Add CLI parameter for running without graphics

Resolves #1547.

copying.md

@@ -146,6 +146,7 @@ _the openage authors_ are:
 | Derek Frogget               | FoggyLight                  | fro22003 à byui dawt edu                          |
 | Martin                      | Starman                     | mstarman à seznam dawt cz                         |
 | Zoltán Ács                  | zoli111                     | acszoltan111 à gmail dawt com                     |
+| Trevor Slocum               | tslocum                     | trevor à rocket9labs dawt com                     |
 
 If you're a first-time committer, add yourself to the above list. This is not
 just for legal reasons, but also to keep an overview of all those nicknames.

libopenage/main.cpp

@@ -25,8 +25,12 @@ int run_game(const main_arguments &args) {
 	auto cvar_manager = std::make_shared<cvar::CVarManager>(args.root_path["cfg"]);
 	cvar_manager->load_all();
 
-	// TODO: select run_mode by launch argument
+	// set engine run_mode
 	openage::engine::Engine::mode run_mode = openage::engine::Engine::mode::FULL;
+	if (args.headless) {
+		run_mode = openage::engine::Engine::mode::HEADLESS;
+	}
+
 	openage::engine::Engine engine{run_mode, args.root_path, args.mods};
 
 	engine.loop();

libopenage/main.h

@@ -27,12 +27,14 @@ namespace openage {
  *     Path root_path
  *     int32_t fps_limit
  *     bool gl_debug
+ *     bool headless
  *     vector[string] mods
  */
 struct main_arguments {
 	util::Path root_path;
 	int32_t fps_limit;
 	bool gl_debug;
+	bool headless;
 	std::vector<std::string> mods;
 };
 

openage/game/main.py

@@ -28,6 +28,10 @@ def init_subparser(cli: ArgumentParser) -> None:
         "--gl-debug", action='store_true',
         help="throw exceptions directly from the OpenGL calls")
 
+    cli.add_argument(
+        "--headless", action='store_true',
+        help="run without displaying graphics")
+
     cli.add_argument(
         "--modpacks", nargs="+", type=bytes,
         help="list of modpacks to load")

openage/game/main_cpp.pyx

@@ -32,6 +32,9 @@ def run_game(args, root_path):
         # opengl debugging
         args_cpp.gl_debug = args.gl_debug
 
+        # headless mode
+        args_cpp.headless = args.headless
+
         # run the game!
         with nogil:
             result = run_game_cpp(args_cpp)

openage/main/main.py

@@ -24,6 +24,10 @@ def init_subparser(cli: ArgumentParser):
         "--gl-debug", action='store_true',
         help="throw exceptions directly from the OpenGL calls")
 
+    cli.add_argument(
+        "--headless", action='store_true',
+        help="run without displaying graphics")
+
     cli.add_argument(
         "--modpacks", nargs="+",
         help="list of modpacks to load")

openage/main/main_cpp.pyx

@@ -35,6 +35,9 @@ def run_game(args, root_path):
         # opengl debugging
         args_cpp.gl_debug = args.gl_debug
 
+        # headless mode
+        args_cpp.headless = args.headless
+
         # mods
         if args.modpacks is not None:
             args_cpp.mods = args.modpacks