bool LineSegment::operator<(const LineSegment& other) const {
clog << *this << " < " << other << endl;
bool yasc_flag, ydesc_flag, xasc_flag, xdesc_flag;
if(this->getLeftEndPoint().x < other.getLeftEndPoint().x) {
ydesc_flag = ydesc(*this,other);
yasc_flag = yasc(*this,other);
} else {
yasc_flag = ydesc(other,*this);
ydesc_flag = yasc(other,*this);
}
if(this->getBottomEndPoint().y < other.getBottomEndPoint().y) {
xdesc_flag = xdesc(*this,other);
xasc_flag = xasc(*this,other);
} else {
xasc_flag = xdesc(other,*this);
xdesc_flag = xasc(other,*this);
}
if(ydesc_flag) {
clog << "ydesc flag" << endl;
return true;
} else if(yasc_flag) {
clog << "yasc flag" << endl;
return false;
} else if(xdesc_flag) {
clog << "xdesc flag" << endl;
return true;
} else if(xasc_flag) {
clog << "xasc flag" << endl;
return false;
}
clog << "equal?" << endl;
// xasc or equal
return false;
}
// returns true if left belongs above right in ascending order
bool LineSegment::yasc(const LineSegment& left, const LineSegment& right) {
// both vertical
if(left.isVertical() && right.isVertical()) {
if(left.getBottomEndPoint().y < right.getBottomEndPoint().y)
return true;
if(left.getBottomEndPoint().y > right.getBottomEndPoint().y)
return false;
return left.getTopEndPoint().y < right.getTopEndPoint().y;
}
// left is vertical
if(left.isVertical())
return left.getBottomEndPoint().y < right.getLeftEndPoint().y;
// left.left, left.right, right.left colinear
if(Point2D::colinear(left.getLeftEndPoint(),
left.getRightEndPoint(),
right.getLeftEndPoint())) {
// all points colinear
if(Point2D::colinear(left.getLeftEndPoint(),
left.getRightEndPoint(),
right.getRightEndPoint())) {
return left.getBottomEndPoint().y < right.getBottomEndPoint().y;
}
// only 3 colinear
return Point2D::leftTurn(left.getLeftEndPoint(),
left.getRightEndPoint(),
right.getRightEndPoint());
}
// normal case
return Point2D::leftTurn(left.getLeftEndPoint(),
left.getRightEndPoint(),
right.getLeftEndPoint());
}
bool LineSegment::xasc(const LineSegment& bottom, const LineSegment& top) {
// both horizontal
if(bottom.isHorizontal() && top.isHorizontal())
return bottom.getLeftEndPoint().x < top.getLeftEndPoint().x;
// left is vertical
if(bottom.isHorizontal())
return bottom.getLeftEndPoint().x < top.getBottomEndPoint().x;
// left.left, left.right, right.left colinear
if(Point2D::colinear(bottom.getBottomEndPoint(),
bottom.getTopEndPoint(),
top.getBottomEndPoint()))
return Point2D::leftTurn(bottom.getBottomEndPoint(),
bottom.getTopEndPoint(),
top.getTopEndPoint());
// normal case
return Point2D::leftTurn(bottom.getBottomEndPoint(),
bottom.getTopEndPoint(),
top.getBottomEndPoint());
}