POLY_BLOCK Class Reference

#include <polyblk.h>

Public Member Functions
	POLY_BLOCK ()
	POLY_BLOCK (const TBOX &box, PolyBlockType type)
	POLY_BLOCK (ICOORDELT_LIST *points, PolyBlockType type)
	~POLY_BLOCK ()
TBOX *	bounding_box ()
ICOORDELT_LIST *	points ()
PolyBlockType	isA () const
bool	IsText () const
POLY_BLOCK::compute_bb
Compute the bounding box from the outline points.
void	compute_bb ()
POLY_BLOCK::rotate
Rotate the POLY_BLOCK. Parameters rotation cos, sin of angle
void	rotate (FCOORD rotation)
POLY_BLOCK::winding_number
Return the winding number of the outline around the given point. Parameters point point to wind around
bool	contains (POLY_BLOCK *other)
inT16	winding_number (const ICOORD &test_pt)

POLY_BLOCK::reflect_in_y_axis
Reflect the coords of the polygon in the y-axis. (Flip the sign of x.)
void	reflect_in_y_axis ()
void	move (ICOORD shift)
void	plot (ScrollView *window, inT32 num)
void	fill (ScrollView *window, ScrollView::Color colour)
bool	overlap (POLY_BLOCK *other)
static ScrollView::Color	ColorForPolyBlockType (PolyBlockType type)
	Returns a color to draw the given type. More...

Detailed Description

Definition at line 28 of file polyblk.h.

Constructor & Destructor Documentation

POLY_BLOCK() [1/3]

POLY_BLOCK::POLY_BLOCK ( )

inline

Definition at line 30 of file polyblk.h.

               {
  }

POLY_BLOCK() [2/3]

POLY_BLOCK::POLY_BLOCK	(	const TBOX &	box,
		PolyBlockType	type
	)

Definition at line 48 of file polyblk.cpp.

                                                       {
  vertices.clear();
  ICOORDELT_IT v = &vertices;
  v.move_to_first();
  v.add_to_end(new ICOORDELT(box.left(), box.top()));
  v.add_to_end(new ICOORDELT(box.left(), box.bottom()));
  v.add_to_end(new ICOORDELT(box.right(), box.bottom()));
  v.add_to_end(new ICOORDELT(box.right(), box.top()));
  compute_bb();
  type = t;
}

POLY_BLOCK() [3/3]

POLY_BLOCK::POLY_BLOCK	(	ICOORDELT_LIST *	points,
		PolyBlockType	type
	)

Definition at line 37 of file polyblk.cpp.

                                                              {
  ICOORDELT_IT v = &vertices;

  vertices.clear();
  v.move_to_first();
  v.add_list_before(points);
  compute_bb();
  type = t;
}

~POLY_BLOCK()

POLY_BLOCK::~POLY_BLOCK ( )

inline

Definition at line 35 of file polyblk.h.

                 {
  }

Member Function Documentation

bounding_box()

TBOX* POLY_BLOCK::bounding_box ( )

inline

Definition at line 38 of file polyblk.h.

                       {  // access function
    return &box;
  }

ColorForPolyBlockType()

ScrollView::Color POLY_BLOCK::ColorForPolyBlockType ( PolyBlockType  type )

static

Returns a color to draw the given type.

Definition at line 397 of file polyblk.cpp.

                                                                    {
  // Keep kPBColors in sync with PolyBlockType.
  const ScrollView::Color kPBColors[PT_COUNT] = {
    ScrollView::WHITE,        // Type is not yet known. Keep as the 1st element.
    ScrollView::BLUE,         // Text that lives inside a column.
    ScrollView::CYAN,         // Text that spans more than one column.
    ScrollView::MEDIUM_BLUE,  // Text that is in a cross-column pull-out region.
    ScrollView::AQUAMARINE,   // Partition belonging to an equation region.
    ScrollView::SKY_BLUE,   // Partition belonging to an inline equation region.
    ScrollView::MAGENTA,      // Partition belonging to a table region.
    ScrollView::GREEN,        // Text-line runs vertically.
    ScrollView::LIGHT_BLUE,   // Text that belongs to an image.
    ScrollView::RED,          // Image that lives inside a column.
    ScrollView::YELLOW,       // Image that spans more than one column.
    ScrollView::ORANGE,       // Image in a cross-column pull-out region.
    ScrollView::BROWN,        // Horizontal Line.
    ScrollView::DARK_GREEN,   // Vertical Line.
    ScrollView::GREY          // Lies outside of any column.
  };
  if (type >= 0 && type < PT_COUNT) {
    return kPBColors[type];
  }
  return ScrollView::WHITE;
}

compute_bb()

void POLY_BLOCK::compute_bb

(

)

Definition at line 66 of file polyblk.cpp.

                            {  //constructor
  ICOORD ibl, itr;               //integer bb
  ICOORD botleft;                //bounding box
  ICOORD topright;
  ICOORD pos;                    //current pos;
  ICOORDELT_IT pts = &vertices;  //iterator

  botleft = *pts.data ();
  topright = botleft;
  do {
    pos = *pts.data ();
    if (pos.x () < botleft.x ())
                                 //get bounding box
      botleft = ICOORD (pos.x (), botleft.y ());
    if (pos.y () < botleft.y ())
      botleft = ICOORD (botleft.x (), pos.y ());
    if (pos.x () > topright.x ())
      topright = ICOORD (pos.x (), topright.y ());
    if (pos.y () > topright.y ())
      topright = ICOORD (topright.x (), pos.y ());
    pts.forward ();
  }
  while (!pts.at_first ());
  ibl = ICOORD (botleft.x (), botleft.y ());
  itr = ICOORD (topright.x (), topright.y ());
  box = TBOX (ibl, itr);
}

contains()

bool POLY_BLOCK::contains

(

POLY_BLOCK *

other

)

Returns

true if other is inside this.

Definition at line 140 of file polyblk.cpp.

                                           {
  inT16 count;                   // winding count
  ICOORDELT_IT it = &vertices;   // iterator
  ICOORD vertex;

  if (!box.overlap (*(other->bounding_box ())))
    return false;                // can't be contained

  /* check that no vertex of this is inside other */

  do {
    vertex = *it.data ();
                                 // get winding number
    count = other->winding_number (vertex);
    if (count != INTERSECTING)
      if (count != 0)
        return false;
    it.forward ();
  }
  while (!it.at_first ());

  /* check that all vertices of other are inside this */

                                 //switch lists
  it.set_to_list (other->points ());
  do {
    vertex = *it.data ();
                                 //try other way round
    count = winding_number (vertex);
    if (count != INTERSECTING)
      if (count == 0)
        return false;
    it.forward ();
  }
  while (!it.at_first ());
  return true;
}

fill()

void POLY_BLOCK::fill	(	ScrollView *	window,
		ScrollView::Color	colour
	)

Definition at line 273 of file polyblk.cpp.

                                                                {
  inT16 y;
  inT16 width;
  PB_LINE_IT *lines;
  ICOORDELT_IT s_it;

  lines = new PB_LINE_IT (this);
  window->Pen(colour);

  for (y = this->bounding_box ()->bottom ();
  y <= this->bounding_box ()->top (); y++) {
    const std::unique_ptr</*non-const*/ ICOORDELT_LIST> segments(lines->get_line (y));
    if (!segments->empty ()) {
      s_it.set_to_list (segments.get());
      for (s_it.mark_cycle_pt (); !s_it.cycled_list (); s_it.forward ()) {
        // Note different use of ICOORDELT, x coord is x coord of pixel
        // at the start of line segment, y coord is length of line segment
        // Last pixel is start pixel + length.
        width = s_it.data ()->y ();
        window->SetCursor(s_it.data ()->x (), y);
        window->DrawTo(s_it.data ()->x () + (float) width, y);
      }
    }
  }

  delete lines;
}

isA()

PolyBlockType POLY_BLOCK::isA ( ) const

inline

Definition at line 48 of file polyblk.h.

                            {
    return type;
  }

IsText()

bool POLY_BLOCK::IsText ( ) const

inline

Definition at line 52 of file polyblk.h.

                      {
    return PTIsTextType(type);
  }

move()

void POLY_BLOCK::move

(

ICOORD

shift

)

POLY_BLOCK::move

Move the POLY_BLOCK.

Parameters

shift

x,y translation vector

Definition at line 231 of file polyblk.cpp.

                                  {
  ICOORDELT *pt;                 //current point
  ICOORDELT_IT pts = &vertices;  //iterator

  do {
    pt = pts.data ();
    *pt += shift;
    pts.forward ();
  }
  while (!pts.at_first ());
  compute_bb();
}

overlap()

bool POLY_BLOCK::overlap

(

POLY_BLOCK *

other

)

Returns

true if the polygons of other and this overlap.

Definition at line 304 of file polyblk.cpp.

                                          {
  inT16 count;                   // winding count
  ICOORDELT_IT it = &vertices;   // iterator
  ICOORD vertex;

  if (!box.overlap(*(other->bounding_box())))
    return false;                // can't be any overlap.

  /* see if a vertex of this is inside other */

  do {
    vertex = *it.data ();
                                 // get winding number
    count = other->winding_number (vertex);
    if (count != INTERSECTING)
      if (count != 0)
        return true;
    it.forward ();
  }
  while (!it.at_first ());

  /* see if a vertex of other is inside this */

                                 // switch lists
  it.set_to_list (other->points ());
  do {
    vertex = *it.data();
                                 // try other way round
    count = winding_number (vertex);
    if (count != INTERSECTING)
      if (count != 0)
        return true;
    it.forward ();
  }
  while (!it.at_first ());
  return false;
}

plot()

void POLY_BLOCK::plot	(	ScrollView *	window,
		inT32	num
	)

Definition at line 246 of file polyblk.cpp.

                                                   {
  ICOORDELT_IT v = &vertices;

  window->Pen(ColorForPolyBlockType(type));

  v.move_to_first ();

  if (num > 0) {
    window->TextAttributes("Times", 80, false, false, false);
    char temp_buff[34];
    #if defined(__UNIX__) || defined(MINGW)
    sprintf(temp_buff, "%" PRId32, num);
    #else
    ltoa (num, temp_buff, 10);
    #endif
    window->Text(v.data ()->x (), v.data ()->y (), temp_buff);
  }

  window->SetCursor(v.data ()->x (), v.data ()->y ());
  for (v.mark_cycle_pt (); !v.cycled_list (); v.forward ()) {
    window->DrawTo(v.data ()->x (), v.data ()->y ());
   }
  v.move_to_first ();
   window->DrawTo(v.data ()->x (), v.data ()->y ());
}

points()

ICOORDELT_LIST* POLY_BLOCK::points ( )

inline

Definition at line 42 of file polyblk.h.

                           {  // access function
    return &vertices;
  }

reflect_in_y_axis()

void POLY_BLOCK::reflect_in_y_axis

(

)

Definition at line 210 of file polyblk.cpp.

                                   {
  ICOORDELT *pt;                 // current point
  ICOORDELT_IT pts = &vertices;  // Iterator.

  do {
    pt = pts.data();
    pt->set_x(-pt->x());
    pts.forward();
  }
  while (!pts.at_first());
  compute_bb();
}

rotate()

void POLY_BLOCK::rotate

(

FCOORD

rotation

)

Definition at line 186 of file polyblk.cpp.

                                       {
  FCOORD pos;                    //current pos;
  ICOORDELT *pt;                 //current point
  ICOORDELT_IT pts = &vertices;  //iterator

  do {
    pt = pts.data ();
    pos.set_x (pt->x ());
    pos.set_y (pt->y ());
    pos.rotate (rotation);
    pt->set_x ((inT16) (floor (pos.x () + 0.5)));
    pt->set_y ((inT16) (floor (pos.y () + 0.5)));
    pts.forward ();
  }
  while (!pts.at_first ());
  compute_bb();
}

winding_number()

inT16 POLY_BLOCK::winding_number

(

const ICOORD &

test_pt

)

Definition at line 102 of file polyblk.cpp.

                                                    {
  inT16 count;                   //winding count
  ICOORD pt;                     //current point
  ICOORD vec;                    //point to current point
  ICOORD vvec;                   //current point to next point
  inT32 cross;                   //cross product
  ICOORDELT_IT it = &vertices;   //iterator

  count = 0;
  do {
    pt = *it.data ();
    vec = pt - point;
    vvec = *it.data_relative (1) - pt;
                                 //crossing the line
    if (vec.y () <= 0 && vec.y () + vvec.y () > 0) {
      cross = vec * vvec;        //cross product
      if (cross > 0)
        count++;                 //crossing right half
      else if (cross == 0)
        return INTERSECTING;     //going through point
    }
    else if (vec.y () > 0 && vec.y () + vvec.y () <= 0) {
      cross = vec * vvec;
      if (cross < 0)
        count--;                 //crossing back
      else if (cross == 0)
        return INTERSECTING;     //illegal
    }
    else if (vec.y () == 0 && vec.x () == 0)
      return INTERSECTING;
    it.forward ();
  }
  while (!it.at_first ());
  return count;                  //winding number
}

---

The documentation for this class was generated from the following files:

• /home/stefan/src/github/tesseract-ocr/tesseract/ccstruct/polyblk.h
• /home/stefan/src/github/tesseract-ocr/tesseract/ccstruct/polyblk.cpp