/SVGPath

Cross-platform Swift library for parsing SVGPath strings

Primary LanguageSwiftMIT LicenseMIT

Build Codecov Platforms Swift 5.1 License Mastodon

Introduction

SVGPath is an open-source parser for the SVG path syntax, making it easy to create CGPaths from this popular format.

SVGPath runs on all Apple platforms, and also Linux (although Linux does not support the CoreGraphics API, so if you need to draw the path you will need to provide your own implementation).

Installation

SVGPath is packaged as a dynamic framework that you can import into your Xcode project. You can install this manually, or by using Swift Package Manager.

Note: SVGPath requires Xcode 10+ to build, and runs on iOS 10+ or macOS 10.12+.

To install using Swift Package Manage, add this to the dependencies: section in your Package.swift file:

.package(url: "https://github.com/nicklockwood/SVGPath.git", .upToNextMinor(from: "1.0.0")),

Usage

You can create an instance of SVGPath as follows:

let svgPath = try SVGPath(string: "M150 0 L75 200 L225 200 Z")

Notice that the SVGPath constructor is a throwing function. It will throw an SVGError if the supplied string is invalid or malformed .

Once you have created an SVGPath object, in most cases you'll want to convert this to a CGPath for rendering on Apple platforms. To do that you can use:

let cgPath = CGPath.from(svgPath: svgPath)

As a shortcut, you can create the CGPath directly from an SVG path string:

let cgPath = try CGPath.from(svgPath: "M150 0 L75 200 L225 200 Z")

Once you have a CGPath you can render it on iOS or macOS using a CoreGraphics context or a CAShapeLayer.

Advanced Usage

You can convert a CGPath to an SVGPath using the init(cgPath:) initializer:

let rect = CGRect(x: 0, y: 0, width: 10, height: 10)
let cgPath = CGPath(rect: rect, transform: nil)
let svgPath = SVGPath(cgPath: cgPath)

To convert an SVGPath back into a String, use the string(with:) method. This can be useful for exporting a CGPath as an SVG string:

let svgPath = SVGPath(cgPath: ...)
let options = SVGPath.WriteOptions(prettyPrinted: true, wrapWidth: 80)
let string = svgPath.string(with: options)

It's also possible to use SVGPath without CoreGraphics. You can iterate over the raw path components using the commands property:

for command in svgPath.commands {
    switch command {
    case .moveTo(let point):
        ...
    case .lineTo(let point):
        ...
    default:
        ...   
    }   
}

Alternatively, you can use the points() or getPoints() methods to convert the entire path to a flar array of points at your preferred level of detail.

These can be used to render the path using simple straight line segments using any graphics API you choose:

let detail = 10 // number of sample points used to represent curved segments
let points = svgPath.points(withDetail: detail)

NOTE: coordinates are stored with inverted Y coordinates internally, to match the coordinate system used by Core Graphics on macOS/iOS.

Credits

The SVGPath library is primarily the work of Nick Lockwood.

(Full list of contributors)