interval for scenedit autosave

src/scenedit/scen.fileio.cpp

@@ -1101,13 +1101,12 @@ struct overrides_sheet {
 	}
 };
 
-const int MAX_ED_AUTOSAVE_DEFAULT = 10; // TODO make a pref
 static fs::path next_autosave_path() {
 	extern fs::path edAutoDir;
 
 	auto ed_autosaves = sorted_file_mtimes(edAutoDir, {".boes"});
 
-	if(ed_autosaves.size() >= MAX_ED_AUTOSAVE_DEFAULT){
+	if(ed_autosaves.size() >= get_int_pref("EdAutoSlots", 10)){ // TODO allow changing the pref
 		return ed_autosaves.back().first; // Reuse oldest auto slot
 	}else if(ed_autosaves.empty()){
 		return edAutoDir / "auto0.boes";

src/scenedit/scen.main.cpp

@@ -195,8 +195,15 @@ static void launch_scenario(eLaunchType type) {
 //Changed to ISO C specified argument and return type.
 int main(int argc, char* argv[]) {
 	extern cUndoList undo_list;
-	undo_list.onChange = []() -> void {
-		save_scenario(false, true);
+	int change_counter = 0;
+	undo_list.onChange = [&change_counter]() -> void {
+		++change_counter;
+		// TODO allow setting this pref (min 1)
+		if(change_counter == get_int_pref("EdAutoInterval", 3)){
+			save_scenario(false, true);
+			change_counter = 0;
+		}
+
 	};
 	try {
 		init_scened(argc, argv);