ICNS icon resizer/generator for use in Unity editor scripting.

ICNSGenerator.cs

// ICNS icon resizer/generator for use in Unity editor scripting.
// The icon is grabbed from the Player settings main icon, which should be at least 512x512 and square.
// you should change the Output folder to whatever makes sense in your project
// Based on info found in this gist: https://gist.github.com/ansarizafar/6fa64f44aa933794c4d6638eec32b9aa
// - made by joon - feb 9 2024 (joon.be / @joonturbo) - no warranty 

// How to use: 
//  Call ICNSGenerator.Generate();

using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using UnityEditor;
using UnityEngine;
using Debug = UnityEngine.Debug;

namespace TurboWing
{
    public class ICNSGenerator
    {
        public static void Generate()
        {
            var iconName = "icontest";
            var outputFolder = $"Automation/macos/ICNS";
            
            // create dirs
            Directory.CreateDirectory($"{outputFolder}/{iconName}.iconset");

            var icon = PlayerSettings.GetIconsForTargetGroup(BuildTargetGroup.Unknown)[0];
            var dimensions = new List<int>() { 16, 32, 128, 256, 512 };

            for (int i = 0; i < dimensions.Count; i++)
            {
                var d = dimensions[i];
                var filename = $"{outputFolder}/{iconName}.iconset/icon_{d}x{d}.png";
                var scaledIcon = ScaleTexture(icon, d);
                var pngbytes = ImageConversion.EncodeToPNG(scaledIcon);
                File.WriteAllBytes(filename, pngbytes);
                Debug.Log("Created " + filename);

                var filename2x = $"{outputFolder}/{iconName}.iconset/icon_{d}x{d}@2.png";
                var scaledIcon2x = ScaleTexture(icon, d * 2);
                var pngbytes2x = ImageConversion.EncodeToPNG(scaledIcon2x);
                File.WriteAllBytes(filename2x, pngbytes2x);
                Debug.Log("Created " + filename2x);

            }

            // execute iconutil
            Debug.Log("Executing iconutil in " +$"{Directory.GetCurrentDirectory()}/{outputFolder}");
            RunTerminalCommand("iconutil", $"--convert icns {iconName}.iconset", $"{Directory.GetCurrentDirectory()}/{outputFolder}");
            Debug.Log("Done");
        }

        static Texture2D ScaleTexture(Texture2D source, int dimension)
        {
            var scaledIconRt = new RenderTexture(dimension,dimension, 0);
            Graphics.Blit(source, scaledIconRt);
            RenderTexture.active = scaledIconRt;
                
            var scaledIcon = new Texture2D(dimension, dimension, TextureFormat.RGBA32, false);
            scaledIcon.ReadPixels(new Rect(0,0, dimension,dimension), 0,0);
            scaledIcon.Apply();

            RenderTexture.active = null;
            Object.DestroyImmediate(scaledIconRt);
            
            return scaledIcon;
        }
        
        static void RunTerminalCommand(string command, string arguments, string workingdirectory)
        {
            Process process = new Process();
            process.StartInfo.FileName = command;
            process.StartInfo.Arguments = arguments;
            process.StartInfo.RedirectStandardOutput = true;
            process.StartInfo.RedirectStandardError = true;
            process.StartInfo.UseShellExecute = false;
            process.StartInfo.CreateNoWindow = true;
            process.StartInfo.WorkingDirectory = workingdirectory;
            
            process.OutputDataReceived += (sender, e) => Debug.Log(e.Data);
            process.ErrorDataReceived += (sender, e) =>
            {
                if (e.Data != null)
                    Debug.LogError(e.Data);
                else
                    Debug.Log(e.Data);
            };

            process.Start();
            process.BeginOutputReadLine();
            process.BeginErrorReadLine();
            process.WaitForExit();
        }
        
    }
}