tesseract/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

  public:
    ///empty constructor
    PDBLK() {
      hand_poly = NULL;
      index_ = 0;
    }
    ///simple constructor
    PDBLK(inT16 xmin,  //< bottom left
          inT16 ymin,
          inT16 xmax,  //< top right
          inT16 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 () {
      if (hand_poly) 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
    BOOL8 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 NULL, 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 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
    BOOL8 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 ymin;                  //< bottom of rectangle
    inT16 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 get_line(inT16 y,
                   inT16 &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