Readme

Author: swhitty

README.md

@@ -7,32 +7,135 @@
 
 # SwiftDraw
 
-A Swift library for parsing and drawing SVG images to CoreGraphics contexts.  SwiftDraw can also convert an SVG into Swift source code.
+A Swift library for parsing and drawing SVG images. SwiftDraw can also convert SVGs into SFSymbol, PNG, PDF and Swift source code.
 
 ## Usage
 
+Vector images can be easily loaded and rasterized to `UIImage` or `NSImage`:
+
+```swift
+let svg = SVG(named: "sample.svg", in: .main)!
+imageView.image = svg.rasterize()
+```
+
+Rasterize to any size:
+
+```swift
+let svg = SVG(named: "sample.svg", in: .main)!
+imageView.image = svg.rasterize(with: CGSize(width: 640, height: 480))
+```
+
+Or crop the image using insets
+
+```swift
+let svg = SVG(named: "sample.svg", in: .main)!
+imageView.image = svg.rasterize(insets: .init(top: 10, left: 0, bottom: 10, bottom: 0))
+```
+
 ## iOS
 
+Create a `UIImage` directly from an SVG within a bundle, `Data` or file `URL`.
+
 ```swift
 import SwiftDraw
 let image = UIImage(svgNamed: "sample.svg")
 ```
 
 ## macOS
 
+Create an `NSImage` directly from an SVG within a bundle, `Data` or file `URL`.
+
 ```swift
 import SwiftDraw
 let image = NSImage(svgNamed: "sample.svg")
 ```
 
-### Command line tool
+## Command line tool
+
+The command line tool converts SVGs to other formats: PNG, JPEG, SFSymbol and Swift source code.
+
+```
+copyright (c) 2022 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
+
+ --hideUnsupportedFilters   hide elements with unsupported filters.
+
+Available keys for --format swift:
+ --api                api of generated code:  appkit | uikit
+
+Available keys for --format sfymbol:
+ --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
+```
+
+```bash
+$ swiftdraw simple.svg --format png --scale 3x
+```
+
+```bash
+$ swiftdraw simple.svg --format pdf
+```
+
+**Installation:**
+
+You can install the `swiftdraw` command-line tool on macOS using [Homebrew](http://brew.sh/). Assuming you already have Homebrew installed, just type:
+
+```bash
+$ brew install swiftdraw
+```
+
+To update to the latest version once installed:
+
+```bash
+$ brew upgrade swiftdraw
+```
+
+Alternatively download the latest command line tool [here](https://github.com/swhitty/SwiftDraw/releases/latest/download/SwiftDraw.dmg).
 
-Download the latest command line tool [here](https://github.com/swhitty/SwiftDraw/releases/latest/download/SwiftDraw.dmg).
+### SF Symbol
 
-`$ swiftdraw sample.svg --format pdf --size 48x48`
+Custom SF Symbols can be generated from a single SVG:
 
+```bash
+$ swiftdraw key.svg --format sfsymbol
+```
+
+Optional variants `--ultralight` and `--black` can also be provided:
+
+```bash
+$ 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.  SwiftDraw will output the alignment insets used:
 
-#### Source code generation
+```bash
+$ swiftdraw simple.svg --format sfsymbol --insets auto
+Alignment: --insets 30,30,30,30
+```
+
+Values can be provided in the form `--insets top,left,bottom,right` specifying an `Double` or `auto` for each inset.
+
+```bash
+$ swiftdraw simple.svg --format sfsymbol --insets 40,auto,40,auto
+Alignment: --insets 40,30,40,30
+```
+
+### Source code generation
 
 Source code can be generated using [www.whileloop.com/swiftdraw](https://www.whileloop.com/swiftdraw).
 
@@ -46,7 +149,9 @@ The command line tool can also convert an SVG image into Swift source code:
 </svg>
 ```
 
-`$ swiftdraw simple.svg --format swift`
+```bash
+$ swiftdraw simple.svg --format swift
+```
 
 ```swift
 extension UIImage {
@@ -62,31 +167,31 @@ extension UIImage {
   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, 0.98039216, 0.98039216, 1.0])!
+    let color1 = CGColor(colorSpace: rgb, components: [1, 0.98, 0.98, 1])!
     ctx.setFillColor(color1)
-    ctx.fill(CGRect(x: 0.0, y: 0.0, width: 160.0, height: 160.0))
-    let color2 = CGColor(colorSpace: rgb, components: [1.0, 0.7529412, 0.79607844, 1.0])!
+    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: 80.0, y: 20.0))
-    path.addCurve(to: CGPoint(x: 30.0, y: 69.99999),
-                   control1: CGPoint(x: 52.38576, y: 20.0),
-                   control2: CGPoint(x: 30.000004, y: 42.385757))
-    path.addCurve(to: CGPoint(x: 79.99998, y: 120.0),
-                   control1: CGPoint(x: 29.999992, y: 97.61423),
-                   control2: CGPoint(x: 52.385742, y: 119.999985))
-    path.addCurve(to: CGPoint(x: 130.0, y: 70.00004),
-                   control1: CGPoint(x: 107.61421, y: 120.000015),
-                   control2: CGPoint(x: 129.99998, y: 97.61427))
-    path.addLine(to: CGPoint(x: 80.0, y: 70.00004))
+    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(using: .evenOdd)
     ctx.setLineCap(.butt)
     ctx.setLineJoin(.miter)
-    ctx.setLineWidth(2.0)
-    ctx.setMiterLimit(4.0)
-    let color3 = CGColor(colorSpace: rgb, components: [0.0, 0.0, 0.0, 1.0])!
+    ctx.setLineWidth(2)
+    ctx.setMiterLimit(4)
+    let color3 = CGColor(colorSpace: rgb, components: [0, 0, 0, 1])!
     ctx.setStrokeColor(color3)
     ctx.addPath(path)
     ctx.strokePath()