edgloop.cpp File Reference

#include "scanedg.h"
#include "drawedg.h"
#include "edgloop.h"

Go to the source code of this file.

Macros
#define	MINEDGELENGTH   8

Functions
void	complete_edge (CRACKEDGE *start, C_OUTLINE_IT *outline_it)
ScrollView::Color	check_path_legal (CRACKEDGE *start)
inT16	loop_bounding_box (CRACKEDGE *&start, ICOORD &botleft, ICOORD &topright)

Macro Definition Documentation

#define MINEDGELENGTH   8

Definition at line 29 of file edgloop.cpp.

Function Documentation

ScrollView::Color check_path_legal

(

CRACKEDGE *

start

)

Definition at line 67 of file edgloop.cpp.

                         {
  int lastchain;              //last chain code
  int chaindiff;               //chain code diff
  inT32 length;                  //length of loop
  inT32 chainsum;                //sum of chain diffs
  CRACKEDGE *edgept;             //current point
  const ERRCODE ED_ILLEGAL_SUM = "Illegal sum of chain codes";

  length = 0;
  chainsum = 0;                  //sum of chain codes
  edgept = start;
  lastchain = edgept->prev->stepdir; //previous chain code
  do {
    length++;
    if (edgept->stepdir != lastchain) {
                                 //chain code difference
      chaindiff = edgept->stepdir - lastchain;
      if (chaindiff > 2)
        chaindiff -= 4;
      else if (chaindiff < -2)
        chaindiff += 4;
      chainsum += chaindiff;     //sum differences
      lastchain = edgept->stepdir;
    }
    edgept = edgept->next;
  }
  while (edgept != start && length < C_OUTLINE::kMaxOutlineLength);

  if ((chainsum != 4 && chainsum != -4)
  || edgept != start || length < MINEDGELENGTH) {
    if (edgept != start) {
     return ScrollView::YELLOW;
    } else if (length < MINEDGELENGTH) {
     return ScrollView::MAGENTA;
    } else {
      ED_ILLEGAL_SUM.error ("check_path_legal", TESSLOG, "chainsum=%d",
        chainsum);
      return ScrollView::GREEN;
    }
  }
                                 //colour on inside
  return chainsum < 0 ? ScrollView::BLUE : ScrollView::RED;
}

void complete_edge	(	CRACKEDGE *	start,
		C_OUTLINE_IT *	outline_it
	)

Definition at line 37 of file edgloop.cpp.

                                             {
  ScrollView::Color colour;                 //colour to draw in
  inT16 looplength;              //steps in loop
  ICOORD botleft;                //bounding box
  ICOORD topright;
  C_OUTLINE *outline;            //new outline

                                 //check length etc.
  colour = check_path_legal (start);

  if (colour == ScrollView::RED || colour == ScrollView::BLUE) {
    looplength = loop_bounding_box (start, botleft, topright);
    outline = new C_OUTLINE (start, botleft, topright, looplength);
                                 //add to list
    outline_it->add_after_then_move (outline);
  }
}

inT16 loop_bounding_box	(	CRACKEDGE *&	start,
		ICOORD &	botleft,
		ICOORD &	topright
	)

Definition at line 119 of file edgloop.cpp.

                                          {
  inT16 length;                  //length of loop
  inT16 leftmost;                //on top row
  CRACKEDGE *edgept;             //current point
  CRACKEDGE *realstart;          //topleft start

  edgept = start;
  realstart = start;
  botleft = topright = ICOORD (edgept->pos.x (), edgept->pos.y ());
  leftmost = edgept->pos.x ();
  length = 0;                    //coutn length
  do {
    edgept = edgept->next;
    if (edgept->pos.x () < botleft.x ())
                                 //get bounding box
      botleft.set_x (edgept->pos.x ());
    else if (edgept->pos.x () > topright.x ())
      topright.set_x (edgept->pos.x ());
    if (edgept->pos.y () < botleft.y ())
                                 //get bounding box
      botleft.set_y (edgept->pos.y ());
    else if (edgept->pos.y () > topright.y ()) {
      realstart = edgept;
      leftmost = edgept->pos.x ();
      topright.set_y (edgept->pos.y ());
    }
    else if (edgept->pos.y () == topright.y ()
    && edgept->pos.x () < leftmost) {
                                 //leftmost on line
      leftmost = edgept->pos.x ();
      realstart = edgept;
    }
    length++;                    //count elements
  }
  while (edgept != start);
  start = realstart;             //shift it to topleft
  return length;
}