Method Length

path.go:1233–1264

Length returns the length of the path in millimeters. The length is approximated for cubic Béziers.

()

// Length returns the length of the path in millimeters. The length is approximated for cubic Béziers.
func (p *Path) Length() float64 {
	d := 0.0
	var start, end Point
	for i := 0; i < len(p.d); {
		cmd := p.d[i]
		switch cmd {
		case MoveToCmd:
			end = Point{p.d[i+1], p.d[i+2]}
		case LineToCmd, CloseCmd:
			end = Point{p.d[i+1], p.d[i+2]}
			d += end.Sub(start).Length()
		case QuadToCmd:
			cp := Point{p.d[i+1], p.d[i+2]}
			end = Point{p.d[i+3], p.d[i+4]}
			d += quadraticBezierLength(start, cp, end)
		case CubeToCmd:
			cp1 := Point{p.d[i+1], p.d[i+2]}
			cp2 := Point{p.d[i+3], p.d[i+4]}
			end = Point{p.d[i+5], p.d[i+6]}
			d += cubicBezierLength(start, cp1, cp2, end)
		case ArcToCmd:
			rx, ry, phi := p.d[i+1], p.d[i+2], p.d[i+3]
			large, sweep := toArcFlags(p.d[i+4])
			end = Point{p.d[i+5], p.d[i+6]}
			_, _, theta1, theta2 := ellipseToCenter(start.X, start.Y, rx, ry, phi, large, sweep, end.X, end.Y)
			d += ellipseLength(rx, ry, theta1, theta2)
		}
		i += cmdLen(cmd)
		start = end
	}
	return d
}

// Transform transforms the path by the given transformation matrix. It modifies the path in-place.
func (p *Path) Transform(m Matrix) *Path {