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/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/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: