Initial work on diagonal symmetry guides

Still no buttons yet, and they cannot be moved yet.

src/Autoload/Global.gd

@@ -179,10 +179,14 @@ var can_draw := true
 var move_guides_on_canvas := true
 
 var play_only_tags := true  ## If [code]true[/code], animation plays only on frames of the same tag.
-## (Intended to be used as getter only) Tells if the x-symmetry guide ( -- ) is visible.
+## If true, the x symmetry guide ( -- ) is visible.
 var show_x_symmetry_axis := false
-## (Intended to be used as getter only) Tells if the y-symmetry guide ( | ) is visible.
+## If true, the y symmetry guide ( | ) is visible.
 var show_y_symmetry_axis := false
+## If true, the x=y symmetry guide ( / ) is visible.
+var show_x_y_symmetry_axis := false
+## If true, the x==y symmetry guide ( \ ) is visible.
+var show_x_minus_y_symmetry_axis := false
 
 # Preferences
 ## Found in Preferences. If [code]true[/code], the last saved project will open on startup.

src/Autoload/Tools.gd

@@ -9,9 +9,14 @@ signal options_reset
 
 enum Dynamics { NONE, PRESSURE, VELOCITY }
 
+const XY_LINE := Vector2(-0.707107, 0.707107)
+const X_MINUS_Y_LINE := Vector2(0.707107, 0.707107)
+
 var picking_color_for := MOUSE_BUTTON_LEFT
 var horizontal_mirror := false
 var vertical_mirror := false
+var diagonal_mirror := false
+var diagonal_opposite_mirror := false
 var pixel_perfect := false
 var alpha_locked := false
 
@@ -524,20 +529,48 @@ func get_mirrored_positions(
 ) -> Array[Vector2i]:
 	var positions: Array[Vector2i] = []
 	if horizontal_mirror:
-		var mirror_x := pos
-		mirror_x.x = project.x_symmetry_point - pos.x + offset
+		var mirror_x := calculate_mirror_horizontal(pos, project, offset)
 		positions.append(mirror_x)
 		if vertical_mirror:
-			var mirror_xy := mirror_x
-			mirror_xy.y = project.y_symmetry_point - pos.y + offset
-			positions.append(mirror_xy)
+			positions.append(calculate_mirror_vertical(mirror_x, project, offset))
+		else:
+			if diagonal_mirror:
+				positions.append(calculate_mirror_xy(mirror_x, project))
+			if diagonal_opposite_mirror:
+				positions.append(calculate_mirror_x_minus_y(mirror_x, project))
 	if vertical_mirror:
-		var mirror_y := pos
-		mirror_y.y = project.y_symmetry_point - pos.y + offset
+		var mirror_y := calculate_mirror_vertical(pos, project, offset)
 		positions.append(mirror_y)
+		if diagonal_mirror:
+			positions.append(calculate_mirror_xy(mirror_y, project))
+		if diagonal_opposite_mirror:
+			positions.append(calculate_mirror_x_minus_y(mirror_y, project))
+	if diagonal_mirror:
+		var mirror_diagonal := calculate_mirror_xy(pos, project)
+		positions.append(mirror_diagonal)
+		if not horizontal_mirror and not vertical_mirror:
+			positions.append(calculate_mirror_x_minus_y(mirror_diagonal, project))
+	if diagonal_opposite_mirror:
+		positions.append(calculate_mirror_x_minus_y(pos, project))
 	return positions
 
 
+func calculate_mirror_horizontal(pos: Vector2i, project: Project, offset := 0) -> Vector2i:
+	return Vector2i(project.x_symmetry_point - pos.x + offset, pos.y)
+
+
+func calculate_mirror_vertical(pos: Vector2i, project: Project, offset := 0) -> Vector2i:
+	return Vector2i(pos.x, project.y_symmetry_point - pos.y + offset)
+
+
+func calculate_mirror_xy(pos: Vector2i, project: Project) -> Vector2i:
+	return Vector2i(Vector2(pos).reflect(XY_LINE).round()) + project.size - Vector2i.ONE
+
+
+func calculate_mirror_x_minus_y(pos: Vector2i, _project: Project) -> Vector2i:
+	return Vector2i(Vector2(pos).reflect(X_MINUS_Y_LINE).round())
+
+
 func set_button_size(button_size: int) -> void:
 	var size := Vector2(24, 24) if button_size == Global.ButtonSize.SMALL else Vector2(32, 32)
 	if not is_instance_valid(_tool_buttons):

src/Classes/Drawers.gd

@@ -1,22 +1,19 @@
 class_name Drawer
 
+const NUMBER_OF_DRAWERS := 8
+
 var pixel_perfect := false:
 	set(value):
 		pixel_perfect = value
 		if pixel_perfect:
 			drawers = pixel_perfect_drawers.duplicate()
 		else:
-			drawers = [simple_drawer, simple_drawer, simple_drawer, simple_drawer]
+			_create_simple_drawers()
 var color_op := ColorOp.new()
 
 var simple_drawer := SimpleDrawer.new()
-var pixel_perfect_drawers: Array[PixelPerfectDrawer] = [
-	PixelPerfectDrawer.new(),
-	PixelPerfectDrawer.new(),
-	PixelPerfectDrawer.new(),
-	PixelPerfectDrawer.new()
-]
-var drawers := [simple_drawer, simple_drawer, simple_drawer, simple_drawer]
+var pixel_perfect_drawers: Array[PixelPerfectDrawer] = []
+var drawers := []
 
 
 class ColorOp:
@@ -60,6 +57,21 @@ class PixelPerfectDrawer:
 			last_pixels[0] = corner
 
 
+func _init() -> void:
+	drawers.resize(NUMBER_OF_DRAWERS)
+	pixel_perfect_drawers.resize(NUMBER_OF_DRAWERS)
+	for i in NUMBER_OF_DRAWERS:
+		drawers[i] = simple_drawer
+		pixel_perfect_drawers[i] = PixelPerfectDrawer.new()
+
+
+func _create_simple_drawers() -> void:
+	drawers = []
+	drawers.resize(NUMBER_OF_DRAWERS)
+	for i in NUMBER_OF_DRAWERS:
+		drawers[i] = simple_drawer
+
+
 func reset() -> void:
 	for drawer in pixel_perfect_drawers:
 		drawer.reset()
@@ -72,7 +84,12 @@ func set_pixel(image: Image, position: Vector2i, color: Color, ignore_mirroring
 	SteamManager.set_achievement("ACH_FIRST_PIXEL")
 	if ignore_mirroring:
 		return
-	if not Tools.horizontal_mirror and not Tools.vertical_mirror:
+	if (
+		not Tools.horizontal_mirror
+		and not Tools.vertical_mirror
+		and not Tools.diagonal_mirror
+		and not Tools.diagonal_opposite_mirror
+	):
 		return
 	# Handle mirroring
 	var mirrored_positions := Tools.get_mirrored_positions(position, project)

src/Classes/Project.gd

@@ -71,6 +71,8 @@ var x_symmetry_point: float
 var y_symmetry_point: float
 var x_symmetry_axis := SymmetryGuide.new()
 var y_symmetry_axis := SymmetryGuide.new()
+var diagonal_xy_symmetry_axis := SymmetryGuide.new()
+var diagonal_x_minus_y_symmetry_axis := SymmetryGuide.new()
 
 var selection_map := SelectionMap.new()
 ## This is useful for when the selection is outside of the canvas boundaries,
@@ -111,17 +113,30 @@ func _init(_frames: Array[Frame] = [], _name := tr("untitled"), _size := Vector2
 
 	x_symmetry_point = size.x - 1
 	y_symmetry_point = size.y - 1
-	x_symmetry_axis.type = x_symmetry_axis.Types.HORIZONTAL
+	x_symmetry_axis.type = Guide.Types.HORIZONTAL
 	x_symmetry_axis.project = self
 	x_symmetry_axis.add_point(Vector2(-19999, y_symmetry_point / 2 + 0.5))
 	x_symmetry_axis.add_point(Vector2(19999, y_symmetry_point / 2 + 0.5))
 	Global.canvas.add_child(x_symmetry_axis)
-	y_symmetry_axis.type = y_symmetry_axis.Types.VERTICAL
+
+	y_symmetry_axis.type = Guide.Types.VERTICAL
 	y_symmetry_axis.project = self
 	y_symmetry_axis.add_point(Vector2(x_symmetry_point / 2 + 0.5, -19999))
 	y_symmetry_axis.add_point(Vector2(x_symmetry_point / 2 + 0.5, 19999))
 	Global.canvas.add_child(y_symmetry_axis)
 
+	diagonal_xy_symmetry_axis.type = Guide.Types.XY
+	diagonal_xy_symmetry_axis.project = self
+	diagonal_xy_symmetry_axis.add_point(Vector2(19999, -19999))
+	diagonal_xy_symmetry_axis.add_point(Vector2i(-19999, 19999) + size)
+	Global.canvas.add_child(diagonal_xy_symmetry_axis)
+
+	diagonal_x_minus_y_symmetry_axis.type = Guide.Types.X_MINUS_Y
+	diagonal_x_minus_y_symmetry_axis.project = self
+	diagonal_x_minus_y_symmetry_axis.add_point(Vector2(-19999, -19999))
+	diagonal_x_minus_y_symmetry_axis.add_point(Vector2(19999, 19999))
+	Global.canvas.add_child(diagonal_x_minus_y_symmetry_axis)
+
 	if OS.get_name() == "Web":
 		export_directory_path = "user://"
 	else:

src/Tools/BaseShapeDrawer.gd

@@ -168,18 +168,9 @@ func draw_preview() -> void:
 			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(points[i]):
 				image.set_pixelv(points[i], Color.WHITE)
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			for point in mirror_array(points, true, false):
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-					image.set_pixelv(point, Color.WHITE)
-			if Tools.vertical_mirror:
-				for point in mirror_array(points, true, true):
-					if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-						image.set_pixelv(point, Color.WHITE)
-		if Tools.vertical_mirror:
-			for point in mirror_array(points, false, true):
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-					image.set_pixelv(point, Color.WHITE)
+		for point in mirror_array(points):
+			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
+				image.set_pixelv(point, Color.WHITE)
 		var texture := ImageTexture.create_from_image(image)
 		canvas.texture = texture
 	else:

src/Tools/BaseTool.gd

@@ -205,18 +205,33 @@ func snap_position(pos: Vector2) -> Vector2:
 	return pos
 
 
-func mirror_array(array: Array[Vector2i], h: bool, v: bool) -> Array[Vector2i]:
+## Returns an array that mirrors each point of the [param array].
+## An optional [param callable] can be passed, which gets called for each type of symmetry.
+func mirror_array(array: Array[Vector2i], callable := func(_array): pass) -> Array[Vector2i]:
 	var new_array: Array[Vector2i] = []
 	var project := Global.current_project
-	for point in array:
-		if h and v:
-			new_array.append(
-				Vector2i(project.x_symmetry_point - point.x, project.y_symmetry_point - point.y)
-			)
-		elif h:
-			new_array.append(Vector2i(project.x_symmetry_point - point.x, point.y))
-		elif v:
-			new_array.append(Vector2i(point.x, project.y_symmetry_point - point.y))
+	if Tools.horizontal_mirror and Tools.vertical_mirror:
+		var hv_array: Array[Vector2i] = []
+		for point in array:
+			var mirror_x := Tools.calculate_mirror_horizontal(point, project)
+			hv_array.append(Tools.calculate_mirror_vertical(mirror_x, project))
+		if callable.is_valid():
+			callable.call(hv_array)
+		new_array += hv_array
+	if Tools.horizontal_mirror:
+		var h_array: Array[Vector2i] = []
+		for point in array:
+			h_array.append(Tools.calculate_mirror_horizontal(point, project))
+		if callable.is_valid():
+			callable.call(h_array)
+		new_array += h_array
+	if Tools.vertical_mirror:
+		var v_array: Array[Vector2i] = []
+		for point in array:
+			v_array.append(Tools.calculate_mirror_vertical(point, project))
+		if callable.is_valid():
+			callable.call(v_array)
+		new_array += v_array
 
 	return new_array
 

src/Tools/DesignTools/CurveTool.gd

@@ -141,18 +141,9 @@ func draw_preview() -> void:
 			image.set_pixelv(points[i], Color.WHITE)
 
 	# Handle mirroring
-	if Tools.horizontal_mirror:
-		for point in mirror_array(points, true, false):
-			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-				image.set_pixelv(point, Color.WHITE)
-		if Tools.vertical_mirror:
-			for point in mirror_array(points, true, true):
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-					image.set_pixelv(point, Color.WHITE)
-	if Tools.vertical_mirror:
-		for point in mirror_array(points, false, true):
-			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-				image.set_pixelv(point, Color.WHITE)
+	for point in mirror_array(points):
+		if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
+			image.set_pixelv(point, Color.WHITE)
 	var texture := ImageTexture.create_from_image(image)
 	previews.texture = texture
 

src/Tools/DesignTools/LineTool.gd

@@ -157,18 +157,9 @@ func draw_preview() -> void:
 			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
 				image.set_pixelv(point, Color.WHITE)
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			for point in mirror_array(points, true, false):
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-					image.set_pixelv(point, Color.WHITE)
-			if Tools.vertical_mirror:
-				for point in mirror_array(points, true, true):
-					if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-						image.set_pixelv(point, Color.WHITE)
-		if Tools.vertical_mirror:
-			for point in mirror_array(points, false, true):
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-					image.set_pixelv(point, Color.WHITE)
+		for point in mirror_array(points):
+			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
+				image.set_pixelv(point, Color.WHITE)
 		var texture := ImageTexture.create_from_image(image)
 		canvas.texture = texture
 	else:

src/Tools/SelectionTools/EllipseSelect.gd

@@ -63,18 +63,9 @@ func draw_preview() -> void:
 			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(points[i]):
 				image.set_pixelv(points[i], Color.WHITE)
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			for point in mirror_array(points, true, false):
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-					image.set_pixelv(point, Color.WHITE)
-			if Tools.vertical_mirror:
-				for point in mirror_array(points, true, true):
-					if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-						image.set_pixelv(point, Color.WHITE)
-		if Tools.vertical_mirror:
-			for point in mirror_array(points, false, true):
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
-					image.set_pixelv(point, Color.WHITE)
+		for point in mirror_array(points):
+			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(point):
+				image.set_pixelv(point, Color.WHITE)
 		var texture := ImageTexture.create_from_image(image)
 		canvas.texture = texture
 	else:

src/Tools/SelectionTools/Lasso.gd

@@ -46,27 +46,12 @@ func draw_preview() -> void:
 				image.set_pixelv(draw_point, Color.WHITE)
 
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			for point in mirror_array(_draw_points, true, false):
-				var draw_point := point
-				if Global.mirror_view:  # This fixes previewing in mirror mode
-					draw_point.x = image.get_width() - draw_point.x - 1
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-					image.set_pixelv(draw_point, Color.WHITE)
-			if Tools.vertical_mirror:
-				for point in mirror_array(_draw_points, true, true):
-					var draw_point := point
-					if Global.mirror_view:  # This fixes previewing in mirror mode
-						draw_point.x = image.get_width() - draw_point.x - 1
-					if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-						image.set_pixelv(draw_point, Color.WHITE)
-		if Tools.vertical_mirror:
-			for point in mirror_array(_draw_points, false, true):
-				var draw_point := point
-				if Global.mirror_view:  # This fixes previewing in mirror mode
-					draw_point.x = image.get_width() - draw_point.x - 1
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-					image.set_pixelv(draw_point, Color.WHITE)
+		for point in mirror_array(_draw_points):
+			var draw_point := point
+			if Global.mirror_view:  # This fixes previewing in mirror mode
+				draw_point.x = image.get_width() - draw_point.x - 1
+			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
+				image.set_pixelv(draw_point, Color.WHITE)
 		var texture := ImageTexture.create_from_image(image)
 		canvas.texture = texture
 	else:
@@ -85,19 +70,10 @@ func apply_selection(_position) -> void:
 	if _draw_points.size() > 3:
 		if _intersect:
 			project.selection_map.clear()
-		lasso_selection(project.selection_map, previous_selection_map, _draw_points)
-
+		lasso_selection(_draw_points, project.selection_map, previous_selection_map)
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			var mirror_x := mirror_array(_draw_points, true, false)
-			lasso_selection(project.selection_map, previous_selection_map, mirror_x)
-			if Tools.vertical_mirror:
-				var mirror_xy := mirror_array(_draw_points, true, true)
-				lasso_selection(project.selection_map, previous_selection_map, mirror_xy)
-		if Tools.vertical_mirror:
-			var mirror_y := mirror_array(_draw_points, false, true)
-			lasso_selection(project.selection_map, previous_selection_map, mirror_y)
-
+		var callable := lasso_selection.bind(project.selection_map, previous_selection_map)
+		mirror_array(_draw_points, callable)
 		Global.canvas.selection.big_bounding_rectangle = project.selection_map.get_used_rect()
 	else:
 		if !cleared:
@@ -109,7 +85,7 @@ func apply_selection(_position) -> void:
 
 
 func lasso_selection(
-	selection_map: SelectionMap, previous_selection_map: SelectionMap, points: Array[Vector2i]
+	points: Array[Vector2i], selection_map: SelectionMap, previous_selection_map: SelectionMap
 ) -> void:
 	var selection_size := selection_map.get_size()
 	var bounding_rect := Rect2i(points[0], Vector2i.ZERO)

src/Tools/SelectionTools/PaintSelect.gd

@@ -74,27 +74,12 @@ func draw_preview() -> void:
 				image.set_pixelv(draw_point, Color.WHITE)
 
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			for point in mirror_array(_draw_points, true, false):
-				var draw_point := point
-				if Global.mirror_view:  # This fixes previewing in mirror mode
-					draw_point.x = image.get_width() - draw_point.x - 1
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-					image.set_pixelv(draw_point, Color.WHITE)
-			if Tools.vertical_mirror:
-				for point in mirror_array(_draw_points, true, true):
-					var draw_point := point
-					if Global.mirror_view:  # This fixes previewing in mirror mode
-						draw_point.x = image.get_width() - draw_point.x - 1
-					if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-						image.set_pixelv(draw_point, Color.WHITE)
-		if Tools.vertical_mirror:
-			for point in mirror_array(_draw_points, false, true):
-				var draw_point := point
-				if Global.mirror_view:  # This fixes previewing in mirror mode
-					draw_point.x = image.get_width() - draw_point.x - 1
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-					image.set_pixelv(draw_point, Color.WHITE)
+		for point in mirror_array(_draw_points):
+			var draw_point := point
+			if Global.mirror_view:  # This fixes previewing in mirror mode
+				draw_point.x = image.get_width() - draw_point.x - 1
+			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
+				image.set_pixelv(draw_point, Color.WHITE)
 		var texture := ImageTexture.create_from_image(image)
 		canvas.texture = texture
 	else:
@@ -115,18 +100,9 @@ func apply_selection(pos: Vector2i) -> void:
 		if _intersect:
 			project.selection_map.clear()
 		paint_selection(project.selection_map, previous_selection_map, _draw_points)
-
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			var mirror_x := mirror_array(_draw_points, true, false)
-			paint_selection(project.selection_map, previous_selection_map, mirror_x)
-			if Tools.vertical_mirror:
-				var mirror_xy := mirror_array(_draw_points, true, true)
-				paint_selection(project.selection_map, previous_selection_map, mirror_xy)
-		if Tools.vertical_mirror:
-			var mirror_y := mirror_array(_draw_points, false, true)
-			paint_selection(project.selection_map, previous_selection_map, mirror_y)
-
+		var mirror := mirror_array(_draw_points)
+		paint_selection(project.selection_map, previous_selection_map, mirror)
 		Global.canvas.selection.big_bounding_rectangle = project.selection_map.get_used_rect()
 	else:
 		if !cleared:

src/Tools/SelectionTools/PolygonSelect.gd

@@ -81,27 +81,12 @@ func draw_preview() -> void:
 			)
 
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			for point in mirror_array(preview_draw_points, true, false):
-				var draw_point := point
-				if Global.mirror_view:  # This fixes previewing in mirror mode
-					draw_point.x = image.get_width() - draw_point.x - 1
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-					image.set_pixelv(draw_point, Color.WHITE)
-			if Tools.vertical_mirror:
-				for point in mirror_array(preview_draw_points, true, true):
-					var draw_point := point
-					if Global.mirror_view:  # This fixes previewing in mirror mode
-						draw_point.x = image.get_width() - draw_point.x - 1
-					if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-						image.set_pixelv(draw_point, Color.WHITE)
-		if Tools.vertical_mirror:
-			for point in mirror_array(preview_draw_points, false, true):
-				var draw_point := point
-				if Global.mirror_view:  # This fixes previewing in mirror mode
-					draw_point.x = image.get_width() - draw_point.x - 1
-				if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
-					image.set_pixelv(draw_point, Color.WHITE)
+		for point in mirror_array(preview_draw_points):
+			var draw_point := point
+			if Global.mirror_view:  # This fixes previewing in mirror mode
+				draw_point.x = image.get_width() - draw_point.x - 1
+			if Rect2i(Vector2i.ZERO, image.get_size()).has_point(draw_point):
+				image.set_pixelv(draw_point, Color.WHITE)
 		var texture := ImageTexture.create_from_image(image)
 		previews.texture = texture
 	else:
@@ -122,19 +107,10 @@ func apply_selection(pos: Vector2i) -> void:
 	if _draw_points.size() > 3:
 		if _intersect:
 			project.selection_map.clear()
-		lasso_selection(project.selection_map, previous_selection_map, _draw_points)
-
+		lasso_selection(_draw_points, project.selection_map, previous_selection_map)
 		# Handle mirroring
-		if Tools.horizontal_mirror:
-			var mirror_x := mirror_array(_draw_points, true, false)
-			lasso_selection(project.selection_map, previous_selection_map, mirror_x)
-			if Tools.vertical_mirror:
-				var mirror_xy := mirror_array(_draw_points, true, true)
-				lasso_selection(project.selection_map, previous_selection_map, mirror_xy)
-		if Tools.vertical_mirror:
-			var mirror_y := mirror_array(_draw_points, false, true)
-			lasso_selection(project.selection_map, previous_selection_map, mirror_y)
-
+		var callable := lasso_selection.bind(project.selection_map, previous_selection_map)
+		mirror_array(_draw_points, callable)
 		Global.canvas.selection.big_bounding_rectangle = project.selection_map.get_used_rect()
 	else:
 		if !cleared:
@@ -152,7 +128,7 @@ func _clear() -> void:
 
 
 func lasso_selection(
-	selection_map: SelectionMap, previous_selection_map: SelectionMap, points: Array[Vector2i]
+	points: Array[Vector2i], selection_map: SelectionMap, previous_selection_map: SelectionMap
 ) -> void:
 	var selection_size := selection_map.get_size()
 	var bounding_rect := Rect2i(points[0], Vector2i.ZERO)

src/UI/Canvas/Rulers/Guide.gd

@@ -1,7 +1,7 @@
 class_name Guide
 extends Line2D
 
-enum Types { HORIZONTAL, VERTICAL }
+enum Types { HORIZONTAL, VERTICAL, XY, X_MINUS_Y }
 
 const INPUT_WIDTH := 4
 
@@ -221,14 +221,22 @@ func set_color(color: Color) -> void:
 	default_color = color
 
 
+func get_direction() -> Vector2:
+	return points[0].direction_to(points[1])
+
+
 func _project_switched() -> void:
 	if self in Global.current_project.guides:
 		visible = Global.show_guides
 		if self is SymmetryGuide:
 			if type == Types.HORIZONTAL:
 				visible = Global.show_x_symmetry_axis and Global.show_guides
-			else:
+			elif type == Types.VERTICAL:
 				visible = Global.show_y_symmetry_axis and Global.show_guides
+			elif type == Types.XY:
+				visible = Global.show_x_y_symmetry_axis and Global.show_guides
+			elif type == Types.X_MINUS_Y:
+				visible = Global.show_x_minus_y_symmetry_axis and Global.show_guides
 	else:
 		visible = false
 

src/UI/TopMenuContainer/TopMenuContainer.gd

@@ -835,8 +835,12 @@ func _toggle_show_guides() -> void:
 			if guide is SymmetryGuide:
 				if guide.type == Guide.Types.HORIZONTAL:
 					guide.visible = Global.show_x_symmetry_axis and Global.show_guides
-				else:
+				elif guide.type == Guide.Types.VERTICAL:
 					guide.visible = Global.show_y_symmetry_axis and Global.show_guides
+				elif guide.type == Guide.Types.XY:
+					guide.visible = Global.show_x_y_symmetry_axis and Global.show_guides
+				elif guide.type == Guide.Types.X_MINUS_Y:
+					guide.visible = Global.show_x_minus_y_symmetry_axis and Global.show_guides
 
 
 func _toggle_show_mouse_guides() -> void: