tesseract/src/ccstruct/pdblock.h

/**********************************************************************
 * File:        pdblock.h  (Formerly pdblk.h)
 * Description: Page block class definition.
 * Author:      Ray Smith
 * Created:     Thu Mar 14 17:32:01 GMT 1991
 *
 * (C) Copyright 1991, Hewlett-Packard Ltd.
 ** 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.
 *
 **********************************************************************/

#ifndef           PDBLOCK_H
#define           PDBLOCK_H

#include          "clst.h"
#include          "strngs.h"
#include          "polyblk.h"

class DLLSYM PDBLK;              //forward decl
struct Pix;

CLISTIZEH (PDBLK)
///page block
class PDBLK {
  friend class BLOCK_RECT_IT;    //< block iterator
  friend class BLOCK;            //< Page Block

 public:
  /// empty constructor
  PDBLK() {
    hand_poly = nullptr;
    index_ = 0;
  }
  /// simple constructor
  PDBLK(int16_t xmin,  //< bottom left
        int16_t ymin,
        int16_t xmax,  //< top right
        int16_t ymax);

  /// set vertex lists
  ///@param left list of left vertices
  ///@param right list of right vertices
  void set_sides(ICOORDELT_LIST *left, ICOORDELT_LIST *right);

  /// destructor
  ~PDBLK() { delete hand_poly; }

  POLY_BLOCK *poly_block() const { return hand_poly; }
  /// set the poly block
  void set_poly_block(POLY_BLOCK *blk) { hand_poly = blk; }
  /// get box
  void bounding_box(ICOORD &bottom_left,        // bottom left
                    ICOORD &top_right) const {  // topright
    bottom_left = box.botleft();
    top_right = box.topright();
  }
  /// get real box
  const TBOX &bounding_box() const { return box; }

  int index() const { return index_; }
  void set_index(int value) { index_ = value; }

  /// is pt inside block
  bool contains(ICOORD pt);

  /// reposition block
  void move(const ICOORD vec);  // by vector

  // Returns a binary Pix mask with a 1 pixel for every pixel within the
  // block. Rotates the coordinate system by rerotation prior to rendering.
  // If not nullptr, mask_box is filled with the position box of the returned
  // mask image.
  Pix *render_mask(const FCOORD &rerotation, TBOX *mask_box);

#ifndef GRAPHICS_DISABLED
  /// draw histogram
  ///@param window window to draw in
  ///@param serial serial number
  ///@param colour colour to draw in
  void plot(ScrollView *window, int32_t serial, ScrollView::Color colour);
#endif  // GRAPHICS_DISABLED

  /// assignment
  ///@param source from this
  PDBLK &operator=(const PDBLK &source);

 protected:
  POLY_BLOCK *hand_poly;     //< weird as well
  ICOORDELT_LIST leftside;   //< left side vertices
  ICOORDELT_LIST rightside;  //< right side vertices
  TBOX box;                  //< bounding box
  int index_;                //< Serial number of this block.
};

class DLLSYM BLOCK_RECT_IT       //rectangle iterator
{
  public:
    ///constructor
    ///@param blkptr block to iterate
    BLOCK_RECT_IT(PDBLK *blkptr);

    ///start (new) block
    void set_to_block (
      PDBLK * blkptr);           //block to iterate

    ///start iteration
    void start_block();

    ///next rectangle
    void forward();

    ///test end
    bool cycled_rects() {
      return left_it.cycled_list() && right_it.cycled_list();
    }

    ///current rectangle
    ///@param bleft bottom left
    ///@param tright top right
    void bounding_box(ICOORD &bleft,
                      ICOORD &tright) {
                                 //bottom left
      bleft = ICOORD (left_it.data ()->x (), ymin);
                                 //top right
      tright = ICOORD (right_it.data ()->x (), ymax);
    }

  private:
    int16_t ymin;                  //< bottom of rectangle
    int16_t ymax;                  //< top of rectangle
    PDBLK *block;                //< block to iterate
    ICOORDELT_IT left_it;        //< boundary iterators
    ICOORDELT_IT right_it;
};

///rectangle iterator
class DLLSYM BLOCK_LINE_IT
{
  public:
    ///constructor
    ///@param blkptr from block
    BLOCK_LINE_IT (PDBLK * blkptr)
    :rect_it (blkptr) {
      block = blkptr;            //remember block
    }

    ///start (new) block
      ///@param blkptr block to start
    void set_to_block (PDBLK * blkptr) {
      block = blkptr;            //remember block
                                 //set iterator
      rect_it.set_to_block (blkptr);
    }

    ///get a line
    ///@param y line to get
    ///@param xext output extent
    int16_t get_line(int16_t y,
                   int16_t &xext);

  private:
    PDBLK * block;               //< block to iterate
    BLOCK_RECT_IT rect_it;       //< rectangle iterator
};

int decreasing_top_order(const void *row1,
                         const void *row2);
#endif