use main.m and SDL_main functionality

CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.24)
 set(CMAKE_OSX_DEPLOYMENT_TARGET "13.6" CACHE STRING "Minimum MacOS version" FORCE)
 set(CMAKE_Swift_LANGUAGE_VERSION 5)
-project(voxelotl LANGUAGES C Swift VERSION "0.1.0")
+project(voxelotl LANGUAGES C OBJC Swift VERSION "0.1.0")
 
 find_library(SDL3 SDL3 REQUIRED PATHS "${CMAKE_SOURCE_DIR}/Frameworks" NO_DEFAULT_PATH)
 

Sources/Voxelotl/CMakeLists.txt

@@ -66,7 +66,10 @@ add_executable(Voxelotl MACOSX_BUNDLE
   GameDelegate.swift
   Application.swift
 
-  main.swift)
+  # Entry point
+  Program.swift
+  main.m
+)
 
 set_source_files_properties(
   shader.metal PROPERTIES
@@ -103,7 +106,7 @@ set_source_files_properties(test.png PROPERTIES MACOSX_PACKAGE_LOCATION Resource
 
 #TODO: should use TREE mode as documented in https://cmake.org/cmake/help/latest/command/source_group.html
 source_group("Resources" FILES Assets.xcassets test.png)
-source_group("Source Files" REGULAR_EXPRESSION "\\.(swift|metal)$")
+source_group("Source Files" REGULAR_EXPRESSION "\\.(swift|metal|m)$")
 source_group("Source Files\\Common" REGULAR_EXPRESSION "Common/")
 source_group("Source Files\\Random" REGULAR_EXPRESSION "Random/")
 source_group("Source Files\\Noise" REGULAR_EXPRESSION "Noise/")

Sources/Voxelotl/Program.swift

@@ -0,0 +1,17 @@
+import Foundation
+
+@objc public class Program: NSObject {
+  @objc public static func run() -> Int32 {
+    Thread.current.qualityOfService = .userInteractive
+
+    let app = Application(
+      delegate: Game(),
+      configuration: ApplicationConfiguration(
+      frame: Size(1280, 720),
+      title: "Voxelotl Demo",
+      flags: [ .resizable, .highDPI ],
+      vsyncMode: .on(interval: 1)))
+
+    return app.run()
+  }
+}

Sources/Voxelotl/main.m

@@ -0,0 +1,6 @@
+#include <SDL3/SDL_main.h>
+#include <Voxelotl-Swift.h>
+
+int main(int argc, char** argv) {
+  return [Program run];
+}

Sources/Voxelotl/main.swift

@@ -1,13 +0,0 @@
-import Foundation
-
-Thread.current.qualityOfService = .userInteractive
-
-let app = Application(
-  delegate: Game(),
-  configuration: ApplicationConfiguration(
-  frame: Size(1280, 720),
-  title: "Voxelotl Demo",
-  flags: [ .resizable, .highDPI ],
-  vsyncMode: .on(interval: 1)))
-
-exit(app.run())