Fix memory leak where the project remained referenced in BaseDraw eve…

…n when its tab was closed

Another memory leak remains in Recorder.gd, where the first project forever remains referenced in memory, until the user changes the project from the option button. Perhaps we should remove that option button completely and always record the current project, that also sounds like the intended behavior to me.

src/Tools/BaseDraw.gd

@@ -273,6 +273,8 @@ func draw_tool(pos: Vector2i) -> void:
 
 func draw_end(pos: Vector2i) -> void:
 	super.draw_end(pos)
+	_stroke_project = null
+	_stroke_images = []
 	_brush_size_dynamics = _brush_size
 	if Tools.dynamics_size != Tools.Dynamics.NONE:
 		_brush_size_dynamics = Tools.brush_size_min

src/Tools/DesignTools/Eraser.gd

@@ -92,8 +92,8 @@ func draw_move(pos_i: Vector2i) -> void:
 
 func draw_end(pos: Vector2i) -> void:
 	pos = snap_position(pos)
-	super.draw_end(pos)
 	if _picking_color:
+		super.draw_end(pos)
 		return
 
 	if _draw_line:
@@ -105,6 +105,7 @@ func draw_end(pos: Vector2i) -> void:
 		draw_fill_gap(_line_start, _line_end)
 		_draw_line = false
 
+	super.draw_end(pos)
 	commit_undo()
 	SteamManager.set_achievement("ACH_ERASE_PIXEL")
 	cursor_text = ""

src/Tools/DesignTools/Pencil.gd

@@ -164,8 +164,8 @@ func draw_move(pos_i: Vector2i) -> void:
 
 func draw_end(pos: Vector2i) -> void:
 	pos = snap_position(pos)
-	super.draw_end(pos)
 	if _picking_color:
+		super.draw_end(pos)
 		return
 
 	if _draw_line:
@@ -194,6 +194,7 @@ func draw_end(pos: Vector2i) -> void:
 							draw_tool(v)
 
 	_fill_inside_rect = Rect2i()
+	super.draw_end(pos)
 	commit_undo()
 	cursor_text = ""
 	update_random_image()

src/Tools/DesignTools/Shading.gd

@@ -291,8 +291,8 @@ func draw_move(pos_i: Vector2i) -> void:
 
 func draw_end(pos: Vector2i) -> void:
 	pos = snap_position(pos)
-	super.draw_end(pos)
 	if _picking_color:
+		super.draw_end(pos)
 		return
 
 	if _draw_line:
@@ -304,6 +304,7 @@ func draw_end(pos: Vector2i) -> void:
 		draw_fill_gap(_line_start, _line_end)
 		_draw_line = false
 
+	super.draw_end(pos)
 	commit_undo()
 	cursor_text = ""
 	update_random_image()