generate the image in swift and remove dependency on imagemagic and graphicsmagick

.github/workflows/main.yml

@@ -18,4 +18,5 @@ jobs:
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install
+      - run: npm run build
       - run: npm test

.gitignore

@@ -1,2 +1,7 @@
 node_modules
 yarn.lock
+.build
+/compose-icon
+/.build
+/xcuserdata
+.DS_Store

build-swift.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Build the Swift package for composing icons
+echo "Building Swift package..."
+cd imageComposition
+xcrun swift build -c release --arch arm64 --arch x86_64 --product compose-icon
+
+# Copy the built executable to the root directory for easy access
+cp ".build/apple/Products/Release/compose-icon" ../compose-icon
+
+echo "Swift executable built successfully: compose-icon"

compose-icon.js

@@ -5,12 +5,10 @@ import path from 'node:path';
 import {fileURLToPath} from 'node:url';
 import {execa} from 'execa';
 import {temporaryFile} from 'tempy';
-import baseGm from 'gm';
 import icns from 'icns-lib';
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
 
-const gm = baseGm.subClass({imageMagick: true});
 const readFile = promisify(fs.readFile);
 const writeFile = promisify(fs.writeFile);
 
@@ -22,48 +20,32 @@ const baseDiskIconPath = `${__dirname}/disk-icon.icns`;
 const biggestPossibleIconType = 'ic10';
 
 async function baseComposeIcon(type, appIcon, mountIcon, composedIcon) {
-	mountIcon = gm(mountIcon);
-	appIcon = gm(appIcon);
-
-	const [appIconSize, mountIconSize] = await Promise.all([
-		promisify(appIcon.size.bind(appIcon))(),
-		promisify(appIcon.size.bind(mountIcon))(),
-	]);
-
-	// Change the perspective of the app icon to match the mount drive icon
-	appIcon = appIcon.out('-matte').out('-virtual-pixel', 'transparent').out('-distort', 'Perspective', `1,1  ${appIconSize.width * 0.08},1     ${appIconSize.width},1  ${appIconSize.width * 0.92},1     1,${appIconSize.height}  1,${appIconSize.height}     ${appIconSize.width},${appIconSize.height}  ${appIconSize.width},${appIconSize.height}`);
-
-	// Resize the app icon to fit it inside the mount icon, aspect ration should not be kept to create the perspective illution
-	appIcon = appIcon.resize(mountIconSize.width / 1.58, mountIconSize.height / 1.82, '!');
-
+	// Write app and mount icons to temporary PNG files
 	const temporaryAppIconPath = temporaryFile({extension: 'png'});
-	await promisify(appIcon.write.bind(appIcon))(temporaryAppIconPath);
-
-	// Compose the two icons
-	const iconGravityFactor = mountIconSize.height * 0.063;
-	mountIcon = mountIcon.composite(temporaryAppIconPath).gravity('Center').geometry(`+0-${iconGravityFactor}`);
+	const temporaryMountIconPath = temporaryFile({extension: 'png'});
+	const temporaryOutputPath = temporaryFile({extension: 'png'});
 
-	composedIcon[type] = await promisify(mountIcon.toBuffer.bind(mountIcon))();
-}
+	await writeFile(temporaryAppIconPath, appIcon);
+	await writeFile(temporaryMountIconPath, mountIcon);
 
-const hasGm = async () => {
+	// Use Swift executable for image processing
+	const swiftExecutablePath = path.join(__dirname, 'compose-icon');
+
 	try {
-		await execa('gm', ['-version']);
-		return true;
+		await execa(swiftExecutablePath, [
+			temporaryAppIconPath,
+			temporaryMountIconPath,
+			temporaryOutputPath
+		]);
+
+		// Read the composed image back
+		composedIcon[type] = await readFile(temporaryOutputPath);
 	} catch (error) {
-		if (error.code === 'ENOENT') {
-			return false;
-		}
-
-		throw error;
+		throw new Error(`Swift image processing failed: ${error.message}`);
 	}
-};
+}
 
 export default async function composeIcon(appIconPath) {
-	if (!await hasGm()) {
-		return baseDiskIconPath;
-	}
-
 	const baseDiskIcons = filterMap(icns.parse(await readFile(baseDiskIconPath)), ([key]) => icns.isImageType(key));
 	const appIcon = filterMap(icns.parse(await readFile(appIconPath)), ([key]) => icns.isImageType(key));
 

imageComposition/Package.swift

@@ -0,0 +1,22 @@
+// swift-tools-version: 5.7
+
+import PackageDescription
+
+let package = Package(
+    name: "ComposeIcon",
+    platforms: [
+        .macOS(.v11)
+    ],
+    products: [
+        .executable(
+            name: "compose-icon",
+            targets: ["ComposeIcon"]
+        )
+    ],
+    targets: [
+        .executableTarget(
+            name: "ComposeIcon",
+            dependencies: []
+        )
+    ]
+)

imageComposition/Sources/ComposeIcon/main.swift

@@ -0,0 +1,153 @@
+import CoreGraphics
+import CoreImage
+import Foundation
+import CoreImage.CIFilterBuiltins
+import ImageIO
+import UniformTypeIdentifiers
+
+func cgContext(width: Int, height: Int) -> CGContext? {
+    CGContext(
+        data: nil,
+        width: width,
+        height: height,
+        bitsPerComponent: 8,
+        bytesPerRow: 0,
+        space: CGColorSpaceCreateDeviceRGB(),
+        bitmapInfo: CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.premultipliedFirst.rawValue
+    )
+}
+
+func perspectiveTransform(image: CGImage, width: Int, height: Int) -> CGImage? {
+    let ciImage = CIImage(cgImage: image)
+    let filter = CIFilter.perspectiveTransform()
+
+    let w = CGFloat(width)
+    let h = CGFloat(height)
+
+    filter.inputImage = ciImage
+    filter.topLeft = CGPoint(x: w * 0.08, y: h)
+    filter.topRight = CGPoint(x: w * 0.92, y: h)
+    filter.bottomLeft = CGPoint(x: 0, y: 0)
+    filter.bottomRight = CGPoint(x: w, y: 0)
+
+    guard let outputImage = filter.outputImage else { return nil }
+
+    let inputExtent = ciImage.extent
+    let croppedImage = outputImage.cropped(to: inputExtent)
+
+    let ciContext = CIContext()
+    return ciContext.createCGImage(croppedImage, from: inputExtent)
+}
+
+func resizeImage(image: CGImage, width: Int, height: Int) -> CGImage? {
+    guard let ctx = cgContext(width: width, height: height) else { return nil }
+
+    ctx.interpolationQuality = .high
+    ctx.clear(CGRect(x: 0, y: 0, width: width, height: height))
+    ctx.draw(image, in: CGRect(x: 0, y: 0, width: width, height: height))
+
+    return ctx.makeImage()
+}
+
+func compositeImages(baseImage: CGImage, overlayImage: CGImage, offsetY: CGFloat) -> CGImage? {
+    let width = baseImage.width
+    let height = baseImage.height
+
+    guard let ctx = cgContext(width: width, height: height) else { return nil }
+
+    // Draw base image
+    ctx.draw(baseImage, in: CGRect(x: 0, y: 0, width: width, height: height))
+
+    // Calculate centered position with offset (matching GraphicsMagick's gravity('Center').geometry('+0-offset'))
+    let overlayWidth = overlayImage.width
+    let overlayHeight = overlayImage.height
+
+    // Center horizontally and vertically, then apply upward offset
+    // CoreGraphics uses bottom-left origin, positive offsetY moves overlay up
+    let x = CGFloat(width - overlayWidth) / 2.0
+    let centerY = CGFloat(height - overlayHeight) / 2.0
+    let y = centerY + offsetY
+
+
+    // Draw overlay image
+    ctx.draw(overlayImage, in: CGRect(x: x, y: y, width: CGFloat(overlayWidth), height: CGFloat(overlayHeight)))
+
+    return ctx.makeImage()
+}
+
+func loadImage(from path: String) -> CGImage? {
+    guard let imageSource = CGImageSourceCreateWithURL(URL(fileURLWithPath: path) as CFURL, nil) else {
+        return nil
+    }
+
+    return CGImageSourceCreateImageAtIndex(imageSource, 0, nil)
+}
+
+func saveImage(_ image: CGImage, to path: String) -> Bool {
+    guard let destination = CGImageDestinationCreateWithURL(URL(fileURLWithPath: path) as CFURL, UTType.png.identifier as CFString, 1, nil) else {
+        return false
+    }
+
+    CGImageDestinationAddImage(destination, image, nil)
+    return CGImageDestinationFinalize(destination)
+}
+
+// Main program
+guard CommandLine.arguments.count == 4 else {
+    fputs("Usage: compose-icon <app-icon-path> <mount-icon-path> <output-path>\n", stderr)
+    exit(1)
+}
+
+let appIconPath = CommandLine.arguments[1]
+let mountIconPath = CommandLine.arguments[2]
+let outputPath = CommandLine.arguments[3]
+
+guard let appImage = loadImage(from: appIconPath),
+      let mountImage = loadImage(from: mountIconPath) else {
+    fputs("Error: Could not load input images\n", stderr)
+    exit(1)
+}
+
+let appIconSize = (width: appImage.width, height: appImage.height)
+let mountIconSize = (width: mountImage.width, height: mountImage.height)
+
+// Apply perspective transformation
+guard let transformedAppImage = perspectiveTransform(
+    image: appImage,
+    width: appIconSize.width,
+    height: appIconSize.height
+) else {
+    fputs("Error: Could not apply perspective transformation\n", stderr)
+    exit(1)
+}
+
+// Resize app icon to fit inside mount icon (from JS: width / 1.58, height / 1.82)
+let resizedWidth = Int((Double(mountIconSize.width) / 1.58).rounded())
+let resizedHeight = Int((Double(mountIconSize.height) / 1.82).rounded())
+
+guard let resizedAppImage = resizeImage(
+    image: transformedAppImage,
+    width: resizedWidth,
+    height: resizedHeight
+) else {
+    fputs("Error: Could not resize app image\n", stderr)
+    exit(1)
+}
+
+// Composite images with offset (from JS: mountIconSize.height * 0.063)
+let offsetY = CGFloat(mountIconSize.height) * 0.063
+
+guard let composedImage = compositeImages(
+    baseImage: mountImage,
+    overlayImage: resizedAppImage,
+    offsetY: offsetY
+) else {
+    fputs("Error: Could not composite images\n", stderr)
+    exit(1)
+}
+
+// Save result
+guard saveImage(composedImage, to: outputPath) else {
+    fputs("Error: Could not save output image\n", stderr)
+    exit(1)
+}

package.json

@@ -18,11 +18,14 @@
 		"node": ">=18"
 	},
 	"scripts": {
-		"test": "ava"
+		"test": "ava",
+		"build": "./build-swift.sh",
+		"prepublishOnly": "npm run build"
 	},
 	"files": [
 		"cli.js",
 		"compose-icon.js",
+		"compose-icon",
 		"assets",
 		"disk-icon.icns",
 		"sla.js",
@@ -44,7 +47,6 @@
 	"dependencies": {
 		"appdmg": "^0.6.6",
 		"execa": "^8.0.1",
-		"gm": "^1.25.0",
 		"icns-lib": "^1.0.1",
 		"meow": "^13.1.0",
 		"ora": "^8.0.1",
@@ -53,6 +55,11 @@
 	},
 	"devDependencies": {
 		"ava": "^6.1.1",
+		"jest-image-snapshot": "^6.5.1",
 		"xo": "^0.56.0"
+	},
+	"ava": {
+		"serial": true,
+		"timeout": "30s"
 	}
 }

readme.md

@@ -50,16 +50,6 @@ If either `license.txt`, `license.rtf`, or `sla.r` ([raw SLAResources file](http
 
 `/usr/bin/rez` (from [Command Line Tools for Xcode](https://developer.apple.com/download/more/)) must be installed.
 
-### DMG icon
-
-[GraphicsMagick](http://www.graphicsmagick.org) is required to create the custom DMG icon that's based on the app icon and the macOS mounted device icon.
-
-#### Steps using [Homebrew](https://brew.sh)
-
-```sh
-brew install graphicsmagick imagemagick
-```
-
 #### Icon example
 
 Original icon → DMG icon