/******************************************************************************

 *

 * File:         findseam.cpp  (Formerly findseam.c)

 * Author:       Mark Seaman, OCR Technology

 *

 * (c) Copyright 1987, Hewlett-Packard Company.

 ** Licensed under the Apache License, Version 2.0 (the "License");

 ** you may not use this file except in compliance with the License.

 ** You may obtain a copy of the License at

 ** http://www.apache.org/licenses/LICENSE-2.0

 ** Unless required by applicable law or agreed to in writing, software

 ** distributed under the License is distributed on an "AS IS" BASIS,

 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 ** See the License for the specific language governing permissions and

 ** limitations under the License.

 *

 *****************************************************************************/

/*----------------------------------------------------------------------

              I n c l u d e s

----------------------------------------------------------------------*/

#include "findseam.h"

#include "outlines.h"

#include "plotedges.h"

#include "seam.h"

#include "wordrec.h"

// Include automatically generated configuration file if running autoconf.

#ifdef HAVE_CONFIG_H

#  include "config_auto.h"

#endif

/**********************************************************************

 * partial_split_priority

 *

 * Assign a priority to this split based on the features that it has.

 * Grade it according to the different rating schemes and return the

 * value of its goodness.

 **********************************************************************/

#define partial_split_priority(split) (grade_split_length(split) + grade_sharpness(split))

/*----------------------------------------------------------------------

              T y p e s

----------------------------------------------------------------------*/

#define SPLIT_CLOSENESS 20 /* Difference in x value */

                           /* How many to keep */

#define MAX_NUM_SEAMS 150

/* How many to keep */

#define NO_FULL_PRIORITY (-1) // Special marker for pri.

                            /* Evaluate right away */

#define BAD_PRIORITY 9999.0

/*----------------------------------------------------------------------

              F u n c t i o n s

----------------------------------------------------------------------*/

namespace tesseract {

/**********************************************************************

 * add_seam_to_queue

 *

 * Adds the given new_seam to the seams priority queue, unless it is full

 * and the new seam is worse than the worst.

 **********************************************************************/

void Wordrec::add_seam_to_queue(float new_priority, SEAM *new_seam, SeamQueue *seams) {

  if (new_seam == nullptr) {

    return;

  }

  if (chop_debug) {

    tprintf("Pushing new seam with priority %g :", new_priority);

    new_seam->Print("seam: ");

  }

  if (seams->size() >= MAX_NUM_SEAMS) {

    SeamPair old_pair(0, nullptr);

    if (seams->PopWorst(&old_pair) && old_pair.key() <= new_priority) {

      if (chop_debug) {

        tprintf("Old seam staying with priority %g\n", old_pair.key());

      }

      delete new_seam;

      seams->Push(&old_pair);

      return;

    } else if (chop_debug) {

      tprintf("New seam with priority %g beats old worst seam with %g\n", new_priority,

              old_pair.key());

    }

  }

  SeamPair new_pair(new_priority, new_seam);

  seams->Push(&new_pair);

}

/**********************************************************************

 * choose_best_seam

 *

 * Choose the best seam that can be created by assembling this a

 * collection of splits.  A queue of all the possible seams is

 * maintained.  Each new split received is placed in that queue with

 * its partial priority value.  These values in the seam queue are

 * evaluated and combined until a good enough seam is found.  If no

 * further good seams are being found then this function returns to the

 * caller, who will send more splits.  If this function is called with

 * a split of nullptr, then no further splits can be supplied by the

 * caller.

 **********************************************************************/

void Wordrec::choose_best_seam(SeamQueue *seam_queue, const SPLIT *split, PRIORITY priority,

                               SEAM **seam_result, TBLOB *blob, SeamPile *seam_pile) {

  SEAM *seam;

  float my_priority;

  /* Add seam of split */

  my_priority = priority;

  if (split != nullptr) {

    TPOINT split_point = split->point1->pos;

    split_point += split->point2->pos;

    split_point /= 2;

    seam = new SEAM(my_priority, split_point, *split);

    if (chop_debug > 1) {

      seam->Print("Partial priority    ");

    }

    add_seam_to_queue(my_priority, seam, seam_queue);

    if (my_priority > chop_good_split) {

      return;

    }

  }

  TBOX bbox = blob->bounding_box();

  /* Queue loop */

  while (!seam_queue->empty()) {

    SeamPair seam_pair;

    seam_queue->Pop(&seam_pair);

    seam = seam_pair.extract_data();

    /* Set full priority */

    my_priority =

        seam->FullPriority(bbox.left(), bbox.right(), chop_overlap_knob, chop_centered_maxwidth,

                           chop_center_knob, chop_width_change_knob);

    if (chop_debug) {

      char str[80];

      snprintf(str, sizeof(str), "Full my_priority %0.0f,  ", my_priority);

      seam->Print(str);

    }

    if ((*seam_result == nullptr || (*seam_result)->priority() > my_priority) &&

        my_priority < chop_ok_split) {

      /* No crossing */

      if (seam->IsHealthy(*blob, chop_min_outline_points, chop_min_outline_area)) {

        delete *seam_result;

        *seam_result = new SEAM(*seam);

        (*seam_result)->set_priority(my_priority);

      } else {

        delete seam;

        seam = nullptr;

        my_priority = BAD_PRIORITY;

      }

    }

    if (my_priority < chop_good_split) {

      delete seam;

      return; /* Made good answer */

    }

    if (seam) {

      /* Combine with others */

      if (seam_pile->size() < chop_seam_pile_size) {

        combine_seam(*seam_pile, seam, seam_queue);

        SeamDecPair pair(seam_pair.key(), seam);

        seam_pile->Push(&pair);

      } else if (chop_new_seam_pile && seam_pile->size() == chop_seam_pile_size &&

                 seam_pile->PeekTop().key() > seam_pair.key()) {

        combine_seam(*seam_pile, seam, seam_queue);

        SeamDecPair pair;

        seam_pile->Pop(&pair); // pop the worst.

        // Replace the seam in pair (deleting the old one) with

        // the new seam and score, then push back into the heap.

        pair.set_key(seam_pair.key());

        pair.set_data(seam);

        seam_pile->Push(&pair);

      } else {

        delete seam;

      }

    }

    my_priority = seam_queue->empty() ? NO_FULL_PRIORITY : seam_queue->PeekTop().key();

    if ((my_priority > chop_ok_split) || (my_priority > chop_good_split && split)) {

      return;

    }

  }

}

/**********************************************************************

 * combine_seam

 *

 * Find other seams to combine with this one.  The new seams that result

 * from this union should be added to the seam queue.  The return value

 * tells whether or not any additional seams were added to the queue.

 **********************************************************************/

void Wordrec::combine_seam(const SeamPile &seam_pile, const SEAM *seam, SeamQueue *seam_queue) {

  for (int x = 0; x < seam_pile.size(); ++x) {

    const SEAM *this_one = seam_pile.get(x).data();

    if (seam->CombineableWith(*this_one, SPLIT_CLOSENESS, chop_ok_split)) {

      SEAM *new_one = new SEAM(*seam);

      new_one->CombineWith(*this_one);

      if (chop_debug > 1) {

        new_one->Print("Combo priority       ");

      }

      add_seam_to_queue(new_one->priority(), new_one, seam_queue);

    }

  }

}

/**********************************************************************

 * pick_good_seam

 *

 * Find and return a good seam that will split this blob into two pieces.

 * Work from the outlines provided.

 **********************************************************************/

SEAM *Wordrec::pick_good_seam(TBLOB *blob) {

  SeamPile seam_pile(chop_seam_pile_size);

  EDGEPT *points[MAX_NUM_POINTS];

  EDGEPT_CLIST new_points;

  SEAM *seam = nullptr;

  TESSLINE *outline;

  int16_t num_points = 0;

#ifndef GRAPHICS_DISABLED

  if (chop_debug > 2) {

    wordrec_display_splits.set_value(true);

  }

  draw_blob_edges(blob);

#endif

  PointHeap point_heap(MAX_NUM_POINTS);

  for (outline = blob->outlines; outline; outline = outline->next) {

    prioritize_points(outline, &point_heap);

  }

  while (!point_heap.empty() && num_points < MAX_NUM_POINTS) {

    points[num_points++] = point_heap.PeekTop().data();

    point_heap.Pop(nullptr);

  }

  /* Initialize queue */

  SeamQueue seam_queue(MAX_NUM_SEAMS);

  try_point_pairs(points, num_points, &seam_queue, &seam_pile, &seam, blob);

  try_vertical_splits(points, num_points, &new_points, &seam_queue, &seam_pile, &seam, blob);

  if (seam == nullptr) {

    choose_best_seam(&seam_queue, nullptr, BAD_PRIORITY, &seam, blob, &seam_pile);

  } else if (seam->priority() > chop_good_split) {

    choose_best_seam(&seam_queue, nullptr, seam->priority(), &seam, blob, &seam_pile);

  }

  EDGEPT_C_IT it(&new_points);

  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {

    EDGEPT *inserted_point = it.data();

    if (seam == nullptr || !seam->UsesPoint(inserted_point)) {

      for (outline = blob->outlines; outline; outline = outline->next) {

        if (outline->loop == inserted_point) {

          outline->loop = outline->loop->next;

        }

      }

      remove_edgept(inserted_point);

    }

  }

  if (seam) {

    if (seam->priority() > chop_ok_split) {

      delete seam;

      seam = nullptr;

    }

#ifndef GRAPHICS_DISABLED

    else if (wordrec_display_splits) {

      seam->Mark(edge_window);

      if (chop_debug > 2) {

        edge_window->Update();

        edge_window->Wait();

      }

    }

#endif

  }

  if (chop_debug) {

    wordrec_display_splits.set_value(false);

  }

  return (seam);

}

/**********************************************************************

 * try_point_pairs

 *

 * Try all the splits that are produced by pairing critical points

 * together.  See if any of them are suitable for use.  Use a seam

 * queue and seam pile that have already been initialized and used.

 **********************************************************************/

void Wordrec::try_point_pairs(EDGEPT *points[MAX_NUM_POINTS], int16_t num_points,

                              SeamQueue *seam_queue, SeamPile *seam_pile, SEAM **seam,

                              TBLOB *blob) {

  int16_t x;

  int16_t y;

  PRIORITY priority;

  for (x = 0; x < num_points; x++) {

    for (y = x + 1; y < num_points; y++) {

      if (points[y] &&

          points[x]->WeightedDistance(*points[y], chop_x_y_weight) < chop_split_length &&

          points[x] != points[y]->next && points[y] != points[x]->next &&

          !is_exterior_point(points[x], points[y]) && !is_exterior_point(points[y], points[x])) {

        SPLIT split(points[x], points[y]);

        priority = partial_split_priority(&split);

        choose_best_seam(seam_queue, &split, priority, seam, blob, seam_pile);

      }

    }

  }

}

/**********************************************************************

 * try_vertical_splits

 *

 * Try all the splits that are produced by vertical projection to see

 * if any of them are suitable for use.  Use a seam queue and seam pile

 * that have already been initialized and used.

 * Return in new_points a collection of points that were inserted into

 * the blob while examining vertical splits and which may safely be

 * removed once a seam is chosen if they are not part of the seam.

 **********************************************************************/

void Wordrec::try_vertical_splits(EDGEPT *points[MAX_NUM_POINTS], int16_t num_points,

                                  EDGEPT_CLIST *new_points, SeamQueue *seam_queue,

                                  SeamPile *seam_pile, SEAM **seam, TBLOB *blob) {

  EDGEPT *vertical_point = nullptr;

  int16_t x;

  PRIORITY priority;

  TESSLINE *outline;

  for (x = 0; x < num_points; x++) {

    vertical_point = nullptr;

    for (outline = blob->outlines; outline; outline = outline->next) {

      vertical_projection_point(points[x], outline->loop, &vertical_point, new_points);

    }

    if (vertical_point && points[x] != vertical_point->next && vertical_point != points[x]->next &&

        points[x]->WeightedDistance(*vertical_point, chop_x_y_weight) < chop_split_length) {

      SPLIT split(points[x], vertical_point);

      priority = partial_split_priority(&split);

      choose_best_seam(seam_queue, &split, priority, seam, blob, seam_pile);

    }

  }

}

} // namespace tesseract