Merge pull request #861 from dalexeev/astar-grid-2d

Rework "Grid-based Navigation with Astar" demo

2d/navigation_astar/README.md

@@ -1,11 +1,11 @@
-# Grid-based Navigation with Astar
+# Grid-based Navigation with AStarGrid2D
 
-This is an example of using AStar for navigation in 2D,
+This is an example of using AStarGrid2D for navigation in 2D,
 complete with Steering Behaviors in order to smooth the movement out.
 
 Language: GDScript
 
-Renderer: GLES 2
+Renderer: Compatibility
 
 Check out this demo on the asset library: https://godotengine.org/asset-library/asset/519
 

2d/navigation_astar/character.gd

@@ -1,61 +1,65 @@
 extends Node2D
 
-enum States { IDLE, FOLLOW }
+enum State { IDLE, FOLLOW }
 
 const MASS = 10.0
 const ARRIVE_DISTANCE = 10.0
 
 @export var speed: float = 200.0
-var _state = States.IDLE
-
-var _path = []
-var _target_point_world = Vector2()
-var _target_position = Vector2()
 
+var _state = State.IDLE
 var _velocity = Vector2()
 
+@onready var _tile_map = $"../TileMap"
+
+var _click_position = Vector2()
+var _path = PackedVector2Array()
+var _next_point = Vector2()
+
 func _ready():
-	_change_state(States.IDLE)
+	_change_state(State.IDLE)
 
 
 func _process(_delta):
-	if _state != States.FOLLOW:
+	if _state != State.FOLLOW:
 		return
-	var _arrived_to_next_point = _move_to(_target_point_world)
-	if _arrived_to_next_point:
+	var arrived_to_next_point = _move_to(_next_point)
+	if arrived_to_next_point:
 		_path.remove_at(0)
-		if len(_path) == 0:
-			_change_state(States.IDLE)
+		if _path.is_empty():
+			_change_state(State.IDLE)
 			return
-		_target_point_world = _path[0]
+		_next_point = _path[0]
 
 
 func _unhandled_input(event):
-	if event.is_action_pressed("click"):
-		var global_mouse_pos = get_global_mouse_position()
-		if Input.is_key_pressed(KEY_SHIFT) and get_parent().get_node("TileMap").check_start_position(global_mouse_pos):
-			global_position = global_mouse_pos
-		else:
-			_target_position = global_mouse_pos
-		_change_state(States.FOLLOW)
+	_click_position = get_global_mouse_position()
+	if _tile_map.is_point_walkable(_click_position):
+		if event.is_action_pressed(&"teleport_to", false, true):
+			_change_state(State.IDLE)
+			global_position = _tile_map.round_local_position(_click_position)
+		elif event.is_action_pressed(&"move_to"):
+			_change_state(State.FOLLOW)
 
 
-func _move_to(world_position):
-	var desired_velocity = (world_position - position).normalized() * speed
+func _move_to(local_position):
+	var desired_velocity = (local_position - position).normalized() * speed
 	var steering = desired_velocity - _velocity
 	_velocity += steering / MASS
 	position += _velocity * get_process_delta_time()
 	rotation = _velocity.angle()
-	return position.distance_to(world_position) < ARRIVE_DISTANCE
+	return position.distance_to(local_position) < ARRIVE_DISTANCE
 
 
 func _change_state(new_state):
-	if new_state == States.FOLLOW:
-		_path = get_parent().get_node(^"TileMap").get_astar_path(position, _target_position)
-		if _path.is_empty() or len(_path) == 1:
-			_change_state(States.IDLE)
+	if new_state == State.IDLE:
+		_tile_map.clear_path()
+	elif new_state == State.FOLLOW:
+		_path = _tile_map.find_path(position, _click_position)
+		if _path.size() < 2:
+			_change_state(State.IDLE)
 			return
 		# The index 0 is the starting cell.
 		# We don't want the character to move back to it in this example.
-		_target_point_world = _path[1]
+		_next_point = _path[1]
 	_state = new_state

2d/navigation_astar/pathfind_astar.gd

@@ -1,177 +1,83 @@
 extends TileMap
 
+enum Tile { OBSTACLE, START_POINT, END_POINT }
+
+const CELL_SIZE = Vector2(64, 64)
 const BASE_LINE_WIDTH = 3.0
 const DRAW_COLOR = Color.WHITE
 
-# The Tilemap node doesn't have clear bounds so we're defining the map's limits here.
-@export var map_size: Vector2i = Vector2.ONE * 18
-
-# The path start and end variables use setter methods, defined below the initial values.
-var path_start_position = Vector2i():
-	set(value):
-		if value in obstacles:
-			return
-		if is_outside_map_bounds(value):
-			return
-
-		set_cell(0, path_start_position, -1)
-		set_cell(0, value, 1, Vector2i())
-		path_start_position = value
-		if path_end_position and path_end_position != path_start_position:
-			_recalculate_path()
-
-var path_end_position = Vector2i():
-	set(value):
-		if value in obstacles:
-			return
-		if is_outside_map_bounds(value):
-			return
-
-		set_cell(0, path_start_position, -1)
-		set_cell(0, value, 2, Vector2i())
-		path_end_position = value
-		if path_start_position != value:
-			_recalculate_path()
-
-var _point_path = []
-
-# You can only create an AStar node from code, not from the Scene tab.
-@onready var astar_node = AStar3D.new()
-# get_used_cells_by_id is a method from the TileMap node.
-# Here the id 0 corresponds to the grey tile, the obstacles.
-@onready var obstacles = get_used_cells(0)
+# The object for pathfinding on 2D grids.
+var _astar = AStarGrid2D.new()
+var _map_rect = Rect2i()
+
+var _start_point = Vector2i()
+var _end_point = Vector2i()
+var _path = PackedVector2Array()
 
 func _ready():
-	var walkable_cells_list = astar_add_walkable_cells(obstacles)
-	astar_connect_walkable_cells(walkable_cells_list)
+	# Let's assume that the entire map is located at non-negative coordinates.
+	var map_size = get_used_rect().end
+	_map_rect = Rect2i(Vector2i(), map_size)
+
+	_astar.size = map_size
+	_astar.cell_size = CELL_SIZE
+	_astar.offset = CELL_SIZE * 0.5
+	_astar.default_compute_heuristic = AStarGrid2D.HEURISTIC_MANHATTAN
+	_astar.default_estimate_heuristic = AStarGrid2D.HEURISTIC_MANHATTAN
+	_astar.diagonal_mode = AStarGrid2D.DIAGONAL_MODE_NEVER
+	_astar.update()
+
+	for i in map_size.x:
+		for j in map_size.y:
+			var pos = Vector2i(i, j)
+			if get_cell_source_id(0, pos) == Tile.OBSTACLE:
+				_astar.set_point_solid(pos)
 
 
 func _draw():
-	if _point_path.is_empty():
+	if _path.is_empty():
 		return
-	var point_start = _point_path[0]
-	var point_end = _point_path[len(_point_path) - 1]
 
-	set_cell(0, Vector2i(point_start.x, point_start.y), 1, Vector2i())
-	set_cell(0, Vector2i(point_end.x, point_end.y), 2, Vector2i())
-
-	var last_point = map_to_local(Vector2i(point_start.x, point_start.y))
-	for index in range(1, len(_point_path)):
-		var current_point = map_to_local(Vector2i(_point_path[index].x, _point_path[index].y))
+	var last_point = _path[0]
+	for index in range(1, len(_path)):
+		var current_point = _path[index]
 		draw_line(last_point, current_point, DRAW_COLOR, BASE_LINE_WIDTH, true)
 		draw_circle(current_point, BASE_LINE_WIDTH * 2.0, DRAW_COLOR)
 		last_point = current_point
 
 
-# Loops through all cells within the map's bounds and
-# adds all points to the astar_node, except the obstacles.
-func astar_add_walkable_cells(obstacle_list = []):
-	var points_array = []
-	for y in range(map_size.y):
-		for x in range(map_size.x):
-			var point = Vector2i(x, y)
-			if point in obstacle_list:
-				continue
-
-			points_array.append(point)
-			# The AStar class references points with indices.
-			# Using a function to calculate the index from a point's coordinates
-			# ensures we always get the same index with the same input point.
-			var point_index = calculate_point_index(point)
-			# AStar works for both 2d and 3d, so we have to convert the point
-			# coordinates from and to Vector3s.
-			astar_node.add_point(point_index, Vector3(point.x, point.y, 0.0))
-	return points_array
-
-
-# Once you added all points to the AStar node, you've got to connect them.
-# The points don't have to be on a grid: you can use this class
-# to create walkable graphs however you'd like.
-# It's a little harder to code at first, but works for 2d, 3d,
-# orthogonal grids, hex grids, tower defense games...
-func astar_connect_walkable_cells(points_array):
-	for point in points_array:
-		var point_index = calculate_point_index(point)
-		# For every cell in the map, we check the one to the top, right.
-		# left and bottom of it. If it's in the map and not an obstalce.
-		# We connect the current point with it.
-		var points_relative = PackedVector2Array([
-			point + Vector2i.RIGHT,
-			point + Vector2i.LEFT,
-			point + Vector2i.DOWN,
-			point + Vector2i.UP,
-		])
-		for point_relative in points_relative:
-			var point_relative_index = calculate_point_index(point_relative)
-			if is_outside_map_bounds(point_relative):
-				continue
-			if not astar_node.has_point(point_relative_index):
-				continue
-			# Note the 3rd argument. It tells the astar_node that we want the
-			# connection to be bilateral: from point A to B and B to A.
-			# If you set this value to false, it becomes a one-way path.
-			# As we loop through all points we can set it to false.
-			astar_node.connect_points(point_index, point_relative_index, false)
-
-
-# This is a variation of the method above.
-# It connects cells horizontally, vertically AND diagonally.
-func astar_connect_walkable_cells_diagonal(points_array):
-	for point in points_array:
-		var point_index = calculate_point_index(point)
-		for local_y in range(3):
-			for local_x in range(3):
-				var point_relative = Vector2i(point.x + local_x - 1, point.y + local_y - 1)
-				var point_relative_index = calculate_point_index(point_relative)
-				if point_relative == point or is_outside_map_bounds(point_relative):
-					continue
-				if not astar_node.has_point(point_relative_index):
-					continue
-				astar_node.connect_points(point_index, point_relative_index, true)
-
-
-func calculate_point_index(point):
-	return point.x + map_size.x * point.y
-
-
-func clear_previous_path_drawing():
-	if _point_path.is_empty():
-		return
-	var point_start = _point_path[0]
-	var point_end = _point_path[len(_point_path) - 1]
-	set_cell(0, Vector2i(point_start.x, point_start.y), -1)
-	set_cell(0, Vector2i(point_end.x, point_end.y), -1)
+func round_local_position(local_position):
+	return map_to_local(local_to_map(local_position))
 
 
-func is_outside_map_bounds(point):
-	return point.x < 0 or point.y < 0 or point.x >= map_size.x or point.y >= map_size.y
+func is_point_walkable(local_position):
+	var map_position = local_to_map(local_position)
+	if _map_rect.has_point(map_position):
+		return not _astar.is_point_solid(map_position)
+	return false
 
 
-func check_start_position(world_start):
-	var start_point = local_to_map(world_start)
-	if start_point in obstacles:
-		return false
+func clear_path():
+	if not _path.is_empty():
+		_path.clear()
+		erase_cell(0, _start_point)
+		erase_cell(0, _end_point)
+		# Queue redraw to clear the lines and circles.
+		queue_redraw()
 
-	return true
 
+func find_path(local_start_point, local_end_point):
+	clear_path()
 
-func get_astar_path(world_start, world_end):
-	self.path_start_position = local_to_map(world_start)
-	self.path_end_position = local_to_map(world_end)
-	_recalculate_path()
-	var path_world = []
-	for point in _point_path:
-		var point_world = map_to_local(Vector2i(point.x, point.y))
-		path_world.append(point_world)
-	return path_world
+	_start_point = local_to_map(local_start_point)
+	_end_point = local_to_map(local_end_point)
+	_path = _astar.get_point_path(_start_point, _end_point)
 
+	if not _path.is_empty():
+		set_cell(0, _start_point, Tile.START_POINT, Vector2i())
+		set_cell(0, _end_point, Tile.END_POINT, Vector2i())
 
-func _recalculate_path():
-	clear_previous_path_drawing()
-	var start_point_index = calculate_point_index(path_start_position)
-	var end_point_index = calculate_point_index(path_end_position)
-	# This method gives us an array of points. Note you need the start and
-	# end points' indices as input.
-	_point_path = astar_node.get_point_path(start_point_index, end_point_index)
 	# Redraw the lines and circles from the start to the end point.
 	queue_redraw()
+
+	return _path.duplicate()

2d/navigation_astar/project.godot

@@ -10,10 +10,10 @@ config_version=5
 
 [application]
 
-config/name="Grid-based Pathfinding with Astar"
-config/description="This is an example of using AStar for navigation in 2D,
+config/name="Grid-based Pathfinding with AStarGrid2D"
+config/description="This is an example of using AStarGrid2D for navigation in 2D,
 complete with Steering Behaviors in order to smooth the movement out."
-run/main_scene="res://Game.tscn"
+run/main_scene="res://game.tscn"
 config/features=PackedStringArray("4.0")
 config/icon="res://icon.png"
 
@@ -24,14 +24,17 @@ window/stretch/aspect="expand"
 
 [input]
 
-click={
+move_to={
 "deadzone": 0.5,
-"events": [Object(InputEventMouseButton,"resource_local_to_scene":false,"resource_name":"","device":0,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"button_mask":0,"position":Vector2(0, 0),"global_position":Vector2(0, 0),"factor":1.0,"button_index":1,"pressed":false,"double_click":false,"script":null)
+"events": [Object(InputEventMouseButton,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"button_mask":1,"position":Vector2(0, 0),"global_position":Vector2(0, 0),"factor":1.0,"button_index":1,"pressed":true,"double_click":false,"script":null)
+]
+}
+teleport_to={
+"deadzone": 0.5,
+"events": [Object(InputEventMouseButton,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":true,"ctrl_pressed":false,"meta_pressed":false,"button_mask":1,"position":Vector2(0, 0),"global_position":Vector2(0, 0),"factor":1.0,"button_index":1,"pressed":true,"double_click":false,"script":null)
 ]
 }
 
 [rendering]
 
-quality/driver/driver_name="GLES2"
-vram_compression/import_etc=true
-vram_compression/import_etc2=false
+renderer/rendering_method="gl_compatibility"

2d/navigation_astar/tileset/tileset_source.tscn

@@ -1,19 +0,0 @@
-[gd_scene load_steps=4 format=2]
-
-[ext_resource path="res://sprites/obstacle.png" type="Texture2D" id=1]
-[ext_resource path="res://sprites/path_start.png" type="Texture2D" id=2]
-[ext_resource path="res://sprites/path_end.png" type="Texture2D" id=3]
-
-[node name="Tileset" type="Node2D"]
-
-[node name="Obstacle" type="Sprite2D" parent="."]
-position = Vector2(32, 32)
-texture = ExtResource( 1 )
-
-[node name="PathStart" type="Sprite2D" parent="."]
-position = Vector2(112, 32)
-texture = ExtResource( 2 )
-
-[node name="PathEnd" type="Sprite2D" parent="."]
-position = Vector2(192, 32)
-texture = ExtResource( 3 )