Swift library and command line tool to convert SVGs into SFSymbol, PNG, PDF and Swift source code.
Introduction
SwiftDraw is Swift library for parsing and drawing SVG images and includes a command line tool to convert SVGs into SFSymbol, PNG, PDF and Swift source code.
Usage
Vector images can be easily loaded and rasterized to UIImage or NSImage:
let svg = SVG(named: "sample.svg", in: .main)!
imageView.image = svg.rasterize()
Rasterize to any size:
let svg = SVG(named: "sample.svg", in: .main)!
imageView.image = svg.rasterize(with: CGSize(width: 640, height: 480))
Crop the image using insets:
let svg = SVG(named: "sample.svg", in: .main)!
imageView.image = svg.rasterize(insets: .init(top: 10, left: 0, bottom: 10, bottom: 0))
Add padding using negative insets:
let svg = SVG(named: "sample.svg", in: .main)!
imageView.image = svg.rasterize(insets: .init(top: -10, left: -10, bottom: -10, bottom: -10))
iOS
Create a UIImage directly from an SVG within a bundle, Data or file URL:
import SwiftDraw
let image = UIImage(svgNamed: "sample.svg")
macOS
Create an NSImage directly from an SVG within a bundle, Data or file URL:
import SwiftDraw
let image = NSImage(svgNamed: "sample.svg")
Command line tool
The command line tool converts SVGs to other formats: PNG, JPEG, SFSymbol and Swift source code.
copyright (c) 2024 Simon Whitty
usage: swiftdraw <file.svg> [--format png | pdf | jpeg | swift | sfsymbol] [--size wxh] [--scale 1x | 2x | 3x]
<file> svg file to be processed
Options:
--format format to output image: png | pdf | jpeg | swift | sfsymbol
--size size of output image: 100x200
--scale scale of output image: 1x | 2x | 3x
--insets crop inset of output image: top,left,bottom,right
--precision maximum number of decimal places
--output optional path of output file
--hideUnsupportedFilters hide elements with unsupported filters.
Available keys for --format swift:
--api api of generated code: appkit | uikit
Available keys for --format sfsymbol:
--insets alignment of regular variant: top,left,bottom,right | auto
--ultralight svg file of ultralight variant
--ultralightInsets alignment of ultralight variant: top,left,bottom,right | auto
--black svg file of black variant
--blackInsets alignment of black variant: top,left,bottom,right | auto
$ swiftdraw simple.svg --format png --scale 3x
$ swiftdraw simple.svg --format pdf
Installation
You can install the swiftdraw command-line tool on macOS using Homebrew. Assuming you already have Homebrew installed, just type:
$ brew install swiftdraw
To update to the latest version once installed:
$ brew upgrade swiftdraw
Alternatively download the latest command line tool here.
SF Symbol
Custom SF Symbols can be created from a single SVG. SwiftDraw expands strokes, winds paths using the non-zero rule and aligns elements generating a symbol that can be imported directly into Xcode.
$ swiftdraw key.svg --format sfsymbol
Optional variants --ultralight and --black can also be provided:
$ swiftdraw key.svg --format sfsymbol --ultralight key-ultralight.svg --black key-black.svg
Alignment
By default, SwiftDraw automatically sizes and aligns the content to the template guides. The auto alignment insets are output by the tool:
$ swiftdraw simple.svg --format sfsymbol --insets auto
Alignment: --insets 30,30,30,30
Insets can be provided in the form --insets top,left,bottom,right specifying a Double or auto for each edge:
$ swiftdraw simple.svg --format sfsymbol --insets 40,auto,40,auto
Alignment: --insets 40,30,40,30
Variants can also be aligned using --ultralightInsets and --blackInsets.
Swift Code Generation
Swift source code can also be generated from an SVG using the tool:
$ swiftdraw simple.svg --format swift
<?xml version="1.0" encoding="utf-8"?>
<svg version="1.1" xmlns="http://www.w3.org/2000/svg" width="160" height="160">
<rect width="160" height="160" fill="snow" />
<path d="m 80 30 a 50 50 0 1 0 50 50 h -50 z" fill="pink" stroke="black" stroke-width="2"/>
</svg>
extension UIImage {
static func svgSimple(size: CGSize = CGSize(width: 160.0, height: 160.0)) -> UIImage {
let f = UIGraphicsImageRendererFormat.preferred()
f.opaque = false
let scale = CGSize(width: size.width / 160.0, height: size.height / 160.0)
return UIGraphicsImageRenderer(size: size, format: f).image {
drawSimple(in: $0.cgContext, scale: scale)
}
}
private static func drawSimple(in ctx: CGContext, scale: CGSize) {
ctx.scaleBy(x: scale.width, y: scale.height)
let rgb = CGColorSpaceCreateDeviceRGB()
let color1 = CGColor(colorSpace: rgb, components: [1, 0.98, 0.98, 1])!
ctx.setFillColor(color1)
ctx.fill(CGRect(x: 0, y: 0, width: 160, height: 160))
let color2 = CGColor(colorSpace: rgb, components: [1, 0.753, 0.796, 1])!
ctx.setFillColor(color2)
let path = CGMutablePath()
path.move(to: CGPoint(x: 80, y: 30))
path.addCurve(to: CGPoint(x: 30, y: 80),
control1: CGPoint(x: 52.39, y: 30),
control2: CGPoint(x: 30, y: 52.39))
path.addCurve(to: CGPoint(x: 80, y: 130),
control1: CGPoint(x: 30, y: 107.61),
control2: CGPoint(x: 52.39, y: 130))
path.addCurve(to: CGPoint(x: 130, y: 80),
control1: CGPoint(x: 107.61, y: 130),
control2: CGPoint(x: 130, y: 107.61))
path.addLine(to: CGPoint(x: 80, y: 80))
path.closeSubpath()
ctx.addPath(path)
ctx.fillPath()
ctx.setLineCap(.butt)
ctx.setLineJoin(.miter)
ctx.setLineWidth(2)
ctx.setMiterLimit(4)
let color3 = CGColor(colorSpace: rgb, components: [0, 0, 0, 1])!
ctx.setStrokeColor(color3)
ctx.addPath(path)
ctx.strokePath()
}
}
Source code can be generated using www.whileloop.com/swiftdraw.
Credits
SwiftDraw is primarily the work of Simon Whitty.