Add script to generate .icns file in macOS 11 design

1 files changed, 81 insertions, 0 deletions

diff --git a/build/create_macos_icon.sh b/build/create_macos_icon.sh
new file mode 100755
index 0000000..ebd711c
--- /dev/null
+++ b/build/create_macos_icon.sh
@@ -0,0 +1,81 @@
+#!/bin/bash
+
+set -eo pipefail
+
+# Config
+SOURCE_FILE_PATH='./1024x1024.png' # has to be of size 1024x1024 px
+OUT_ICON_NAME='icon'
+
+
+# The "design" and magic numbers below are derived from Apple's macOS app icon
+# guidelines and design templates:
+# https://developer.apple.com/design/human-interface-guidelines/macos/icons-and-images/app-icon/
+# https://developer.apple.com/design/resources/#macos-apps
+#
+# Specifically, for an icon of 1024x:
+# - outer bounding box: 1024x1024 px
+# - border radius: ~22,85% (= 234 px)
+# - icon grid size: 824x824 px
+# - icon grid shadow size: x: 0px, y: 10px, blur: 10px, 30% black
+
+
+# Make sure ImageMagick's convert and iconutil are available.
+if ! hash convert 2>/dev/null || ! hash iconutil 2>/dev/null; then
+    echo "ERROR: This script requires ImageMagick and iconutil."
+    exit 1
+fi
+
+
+# Prepare an iconset folder
+mkdir "./${OUT_ICON_NAME}.iconset"
+
+
+# Add rounded corners to the 1024px image.
+#
+# This works by:
+# 1. Generating a black square (1024 px) with rounded corners (radius 234 px)
+#    on transparent background, via `-size [...] xc:none -draw [...]`
+# 2. Applying the square as a mask to the the source image, via `-matte [...]`
+convert "${SOURCE_FILE_PATH}" \
+    -matte \( \
+        -size 1024x1024 xc:none -draw "roundrectangle 0,0,1024,1024,234,234" \
+    \) \
+    -compose DstIn -composite \
+    "./${OUT_ICON_NAME}.iconset/temp_1024_rounded.png"
+
+
+# Apply sizing and add shadow to the 1024px image.
+#
+# This works by:
+# 1. Resizing to 'icon grid size' (824px), via `-resize`
+# 2. Adding padding (100px) to get 'outer bounding box' size,
+#    via `-bordercolor none -border [...]`
+# 3. Adding shadow, via `+clone -background black -shadow [...]`
+convert "./${OUT_ICON_NAME}.iconset/temp_1024_rounded.png" \
+    -resize 824x824 \
+    -bordercolor none -border 100x100 \
+    \( +clone -background black -shadow 30x10+0+10 -background none \) \
+    -compose DstOver -flatten \
+    "./${OUT_ICON_NAME}.iconset/icon_512x512@2x.png"
+
+# Remove temporary file
+rm "./${OUT_ICON_NAME}.iconset/temp_1024_rounded.png"
+
+# Generate all sizes.
+# 16/32/128/256/512, each single & double resolution
+cd "./${OUT_ICON_NAME}.iconset/"
+convert './icon_512x512@2x.png' \
+    \( +clone -resize  x16 -write './icon_16x16.png'      +delete \) \
+    \( +clone -resize  x32 -write './icon_16x16@2x.png'   +delete \) \
+    \( +clone -resize  x32 -write './icon_32x32.png'      +delete \) \
+    \( +clone -resize  x64 -write './icon_32x32@2x.png'   +delete \) \
+    \( +clone -resize x128 -write './icon_128x128.png'    +delete \) \
+    \( +clone -resize x256 -write './icon_128x128@2x.png' +delete \) \
+    \( +clone -resize x256 -write './icon_256x256.png'    +delete \) \
+    \( +clone -resize x512 -write './icon_256x256@2x.png' +delete \) \
+              -resize x512        './icon_512x512.png'
+cd '..'
+
+# Convert to .icns format and remove iconset
+iconutil -c icns "./${OUT_ICON_NAME}.iconset"
+rm -r "./${OUT_ICON_NAME}.iconset"