/*
 * Copyright (c) 2001-2003, David Janssens
 * Copyright (c) 2002-2003, Yannick Verschueren
 * Copyright (c) 2003-2005, Francois Devaux and Antonin Descampe
 * Copyright (c) 2005, Hervé Drolon, FreeImage Team
 * Copyright (c) 2002-2005, Communications and remote sensing Laboratory, Universite catholique de Louvain, Belgium
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "opj_includes.h"

/* 
==========================================================
   Tag-tree coder interface
==========================================================
*/

opj_tgt_tree_t *tgt_create(int numleafsh, int numleafsv) {
  int nplh[32];
  int nplv[32];
  opj_tgt_node_t *node = NULL;
  opj_tgt_node_t *parentnode = NULL;
  opj_tgt_node_t *parentnode0 = NULL;
  opj_tgt_tree_t *tree = NULL;
  int i, j, k;
  int numlvls;
  int n;

  tree = (opj_tgt_tree_t *) opj_malloc(sizeof(opj_tgt_tree_t));
  if(!tree) return NULL;
  tree->numleafsh = numleafsh;
  tree->numleafsv = numleafsv;

  numlvls = 0;
  nplh[0] = numleafsh;
  nplv[0] = numleafsv;
  tree->numnodes = 0;
  do {
    n = nplh[numlvls] * nplv[numlvls];
    nplh[numlvls + 1] = (nplh[numlvls] + 1) / 2;
    nplv[numlvls + 1] = (nplv[numlvls] + 1) / 2;
    tree->numnodes += n;
    ++numlvls;
  } while (n > 1);
  
  /* ADD */
  if (tree->numnodes == 0) {
    opj_free(tree);
    return NULL;
  }

  tree->nodes = (opj_tgt_node_t *) opj_malloc(tree->numnodes * sizeof(opj_tgt_node_t));
  if(!tree->nodes) {
    opj_free(tree);
    return NULL;
  }

  node = tree->nodes;
  parentnode = &tree->nodes[tree->numleafsh * tree->numleafsv];
  parentnode0 = parentnode;
  
  for (i = 0; i < numlvls - 1; ++i) {
    for (j = 0; j < nplv[i]; ++j) {
      k = nplh[i];
      while (--k >= 0) {
        node->parent = parentnode;
        ++node;
        if (--k >= 0) {
          node->parent = parentnode;
          ++node;
        }
        ++parentnode;
      }
      if ((j & 1) || j == nplv[i] - 1) {
        parentnode0 = parentnode;
      } else {
        parentnode = parentnode0;
        parentnode0 += nplh[i];
      }
    }
  }
  node->parent = 0;
  
  tgt_reset(tree);
  
  return tree;
}

void tgt_destroy(opj_tgt_tree_t *tree) {
  opj_free(tree->nodes);
  opj_free(tree);
}

void tgt_reset(opj_tgt_tree_t *tree) {
  int i;

  if (NULL == tree)
    return;
  
  for (i = 0; i < tree->numnodes; i++) {
    tree->nodes[i].value = 999;
    tree->nodes[i].low = 0;
    tree->nodes[i].known = 0;
  }
}

void tgt_setvalue(opj_tgt_tree_t *tree, int leafno, int value) {
  opj_tgt_node_t *node;
  node = &tree->nodes[leafno];
  while (node && node->value > value) {
    node->value = value;
    node = node->parent;
  }
}

void tgt_encode(opj_bio_t *bio, opj_tgt_tree_t *tree, int leafno, int threshold) {
  opj_tgt_node_t *stk[31];
  opj_tgt_node_t **stkptr;
  opj_tgt_node_t *node;
  int low;

  stkptr = stk;
  node = &tree->nodes[leafno];
  while (node->parent) {
    *stkptr++ = node;
    node = node->parent;
  }
  
  low = 0;
  for (;;) {
    if (low > node->low) {
      node->low = low;
    } else {
      low = node->low;
    }
    
    while (low < threshold) {
      if (low >= node->value) {
        if (!node->known) {
          bio_write(bio, 1, 1);
          node->known = 1;
        }
        break;
      }
      bio_write(bio, 0, 1);
      ++low;
    }
    
    node->low = low;
    if (stkptr == stk)
      break;
    node = *--stkptr;
  }
}

int tgt_decode(opj_bio_t *bio, opj_tgt_tree_t *tree, int leafno, int threshold) {
  opj_tgt_node_t *stk[31];
  opj_tgt_node_t **stkptr;
  opj_tgt_node_t *node;
  int low;

  stkptr = stk;
  node = &tree->nodes[leafno];
  while (node->parent) {
    *stkptr++ = node;
    node = node->parent;
  }
  
  low = 0;
  for (;;) {
    if (low > node->low) {
      node->low = low;
    } else {
      low = node->low;
    }
    while (low < threshold && low < node->value) {
      if (bio_read(bio, 1)) {
        node->value = low;
      } else {
        ++low;
      }
    }
    node->low = low;
    if (stkptr == stk) {
      break;
    }
    node = *--stkptr;
  }
  
  return (node->value < threshold) ? 1 : 0;
}
