Added a single bezier mode in curve tool

src/Tools/DesignTools/CurveTool.gd

@@ -1,5 +1,8 @@
 extends BaseDrawTool
 
+enum SingleState { START, END, MIDDLE_A, MIDDLE_B, READY }
+enum Bezier { CHAINED, SINGLE }
+
 var _curve := Curve2D.new()  ## The [Curve2D] responsible for the shape of the curve being drawn.
 var _drawing := false  ## Set to true when a curve is being drawn.
 var _fill_inside := false  ## When true, the inside area of the curve gets filled.
@@ -8,6 +11,11 @@ var _editing_bezier := false  ## Needed to determine when to show the control po
 var _editing_out_control_point := false  ## True when controlling the out control point only.
 var _thickness := 1  ## The thickness of the curve.
 var _last_mouse_position := Vector2.INF  ## The last position of the mouse
+## chained means Krita-like behavior, single means Aseprite-like.
+var _bezier_mode: int = Bezier.CHAINED
+var _current_state: int = SingleState.START  ## Current state of the bezier curve (in SINGLE mode)
+
+@onready var bezier_option_button: OptionButton = $BezierOptions/BezierMode
 
 
 func _init() -> void:
@@ -28,6 +36,12 @@ func _on_thickness_value_changed(value: int) -> void:
 	save_config()
 
 
+func _on_bezier_mode_item_selected(index: int) -> void:
+	_bezier_mode = index
+	update_config()
+	save_config()
+
+
 func _on_fill_checkbox_toggled(toggled_on: bool) -> void:
 	_fill_inside = toggled_on
 	update_config()
@@ -46,19 +60,22 @@ func get_config() -> Dictionary:
 	var config := super.get_config()
 	config["fill_inside"] = _fill_inside
 	config["thickness"] = _thickness
+	config["bezier_mode"] = _bezier_mode
 	return config
 
 
 func set_config(config: Dictionary) -> void:
 	super.set_config(config)
 	_fill_inside = config.get("fill_inside", _fill_inside)
 	_thickness = config.get("thickness", _thickness)
+	_bezier_mode = config.get("bezier_mode", _bezier_mode)
 
 
 func update_config() -> void:
 	super.update_config()
 	$FillCheckbox.button_pressed = _fill_inside
 	$ThicknessSlider.value = _thickness
+	bezier_option_button.select(_bezier_mode)
 
 
 ## This tool has no brush, so just return the indicator as it is.
@@ -72,18 +89,44 @@ func _input(event: InputEvent) -> void:
 			_last_mouse_position = Global.canvas.current_pixel.floor()
 			if Global.mirror_view:
 				_last_mouse_position.x = Global.current_project.size.x - 1 - _last_mouse_position.x
+			if _bezier_mode == Bezier.SINGLE and _current_state >= SingleState.MIDDLE_A:
+				# if bezier's curvature is being changed in SINGLE mode
+				if _current_state == SingleState.MIDDLE_A:
+					_curve.set_point_out(
+						0, Vector2(_last_mouse_position) - _curve.get_point_position(0)
+					)
+				_curve.set_point_in(
+					1,
+					(
+						Vector2(_last_mouse_position)
+						- _curve.get_point_position(_curve.point_count - 1)
+					)
+				)
 		elif event is InputEventMouseButton:
 			if event.double_click and event.button_index == tool_slot.button:
 				$DoubleClickTimer.start()
 				_draw_shape()
 		else:
-			if event.is_action_pressed("shape_perfect"):
-				_editing_out_control_point = true
-			elif event.is_action_released("shape_perfect"):
-				_editing_out_control_point = false
+			if _bezier_mode == Bezier.CHAINED:
+				if event.is_action_pressed("shape_perfect"):
+					_editing_out_control_point = true
+				elif event.is_action_released("shape_perfect"):
+					_editing_out_control_point = false
 			if event.is_action_pressed("change_tool_mode"):  # Control removes the last added point
 				if _curve.point_count > 1:
-					_curve.remove_point(_curve.point_count - 1)
+					match _current_state:
+						SingleState.START:  # Point removed in CHAINED mode
+							_curve.remove_point(_curve.point_count - 1)
+						SingleState.MIDDLE_A:  # End point is to be removed in SINGLE mode
+							_curve.remove_point(_curve.point_count - 1)
+							_curve.set_point_out(0, Vector2.ZERO)
+							_editing_bezier = false
+							_current_state -= 1
+						SingleState.MIDDLE_B:  # Bezier curvature is to be reset in SINGLE mode
+							_curve.set_point_out(
+								0, _last_mouse_position - _curve.get_point_position(0)
+							)
+							_current_state -= 1
 
 
 func draw_start(pos: Vector2i) -> void:
@@ -95,11 +138,18 @@ func draw_start(pos: Vector2i) -> void:
 		_picking_color = true
 		_pick_color(pos)
 		return
+	_picking_color = false  # fixes _picking_color being true indefinitely after we pick color
 	Global.canvas.selection.transform_content_confirm()
 	update_mask()
 	if !_drawing:
+		bezier_option_button.disabled = true
 		_drawing = true
-	_curve.add_point(pos)
+		_current_state = SingleState.START
+	# NOTE: _current_state of CHAINED mode is always SingleState.START so it will always pass this.
+	if _current_state == SingleState.START or _current_state == SingleState.END:
+		_curve.add_point(pos)
+	if _bezier_mode == Bezier.SINGLE:
+		_current_state += 1
 	_fill_inside_rect = Rect2i(pos, Vector2i.ZERO)
 
 
@@ -110,7 +160,7 @@ func draw_move(pos: Vector2i) -> void:
 		if Input.is_action_pressed("shape_displace"):
 			_pick_color(pos)
 		return
-	if _drawing:
+	if _drawing and _bezier_mode == Bezier.CHAINED:
 		_editing_bezier = true
 		var current_position := _curve.get_point_position(_curve.point_count - 1) - Vector2(pos)
 		if not _editing_out_control_point:
@@ -119,8 +169,15 @@ func draw_move(pos: Vector2i) -> void:
 
 
 func draw_end(pos: Vector2i) -> void:
-	_editing_bezier = false
-	if _is_hovering_first_position(pos) and _curve.point_count > 1:
+	# we still need bezier preview when curve is in SINGLE mode.
+	if _current_state == SingleState.MIDDLE_A or _current_state == SingleState.MIDDLE_B:
+		_editing_bezier = true
+	else:
+		_editing_bezier = false
+	if (
+		(_is_hovering_first_position(pos) and _curve.point_count > 1)
+		or _current_state == SingleState.READY
+	):
 		_draw_shape()
 	super.draw_end(pos)
 
@@ -155,11 +212,15 @@ func draw_preview() -> void:
 		circle_center += Vector2.ONE * 0.5
 		draw_empty_circle(canvas, circle_center, circle_radius * 2.0, Color.BLACK)
 	if _editing_bezier:
-		var current_position := _curve.get_point_position(_curve.point_count - 1)
+		var current_point = _curve.point_count - 1
+		if _current_state == SingleState.MIDDLE_A:
+			# We need this when we are modifying curve of "first" point in SINGLE mode
+			current_point = 0
+		var current_position := _curve.get_point_position(current_point)
 		var start := current_position
-		if _curve.point_count > 1:
-			start = current_position + _curve.get_point_in(_curve.point_count - 1)
-		var end := current_position + _curve.get_point_out(_curve.point_count - 1)
+		if current_point > 0:
+			start = current_position + _curve.get_point_in(current_point)
+		var end := current_position + _curve.get_point_out(current_point)
 		if Global.mirror_view:  # This fixes previewing in mirror mode
 			current_position.x = Global.current_project.size.x - current_position.x - 1
 			start.x = Global.current_project.size.x - start.x - 1
@@ -172,6 +233,7 @@ func draw_preview() -> void:
 
 
 func _draw_shape() -> void:
+	bezier_option_button.disabled = false
 	var points := _bezier()
 	prepare_undo("Draw Shape")
 	var images := _get_selected_draw_images()
@@ -218,9 +280,11 @@ func _bezier() -> Array[Vector2i]:
 	if Global.mirror_view:
 		# Mirror the last point of the curve
 		last_pixel.x = (Global.current_project.size.x - 1) - last_pixel.x
-	_curve.add_point(last_pixel)
+	if _current_state <= SingleState.END:  # this is general for both modes
+		_curve.add_point(last_pixel)
 	var points := _curve.get_baked_points()
-	_curve.remove_point(_curve.point_count - 1)
+	if _current_state <= SingleState.END:  # this is general for both modes
+		_curve.remove_point(_curve.point_count - 1)
 	var final_points: Array[Vector2i] = []
 	for i in points.size() - 1:
 		var point1 := points[i]

src/Tools/DesignTools/CurveTool.tscn

@@ -20,7 +20,28 @@ suffix = "px"
 global_increment_action = "brush_size_increment"
 global_decrement_action = "brush_size_decrement"
 
-[node name="FillCheckbox" type="CheckBox" parent="." index="3"]
+[node name="BezierOptions" type="HBoxContainer" parent="." index="3"]
+layout_mode = 2
+
+[node name="Label" type="Label" parent="BezierOptions" index="0"]
+layout_mode = 2
+text = "Mode:"
+
+[node name="BezierMode" type="OptionButton" parent="BezierOptions" index="1"]
+layout_mode = 2
+size_flags_horizontal = 3
+tooltip_text = "Chained: Makes a chain of multiple bezier curves (Krita inspired).
+
+Single: Makes a single bezier curve (Asiprite inspired)"
+alignment = 1
+selected = 0
+item_count = 2
+popup/item_0/text = "Chained"
+popup/item_0/id = 0
+popup/item_1/text = "Single"
+popup/item_1/id = 1
+
+[node name="FillCheckbox" type="CheckBox" parent="." index="4"]
 layout_mode = 2
 tooltip_text = "Fills the drawn shape with color, instead of drawing a hollow shape"
 mouse_default_cursor_shape = 2
@@ -35,12 +56,13 @@ button_group = SubResource("ButtonGroup_drx24")
 [node name="Rotate270" parent="RotationOptions/GridContainer/Rotate" index="2"]
 button_group = SubResource("ButtonGroup_drx24")
 
-[node name="Brush" parent="." index="5"]
+[node name="Brush" parent="." index="6"]
 visible = false
 
-[node name="DoubleClickTimer" type="Timer" parent="." index="7"]
+[node name="DoubleClickTimer" type="Timer" parent="." index="8"]
 wait_time = 0.2
 one_shot = true
 
 [connection signal="value_changed" from="ThicknessSlider" to="." method="_on_thickness_value_changed"]
+[connection signal="item_selected" from="BezierOptions/BezierMode" to="." method="_on_bezier_mode_item_selected"]
 [connection signal="toggled" from="FillCheckbox" to="." method="_on_fill_checkbox_toggled"]