gg/line.go

51 lines
890 B
Go

package gg
//import "fmt"
// The type represents mathematical equation of line and line itself.
type Line struct {
K, C, X Float
Vertical bool
}
// 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, 0, false}
pc, ok := l.crossesLine(buf)
if !ok {
return false
}
//Println("points:", l, p, pc)
return Neq(pc.X, p.X) && Neq(pc.Y, p.Y)
}
func (l1 Line) crossesLine(l2 Line) (Point, bool) {
var x, y Float
if LinersParallel(l1, l2) {
return Point{}, false
}
switch {
case l1.Vertical :
x = l1.X
y = l2.K*x + l2.C
//Println("l1-vert:", x, y)
case l2.Vertical :
x = l2.X
y = l1.K*x + l1.C
//Println("l2-vert:", x, y)
default:
x = (l1.C - l2.C) / (l2.K - l1.K)
y = l1.K*x + l1.C
}
//Println("in:", x, y)
return Point{x, y}, true
}