Bounding Box - new method align_to_grid

This commit is contained in:
bubnikv 2016-11-29 19:25:10 +01:00
parent bde2ee6a7e
commit 792856a505
2 changed files with 25 additions and 0 deletions

View File

@ -277,4 +277,26 @@ BoundingBoxBase<PointClass>::overlap(const BoundingBoxBase<PointClass> &other) c
template bool BoundingBoxBase<Point>::overlap(const BoundingBoxBase<Point> &point) const;
template bool BoundingBoxBase<Pointf>::overlap(const BoundingBoxBase<Pointf> &point) const;
// Align a coordinate to a grid. The coordinate may be negative,
// the aligned value will never be bigger than the original one.
static inline coord_t _align_to_grid(const coord_t coord, const coord_t spacing) {
// Current C++ standard defines the result of integer division to be rounded to zero,
// for both positive and negative numbers. Here we want to round down for negative
// numbers as well.
coord_t aligned = (coord < 0) ?
((coord - spacing + 1) / spacing) * spacing :
(coord / spacing) * spacing;
assert(aligned <= coord);
return aligned;
}
void BoundingBox::align_to_grid(const coord_t cell_size)
{
if (this->defined) {
min.x = _align_to_grid(min.x, cell_size);
min.y = _align_to_grid(min.y, cell_size);
}
}
}

View File

@ -65,6 +65,9 @@ class BoundingBox : public BoundingBoxBase<Point>
BoundingBox rotated(double angle, const Point &center) const;
void rotate(double angle) { (*this) = this->rotated(angle); }
void rotate(double angle, const Point &center) { (*this) = this->rotated(angle, center); }
// Align the min corner to a grid of cell_size x cell_size cells,
// to encompass the original bounding box.
void align_to_grid(const coord_t cell_size);
BoundingBox() : BoundingBoxBase<Point>() {};
BoundingBox(const Point &pmin, const Point &pmax) : BoundingBoxBase<Point>(pmin, pmax) {};