gamepad: initialize in a thread

Speeds up game startup, at least on Linux

src/events.h

@@ -41,6 +41,7 @@ typedef enum {
 	TE_GAMEPAD_BUTTON_UP,
 	TE_GAMEPAD_AXIS,
 	TE_GAMEPAD_AXIS_DIGITAL,
+	TE_GAMEPAD_SDL_INITIALIZED,
 
 	TE_VIDEO_MODE_CHANGED,
 

src/gamepad.c

@@ -13,6 +13,7 @@
 #include "events.h"
 #include "global.h"
 #include "hirestime.h"
+#include "taskmanager.h"
 
 typedef struct GamepadAxisState {
 	int16_t raw;
@@ -34,7 +35,9 @@ static struct {
 	GamepadAxisState *axes;
 	GamepadButtonState *buttons;
 	DYNAMIC_ARRAY(GamepadDevice) devices;
+	Task *init_task;
 	int active_dev_num;
+	bool initializing;
 	bool initialized;
 	bool update_needed;
 } gamepad;
@@ -281,23 +284,26 @@ static inline void set_events_state(int state) {
 	SDL_GameControllerEventState(state);
 }
 
-void gamepad_init(void) {
-	if(gamepad.initialized) {
-		return;
+static void *gamepad_init_task(void *arg) {
+	if(SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER) < 0) {
+		log_sdl_error(LOG_ERROR, "SDL_InitSubSystem");
 	}
 
-	set_events_state(SDL_IGNORE);
+	events_emit(TE_GAMEPAD_SDL_INITIALIZED, 0, NULL, NULL);
+	return NULL;
+}
 
-	if(!config_get_int(CONFIG_GAMEPAD_ENABLED)) {
-		return;
-	}
+static bool gamepad_post_init_event(SDL_Event *evt, void *arg) {
+	assert(evt->type == MAKE_TAISEI_EVENT(TE_GAMEPAD_SDL_INITIALIZED));
+	bool success = SDL_WasInit(SDL_INIT_GAMECONTROLLER);
 
-	if(SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER) < 0) {
-		log_sdl_error(LOG_ERROR, "SDL_InitSubSystem");
-		return;
+	events_unregister_handler(gamepad_post_init_event);
+
+	if(!success) {
+		log_debug("Gamepad init failed");
+		goto end;
 	}
 
-	gamepad.initialized = true;
 	gamepad.update_needed = true;
 	gamepad.axes = ALLOC_ARRAY(GAMEPAD_AXIS_MAX, typeof(*gamepad.axes));
 	gamepad.buttons = ALLOC_ARRAY(GAMEPAD_BUTTON_MAX + GAMEPAD_EMULATED_BUTTON_MAX, typeof(*gamepad.buttons));
@@ -310,13 +316,51 @@ void gamepad_init(void) {
 	});
 
 	set_events_state(SDL_ENABLE);
+	gamepad.initialized = true;
+
+end:
+	task_finish(gamepad.init_task, NULL);
+	gamepad.init_task = NULL;
+	gamepad.initializing = false;
+	return true;
+}
+
+void gamepad_init(void) {
+	if(gamepad.initialized || gamepad.initializing) {
+		return;
+	}
+
+	set_events_state(SDL_IGNORE);
+
+	if(!config_get_int(CONFIG_GAMEPAD_ENABLED)) {
+		return;
+	}
+
+	gamepad.initializing = true;
+
+	events_register_handler(&(EventHandler){
+		.proc = gamepad_post_init_event,
+		.priority = EPRIO_SYSTEM,
+		.event_type = MAKE_TAISEI_EVENT(TE_GAMEPAD_SDL_INITIALIZED),
+	});
+
+	gamepad.init_task = taskmgr_global_submit((TaskParams) {
+		.callback = gamepad_init_task,
+		.prio = -10,
+		.topmost = true,
+	});
 }
 
 void gamepad_shutdown(void) {
 	if(!gamepad.initialized) {
 		return;
 	}
 
+	if(gamepad.init_task) {
+		task_finish(gamepad.init_task, NULL);
+		gamepad.init_task = NULL;
+	}
+
 	log_info("Disabled the gamepad subsystem");
 
 	mem_free(gamepad.axes);