Blocks background: Separate draw for each type

Refactor to have an easier to read separate draw function for each block
type. Each draw function is now straightforward, without if/else
conditionals.

Instead of having multiple attributes like "shift_top", "show_top" to
instruct the drawing, directly pass the block type. For control blocks
that have 2 backgrounds, one for top and one for the bottom part, also
expose a control_part attribute.

addons/block_code/ui/blocks/control_block/control_block.gd

@@ -9,9 +9,7 @@ func _ready():
 	super()
 
 	%TopBackground.color = color
-	%TopBackground.shift_bottom = Constants.CONTROL_MARGIN
 	%BottomBackground.color = color
-	%BottomBackground.shift_top = Constants.CONTROL_MARGIN
 	%SnapPoint.add_theme_constant_override("margin_left", Constants.CONTROL_MARGIN)
 	%SnapGutter.color = color
 	%SnapGutter.custom_minimum_size.x = Constants.CONTROL_MARGIN

addons/block_code/ui/blocks/control_block/control_block.tscn

@@ -46,7 +46,7 @@ unique_name_in_owner = true
 layout_mode = 2
 script = ExtResource("2_tx0qr")
 color = Color(1, 1, 1, 1)
-shift_bottom = 20.0
+block_type = 4
 
 [node name="DragDropArea" parent="VBoxContainer/MarginContainer/Rows/Row" instance=ExtResource("3_21e8n")]
 layout_mode = 2
@@ -91,7 +91,8 @@ layout_mode = 2
 size_flags_horizontal = 0
 script = ExtResource("2_tx0qr")
 color = Color(1, 1, 1, 1)
-shift_top = 20.0
+block_type = 4
+control_part = 1
 
 [node name="SnapPoint" parent="VBoxContainer" instance=ExtResource("3_nhryi")]
 layout_mode = 2

addons/block_code/ui/blocks/entry_block/entry_block.tscn

@@ -35,7 +35,7 @@ layout_mode = 2
 mouse_filter = 1
 script = ExtResource("2_yrw8l")
 color = Color(1, 1, 1, 1)
-show_top = false
+block_type = 1
 
 [node name="DragDropArea" parent="VBoxContainer/TopMarginContainer" instance=ExtResource("3_swkpp")]
 layout_mode = 2

addons/block_code/ui/blocks/statement_block/statement_block.gd

@@ -12,9 +12,6 @@ var args_to_add_after_format: Dictionary  # Only used when loading
 
 func _ready():
 	super()
-
-	if definition != null and definition.type != Types.BlockType.STATEMENT:
-		_background.show_top = false
 	_background.color = color
 
 

addons/block_code/ui/blocks/statement_block/statement_block.tscn

@@ -34,7 +34,6 @@ unique_name_in_owner = true
 layout_mode = 2
 mouse_filter = 1
 script = ExtResource("2_lctqt")
-color = Color(1, 1, 1, 1)
 
 [node name="DragDropArea" parent="VBoxContainer/TopMarginContainer" instance=ExtResource("3_mbxhq")]
 layout_mode = 2

addons/block_code/ui/blocks/utilities/background/background.gd

@@ -3,23 +3,25 @@ extends Control
 
 const BlockTreeUtil = preload("res://addons/block_code/ui/block_tree_util.gd")
 const Constants = preload("res://addons/block_code/ui/constants.gd")
+const Types = preload("res://addons/block_code/types/types.gd")
+
+enum ControlPart {
+	TOP,
+	BOTTOM,
+}
 
 var outline_color: Color
 var parent_block: Block
 
 @export var color: Color:
 	set = _set_color
 
-@export var show_top: bool = true:
-	set = _set_show_top
-
-## Horizontally shift the top knob
-@export var shift_top: float = 0.0:
-	set = _set_shift_top
+@export var block_type: Types.BlockType = Types.BlockType.STATEMENT:
+	set = _set_block_type
 
-## Horizontally shift the bottom knob
-@export var shift_bottom: float = 0.0:
-	set = _set_shift_bottom
+## Only relevant if block_type is CONTROL.
+@export var control_part: ControlPart = ControlPart.TOP:
+	set = _set_control_part
 
 
 func _set_color(new_color):
@@ -28,18 +30,13 @@ func _set_color(new_color):
 	queue_redraw()
 
 
-func _set_show_top(new_show_top):
-	show_top = new_show_top
-	queue_redraw()
-
-
-func _set_shift_top(new_shift_top):
-	shift_top = new_shift_top
+func _set_block_type(new_block_type):
+	block_type = new_block_type
 	queue_redraw()
 
 
-func _set_shift_bottom(new_shift_bottom):
-	shift_bottom = new_shift_bottom
+func _set_control_part(new_control_part):
+	control_part = new_control_part
 	queue_redraw()
 
 
@@ -55,47 +52,91 @@ func _get_border_color() -> Color:
 	return outline_color
 
 
-func _draw():
-	var fill_polygon: PackedVector2Array
-	fill_polygon.append(Vector2(0.0, 0.0))
-	if show_top:
-		fill_polygon.append(Vector2(Constants.KNOB_X + shift_top, 0.0))
-		fill_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z + shift_top, Constants.KNOB_H))
-		fill_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z + Constants.KNOB_W + shift_top, Constants.KNOB_H))
-		fill_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z * 2 + Constants.KNOB_W + shift_top, 0.0))
-
-	fill_polygon.append(Vector2(size.x, 0.0))
-	fill_polygon.append(Vector2(size.x, size.y))
-	fill_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z * 2 + Constants.KNOB_W + shift_bottom, size.y))
-	fill_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z + Constants.KNOB_W + shift_bottom, size.y + Constants.KNOB_H))
-	fill_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z + shift_bottom, size.y + Constants.KNOB_H))
-	fill_polygon.append(Vector2(Constants.KNOB_X + shift_bottom, size.y))
-	fill_polygon.append(Vector2(0.0, size.y))
-	fill_polygon.append(Vector2(0.0, 0.0))
+func _get_box_shape(box_size: Vector2 = Vector2.ONE) -> PackedVector2Array:
+	return PackedVector2Array(
+		[
+			Vector2(0.0, 0.0),
+			Vector2(box_size.x, 0.0),
+			Vector2(box_size.x, box_size.y),
+			Vector2(0.0, box_size.y),
+			Vector2(0.0, 0.0),
+		]
+	)
 
-	var stroke_polygon: PackedVector2Array
 
-	if shift_bottom > 0 or shift_top == 0:
-		stroke_polygon.append(Vector2(0.0, size.y))
+func _get_knob_shape(displacement: Vector2 = Vector2.ZERO) -> PackedVector2Array:
+	return PackedVector2Array(
+		[
+			Vector2(displacement.x, displacement.y),
+			Vector2(displacement.x + Constants.KNOB_Z, displacement.y + Constants.KNOB_H),
+			Vector2(displacement.x + Constants.KNOB_Z + Constants.KNOB_W, displacement.y + Constants.KNOB_H),
+			Vector2(displacement.x + Constants.KNOB_Z * 2 + Constants.KNOB_W, displacement.y),
+		]
+	)
+
+
+func _get_entry_shape() -> PackedVector2Array:
+	var box_shape = _get_box_shape(size)
+	var bottom_knob_shape = _get_knob_shape(Vector2(Constants.KNOB_X, size.y))
+	bottom_knob_shape.reverse()
+	return box_shape.slice(0, 3) + bottom_knob_shape + box_shape.slice(3)
+
 
-	stroke_polygon.append(Vector2(shift_top, 0.0))
+func _get_statement_shape() -> PackedVector2Array:
+	var box_shape = _get_box_shape(size)
+	var top_knob_shape = _get_knob_shape(Vector2(Constants.KNOB_X, 0.0))
+	var bottom_knob_shape = _get_knob_shape(Vector2(Constants.KNOB_X, size.y))
+	bottom_knob_shape.reverse()
+	return box_shape.slice(0, 1) + top_knob_shape + box_shape.slice(1, 3) + bottom_knob_shape + box_shape.slice(3)
 
-	if show_top:
-		stroke_polygon.append(Vector2(Constants.KNOB_X + shift_top, 0.0))
-		stroke_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z + shift_top, Constants.KNOB_H))
-		stroke_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z + Constants.KNOB_W + shift_top, Constants.KNOB_H))
-		stroke_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z * 2 + Constants.KNOB_W + shift_top, 0.0))
 
-	stroke_polygon.append(Vector2(size.x, 0.0))
-	stroke_polygon.append(Vector2(size.x, size.y))
-	stroke_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z * 2 + Constants.KNOB_W + shift_bottom, size.y))
-	stroke_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z + Constants.KNOB_W + shift_bottom, size.y + Constants.KNOB_H))
-	stroke_polygon.append(Vector2(Constants.KNOB_X + Constants.KNOB_Z + shift_bottom, size.y + Constants.KNOB_H))
-	stroke_polygon.append(Vector2(Constants.KNOB_X + shift_bottom, size.y))
-	stroke_polygon.append(Vector2(shift_bottom, size.y))
+func _get_control_top_fill_shape() -> PackedVector2Array:
+	var box_shape = _get_box_shape(size)
+	var top_knob_shape = _get_knob_shape(Vector2(Constants.KNOB_X, 0.0))
+	var bottom_knob_shape = _get_knob_shape(Vector2(Constants.CONTROL_MARGIN + Constants.KNOB_X, size.y))
+	bottom_knob_shape.reverse()
+	return box_shape.slice(0, 1) + top_knob_shape + box_shape.slice(1, 3) + bottom_knob_shape + box_shape.slice(3)
+
+
+func _get_control_top_stroke_shape() -> PackedVector2Array:
+	var shape = _get_control_top_fill_shape()
+	shape = shape.slice(shape.size() - 2) + shape.slice(0, shape.size() - 2)
+	shape.append(Vector2(Constants.CONTROL_MARGIN - Constants.OUTLINE_WIDTH / 2, size.y))
+	return shape
+
+
+func _get_control_bottom_fill_shape() -> PackedVector2Array:
+	var box_shape = _get_box_shape(size)
+	var top_knob_shape = _get_knob_shape(Vector2(Constants.CONTROL_MARGIN + Constants.KNOB_X, 0.0))
+	var bottom_knob_shape = _get_knob_shape(Vector2(Constants.KNOB_X, size.y))
+	bottom_knob_shape.reverse()
+	return box_shape.slice(0, 1) + top_knob_shape + box_shape.slice(1, 3) + bottom_knob_shape + box_shape.slice(3)
+
+
+func _get_control_bottom_stroke_shape() -> PackedVector2Array:
+	var shape = PackedVector2Array([Vector2(Constants.CONTROL_MARGIN - Constants.OUTLINE_WIDTH / 2, 0.0)])
+	return shape + _get_control_bottom_fill_shape().slice(1)
+
+
+func _draw():
+	var fill_polygon: PackedVector2Array
+	var stroke_polygon: PackedVector2Array
 
-	if shift_top > 0:
-		stroke_polygon.append(Vector2(0.0, 0.0))
+	if block_type == Types.BlockType.ENTRY:
+		var shape = _get_entry_shape()
+		fill_polygon = shape
+		stroke_polygon = shape
+	elif block_type == Types.BlockType.STATEMENT:
+		var shape = _get_statement_shape()
+		fill_polygon = shape
+		stroke_polygon = shape
+	elif block_type == Types.BlockType.CONTROL:
+		if control_part == ControlPart.TOP:
+			fill_polygon = _get_control_top_fill_shape()
+			stroke_polygon = _get_control_top_stroke_shape()
+		else:
+			fill_polygon = _get_control_bottom_fill_shape()
+			stroke_polygon = _get_control_bottom_stroke_shape()
 
 	draw_colored_polygon(fill_polygon, color)
 	draw_polyline(stroke_polygon, _get_border_color(), Constants.OUTLINE_WIDTH)