Method LineTo

path.go:411–450

LineTo adds a linear path to (x,y).

(x, y float64)

// LineTo adds a linear path to (x,y).
func (p *Path) LineTo(x, y float64) {
	start := p.Pos()
	end := Point{x, y}
	if start.Equals(end) {
		return
	} else if cmdLen(LineToCmd) <= len(p.d) && p.d[len(p.d)-1] == LineToCmd {
		prevStart := Point{}
		if cmdLen(LineToCmd) < len(p.d) {
			prevStart = Point{p.d[len(p.d)-cmdLen(LineToCmd)-3], p.d[len(p.d)-cmdLen(LineToCmd)-2]}
		}

		// divide by length^2 since otherwise the perpdot between very small segments may be
		// below Epsilon
		da := start.Sub(prevStart)
		db := end.Sub(start)
		div := da.PerpDot(db)
		if length := da.Length() * db.Length(); Equal(div/length, 0.0) {
			// lines are parallel
			extends := false
			if da.Y < da.X {
				extends = math.Signbit(da.X) == math.Signbit(db.X)
			} else {
				extends = math.Signbit(da.Y) == math.Signbit(db.Y)
			}
			if extends {
				//if Equal(end.Sub(start).AngleBetween(start.Sub(prevStart)), 0.0) {
				p.d[len(p.d)-3] = x
				p.d[len(p.d)-2] = y
				return
			}
		}
	}

	if len(p.d) == 0 {
		p.MoveTo(0.0, 0.0)
	} else if p.d[len(p.d)-1] == CloseCmd {
		p.MoveTo(p.d[len(p.d)-3], p.d[len(p.d)-2])
	}
	p.d = append(p.d, LineToCmd, end.X, end.Y, LineToCmd)
}

// QuadTo adds a quadratic Bézier path with control point (cpx,cpy) and end point (x,y).
func (p *Path) QuadTo(cpx, cpy, x, y float64) {