caching totalKeyCount and startingID

source/funkin/editors/charter/Charter.hx

@@ -1060,6 +1060,7 @@ class Charter extends UIState {
 	public function createStrumline(strumLineID:Int, strL:ChartStrumLine, addToUndo:Bool = true, ?__createNotes:Bool = true) {
 		var cStr = new CharterStrumline(strL);
 		strumLines.insert(strumLineID, cStr);
+		strumLines.refreshStrumlineIDs();
 		strumLines.snapStrums();
 
 		if (__createNotes) {
@@ -1093,6 +1094,7 @@ class Charter extends UIState {
 		var strL = strumLines.members[strumLineID].strumLine;
 		strumLines.members[strumLineID].destroy();
 		strumLines.members.remove(strumLines.members[strumLineID]);
+		strumLines.refreshStrumlineIDs();
 		strumLines.snapStrums();
 
 		if (addToUndo) {
@@ -1132,6 +1134,7 @@ class Charter extends UIState {
 		FlxG.state.openSubState(new CharterStrumlineScreen(strID, strL, (_) -> {
 			strumLines.members[strID].strumLine = _;
 			strumLines.members[strID].updateInfo();
+			strumLines.refreshStrumlineIDs();
 
 			undos.addToUndo(CEditStrumLine(strID, oldData, _));
 
@@ -1465,6 +1468,7 @@ class Charter extends UIState {
 			case CEditStrumLine(strumLineID, oldStrumLine, newStrumLine):
 				strumLines.members[strumLineID].strumLine = oldStrumLine;
 				strumLines.members[strumLineID].updateInfo();
+				strumLines.refreshStrumlineIDs();
 			case CCreateSelection(selection):
 				deleteSelection(selection, false);
 			case CDeleteSelection(selection):
@@ -1511,6 +1515,7 @@ class Charter extends UIState {
 			case CEditStrumLine(strumLineID, oldStrumLine, newStrumLine):
 				strumLines.members[strumLineID].strumLine = newStrumLine;
 				strumLines.members[strumLineID].updateInfo();
+				strumLines.refreshStrumlineIDs();
 			case CCreateSelection(selection):
 				createSelection(selection, false);
 			case CDeleteSelection(selection):

source/funkin/editors/charter/CharterStrumLineGroup.hx

@@ -9,10 +9,13 @@ class CharterStrumLineGroup extends FlxTypedGroup<CharterStrumline> {
 	var draggingOffset:Float = 0;
 
 	public var totalKeyCount(get, never):Int;
+	private var __totalKeyCount:Int = -1;
 	public function get_totalKeyCount():Int {
+		if (__totalKeyCount != -1) return __totalKeyCount;
+
 		var v:Int = 0;
 		for (strumLine in members) v += strumLine.keyCount;
-		return v;
+		return __totalKeyCount = v;
 	}
 
 	public var draggable:Bool = false;
@@ -40,6 +43,7 @@ class CharterStrumLineGroup extends FlxTypedGroup<CharterStrumline> {
 		if (isDragging) {
 			draggingObj.x = __mousePos.x - draggingOffset;
 			this.sort(function(o, a, b) return FlxSort.byValues(o, a.x, b.x), -1);
+			refreshStrumlineIDs();
 		}
 
 		for (i=>strum in members)
@@ -69,6 +73,7 @@ class CharterStrumLineGroup extends FlxTypedGroup<CharterStrumline> {
 		members.remove(strumLine);
 		members.insert(newID, strumLine);
 
+		refreshStrumlineIDs();
 		finishDrag(false);
 	}
 
@@ -85,6 +90,7 @@ class CharterStrumLineGroup extends FlxTypedGroup<CharterStrumline> {
 
 		draggingObj = null;
 		fixEvents();
+		refreshStrumlineIDs();
 	}
 
 	public inline function fixEvents() {
@@ -100,6 +106,12 @@ class CharterStrumLineGroup extends FlxTypedGroup<CharterStrumline> {
 		__pastStrumlines = null;
 	}
 
+	public inline function refreshStrumlineIDs() {
+		__totalKeyCount = -1;
+		@:privateAccess
+		for (strumLine in members) strumLine.__startingID = -1;
+	}
+
 	public function getStrumlineFromID(id:Int) {
 		var v:Int = 0;
 		for (strumLine in members) {

source/funkin/editors/charter/CharterStrumline.hx

@@ -25,13 +25,16 @@ class CharterStrumline extends UISprite {
 
 	public var keyCount:Int = 4;
 	public var startingID(get, null):Int;
+	private var __startingID:Int = -1;
 	public function get_startingID():Int {
+		if (__startingID != -1) return __startingID;
+
 		var index = Charter.instance.strumLines.members.indexOf(this);
-		if (index < 1) return 0; //-1 or 0
+		if (index < 1) return __startingID = 0; //-1 or 0
 
 		var v:Int = 0;
 		for (i in 0...index) v += Charter.instance.strumLines.members[i].keyCount;
-		return v;
+		return __startingID = v;
 	}
 
 	public var selectedWaveform(default, set):Int = -1;