Method FastBounds

path.go:1056–1105

FastBounds returns the maximum bounding box rectangle of the path. It is quicker than Bounds.

()

// FastBounds returns the maximum bounding box rectangle of the path. It is quicker than Bounds.
func (p *Path) FastBounds() Rect {
	if len(p.d) < 4 {
		return Rect{}
	}

	// first command is MoveTo
	start, end := Point{p.d[1], p.d[2]}, Point{}
	xmin, xmax := start.X, start.X
	ymin, ymax := start.Y, start.Y
	for i := 4; i < len(p.d); {
		cmd := p.d[i]
		switch cmd {
		case MoveToCmd, LineToCmd, CloseCmd:
			end = Point{p.d[i+1], p.d[i+2]}
			xmin = math.Min(xmin, end.X)
			xmax = math.Max(xmax, end.X)
			ymin = math.Min(ymin, end.Y)
			ymax = math.Max(ymax, end.Y)
		case QuadToCmd:
			cp := Point{p.d[i+1], p.d[i+2]}
			end = Point{p.d[i+3], p.d[i+4]}
			xmin = math.Min(xmin, math.Min(cp.X, end.X))
			xmax = math.Max(xmax, math.Max(cp.X, end.X))
			ymin = math.Min(ymin, math.Min(cp.Y, end.Y))
			ymax = math.Max(ymax, math.Max(cp.Y, end.Y))
		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]}
			xmin = math.Min(xmin, math.Min(cp1.X, math.Min(cp2.X, end.X)))
			xmax = math.Max(xmax, math.Max(cp1.X, math.Min(cp2.X, end.X)))
			ymin = math.Min(ymin, math.Min(cp1.Y, math.Min(cp2.Y, end.Y)))
			ymax = math.Max(ymax, math.Max(cp1.Y, math.Min(cp2.Y, end.Y)))
		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]}
			cx, cy, _, _ := ellipseToCenter(start.X, start.Y, rx, ry, phi, large, sweep, end.X, end.Y)
			r := math.Max(rx, ry)
			xmin = math.Min(xmin, cx-r)
			xmax = math.Max(xmax, cx+r)
			ymin = math.Min(ymin, cy-r)
			ymax = math.Max(ymax, cy+r)

		}
		i += cmdLen(cmd)
		start = end
	}
	return Rect{xmin, ymin, xmax, ymax}
}

// Bounds returns the exact bounding box rectangle of the path.
func (p *Path) Bounds() Rect {