Merge pull request #32 from endlessm/refactor-block-types

Type casting

Author: manuq

addons/block_code/block_code_plugin.gd

@@ -45,6 +45,8 @@ const DISABLED_CLASSES := [
 
 
 func _enter_tree():
+	Types.init_cast_graph()
+
 	main_panel = MainPanel.instantiate()
 	main_panel.undo_redo = get_undo_redo()
 

addons/block_code/drag_manager/drag_manager.gd

@@ -45,22 +45,23 @@ func _process(_delta):
 				if snap_point.block == null:
 					push_error("Warning: a snap point does not reference it's parent block.")
 					continue
-				if snap_point.block.on_canvas and snap_point.block_type == dragging.block_type:
-					var snap_global_pos: Vector2 = snap_point.get_global_rect().position
-					var temp_dist: float = dragging_global_pos.distance_to(snap_global_pos)
-					if temp_dist < closest_dist:
-						# Check if any parent node is this node
-						var is_child: bool = false
-						var parent = snap_point
-						while parent is SnapPoint:
-							if parent.block == dragging:
-								is_child = true
-
-							parent = parent.block.get_parent()
-
-						if not is_child:
-							closest_dist = temp_dist
-							closest_snap_point = snap_point
+				if snap_point.block.on_canvas:
+					if Types.can_cast(dragging.block_type, snap_point.block_type):
+						var snap_global_pos: Vector2 = snap_point.get_global_rect().position
+						var temp_dist: float = dragging_global_pos.distance_to(snap_global_pos)
+						if temp_dist < closest_dist:
+							# Check if any parent node is this node
+							var is_child: bool = false
+							var parent = snap_point
+							while parent is SnapPoint:
+								if parent.block == dragging:
+									is_child = true
+
+								parent = parent.block.get_parent()
+
+							if not is_child:
+								closest_dist = temp_dist
+								closest_snap_point = snap_point
 
 		if closest_dist > 80.0:
 			closest_snap_point = null

addons/block_code/types/types.gd

@@ -14,3 +14,143 @@ enum BlockType {
 	COLOR,
 	NODE
 }
+
+const cast_relationships = [
+	[BlockType.INT, BlockType.FLOAT, "float(%s)"],
+	[BlockType.FLOAT, BlockType.INT, "int(%s)"],
+	[BlockType.INT, BlockType.STRING, "str(%s)"],
+	[BlockType.FLOAT, BlockType.STRING, "str(%s)"],
+]
+
+# Directed graph, edges are CastGraphEdge
+static var cast_graph: Dictionary
+
+
+class CastGraphEdge:
+	var to: BlockType
+	var cast_format: String
+
+	func _init(p_to: BlockType, p_cast_format: String):
+		to = p_to
+		cast_format = p_cast_format
+
+
+static func init_cast_graph():
+	cast_graph = {}
+
+	for rel in cast_relationships:
+		if not cast_graph.has(rel[0]):
+			cast_graph[rel[0]] = []
+
+		if not cast_graph.has(rel[1]):
+			cast_graph[rel[1]] = []
+
+		var edges: Array = cast_graph[rel[0]]
+
+		edges.append(CastGraphEdge.new(rel[1], rel[2]))
+
+
+# Graph recursive utils
+static var prev: Dictionary
+static var dist: Dictionary
+const INT_MAX: int = 1000000000
+
+
+static func dijkstra(source: BlockType):
+	prev = {}
+	dist = {}
+
+	var queue := PriorityQueue.new()
+
+	dist[source] = 0
+	queue.push(source, 0)
+
+	for v in cast_graph.keys():
+		if v != source:
+			dist[v] = INT_MAX
+			prev[v] = null
+			queue.push(v, INT_MAX)
+
+	while not queue.is_empty():
+		var u = queue.pop()
+
+		if !cast_graph.has(u):
+			continue
+
+		for edge in cast_graph[u]:
+			var v = edge.to
+			var alt = dist[u] + 1
+			if alt < dist[v]:
+				dist[v] = alt
+				prev[v] = CastGraphEdge.new(u, edge.cast_format)
+				queue.update_priority(v, alt)
+
+
+static func can_cast(type: BlockType, parent_type: BlockType) -> bool:
+	if type == parent_type:
+		return true
+
+	if cast_graph.has(type) and cast_graph.has(parent_type):
+		dijkstra(type)
+		return dist[parent_type] < INT_MAX
+	return false
+
+
+static func cast(val: String, type: BlockType, parent_type: BlockType):
+	if type == parent_type:
+		return val
+
+	if cast_graph.has(type) and cast_graph.has(parent_type):
+		dijkstra(type)
+		if dist[parent_type] < INT_MAX:
+			var prev_edge = prev[parent_type]
+			var cast_string = "%s"
+			while prev_edge:
+				cast_string %= prev_edge.cast_format
+				if prev.has(prev_edge.to):
+					prev_edge = prev[prev_edge.to]
+				else:
+					prev_edge = null
+
+			return cast_string % val
+
+	return null
+
+
+# TODO: replace with max heap
+class PriorityQueue:
+	var data: Array = []
+
+	func _init():
+		data = []
+
+	func push(element, priority):
+		data.append([element, priority])
+		_sort()
+
+	func _sort():
+		data.sort_custom(func(a, b): a[1] < b[1])
+
+	func pop():
+		if data.size() > 0:
+			return data.pop_front()[0]
+		return null
+
+	func peek():
+		if data.size() > 0:
+			return data[0][0]
+		return null
+
+	func is_empty():
+		return data.size() == 0
+
+	func update_priority(element, priority):
+		var found_pair = null
+		for pair in data:
+			if pair[0] == element:
+				found_pair = pair
+				break
+
+		if found_pair:
+			found_pair[1] = priority
+			_sort()

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

@@ -52,7 +52,8 @@ func get_snapped_block() -> Block:
 func get_string() -> String:
 	var snapped_block: Block = get_snapped_block()
 	if snapped_block:
-		return snapped_block.get_parameter_string()
+		var generated_string = snapped_block.get_parameter_string()
+		return Types.cast(generated_string, snapped_block.block_type, block_type)
 
 	var text: String = get_plain_text()