pdblock.cpp

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/**********************************************************************
 * File:        pdblock.cpp
 * Description: PDBLK member functions and iterator functions.
 * Author:      Ray Smith
 *
 * (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.
 *
 **********************************************************************/
 
// Include automatically generated configuration file if running autoconf.
#ifdef HAVE_CONFIG_H
#  include "config_auto.h"
#endif
 
#include "pdblock.h"
 
#include <allheaders.h>
 
#include <cinttypes> // for PRId32
#include <cstdlib>
#include <memory> // std::unique_ptr
 
namespace tesseract {
 
#define BLOCK_LABEL_HEIGHT 150 // char height of block id
 
constexpr ERRCODE BADBLOCKLINE("Y coordinate in block out of bounds");
constexpr ERRCODE LOSTBLOCKLINE("Can't find rectangle for line");
 
/**********************************************************************
 * PDBLK::PDBLK
 *
 * Constructor for a simple rectangular block.
 **********************************************************************/
PDBLK::PDBLK(                   // rectangular block
    TDimension xmin,            // bottom left
    TDimension ymin,
    TDimension xmax,            // top right
    TDimension ymax)
    : box(ICOORD(xmin, ymin), ICOORD(xmax, ymax)) {
  // boundaries
  ICOORDELT_IT left_it = &leftside;
  ICOORDELT_IT right_it = &rightside;
 
  hand_poly = nullptr;
  left_it.set_to_list(&leftside);
  right_it.set_to_list(&rightside);
  // make default box
  left_it.add_to_end(new ICOORDELT(xmin, ymin));
  left_it.add_to_end(new ICOORDELT(xmin, ymax));
  right_it.add_to_end(new ICOORDELT(xmax, ymin));
  right_it.add_to_end(new ICOORDELT(xmax, ymax));
  index_ = 0;
}
 
/**********************************************************************
 * PDBLK::set_sides
 *
 * Sets left and right vertex lists
 **********************************************************************/
 
void PDBLK::set_sides(    // set vertex lists
    ICOORDELT_LIST *left, // left vertices
    ICOORDELT_LIST *right // right vertices
) {
  // boundaries
  ICOORDELT_IT left_it = &leftside;
  ICOORDELT_IT right_it = &rightside;
 
  leftside.clear();
  left_it.move_to_first();
  left_it.add_list_before(left);
  rightside.clear();
  right_it.move_to_first();
  right_it.add_list_before(right);
}
 
/**********************************************************************
 * PDBLK::contains
 *
 * Return true if the given point is within the block.
 **********************************************************************/
 
bool PDBLK::contains( // test containment
    ICOORD pt         // point to test
) {
  BLOCK_RECT_IT it = this; // rectangle iterator
  ICOORD bleft, tright;    // corners of rectangle
 
  for (it.start_block(); !it.cycled_rects(); it.forward()) {
    // get rectangle
    it.bounding_box(bleft, tright);
    // inside rect
    if (pt.x() >= bleft.x() && pt.x() <= tright.x() && pt.y() >= bleft.y() &&
        pt.y() <= tright.y()) {
      return true; // is inside
    }
  }
  return false; // not inside
}
 
/**********************************************************************
 * PDBLK::move
 *
 * Reposition block
 **********************************************************************/
 
void PDBLK::move(    // reposition block
    const ICOORD vec // by vector
) {
  ICOORDELT_IT it(&leftside);
 
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    *(it.data()) += vec;
  }
 
  it.set_to_list(&rightside);
 
  for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
    *(it.data()) += vec;
  }
 
  box.move(vec);
}
 
// Returns a binary Pix mask with a 1 pixel for every pixel within the
// block. Rotates the coordinate system by rerotation prior to rendering.
Image PDBLK::render_mask(const FCOORD &rerotation, TBOX *mask_box) {
  TBOX rotated_box(box);
  rotated_box.rotate(rerotation);
  Image pix = pixCreate(rotated_box.width(), rotated_box.height(), 1);
  if (hand_poly != nullptr) {
    // We are going to rotate, so get a deep copy of the points and
    // make a new POLY_BLOCK with it.
    ICOORDELT_LIST polygon;
    polygon.deep_copy(hand_poly->points(), ICOORDELT::deep_copy);
    POLY_BLOCK image_block(&polygon, hand_poly->isA());
    image_block.rotate(rerotation);
    // Block outline is a polygon, so use a PB_LINE_IT to get the
    // rasterized interior. (Runs of interior pixels on a line.)
    auto *lines = new PB_LINE_IT(&image_block);
    for (int y = box.bottom(); y < box.top(); ++y) {
      const std::unique_ptr</*non-const*/ ICOORDELT_LIST> segments(lines->get_line(y));
      if (!segments->empty()) {
        ICOORDELT_IT s_it(segments.get());
        // Each element of segments is a start x and x size of the
        // run of interior pixels.
        for (s_it.mark_cycle_pt(); !s_it.cycled_list(); s_it.forward()) {
          int start = s_it.data()->x();
          int xext = s_it.data()->y();
          // Set the run of pixels to 1.
          pixRasterop(pix, start - rotated_box.left(),
                      rotated_box.height() - 1 - (y - rotated_box.bottom()), xext, 1, PIX_SET,
                      nullptr, 0, 0);
        }
      }
    }
    delete lines;
  } else {
    // Just fill the whole block as there is only a bounding box.
    pixRasterop(pix, 0, 0, rotated_box.width(), rotated_box.height(), PIX_SET, nullptr, 0, 0);
  }
  if (mask_box != nullptr) {
    *mask_box = rotated_box;
  }
  return pix;
}
 
/**********************************************************************
 * PDBLK::plot
 *
 * Plot the outline of a block in the given colour.
 **********************************************************************/
 
#ifndef GRAPHICS_DISABLED
void PDBLK::plot(            // draw outline
    ScrollView *window,      // window to draw in
    int32_t serial,          // serial number
    ScrollView::Color colour // colour to draw in
) {
  ICOORD startpt;              // start of outline
  ICOORD endpt;                // end of outline
  ICOORD prevpt;               // previous point
  ICOORDELT_IT it = &leftside; // iterator
 
  // set the colour
  window->Pen(colour);
  window->TextAttributes("Times", BLOCK_LABEL_HEIGHT, false, false, false);
 
  if (hand_poly != nullptr) {
    hand_poly->plot(window, serial);
  } else if (!leftside.empty()) {
    startpt = *(it.data()); // bottom left corner
    //              tprintf("Block %d bottom left is (%d,%d)\n",
    //                      serial,startpt.x(),startpt.y());
    char temp_buff[34];
#  if !defined(_WIN32) || defined(__MINGW32__)
    snprintf(temp_buff, sizeof(temp_buff), "%" PRId32, serial);
#  else
    _ultoa(serial, temp_buff, 10);
#  endif
    window->Text(startpt.x(), startpt.y(), temp_buff);
 
    window->SetCursor(startpt.x(), startpt.y());
    do {
      prevpt = *(it.data()); // previous point
      it.forward();          // move to next point
                             // draw round corner
      window->DrawTo(prevpt.x(), it.data()->y());
      window->DrawTo(it.data()->x(), it.data()->y());
    } while (!it.at_last()); // until end of list
    endpt = *(it.data());    // end point
 
    // other side of boundary
    window->SetCursor(startpt.x(), startpt.y());
    it.set_to_list(&rightside);
    prevpt = startpt;
    for (it.mark_cycle_pt(); !it.cycled_list(); it.forward()) {
      // draw round corner
      window->DrawTo(prevpt.x(), it.data()->y());
      window->DrawTo(it.data()->x(), it.data()->y());
      prevpt = *(it.data()); // previous point
    }
    // close boundary
    window->DrawTo(endpt.x(), endpt.y());
  }
}
#endif
 
/**********************************************************************
 * PDBLK::operator=
 *
 * Assignment - duplicate the block structure, but with an EMPTY row list.
 **********************************************************************/
 
PDBLK &PDBLK::operator=( // assignment
    const PDBLK &source  // from this
) {
  //      this->ELIST_LINK::operator=(source);
  if (!leftside.empty()) {
    leftside.clear();
  }
  if (!rightside.empty()) {
    rightside.clear();
  }
  leftside.deep_copy(&source.leftside, &ICOORDELT::deep_copy);
  rightside.deep_copy(&source.rightside, &ICOORDELT::deep_copy);
  box = source.box;
  return *this;
}
 
/**********************************************************************
 * BLOCK_RECT_IT::BLOCK_RECT_IT
 *
 * Construct a block rectangle iterator.
 **********************************************************************/
 
BLOCK_RECT_IT::BLOCK_RECT_IT(
    // iterate rectangles
    PDBLK *blkptr // from block
    )
    : left_it(&blkptr->leftside), right_it(&blkptr->rightside) {
  block = blkptr; // remember block
                  // non empty list
  if (!blkptr->leftside.empty()) {
    start_block(); // ready for iteration
  }
}
 
/**********************************************************************
 * BLOCK_RECT_IT::set_to_block
 *
 * Start a new block.
 **********************************************************************/
 
void BLOCK_RECT_IT::set_to_block( // start (new) block
    PDBLK *blkptr) {              // block to start
  block = blkptr;                 // remember block
                                  // set iterators
  left_it.set_to_list(&blkptr->leftside);
  right_it.set_to_list(&blkptr->rightside);
  if (!blkptr->leftside.empty()) {
    start_block(); // ready for iteration
  }
}
 
/**********************************************************************
 * BLOCK_RECT_IT::start_block
 *
 * Restart a block.
 **********************************************************************/
 
void BLOCK_RECT_IT::start_block() { // start (new) block
  left_it.move_to_first();
  right_it.move_to_first();
  left_it.mark_cycle_pt();
  right_it.mark_cycle_pt();
  ymin = left_it.data()->y(); // bottom of first box
  ymax = left_it.data_relative(1)->y();
  if (right_it.data_relative(1)->y() < ymax) {
    // smallest step
    ymax = right_it.data_relative(1)->y();
  }
}
 
/**********************************************************************
 * BLOCK_RECT_IT::forward
 *
 * Move to the next rectangle in the block.
 **********************************************************************/
 
void BLOCK_RECT_IT::forward() { // next rectangle
  if (!left_it.empty()) {       // non-empty list
    if (left_it.data_relative(1)->y() == ymax) {
      left_it.forward(); // move to meet top
    }
    if (right_it.data_relative(1)->y() == ymax) {
      right_it.forward();
    }
    // last is special
    if (left_it.at_last() || right_it.at_last()) {
      left_it.move_to_first(); // restart
      right_it.move_to_first();
      // now at bottom
      ymin = left_it.data()->y();
    } else {
      ymin = ymax; // new bottom
    }
    // next point
    ymax = left_it.data_relative(1)->y();
    if (right_it.data_relative(1)->y() < ymax) {
      // least step forward
      ymax = right_it.data_relative(1)->y();
    }
  }
}
 
/**********************************************************************
 * BLOCK_LINE_IT::get_line
 *
 * Get the start and width of a line in the block.
 **********************************************************************/
 
TDimension BLOCK_LINE_IT::get_line( // get a line
    TDimension y,                   // line to get
    TDimension &xext                // output extent
) {
  ICOORD bleft;  // bounding box
  ICOORD tright; // of block & rect
 
  // get block box
  block->bounding_box(bleft, tright);
  if (y < bleft.y() || y >= tright.y()) {
    //              block->print(stderr,false);
    BADBLOCKLINE.error("BLOCK_LINE_IT::get_line", ABORT, "Y=%d", y);
  }
 
  // get rectangle box
  rect_it.bounding_box(bleft, tright);
  // inside rectangle
  if (y >= bleft.y() && y < tright.y()) {
    // width of line
    xext = tright.x() - bleft.x();
    return bleft.x(); // start of line
  }
  for (rect_it.start_block(); !rect_it.cycled_rects(); rect_it.forward()) {
    // get rectangle box
    rect_it.bounding_box(bleft, tright);
    // inside rectangle
    if (y >= bleft.y() && y < tright.y()) {
      // width of line
      xext = tright.x() - bleft.x();
      return bleft.x(); // start of line
    }
  }
  LOSTBLOCKLINE.error("BLOCK_LINE_IT::get_line", ABORT, "Y=%d", y);
  return 0; // dummy to stop warning
}
 
} // namespace tesseract