package gg

// The type represents mathematical equation of line and line itself.
type Line struct {
	K, C Float
}

// Returns the line itself. Made to implement the Liner interface.
func (l Line) Line() Line {
	return l
}

func (l Line) ContainsPoint(p Point) bool {
	buf := Line{0, p.Y}
	pc, ok := l.crossesLine(buf)
	if !ok {
		return false
	}
	
	return pc == p 
}

func (l1 Line) crossesLine(l2 Line) (Point, bool) {
	if LinersParallel(l1, l2) {
		return Point{}, false
	}
	
	x := (l1.C - l2.C) / (l2.K - l1.K)
	y := l1.K*x + l1.C
	return Point{x, y}, true
}