Improve scrolling

ui/component/DialogueTextbox.gd

@@ -22,6 +22,7 @@ var _linesPerPage:int = 0
 var _revealTimer:float = 0.0
 var _pauseTimer:float = 0.0
 var _autoAdvanceTimer:float = 0.0
+var _layoutReady:bool = false
 var _isRevealing:bool = false
 var _isWaitingForInput:bool = false
 var _hasLetGoOfInteract:bool = true
@@ -44,20 +45,23 @@ func setup(line:DialogueLine, entity:Entity, mode:AdvancementMode = AdvancementM
   _advancementMode = mode
   _speakerLabel.text = entity.displayName if entity else ""
   _speakerLabel.visible = _speakerLabel.text != ""
+  # Show all characters so Godot shapes the full text and computes line-break
+  # positions before reveal starts. The box is transparent this frame.
   _bodyLabel.text = line.text
-  _bodyLabel.visible_characters = 0
+  _bodyLabel.visible_characters = -1
   _bodyLabel.scroll_to_line(0)
   _startLine = 0
   _linesPerPage = LINES_PER_PAGE
   _revealTimer = 0.0
   _pauseTimer = 0.0
   _autoAdvanceTimer = 0.0
+  _layoutReady = false
+  _isRevealing = false
   _isWaitingForInput = false
   _hasLetGoOfInteract = !Input.is_action_pressed("interact")
   size.x = MAX_WIDTH
+  modulate.a = 0.0
   visible = true
-  _parsedText = _bodyLabel.get_parsed_text()
-  _isRevealing = true
 
 func _process(delta:float) -> void:
   if not visible:
@@ -68,6 +72,10 @@ func _process(delta:float) -> void:
   if _isWaitingForInput:
     _advanceIndicator.modulate.a = 0.5 + 0.5 * sin(Time.get_ticks_msec() / 300.0)
 
+  if not _layoutReady:
+    _finishLayout()
+    return
+
   if _isRevealing:
     _processReveal(delta)
     return
@@ -79,6 +87,40 @@ func _process(delta:float) -> void:
   if _advancementMode == AdvancementMode.TIMED:
     _processAutoAdvance(delta)
 
+# Called on the first _process frame after setup(). By this point Godot has
+# shaped the full text, so get_character_line() returns stable positions.
+# We bake explicit \n characters into the text at every wrap boundary, then
+# disable autowrap so the layout never changes during reveal.
+func _finishLayout() -> void:
+  var raw:String = _bodyLabel.get_parsed_text()
+  _parsedText = _buildPreWrappedText(raw)
+  _bodyLabel.text = _parsedText
+  _bodyLabel.autowrap_mode = TextServer.AUTOWRAP_OFF
+  _bodyLabel.visible_characters = 0
+  modulate.a = 1.0
+  _layoutReady = true
+  _isRevealing = true
+
+func _buildPreWrappedText(parsed:String) -> String:
+  if parsed.is_empty():
+    return parsed
+  var result:String = ""
+  var prevLine:int = 0
+  for i in range(len(parsed)):
+    var ch:String = parsed[i]
+    # Source-level newlines advance the expected line counter directly;
+    # skip the charLine check so we never double-insert.
+    if ch == "\n":
+      result += "\n"
+      prevLine += 1
+      continue
+    var charLine:int = _bodyLabel.get_character_line(i)
+    if charLine > prevLine:
+      result += "\n"
+      prevLine = charLine
+    result += ch
+  return result
+
 func _processReveal(delta:float) -> void:
   if _pauseTimer > 0.0:
     var speedMult:float = SPEEDUP_MULTIPLIER if Input.is_action_pressed("interact") else 1.0
@@ -102,16 +144,20 @@ func _revealNextChar() -> bool:
   _bodyLabel.visible_characters += 1
   var idx:int = _bodyLabel.visible_characters - 1
 
-  # Stop if this character has wrapped onto the next page.
-  if idx > 0:
-    var charLine:int = _bodyLabel.get_character_line(idx)
-    if charLine >= _startLine + _linesPerPage:
-      _bodyLabel.visible_characters -= 1
-      _onPageFull()
-      return false
+  # Count newlines up to idx to get the current line — no Godot layout call needed.
+  var charLine:int = _parsedText.left(idx + 1).count("\n")
+  if charLine >= _startLine + _linesPerPage:
+    _bodyLabel.visible_characters -= 1
+    _onPageFull()
+    return false
 
   if idx < len(_parsedText):
-    _pauseTimer = _getPauseForChar(idx)
+    var isLastVisible:bool = idx >= len(_parsedText) - 1
+    if not isLastVisible:
+      var nextCharLine:int = _parsedText.left(idx + 2).count("\n")
+      isLastVisible = nextCharLine >= _startLine + _linesPerPage
+    if not isLastVisible:
+      _pauseTimer = _getPauseForChar(idx)
 
   return true
 
@@ -157,7 +203,8 @@ func _processAutoAdvance(delta:float) -> void:
 func _advance() -> void:
   _advanceIndicator.visible = false
   _advanceIndicator.modulate.a = 1.0
-  var hasMorePages:bool = _startLine + _linesPerPage < _bodyLabel.get_line_count()
+  var totalLines:int = _parsedText.count("\n") + 1
+  var hasMorePages:bool = _startLine + _linesPerPage < totalLines
   if hasMorePages:
     _startLine += _linesPerPage
     _bodyLabel.scroll_to_line(_startLine)