void find_cblob_hlimits( //get x limits
C_BLOB *blob, //blob to search
float bottomy, //y limits
float topy,
float &xmin, //output x limits
float &xmax) {
inT16 stepindex; //current point
ICOORD pos; //current coords
ICOORD vec; //rotated step
C_OUTLINE *outline; //current outline
//outlines
C_OUTLINE_IT out_it = blob->out_list ();
xmin = (float) MAX_INT32;
xmax = (float) -MAX_INT32;
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
outline = out_it.data ();
pos = outline->start_pos (); //get coords
for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
//inside
if (pos.y () >= bottomy && pos.y () <= topy) {
UpdateRange(pos.x(), &xmin, &xmax);
}
vec = outline->step (stepindex);
pos += vec; //move to next
}
}
}
void find_cblob_vlimits( //get y limits
C_BLOB *blob, //blob to search
float leftx, //x limits
float rightx,
float &ymin, //output y limits
float &ymax) {
INT16 stepindex; //current point
ICOORD pos; //current coords
ICOORD vec; //rotated step
C_OUTLINE *outline; //current outline
//outlines
C_OUTLINE_IT out_it = blob->out_list ();
ymin = (float) MAX_INT32;
ymax = (float) -MAX_INT32;
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
outline = out_it.data ();
pos = outline->start_pos (); //get coords
for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
//inside
if (pos.x () >= leftx && pos.x () <= rightx) {
if (pos.y () > ymax)
ymax = pos.y ();
if (pos.y () < ymin)
ymin = pos.y ();
}
vec = outline->step (stepindex);
pos += vec; //move to next
}
}
}
inT32 C_OUTLINE::area() { //winding number
int stepindex; //current step
inT32 total_steps; //steps to do
inT32 total; //total area
ICOORD pos; //position of point
ICOORD next_step; //step to next pix
C_OUTLINE_IT it = child ();
pos = start_pos ();
total_steps = pathlength ();
total = 0;
for (stepindex = 0; stepindex < total_steps; stepindex++) {
//all intersected
next_step = step (stepindex);
if (next_step.x () < 0)
total += pos.y ();
else if (next_step.x () > 0)
total -= pos.y ();
pos += next_step;
}
for (it.mark_cycle_pt (); !it.cycled_list (); it.forward ())
total += it.data ()->area ();//add areas of children
return total;
}
void POLY_BLOCK::compute_bb() { //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);
}
void C_OUTLINE::plot( //draw it
ScrollView* window, // window to draw in
ScrollView::Color colour // colour to draw in
) const {
inT16 stepindex; // index to cstep
ICOORD pos; // current position
DIR128 stepdir; // direction of step
pos = start; // current position
window->Pen(colour);
if (stepcount == 0) {
window->Rectangle(box.left(), box.top(), box.right(), box.bottom());
return;
}
window->SetCursor(pos.x(), pos.y());
stepindex = 0;
while (stepindex < stepcount) {
pos += step(stepindex); // step to next
stepdir = step_dir(stepindex);
stepindex++; // count steps
// merge straight lines
while (stepindex < stepcount &&
stepdir.get_dir() == step_dir(stepindex).get_dir()) {
pos += step(stepindex);
stepindex++;
}
window->DrawTo(pos.x(), pos.y());
}
}
void save_chop_cfragment( //chop the outline
int16_t head_index, //head of fragment
ICOORD head_pos, //head of fragment
int16_t tail_index, //tail of fragment
ICOORD tail_pos, //tail of fragment
C_OUTLINE *srcline, //source of edgesteps
C_OUTLINE_FRAG_LIST *frags //fragment list
) {
int16_t jump; //gap across end
int16_t stepcount; //total steps
C_OUTLINE_FRAG *head; //head of fragment
C_OUTLINE_FRAG *tail; //tail of fragment
int16_t tail_y; //ycoord of tail
ASSERT_HOST (tail_pos.x () == head_pos.x ());
ASSERT_HOST (tail_index != head_index);
stepcount = tail_index - head_index;
if (stepcount < 0)
stepcount += srcline->pathlength ();
jump = tail_pos.y () - head_pos.y ();
if (jump < 0)
jump = -jump;
if (jump == stepcount)
return; //its a nop
tail_y = tail_pos.y ();
head = new C_OUTLINE_FRAG (head_pos, tail_pos, srcline,
head_index, tail_index);
tail = new C_OUTLINE_FRAG (head, tail_y);
head->other_end = tail;
add_frag_to_list(head, frags);
add_frag_to_list(tail, frags);
}
void vertical_coutline_projection( //project outlines
C_OUTLINE *outline, //outline to project
STATS *stats //output
) {
ICOORD pos; //current point
ICOORD step; //edge step
inT32 length; //of outline
inT16 stepindex; //current step
C_OUTLINE_IT out_it = outline->child ();
pos = outline->start_pos ();
length = outline->pathlength ();
for (stepindex = 0; stepindex < length; stepindex++) {
step = outline->step (stepindex);
if (step.x () > 0) {
stats->add (pos.x (), -pos.y ());
} else if (step.x () < 0) {
stats->add (pos.x () - 1, pos.y ());
}
pos += step;
}
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
vertical_coutline_projection (out_it.data (), stats);
}
}
inT32 C_OUTLINE::area() const {
int stepindex; //current step
inT32 total_steps; //steps to do
inT32 total; //total area
ICOORD pos; //position of point
ICOORD next_step; //step to next pix
// We aren't going to modify the list, or its contents, but there is
// no const iterator.
C_OUTLINE_IT it(const_cast<C_OUTLINE_LIST*>(&children));
pos = start_pos ();
total_steps = pathlength ();
total = 0;
for (stepindex = 0; stepindex < total_steps; stepindex++) {
//all intersected
next_step = step (stepindex);
if (next_step.x () < 0)
total += pos.y ();
else if (next_step.x () > 0)
total -= pos.y ();
pos += next_step;
}
for (it.mark_cycle_pt (); !it.cycled_list (); it.forward ())
total += it.data ()->area ();//add areas of children
return total;
}
OL_BUCKETS::OL_BUCKETS(
ICOORD bleft, // corners
ICOORD tright): bl(bleft), tr(tright) {
bxdim =(tright.x() - bleft.x()) / BUCKETSIZE + 1;
bydim =(tright.y() - bleft.y()) / BUCKETSIZE + 1;
// make array
buckets = new C_OUTLINE_LIST[bxdim * bydim];
index = 0;
}
// (Re)Initialize the grid. The gridsize is the size in pixels of each cell,
// and bleft, tright are the bounding box of everything to go in it.
void GridBase::Init(int gridsize, const ICOORD& bleft, const ICOORD& tright) {
gridsize_ = gridsize;
bleft_ = bleft;
tright_ = tright;
if (gridsize_ == 0)
gridsize_ = 1;
gridwidth_ = (tright.x() - bleft.x() + gridsize_ - 1) / gridsize_;
gridheight_ = (tright.y() - bleft.y() + gridsize_ - 1) / gridsize_;
gridbuckets_ = gridwidth_ * gridheight_;
}
/**********************************************************************
* C_OUTLINE::C_OUTLINE
*
* Constructor to build a C_OUTLINE from a C_OUTLINE_FRAG.
**********************************************************************/
C_OUTLINE::C_OUTLINE (
//constructor
//steps to copy
ICOORD startpt, DIR128 * new_steps,
inT16 length //length of loop
):start (startpt), offsets(NULL) {
inT8 dirdiff; //direction difference
DIR128 prevdir; //previous direction
DIR128 dir; //current direction
DIR128 lastdir; //dir of last step
TBOX new_box; //easy bounding
inT16 stepindex; //index to step
inT16 srcindex; //source steps
ICOORD pos; //current position
pos = startpt;
stepcount = length; // No. of steps.
ASSERT_HOST(length >= 0);
steps = reinterpret_cast<uinT8*>(alloc_mem(step_mem())); // Get memory.
memset(steps, 0, step_mem());
lastdir = new_steps[length - 1];
prevdir = lastdir;
for (stepindex = 0, srcindex = 0; srcindex < length;
stepindex++, srcindex++) {
new_box = TBOX (pos, pos);
box += new_box;
//copy steps
dir = new_steps[srcindex];
set_step(stepindex, dir);
dirdiff = dir - prevdir;
pos += step (stepindex);
if ((dirdiff == 64 || dirdiff == -64) && stepindex > 0) {
stepindex -= 2; //cancel there-and-back
prevdir = stepindex >= 0 ? step_dir (stepindex) : lastdir;
}
else
prevdir = dir;
}
ASSERT_HOST (pos.x () == startpt.x () && pos.y () == startpt.y ());
do {
dirdiff = step_dir (stepindex - 1) - step_dir (0);
if (dirdiff == 64 || dirdiff == -64) {
start += step (0);
stepindex -= 2; //cancel there-and-back
for (int i = 0; i < stepindex; ++i)
set_step(i, step_dir(i + 1));
}
}
while (stepindex > 1 && (dirdiff == 64 || dirdiff == -64));
stepcount = stepindex;
ASSERT_HOST (stepcount >= 4);
}
void PDBLK::plot( //draw outline
ScrollView* window, //window to draw in
inT32 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 != NULL) {
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];
#ifdef __UNIX__
sprintf(temp_buff, INT32FORMAT, 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());
}
}
// Renders the outline to the given pix, with left and top being
// the coords of the upper-left corner of the pix.
void C_OUTLINE::render(int left, int top, Pix* pix) const {
ICOORD pos = start;
for (int stepindex = 0; stepindex < stepcount; ++stepindex) {
ICOORD next_step = step(stepindex);
if (next_step.y() < 0) {
pixRasterop(pix, 0, top - pos.y(), pos.x() - left, 1,
PIX_NOT(PIX_DST), NULL, 0, 0);
} else if (next_step.y() > 0) {
pixRasterop(pix, 0, top - pos.y() - 1, pos.x() - left, 1,
PIX_NOT(PIX_DST), NULL, 0, 0);
}
pos += next_step;
}
}
TBOX::TBOX( //construtor
const ICOORD pt1, //one corner
const ICOORD pt2 //the other corner
) {
if (pt1.x () <= pt2.x ()) {
if (pt1.y () <= pt2.y ()) {
bot_left = pt1;
top_right = pt2;
}
else {
bot_left = ICOORD (pt1.x (), pt2.y ());
top_right = ICOORD (pt2.x (), pt1.y ());
}
}
else {
if (pt1.y () <= pt2.y ()) {
bot_left = ICOORD (pt2.x (), pt1.y ());
top_right = ICOORD (pt1.x (), pt2.y ());
}
else {
bot_left = pt2;
top_right = pt1;
}
}
}
void find_cblob_limits( //get y limits
C_BLOB *blob, //blob to search
float leftx, //x limits
float rightx,
FCOORD rotation, //for landscape
float &ymin, //output y limits
float &ymax) {
int16_t stepindex; //current point
ICOORD pos; //current coords
ICOORD vec; //rotated step
C_OUTLINE *outline; //current outline
//outlines
C_OUTLINE_IT out_it = blob->out_list ();
ymin = (float) INT32_MAX;
ymax = (float) -INT32_MAX;
for (out_it.mark_cycle_pt (); !out_it.cycled_list (); out_it.forward ()) {
outline = out_it.data ();
pos = outline->start_pos (); //get coords
pos.rotate (rotation);
for (stepindex = 0; stepindex < outline->pathlength (); stepindex++) {
//inside
if (pos.x () >= leftx && pos.x () <= rightx) {
UpdateRange(pos.y(), &ymin, &ymax);
}
vec = outline->step (stepindex);
vec.rotate (rotation);
pos += vec; //move to next
}
}
}
BOOL8 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
}
// As TraceOutlineOnReducedPix above, but on a BLOCK instead of a C_OUTLINE.
Pix* TraceBlockOnReducedPix(BLOCK* block, int gridsize,
ICOORD bleft, int* left, int* bottom) {
TBOX box = block->bounding_box();
Pix* pix = GridReducedPix(box, gridsize, bleft, left, bottom);
int wpl = pixGetWpl(pix);
l_uint32* data = pixGetData(pix);
ICOORDELT_IT it(block->poly_block()->points());
for (it.mark_cycle_pt(); !it.cycled_list();) {
ICOORD pos = *it.data();
it.forward();
ICOORD next_pos = *it.data();
ICOORD line_vector = next_pos - pos;
int major, minor;
ICOORD major_step, minor_step;
line_vector.setup_render(&major_step, &minor_step, &major, &minor);
int accumulator = major / 2;
while (pos != next_pos) {
int grid_x = (pos.x() - bleft.x()) / gridsize - *left;
int grid_y = (pos.y() - bleft.y()) / gridsize - *bottom;
SET_DATA_BIT(data + grid_y * wpl, grid_x);
pos += major_step;
accumulator += minor;
if (accumulator >= major) {
accumulator -= major;
pos += minor_step;
}
}
}
return pix;
}
C_OUTLINE_FRAG::C_OUTLINE_FRAG( //record fragment
ICOORD start_pt, //start coord
ICOORD end_pt, //end coord
C_OUTLINE *outline, //source of steps
int16_t start_index,
int16_t end_index) {
start = start_pt;
end = end_pt;
ycoord = start_pt.y ();
stepcount = end_index - start_index;
if (stepcount < 0)
stepcount += outline->pathlength ();
ASSERT_HOST (stepcount > 0);
steps = new DIR128[stepcount];
if (end_index > start_index) {
for (int i = start_index; i < end_index; ++i)
steps[i - start_index] = outline->step_dir(i);
}
else {
int len = outline->pathlength();
int i = start_index;
for (; i < len; ++i)
steps[i - start_index] = outline->step_dir(i);
if (end_index > 0)
for (; i < end_index + len; ++i)
steps[i - start_index] = outline->step_dir(i - len);
}
other_end = nullptr;
delete close();
}
// Renders just the outline to the given pix (no fill), with left and top
// being the coords of the upper-left corner of the pix.
void C_OUTLINE::render_outline(int left, int top, Pix* pix) const {
ICOORD pos = start;
for (int stepindex = 0; stepindex < stepcount; ++stepindex) {
ICOORD next_step = step(stepindex);
if (next_step.y() < 0) {
pixSetPixel(pix, pos.x() - left, top - pos.y(), 1);
} else if (next_step.y() > 0) {
pixSetPixel(pix, pos.x() - left - 1, top - pos.y() - 1, 1);
} else if (next_step.x() < 0) {
pixSetPixel(pix, pos.x() - left - 1, top - pos.y(), 1);
} else if (next_step.x() > 0) {
pixSetPixel(pix, pos.x() - left, top - pos.y() - 1, 1);
}
pos += next_step;
}
}
DLLSYM void block_edges( //get edges in a block
IMAGE *t_image, //threshold image
PDBLK *block, //block in image
ICOORD page_tr //corner of page
) {
uinT8 margin; //margin colour
inT16 x; //line coords
inT16 y; //current line
ICOORD bleft; //bounding box
ICOORD tright;
ICOORD block_bleft; //bounding box
ICOORD block_tright;
int xindex; //index to pixel
BLOCK_LINE_IT line_it = block; //line iterator
IMAGELINE bwline; //thresholded line
//lines in progress
CRACKEDGE **ptrline = new CRACKEDGE*[t_image->get_xsize()+1];
block->bounding_box (bleft, tright); // block box
block_bleft = bleft;
block_tright = tright;
for (x = tright.x () - bleft.x (); x >= 0; x--)
ptrline[x] = NULL; //no lines in progress
bwline.init (t_image->get_xsize());
margin = WHITE_PIX;
for (y = tright.y () - 1; y >= bleft.y () - 1; y--) {
if (y >= block_bleft.y () && y < block_tright.y ()) {
t_image->get_line (bleft.x (), y, tright.x () - bleft.x (), &bwline,
0);
make_margins (block, &line_it, bwline.pixels, margin, bleft.x (),
tright.x (), y);
}
else {
x = tright.x () - bleft.x ();
for (xindex = 0; xindex < x; xindex++)
bwline.pixels[xindex] = margin;
}
line_edges (bleft.x (), y, tright.x () - bleft.x (),
margin, bwline.pixels, ptrline);
}
free_crackedges(free_cracks); //really free them
free_cracks = NULL;
delete [] ptrline;
}
// Helper function to compute a fictitious end point that is on a line
// of a given gradient through the given start.
ICOORD ComputeEndFromGradient(const ICOORD& start, double m) {
if (m > 1.0 || m < -1.0) {
// dy dominates. Force it to have the opposite sign of start.y() and
// compute dx based on dy being as large as possible
int dx = static_cast<int>(floor(MAX_INT16 / m));
if (dx < 0) ++dx; // Truncate towards 0.
if (start.y() > 0) dx = - dx; // Force dy to be opposite to start.y().
// Constrain dx so the result fits in an inT16.
while (start.x() + dx > MAX_INT16 || start.x() + dx < -MAX_INT16)
dx /= 2;
if (-1 <= dx && dx <= 1) {
return ICOORD(start.x(), start.y() + 1); // Too steep for anything else.
}
int y = start.y() + static_cast<int>(floor(dx * m + 0.5));
ASSERT_HOST(-MAX_INT16 <= y && y <= MAX_INT16);
return ICOORD(start.x() + dx, y);
} else {
// dx dominates. Force it to have the opposite sign of start.x() and
// compute dy based on dx being as large as possible.
int dy = static_cast<int>(floor(MAX_INT16 * m));
if (dy < 0) ++dy; // Truncate towards 0.
if (start.x() > 0) dy = - dy; // Force dx to be opposite to start.x().
// Constrain dy so the result fits in an inT16.
while (start.y() + dy > MAX_INT16 || start.y() + dy < -MAX_INT16)
dy /= 2;
if (-1 <= dy && dy <= 1) {
return ICOORD(start.x() + 1, start.y()); // Too flat for anything else.
}
int x = start.x() + static_cast<int>(floor(dy / m + 0.5));
ASSERT_HOST(-MAX_INT16 <= x && x <= MAX_INT16);
return ICOORD(x, start.y() + dy);
}
}
inT16 POLY_BLOCK::winding_number(const ICOORD &point) {
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
}
// Moves by the given vec in place.
void TESSLINE::Move(const ICOORD vec) {
EDGEPT* pt = loop;
do {
pt->pos.x += vec.x();
pt->pos.y += vec.y();
pt = pt->next;
} while (pt != loop);
SetupFromPos();
}
void block_edges(Pix *t_pix, // thresholded image
PDBLK *block, // block in image
C_OUTLINE_IT* outline_it) {
ICOORD bleft; // bounding box
ICOORD tright;
BLOCK_LINE_IT line_it = block; // line iterator
int width = pixGetWidth(t_pix);
int height = pixGetHeight(t_pix);
int wpl = pixGetWpl(t_pix);
// lines in progress
CRACKEDGE **ptrline = new CRACKEDGE*[width + 1];
CRACKEDGE *free_cracks = NULL;
block->bounding_box(bleft, tright); // block box
int block_width = tright.x() - bleft.x();
for (int x = block_width; x >= 0; x--)
ptrline[x] = NULL; // no lines in progress
uinT8* bwline = new uinT8[width];
uinT8 margin = WHITE_PIX;
for (int y = tright.y() - 1; y >= bleft.y() - 1; y--) {
if (y >= bleft.y() && y < tright.y()) {
// Get the binary pixels from the image.
l_uint32* line = pixGetData(t_pix) + wpl * (height - 1 - y);
for (int x = 0; x < block_width; ++x) {
bwline[x] = GET_DATA_BIT(line, x + bleft.x()) ^ 1;
}
make_margins(block, &line_it, bwline, margin, bleft.x(), tright.x(), y);
} else {
memset(bwline, margin, block_width * sizeof(bwline[0]));
}
line_edges(bleft.x(), y, block_width,
margin, bwline, ptrline, &free_cracks, outline_it);
}
free_crackedges(free_cracks); // really free them
delete[] ptrline;
delete[] bwline;
}
inT16 loop_bounding_box( //get bounding box
CRACKEDGE *&start, //edge loop
ICOORD &botleft, //bounding box
ICOORD &topright) {
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;
}
// Adds sub-pixel resolution EdgeOffsets for the outline using only
// a binary image source.
// Runs a sliding window of 5 edge steps over the outline, maintaining a count
// of the number of steps in each of the 4 directions in the window, and a
// sum of the x or y position of each step (as appropriate to its direction.)
// Ignores single-count steps EXCEPT the sharp U-turn and smoothes out the
// perpendicular direction. Eg
// ___ ___ Chain code from the left:
// |___ ___ ___| 222122212223221232223000
// |___| |_| Corresponding counts of each direction:
// 0 00000000000000000123
// 1 11121111001111100000
// 2 44434443443333343321
// 3 00000001111111112111
// Count of direction at center 41434143413313143313
// Step gets used? YNYYYNYYYNYYNYNYYYyY (y= U-turn exception)
// Path redrawn showing only the used points:
// ___ ___
// ___ ___ ___|
// ___ _
// Sub-pixel edge position cannot be shown well with ASCII-art, but each
// horizontal step's y position is the mean of the y positions of the steps
// in the same direction in the sliding window, which makes a much smoother
// outline, without losing important detail.
void C_OUTLINE::ComputeBinaryOffsets() {
delete [] offsets;
offsets = new EdgeOffset[stepcount];
// Count of the number of steps in each direction in the sliding window.
int dir_counts[4];
// Sum of the positions (y for a horizontal step, x for vertical) in each
// direction in the sliding window.
int pos_totals[4];
memset(dir_counts, 0, sizeof(dir_counts));
memset(pos_totals, 0, sizeof(pos_totals));
ICOORD pos = start;
ICOORD tail_pos = pos;
// tail_pos is the trailing position, with the next point to be lost from
// the window.
tail_pos -= step(stepcount - 1);
tail_pos -= step(stepcount - 2);
// head_pos is the leading position, with the next point to be added to the
// window.
ICOORD head_pos = tail_pos;
// Set up the initial window with 4 points in [-2, 2)
for (int s = -2; s < 2; ++s) {
increment_step(s, 1, &head_pos, dir_counts, pos_totals);
}
for (int s = 0; s < stepcount; pos += step(s++)) {
// At step s, s in in the middle of [s-2, s+2].
increment_step(s + 2, 1, &head_pos, dir_counts, pos_totals);
int dir_index = chain_code(s);
ICOORD step_vec = step(s);
int best_diff = 0;
int offset = 0;
// Use only steps that have a count of >=2 OR the strong U-turn with a
// single d and 2 at d-1 and 2 at d+1 (mod 4).
if (dir_counts[dir_index] >= 2 || (dir_counts[dir_index] == 1 &&
dir_counts[Modulo(dir_index - 1, 4)] == 2 &&
dir_counts[Modulo(dir_index + 1, 4)] == 2)) {
// Valid step direction.
best_diff = dir_counts[dir_index];
int edge_pos = step_vec.x() == 0 ? pos.x() : pos.y();
// The offset proposes that the actual step should be positioned at
// the mean position of the steps in the window of the same direction.
// See ASCII art above.
offset = pos_totals[dir_index] - best_diff * edge_pos;
}
offsets[s].offset_numerator =
static_cast<inT8>(ClipToRange(offset, -MAX_INT8, MAX_INT8));
offsets[s].pixel_diff = static_cast<uinT8>(ClipToRange(best_diff, 0 ,
MAX_UINT8));
// The direction is just the vector from start to end of the window.
FCOORD direction(head_pos.x() - tail_pos.x(), head_pos.y() - tail_pos.y());
offsets[s].direction = direction.to_direction();
increment_step(s - 2, -1, &tail_pos, dir_counts, pos_totals);
}
}
inT16 BLOCK_LINE_IT::get_line( //get a line
inT16 y, //line to get
inT16 &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
}
inT16 C_OUTLINE::winding_number( //winding number
ICOORD point //point to wind around
) const {
inT16 stepindex; //index to cstep
inT16 count; //winding count
ICOORD vec; //to current point
ICOORD stepvec; //step vector
inT32 cross; //cross product
vec = start - point; //vector to it
count = 0;
for (stepindex = 0; stepindex < stepcount; stepindex++) {
stepvec = step (stepindex); //get the step
//crossing the line
if (vec.y () <= 0 && vec.y () + stepvec.y () > 0) {
cross = vec * stepvec; //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 () + stepvec.y () <= 0) {
cross = vec * stepvec;
if (cross < 0)
count--; //crossing back
else if (cross == 0)
return INTERSECTING; //illegal
}
vec += stepvec; //sum vectors
}
return count; //winding number
}
inT32 C_OUTLINE::outer_area() const {
int stepindex; //current step
inT32 total_steps; //steps to do
inT32 total; //total area
ICOORD pos; //position of point
ICOORD next_step; //step to next pix
pos = start_pos ();
total_steps = pathlength ();
if (total_steps == 0)
return box.area();
total = 0;
for (stepindex = 0; stepindex < total_steps; stepindex++) {
//all intersected
next_step = step (stepindex);
if (next_step.x () < 0)
total += pos.y ();
else if (next_step.x () > 0)
total -= pos.y ();
pos += next_step;
}
return total;
}
// Helper function to return a scaled Pix with one pixel per grid cell,
// set (black) where the given outline enters the corresponding grid cell,
// and clear where the outline does not touch the grid cell.
// Also returns the grid coords of the bottom-left of the Pix, in *left
// and *bottom, which corresponds to (0, 0) on the Pix.
// Note that the Pix is used upside-down, with (0, 0) being the bottom-left.
Pix* TraceOutlineOnReducedPix(C_OUTLINE* outline, int gridsize,
ICOORD bleft, int* left, int* bottom) {
TBOX box = outline->bounding_box();
Pix* pix = GridReducedPix(box, gridsize, bleft, left, bottom);
int wpl = pixGetWpl(pix);
l_uint32* data = pixGetData(pix);
int length = outline->pathlength();
ICOORD pos = outline->start_pos();
for (int i = 0; i < length; ++i) {
int grid_x = (pos.x() - bleft.x()) / gridsize - *left;
int grid_y = (pos.y() - bleft.y()) / gridsize - *bottom;
SET_DATA_BIT(data + grid_y * wpl, grid_x);
pos += outline->step(i);
}
return pix;
}
