->data != NULL) { free(root->data); }
        dg_tent_free_explicit_rep(root->ch[0]);
        dg_tent_free_explicit_rep(root->ch[1]); 
      }
   }

void dg_tent_flatten(dg_tent_vec_t *tv, double_vect_t *a, dg_node_t_t *root);
  /* Computes the dyadic spline which is the linear combination 
      
      { SUM {a[i]*tv[i] : i = 0..tv.nel-1} } 
      
    and stores its explicit Bézier representation in the leaves of
    tree {root}. Assumes that the grid dimension is {d} and that the
    tents have degree {g} and continuity {c}. Assumes also that the
    data pointer of each node points to a Bézier control point array
    of degree {g} and dimension {d}. */