tesseract::POLY_BLOCK Class Reference

#include <polyblk.h>

Public Member Functions
	POLY_BLOCK ()=default
	POLY_BLOCK (const TBOX &tbox, PolyBlockType type)
	POLY_BLOCK (ICOORDELT_LIST *points, PolyBlockType type)
	~POLY_BLOCK ()=default
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_t	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_t 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 30 of file polyblk.h.

Constructor & Destructor Documentation

POLY_BLOCK() [1/3]

tesseract::POLY_BLOCK::POLY_BLOCK ( )

default

POLY_BLOCK() [2/3]

tesseract::POLY_BLOCK::POLY_BLOCK	(	const TBOX &	tbox,
		PolyBlockType	type
	)

Definition at line 50 of file polyblk.cpp.

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

POLY_BLOCK() [3/3]

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

Definition at line 39 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()

tesseract::POLY_BLOCK::~POLY_BLOCK ( )

default

Member Function Documentation

bounding_box()

TBOX * tesseract::POLY_BLOCK::bounding_box ( )

inline

Definition at line 38 of file polyblk.h.

                       { // access function
    return &box;
  }

ColorForPolyBlockType()

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

static

Returns a color to draw the given type.

Definition at line 389 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 < PT_COUNT) {
    return kPBColors[type];
  }
  return ScrollView::WHITE;
}

compute_bb()

void tesseract::POLY_BLOCK::compute_bb

(

)

Definition at line 68 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 tesseract::POLY_BLOCK::contains

(

POLY_BLOCK *

other

)

Returns

true if other is inside this.

Definition at line 143 of file polyblk.cpp.

                                           {
  int16_t 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 tesseract::POLY_BLOCK::fill	(	ScrollView *	window,
		ScrollView::Color	colour
	)

Definition at line 272 of file polyblk.cpp.

                                                                {
  ICOORDELT_IT s_it;
 
  std::unique_ptr<PB_LINE_IT> lines(new PB_LINE_IT(this));
  window->Pen(colour);
 
  for (auto 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.
        auto width = s_it.data()->y();
        window->SetCursor(s_it.data()->x(), y);
        window->DrawTo(s_it.data()->x() + static_cast<float>(width), y);
      }
    }
  }
}

isA()

PolyBlockType tesseract::POLY_BLOCK::isA ( ) const

inline

Definition at line 48 of file polyblk.h.

                            {
    return type;
  }

IsText()

bool tesseract::POLY_BLOCK::IsText ( ) const

inline

Definition at line 52 of file polyblk.h.

                      {
    return PTIsTextType(type);
  }

move()

void tesseract::POLY_BLOCK::move

(

ICOORD

shift

)

POLY_BLOCK::move

Move the POLY_BLOCK.

Parameters

shift

x,y translation vector

Definition at line 233 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 tesseract::POLY_BLOCK::overlap

(

POLY_BLOCK *

other

)

Returns

true if the polygons of other and this overlap.

Definition at line 296 of file polyblk.cpp.

                                          {
  int16_t 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 tesseract::POLY_BLOCK::plot	(	ScrollView *	window,
		int32_t	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(_WIN32) || defined(__MINGW32__)
    snprintf(temp_buff, sizeof(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 * tesseract::POLY_BLOCK::points ( )

inline

Definition at line 42 of file polyblk.h.

                           { // access function
    return &vertices;
  }

reflect_in_y_axis()

void tesseract::POLY_BLOCK::reflect_in_y_axis

(

)

Definition at line 214 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 tesseract::POLY_BLOCK::rotate

(

FCOORD

rotation

)

Definition at line 191 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(static_cast<TDimension>(floor(pos.x() + 0.5)));
    pt->set_y(static_cast<TDimension>(floor(pos.y() + 0.5)));
    pts.forward();
  } while (!pts.at_first());
  compute_bb();
}

winding_number()

int16_t tesseract::POLY_BLOCK::winding_number

(

const ICOORD &

test_pt

)

Definition at line 106 of file polyblk.cpp.

                                                      {
  int16_t count;               // winding count
  ICOORD pt;                   // current point
  ICOORD vec;                  // point to current point
  ICOORD vvec;                 // current point to next point
  int32_t 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:

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