Function ParseSVGPath

path.go:2084–2254

ParseSVGPath parses an SVG path data string.

(s string)

// ParseSVGPath parses an SVG path data string.
func ParseSVGPath(s string) (*Path, error) {
	if len(s) == 0 {
		return &Path{}, nil
	}

	i := 0
	path := []byte(s)
	i += skipCommaWhitespace(path[i:])
	if path[0] == ',' || path[i] < 'A' {
		return nil, fmt.Errorf("bad path: path should start with command")
	}

	cmdLens := map[byte]int{
		'M': 2,
		'Z': 0,
		'L': 2,
		'H': 1,
		'V': 1,
		'C': 6,
		'S': 4,
		'Q': 4,
		'T': 2,
		'A': 7,
	}
	f := [7]float64{}

	p := &Path{}
	var q, c Point
	var p0, p1 Point
	prevCmd := byte('z')
	for {
		i += skipCommaWhitespace(path[i:])
		if len(path) <= i {
			break
		}

		cmd := prevCmd
		repeat := true
		if cmd == 'z' || cmd == 'Z' || !(path[i] >= '0' && path[i] <= '9' || path[i] == '.' || path[i] == '-' || path[i] == '+') {
			cmd = path[i]
			repeat = false
			i++
			i += skipCommaWhitespace(path[i:])
		}

		CMD := cmd
		if 'a' <= cmd && cmd <= 'z' {
			CMD -= 'a' - 'A'
		}
		for j := 0; j < cmdLens[CMD]; j++ {
			if CMD == 'A' && (j == 3 || j == 4) {
				// parse largeArc and sweep booleans for A command
				if i < len(path) && path[i] == '1' {
					f[j] = 1.0
				} else if i < len(path) && path[i] == '0' {
					f[j] = 0.0
				} else {
					return nil, fmt.Errorf("bad path: largeArc and sweep flags should be 0 or 1 in command '%c' at position %d", cmd, i+1)