Function SegmentCoords

deps/tesseract/ccstruct/blobs.cpp:613–631

Adds any edges from a single segment of outline between pt1 and pt2 to the x_coords, y_coords vectors. pt1 and pt2 should be relative to the bottom-left of the bounding box, hence indices to x_coords, y_coords are clipped to ([0,x_limit], [0,y_limit]). See GetEdgeCoords above for a description of x_coords, y_coords.

// are clipped to ([0,x_limit], [0,y_limit]).
// See GetEdgeCoords above for a description of x_coords, y_coords.
static void SegmentCoords(const FCOORD& pt1, const FCOORD& pt2,
                          int x_limit, int y_limit,
                          GenericVector<GenericVector<int> >* x_coords,
                          GenericVector<GenericVector<int> >* y_coords) {
  FCOORD step(pt2);
  step -= pt1;
  int start = ClipToRange(IntCastRounded(MIN(pt1.x(), pt2.x())), 0, x_limit);
  int end = ClipToRange(IntCastRounded(MAX(pt1.x(), pt2.x())), 0, x_limit);
  for (int x = start; x < end; ++x) {
    int y = IntCastRounded(pt1.y() + step.y() * (x + 0.5 - pt1.x()) / step.x());
    (*y_coords)[x].push_back(y);
  }
  start = ClipToRange(IntCastRounded(MIN(pt1.y(), pt2.y())), 0, y_limit);
  end = ClipToRange(IntCastRounded(MAX(pt1.y(), pt2.y())), 0, y_limit);
  for (int y = start; y < end; ++y) {
    int x = IntCastRounded(pt1.x() + step.x() * (y + 0.5 - pt1.y()) / step.y());
    (*x_coords)[y].push_back(x);
  }
}

// Adds any edges from a single segment of outline between pt1 and pt2 to
// the bbox such that it guarantees to contain anything produced by