"Fill inside" option in pencil tool (#489)

I modified some code from  "EIRTeam/Pixelorama" and merged it with pencil tool.

src/Tools/Pencil.gd

@@ -4,13 +4,13 @@ extends "res://src/Tools/Draw.gd"
 var _last_position := Vector2.INF
 var _changed := false
 var _overwrite := false
-
+var _fill_inside := false
+var _draw_points := Array()
 
 class PencilOp extends Drawer.ColorOp:
 	var changed := false
 	var overwrite := false
 
-
 	func process(src: Color, dst: Color) -> Color:
 		changed = true
 		src.a *= strength
@@ -29,20 +29,29 @@ func _on_Overwrite_toggled(button_pressed : bool):
 	save_config()
 
 
+func _on_FillInside_toggled(button_pressed):
+	_fill_inside = button_pressed
+	update_config()
+	save_config()
+
+
 func get_config() -> Dictionary:
 	var config := .get_config()
 	config["overwrite"] = _overwrite
+	config["fill_inside"] = _fill_inside
 	return config
 
 
 func set_config(config : Dictionary) -> void:
 	.set_config(config)
 	_overwrite = config.get("overwrite", _overwrite)
+	_fill_inside = config.get("fill_inside", _fill_inside)
 
 
 func update_config() -> void:
 	.update_config()
 	$Overwrite.pressed = _overwrite
+	$FillInside.pressed = _fill_inside
 
 
 func draw_start(position : Vector2) -> void:
@@ -51,6 +60,7 @@ func draw_start(position : Vector2) -> void:
 	_changed = false
 	_drawer.color_op.changed = false
 	_drawer.color_op.overwrite = _overwrite
+	_draw_points = Array()
 
 	prepare_undo()
 	_drawer.reset()
@@ -61,6 +71,8 @@ func draw_start(position : Vector2) -> void:
 		_line_end = position
 		update_line_polylines(_line_start, _line_end)
 	else:
+		if _fill_inside:
+			_draw_points.append(position)
 		draw_tool(position)
 		_last_position = position
 		Global.canvas.sprite_changed_this_frame = true
@@ -78,6 +90,8 @@ func draw_move(position : Vector2) -> void:
 		_last_position = position
 		cursor_text = ""
 		Global.canvas.sprite_changed_this_frame = true
+		if _fill_inside:
+			_draw_points.append(position)
 
 
 func draw_end(_position : Vector2) -> void:
@@ -85,6 +99,21 @@ func draw_end(_position : Vector2) -> void:
 		draw_tool(_line_start)
 		draw_fill_gap(_line_start, _line_end)
 		_draw_line = false
+	else:
+		if _fill_inside:
+			_draw_points.append(_position)
+			if _draw_points.size() > 3:
+				var image = _get_draw_image()
+				var v = Vector2()
+				var image_size = image.get_size()
+				for x in image_size.x:
+					v.x = x
+					for y in image_size.y:
+						v.y = y
+						if Geometry.is_point_in_polygon(v, _draw_points):
+							image.lock()
+							draw_tool(v)
+							image.unlock()
 	if _changed or _drawer.color_op.changed:
 		commit_undo("Draw")
 	cursor_text = ""
@@ -97,3 +126,5 @@ func _draw_brush_image(image : Image, src_rect: Rect2, dst: Vector2) -> void:
 		_get_draw_image().blit_rect(image, src_rect, dst)
 	else:
 		_get_draw_image().blend_rect(image, src_rect, dst)
+
+

src/Tools/Pencil.tscn

@@ -13,12 +13,12 @@ margin_right = 128.0
 margin_right = 128.0
 
 [node name="Type" parent="Brush" index="0"]
-margin_left = 7.0
+margin_left = 9.0
-margin_right = 43.0
+margin_right = 41.0
 
 [node name="Size" parent="Brush" index="1"]
-margin_left = 47.0
+margin_left = 45.0
-margin_right = 121.0
+margin_right = 119.0
 
 [node name="BrushSize" parent="." index="2"]
 margin_left = 18.0
@@ -45,15 +45,27 @@ margin_top = 102.0
 margin_right = 118.0
 margin_bottom = 126.0
 
-[node name="EmptySpacer" parent="." index="6"]
+[node name="FillInside" type="CheckBox" parent="." index="5"]
+margin_left = 19.0
 margin_top = 130.0
-margin_right = 128.0
+margin_right = 109.0
-margin_bottom = 142.0
+margin_bottom = 154.0
+size_flags_horizontal = 4
+text = "Fill inside"
+align = 1
+__meta__ = {
+"_editor_description_": ""
+}
 
-[node name="Mirror" parent="." index="7"]
+[node name="EmptySpacer" parent="." index="7"]
-margin_top = 146.0
+margin_top = 158.0
 margin_right = 128.0
-margin_bottom = 163.0
+margin_bottom = 170.0
+
+[node name="Mirror" parent="." index="8"]
+margin_top = 174.0
+margin_right = 128.0
+margin_bottom = 191.0
 
 [node name="Horizontal" parent="Mirror" index="0"]
 margin_left = 26.0
@@ -62,4 +74,6 @@ margin_right = 41.0
 [node name="Vertical" parent="Mirror" index="1"]
 margin_left = 85.0
 margin_right = 102.0
+
 [connection signal="toggled" from="Overwrite" to="." method="_on_Overwrite_toggled"]
+[connection signal="toggled" from="FillInside" to="." method="_on_FillInside_toggled"]