Node graph

extends Node

const NODES: Array = [
	{title = 'Noise', at = Vector2(60, 80), outputs = 1, inputs = 0, color = '#8eef97'},
	{title = 'Color ramp', at = Vector2(360, 60), outputs = 1, inputs = 1, color = '#8da5f3'},
	{title = 'Multiply', at = Vector2(360, 260), outputs = 1, inputs = 2, color = '#f3d48d'},
	{title = 'Output', at = Vector2(680, 160), outputs = 0, inputs = 1, color = '#fc7f7f'},
]

var graph: GraphEdit
var status: Label


func _ready() -> void:
	var background: ColorRect = ColorRect.new()
	background.color = Color('#12141a')
	add_child(background)
	background.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)

	var column: VBoxContainer = VBoxContainer.new()
	add_child(column)
	column.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)

	# outside the GraphEdit, whose plain children stay pinned to a corner over the nodes
	status = Label.new()
	status.text = 'drag from a port to another to wire the nodes'
	status.add_theme_color_override('font_color', Color('#999999'))
	column.add_child(status)

	graph = GraphEdit.new()
	graph.show_grid = true
	graph.minimap_enabled = false
	graph.size_flags_vertical = Control.SIZE_EXPAND_FILL
	column.add_child(graph)

	for entry in NODES:
		graph.add_child(_make_node(entry))

	graph.connection_request.connect(_on_connect)
	graph.disconnection_request.connect(_on_disconnect)

	print('GraphEdit does the dragging and the curves, the connection is yours to accept')


func _make_node(entry: Dictionary) -> GraphNode:
	var node: GraphNode = GraphNode.new()
	node.title = entry.title
	node.position_offset = entry.at
	node.custom_minimum_size = Vector2(190, 0)

	var rows: int = max(entry.inputs, entry.outputs)

	for i in rows:
		var label: Label = Label.new()
		label.text = 'port %d' % i
		label.add_theme_color_override('font_color', Color('#999999'))
		node.add_child(label)

		node.set_slot(i, i < entry.inputs, 0, Color(entry.color), i < entry.outputs, 0, Color(entry.color))

	return node


func _on_connect(from_node: StringName, from_port: int, to_node: StringName, to_port: int) -> void:
	graph.connect_node(from_node, from_port, to_node, to_port)
	status.text = '%s:%d -> %s:%d' % [from_node, from_port, to_node, to_port]


func _on_disconnect(from_node: StringName, from_port: int, to_node: StringName, to_port: int) -> void:
	graph.disconnect_node(from_node, from_port, to_node, to_port)
	status.text = 'disconnected %s from %s' % [from_node, to_node]