Added AnimationTag class

Replaces nested Global.animation_tags arrays. Also replaced array.duplicate(true) with looping through the array and creating a new class for each array element, because duplicate(true) does not create new classes, unfortunately, which was causing issues with undo/redo.

src/Classes/AnimationTag.gd

@@ -0,0 +1,15 @@
+class_name AnimationTag extends Reference
+# A class for frame tag properties
+
+
+var name : String
+var color : Color
+var from : int
+var to : int
+
+
+func _init(_name, _color, _from, _to) -> void:
+	name = _name
+	color = _color
+	from = _from
+	to = _to

src/Classes/Cel.gd

@@ -0,0 +1,18 @@
+class_name Cel extends Reference
+# A class for cel properties
+
+
+var image : Image setget image_changed
+var image_texture : ImageTexture
+var opacity : float
+
+
+func _init(_image := Image.new(), _opacity := 1.0) -> void:
+	self.image = _image
+	opacity = _opacity
+
+
+func image_changed(value : Image) -> void:
+	image = value
+	image_texture = ImageTexture.new()
+	image_texture.create_from_image(image, 0)

src/Classes/Drawers.gd

@@ -0,0 +1,40 @@
+class Drawer:
+	func reset() -> void:
+		pass
+
+	func set_pixel(_sprite: Image, _pos: Vector2, _new_color: Color) -> void:
+		pass
+
+
+class SimpleDrawer extends Drawer:
+	func reset() -> void:
+		pass
+
+
+	func set_pixel(_sprite: Image, _pos: Vector2, _new_color: Color) -> void:
+		_sprite.set_pixel(_pos.x, _pos.y, _new_color)
+
+
+class PixelPerfectDrawer extends Drawer:
+	const neighbours = [Vector2(0, 1), Vector2(1, 0), Vector2(-1, 0), Vector2(0, -1)]
+	const corners = [Vector2(1, 1), Vector2(-1, -1), Vector2(-1, 1), Vector2(1, -1)]
+	var last_pixels = [null, null]
+
+
+	func reset() -> void:
+		last_pixels = [null, null]
+
+
+	func set_pixel(_sprite: Image, _pos: Vector2, _new_color: Color) -> void:
+		last_pixels.push_back([_pos, _sprite.get_pixel(_pos.x, _pos.y)])
+		_sprite.set_pixel(_pos.x, _pos.y, _new_color)
+
+		var corner = last_pixels.pop_front()
+		var neighbour = last_pixels[0]
+
+		if corner == null or neighbour == null:
+			return
+
+		if _pos - corner[0] in corners and _pos - neighbour[0] in neighbours:
+			_sprite.set_pixel(neighbour[0].x, neighbour[0].y, neighbour[1])
+			last_pixels[0] = corner

src/Classes/Layer.gd

@@ -0,0 +1,19 @@
+class_name Layer extends Reference
+# A class for layer properties
+
+
+var name := ""
+var visible := true
+var locked := false
+var frame_container : HBoxContainer
+var new_cels_linked := false
+var linked_cels := [] # Array of Canvases
+
+
+func _init(_name := tr("Layer") + " 0", _visible := true, _locked := false, _frame_container := HBoxContainer.new(), _new_cels_linked := false, _linked_cels := []) -> void:
+	name = _name
+	visible = _visible
+	locked = _locked
+	frame_container = _frame_container
+	new_cels_linked = _new_cels_linked
+	linked_cels = _linked_cels