Initial commit.

.gitignore

@@ -0,0 +1,5 @@
+*.obj
+*.exp
+*.lib
+.sconsign.dblite
+*.dll

.gitmodules

@@ -0,0 +1,4 @@
+[submodule "godot-cpp"]
+	path = godot-cpp
+	url = https://github.com/godotengine/godot-cpp
+	branch = 4.2

SConstruct

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+import os
+import sys
+
+env = SConscript("godot-cpp/SConstruct")
+
+# For reference:
+# - CCFLAGS are compilation flags shared between C and C++
+# - CFLAGS are for C-specific compilation flags
+# - CXXFLAGS are for C++-specific compilation flags
+# - CPPFLAGS are for pre-processor flags
+# - CPPDEFINES are for pre-processor defines
+# - LINKFLAGS are for linking flags
+
+# tweak this if you want to use different folders, or more folders, to store your source code in.
+env.Append(CPPPATH=["src/"])
+sources = Glob("src/*.cpp")
+
+if env["platform"] == "macos":
+    library = env.SharedLibrary(
+        "demo/bin/libMultilevelAStarExt.{}.{}.framework/libMultilevelAStarExt.{}.{}".format(
+            env["platform"], env["target"], env["platform"], env["target"]
+        ),
+        source=sources,
+    )
+else:
+    library = env.SharedLibrary(
+        "demo/bin/libMultilevelAStarExt{}{}".format(env["suffix"], env["SHLIBSUFFIX"]),
+        source=sources,
+    )
+
+Default(library)

build.cmd

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+scons platform=windows 

demo/.gitattributes

@@ -0,0 +1,2 @@
+# Normalize EOL for all files that Git considers text files.
+* text=auto eol=lf

demo/.gitignore

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+# Godot 4+ specific ignores
+.godot/
+
+# Misc
+*.tmp

demo/bin/MultilevelAStarExt.gdextension

@@ -0,0 +1,13 @@
+[configuration]
+
+entry_symbol = "my_astar_ext_init"
+compatibility_minimum = "4.2"
+
+[libraries]
+
+macos.debug = "res://bin/libMultilevelAStarExt.macos.template_debug.framework"
+macos.release = "res://bin/libMultilevelAStarExt.macos.template_release.framework"
+windows.debug.x86_64 = "res://bin/libMultilevelAStarExt.windows.template_debug.x86_64.dll"
+windows.release.x86_64 = "res://bin/libMultilevelAStarExt.windows.template_release.x86_64.dll"
+linux.debug.x86_64 = "res://bin/libMultilevelAStarExt.linux.template_debug.x86_64.so"
+linux.release.x86_64 = "res://bin/libMultilevelAStarExt.linux.template_release.x86_64.so"

demo/bin/multilevel_astar.gd

@@ -0,0 +1,63 @@
+extends RefCounted
+class_name MultilevelAStar
+
+# tile custom data "type":
+#  0     => blocked
+#  1(+)  => can move to same number
+# -1(-)  => can move to same, one larger or one smaller as long as they're both negative
+#        => can move to and from its absolute value and one larger than its absolute value
+
+# private variables start with an _ as per the GDScript style guide
+var _used_rect: Rect2i
+var _astar: MultilevelAStarEx
+
+
+func _init(map: TileMap):
+	_used_rect = map.get_used_rect()
+	
+	# assert stuff here because the extension's assertions just crash without a message
+	assert(_used_rect.get_area() > 0)
+	
+	_astar = MultilevelAStarEx.new()
+	_astar.init(_used_rect)
+	
+	for layer in map.get_layers_count():
+		var cells := map.get_used_cells(layer)
+		for cell in cells:
+			var tile_data := map.get_cell_tile_data(layer, cell)
+			if tile_data != null:
+				var type = tile_data.get_custom_data("type")
+				assert(type is int)
+				_astar.set_terrain(cell, type)
+
+
+func is_unit(point: Vector2i) -> bool:
+	assert(_used_rect.has_point(point))
+	return _astar.get_unit(point)
+
+
+func set_unit(point: Vector2i, solid: bool = true) -> void:
+	assert(_used_rect.has_point(point))
+	_astar.set_unit(point, solid)
+
+
+func get_terrain(point: Vector2i) -> MultilevelAStarEx.TerrainType:
+	assert(_used_rect.has_point(point))
+	return _astar.get_terrain(point)
+
+
+func set_terrain(point: Vector2i, type: MultilevelAStarEx.TerrainType) -> void:
+	assert(_used_rect.has_point(point))
+	_astar.set_terrain(point, type)
+
+
+func find_path(from: Vector2i, to: Vector2i, return_closest: bool = false) -> Array[Vector2i]:
+	assert(_used_rect.has_point(from))
+	assert(_used_rect.has_point(to))
+	
+	var res = _astar.find_path(from, to, return_closest) # vrne Variant: null ali Array[Vector2i]
+	
+	if res != null:
+		return res
+	else:
+		return []

demo/icon.svg

@@ -0,0 +1 @@
+<svg height="128" width="128" xmlns="http://www.w3.org/2000/svg"><rect x="2" y="2" width="124" height="124" rx="14" fill="#363d52" stroke="#212532" stroke-width="4"/><g transform="scale(.101) translate(122 122)"><g fill="#fff"><path d="M105 673v33q407 354 814 0v-33z"/><path d="m105 673 152 14q12 1 15 14l4 67 132 10 8-61q2-11 15-15h162q13 4 15 15l8 61 132-10 4-67q3-13 15-14l152-14V427q30-39 56-81-35-59-83-108-43 20-82 47-40-37-88-64 7-51 8-102-59-28-123-42-26 43-46 89-49-7-98 0-20-46-46-89-64 14-123 42 1 51 8 102-48 27-88 64-39-27-82-47-48 49-83 108 26 42 56 81zm0 33v39c0 276 813 276 814 0v-39l-134 12-5 69q-2 10-14 13l-162 11q-12 0-16-11l-10-65H446l-10 65q-4 11-16 11l-162-11q-12-3-14-13l-5-69z" fill="#478cbf"/><path d="M483 600c0 34 58 34 58 0v-86c0-34-58-34-58 0z"/><circle cx="725" cy="526" r="90"/><circle cx="299" cy="526" r="90"/></g><g fill="#414042"><circle cx="307" cy="532" r="60"/><circle cx="717" cy="532" r="60"/></g></g></svg>

demo/icon.svg.import

@@ -0,0 +1,37 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://cpupav84hxj1u"
+path="res://.godot/imported/icon.svg-218a8f2b3041327d8a5756f3a245f83b.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://icon.svg"
+dest_files=["res://.godot/imported/icon.svg-218a8f2b3041327d8a5756f3a245f83b.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
+svg/scale=1.0
+editor/scale_with_editor_scale=false
+editor/convert_colors_with_editor_theme=false

demo/main.gd

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+extends Node2D
+
+
+const CELL_SIZE: int = 32
+
+@onready var map: TileMap = $TileMap
+@onready var marker_from: Node2D = $MarkerFrom
+@onready var marker_to: Node2D = $MarkerTo
+@onready var path_line: Line2D = $PathLine
+@onready var check_box: CheckBox = $CheckBox
+
+var astar: MultilevelAStar
+var used_rect: Rect2i
+
+
+# Called when the node enters the scene tree for the first time.
+func _ready() -> void:
+	# mapa začne na -1, -1. tukaj premaknem da se vidi vse na mapi
+	# (saj verjetno obstaja boljši način ma ga ne poznam - mogoče kakšna kamera)
+	position = Vector2i.ONE * CELL_SIZE
+	
+	used_rect = map.get_used_rect()
+	print(used_rect)
+	
+	astar = MultilevelAStar.new(map)
+	
+	mark_units()
+	
+	marker_from.modulate = Color.html("#ff0000ff")
+	marker_to.modulate = Color.html("#00ff00ff")
+	
+	marker_from.position = Vector2i(-1, -1) * CELL_SIZE
+	marker_to.position = (used_rect.position + used_rect.size - Vector2i.ONE) * CELL_SIZE
+	
+	find_path()
+
+
+func mark_units() -> void:
+	for unit in $Units.get_tree().get_nodes_in_group("unit"):
+		astar.set_unit(unit.position / CELL_SIZE)
+
+
+func _unhandled_input(event: InputEvent) -> void:
+	if event is InputEventMouseButton:
+		if event.pressed:
+			var cell := map.local_to_map(map.get_local_mouse_position())
+			if map.get_used_rect().has_point(cell):
+				if event.button_index == 1:
+					marker_to.position = Vector2(cell.x * CELL_SIZE, cell.y * CELL_SIZE)
+					find_path();
+				elif event.button_index == 2:
+					marker_from.position = Vector2(cell.x * CELL_SIZE, cell.y * CELL_SIZE)
+					find_path();
+
+
+func find_path() -> void:
+	path_line.clear_points()
+	
+	var from: Vector2i = Vector2i(marker_from.position / CELL_SIZE)
+	var to: Vector2i = Vector2i(marker_to.position / CELL_SIZE)
+	
+	var arr = astar.find_path(from, to, check_box.button_pressed) # vrne Variant: null ali Array
+	#print(arr)
+	
+	if arr.size() > 0:
+		# add new path
+		path_line.add_point(from * CELL_SIZE + Vector2i(16, 16))
+		for vec in arr:
+			#print("%s, %s" % [vec.x, vec.y])
+			path_line.add_point(vec * CELL_SIZE + Vector2i(16, 16))
+
+
+func _on_check_box_pressed() -> void:
+	find_path()

demo/markers/marker.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://ydnd8d7pbpct"
+path="res://.godot/imported/marker.png-302bb6fffff2bb75ddac5872ea46d55a.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://markers/marker.png"
+dest_files=["res://.godot/imported/marker.png-302bb6fffff2bb75ddac5872ea46d55a.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1

demo/markers/marker.tscn

@@ -0,0 +1,9 @@
+[gd_scene load_steps=2 format=3 uid="uid://cnrhrho63n4n2"]
+
+[ext_resource type="Texture2D" uid="uid://ydnd8d7pbpct" path="res://markers/marker.png" id="1_mefdn"]
+
+[node name="Marker" type="Node2D"]
+
+[node name="Sprite2D" type="Sprite2D" parent="."]
+texture = ExtResource("1_mefdn")
+offset = Vector2(16, 16)

demo/markers/unit.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://b6j8es5qgtv05"
+path="res://.godot/imported/unit.png-1fe68df64273b07deeeaa2e1953638b5.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://markers/unit.png"
+dest_files=["res://.godot/imported/unit.png-1fe68df64273b07deeeaa2e1953638b5.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1

demo/markers/unit.tscn

@@ -0,0 +1,9 @@
+[gd_scene load_steps=2 format=3 uid="uid://cj34xrleexqf6"]
+
+[ext_resource type="Texture2D" uid="uid://b6j8es5qgtv05" path="res://markers/unit.png" id="1_qutcq"]
+
+[node name="Unit" type="Node2D" groups=["unit"]]
+
+[node name="Sprite2D" type="Sprite2D" parent="."]
+position = Vector2(16, 16)
+texture = ExtResource("1_qutcq")

demo/project.godot

@@ -0,0 +1,20 @@
+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; since the parameters that go here are not all obvious.
+;
+; Format:
+;   [section] ; section goes between []
+;   param=value ; assign values to parameters
+
+config_version=5
+
+[application]
+
+config/name="MultilevelAStarTest"
+run/main_scene="res://main.tscn"
+config/features=PackedStringArray("4.2", "Forward Plus")
+config/icon="res://icon.svg"
+
+[display]
+
+window/stretch/mode="canvas_items"

demo/tiles/socerb.png.import

@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://dh20x6lnm6ly8"
+path="res://.godot/imported/socerb.png-80780b522a349cb35f220b47d0cdac2c.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://tiles/socerb.png"
+dest_files=["res://.godot/imported/socerb.png-80780b522a349cb35f220b47d0cdac2c.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1

demo/tiles/socerb.tres

@@ -0,0 +1,204 @@
+[gd_resource type="TileSet" load_steps=3 format=3 uid="uid://dsc2e3ohtmv01"]
+
+[ext_resource type="Texture2D" uid="uid://dh20x6lnm6ly8" path="res://tiles/socerb.png" id="1_e53on"]
+
+[sub_resource type="TileSetAtlasSource" id="TileSetAtlasSource_dokfe"]
+texture = ExtResource("1_e53on")
+texture_region_size = Vector2i(32, 32)
+0:0/0 = 0
+0:0/0/custom_data_0 = 1
+1:0/0 = 0
+1:0/0/custom_data_0 = -1
+2:0/0 = 0
+2:0/0/custom_data_0 = -1
+3:0/0 = 0
+3:0/0/custom_data_0 = -1
+4:0/0 = 0
+4:0/0/custom_data_0 = -2
+8:0/0 = 0
+9:0/0 = 0
+10:0/0 = 0
+11:0/0 = 0
+12:0/0 = 0
+13:0/0 = 0
+0:1/0 = 0
+0:1/0/custom_data_0 = 1
+1:1/0 = 0
+1:1/0/custom_data_0 = 1
+2:1/0 = 0
+3:1/0 = 0
+4:1/0 = 0
+5:1/0 = 0
+6:1/0 = 0
+7:1/0 = 0
+8:1/0 = 0
+9:1/0 = 0
+9:1/0/custom_data_0 = 3
+10:1/0 = 0
+10:1/0/custom_data_0 = 3
+11:1/0 = 0
+11:1/0/custom_data_0 = 3
+12:1/0 = 0
+12:1/0/custom_data_0 = 3
+13:1/0 = 0
+14:1/0 = 0
+0:2/0 = 0
+0:2/0/custom_data_0 = 1
+1:2/0 = 0
+1:2/0/custom_data_0 = 1
+2:2/0 = 0
+3:2/0 = 0
+4:2/0 = 0
+5:2/0 = 0
+6:2/0 = 0
+7:2/0 = 0
+8:2/0 = 0
+8:2/0/custom_data_0 = 3
+9:2/0 = 0
+9:2/0/custom_data_0 = 3
+10:2/0 = 0
+10:2/0/custom_data_0 = 3
+11:2/0 = 0
+11:2/0/custom_data_0 = 3
+12:2/0 = 0
+12:2/0/custom_data_0 = 3
+13:2/0 = 0
+13:2/0/custom_data_0 = 3
+14:2/0 = 0
+0:3/0 = 0
+0:3/0/custom_data_0 = 1
+1:3/0 = 0
+1:3/0/custom_data_0 = 1
+2:3/0 = 0
+3:3/0 = 0
+3:3/0/custom_data_0 = 1
+4:3/0 = 0
+4:3/0/custom_data_0 = 1
+5:3/0 = 0
+5:3/0/custom_data_0 = 1
+6:3/0 = 0
+7:3/0 = 0
+8:3/0 = 0
+8:3/0/custom_data_0 = 3
+9:3/0 = 0
+9:3/0/custom_data_0 = 3
+10:3/0 = 0
+10:3/0/custom_data_0 = 3
+11:3/0 = 0
+11:3/0/custom_data_0 = 3
+12:3/0 = 0
+12:3/0/custom_data_0 = 3
+13:3/0 = 0
+13:3/0/custom_data_0 = 3
+14:3/0 = 0
+1:4/0 = 0
+2:4/0 = 0
+3:4/0 = 0
+4:4/0 = 0
+5:4/0 = 0
+5:4/0/custom_data_0 = 1
+6:4/0 = 0
+7:4/0 = 0
+8:4/0 = 0
+8:4/0/custom_data_0 = 3
+9:4/0 = 0
+9:4/0/custom_data_0 = 3
+10:4/0 = 0
+10:4/0/custom_data_0 = 3
+11:4/0 = 0
+11:4/0/custom_data_0 = 3
+12:4/0 = 0
+12:4/0/custom_data_0 = 3
+13:4/0 = 0
+13:4/0/custom_data_0 = 3
+14:4/0 = 0
+2:5/0 = 0
+3:5/0 = 0
+4:5/0 = 0
+5:5/0 = 0
+6:5/0 = 0
+7:5/0 = 0
+8:5/0 = 0
+8:5/0/custom_data_0 = 3
+9:5/0 = 0
+9:5/0/custom_data_0 = 3
+10:5/0 = 0
+10:5/0/custom_data_0 = 3
+11:5/0 = 0
+11:5/0/custom_data_0 = 3
+12:5/0 = 0
+12:5/0/custom_data_0 = 3
+13:5/0 = 0
+13:5/0/custom_data_0 = 3
+14:5/0 = 0
+2:6/0 = 0
+3:6/0 = 0
+4:6/0 = 0
+5:6/0 = 0
+6:6/0 = 0
+7:6/0 = 0
+8:6/0 = 0
+9:6/0 = 0
+9:6/0/custom_data_0 = 3
+10:6/0 = 0
+10:6/0/custom_data_0 = 3
+11:6/0 = 0
+11:6/0/custom_data_0 = 3
+12:6/0 = 0
+12:6/0/custom_data_0 = 3
+13:6/0 = 0
+14:6/0 = 0
+2:7/0 = 0
+3:7/0 = 0
+3:7/0/custom_data_0 = 2
+4:7/0 = 0
+4:7/0/custom_data_0 = 2
+5:7/0 = 0
+5:7/0/custom_data_0 = 2
+6:7/0 = 0
+8:7/0 = 0
+9:7/0 = 0
+10:7/0 = 0
+11:7/0 = 0
+12:7/0 = 0
+13:7/0 = 0
+2:8/0 = 0
+3:8/0 = 0
+3:8/0/custom_data_0 = 2
+4:8/0 = 0
+4:8/0/custom_data_0 = 2
+5:8/0 = 0
+5:8/0/custom_data_0 = 2
+6:8/0 = 0
+2:9/0 = 0
+3:9/0 = 0
+3:9/0/custom_data_0 = 2
+4:9/0 = 0
+4:9/0/custom_data_0 = 2
+5:9/0 = 0
+5:9/0/custom_data_0 = 2
+6:9/0 = 0
+2:10/0 = 0
+3:10/0 = 0
+4:10/0 = 0
+5:10/0 = 0
+6:10/0 = 0
+0:11/0 = 0
+0:12/0 = 0
+1:12/0 = 0
+2:12/0 = 0
+0:13/0 = 0
+1:13/0 = 0
+2:13/0 = 0
+0:14/0 = 0
+1:14/0 = 0
+2:14/0 = 0
+0:15/0 = 0
+1:15/0 = 0
+2:15/0 = 0
+
+[resource]
+tile_size = Vector2i(32, 32)
+custom_data_layer_0/name = "type"
+custom_data_layer_0/type = 2
+sources/0 = SubResource("TileSetAtlasSource_dokfe")

src/MultilevelAStarEx.cpp

@@ -0,0 +1,346 @@
+#include "MultilevelAStarEx.h"
+
+#include <godot_cpp/core/class_db.hpp>
+#include <godot_cpp/core/error_macros.hpp>
+#include <godot_cpp/variant/utility_functions.hpp>
+
+#include <cstdlib>
+#include <algorithm>
+#include <cassert>
+
+#define TERRAIN(x, y) (_terrain[(x) + (y) * _width])
+#define UNITS(x, y) (_units[(x) + (y) * _width])
+#define NODES(x, y) (_nodes[(x) + (y) * _width])
+
+using namespace godot;
+
+Node::Node() { }
+
+Node::Node(int x, int y)
+{
+	this->x = x;
+	this->y = y;
+	this->state = UNUSED;
+}
+
+void Node::init(Node* parent, int distanceFromStart, const Vector2i &end)
+{
+	this->state = OPEN;
+	this->parent = parent;
+	this->distanceFromStart = distanceFromStart;
+
+	int dx = abs(x - end.x);
+	int dy = abs(y - end.y);
+	this->distanceToEnd = (dx + dy) * 10;
+
+	if ((dx == 0 || dx == 1) && (dy == 0 || dy == 1))
+	{
+		this->distanceToEndForClosest = 10;
+	}
+	else
+	{
+		this->distanceToEndForClosest = this->distanceToEnd;
+	}
+}
+
+int Node::total_cost() const
+{
+	return distanceFromStart + distanceToEnd;
+}
+
+void MultilevelAStarEx::_bind_methods()
+{
+	ClassDB::bind_method(D_METHOD("init", "region"), &MultilevelAStarEx::init);
+	ClassDB::bind_method(D_METHOD("get_region"), &MultilevelAStarEx::get_region);
+	ClassDB::bind_method(D_METHOD("set_terrain", "cell", "type"), &MultilevelAStarEx::set_terrain);
+	ClassDB::bind_method(D_METHOD("get_terrain", "cell"), &MultilevelAStarEx::get_terrain);
+	ClassDB::bind_method(D_METHOD("set_unit", "cell", "blocked"), &MultilevelAStarEx::set_unit);
+	ClassDB::bind_method(D_METHOD("get_unit", "cell"), &MultilevelAStarEx::get_unit);
+	ClassDB::bind_method(D_METHOD("find_path", "from", "to", "return_closest"), &MultilevelAStarEx::find_path);
+
+	BIND_ENUM_CONSTANT(STAIRS);
+	BIND_ENUM_CONSTANT(BLOCKED);
+	BIND_ENUM_CONSTANT(GROUND);
+}
+
+MultilevelAStarEx::MultilevelAStarEx()
+{
+	//UtilityFunctions::print("Constructor.");
+
+	_init = false;
+}
+
+MultilevelAStarEx::~MultilevelAStarEx()
+{
+	//UtilityFunctions::print("Destructor.");
+}
+
+void MultilevelAStarEx::init(const Rect2i &region)
+{
+	DEV_ASSERT(!_init);
+
+	DEV_ASSERT(region.get_area() > 0);
+
+	_region = region;
+	_width = region.get_size().width;
+	_height = region.get_size().height;
+	_trans = region.get_position();
+
+	_terrain.resize(_width * _height, BLOCKED);
+	_units.resize(_width * _height, false);
+	_nodes.resize(_width * _height);
+
+	std::vector<Node>::iterator iter = _nodes.begin();
+	for (int y = 0; y < _height; y++)
+	{
+		for (int x = 0; x < _width; x++)
+		{
+			*iter++ = Node(x, y);
+		}
+	}
+
+	_init = true;
+}
+
+Rect2i MultilevelAStarEx::get_region() const
+{
+	DEV_ASSERT(_init);
+
+	return _region;
+}
+
+void MultilevelAStarEx::set_terrain(const Vector2i &cell, TerrainType type)
+{
+	DEV_ASSERT(_init);
+	DEV_ASSERT(_region.has_point(cell));
+
+	Vector2i cell2 = cell - _trans;
+	TERRAIN(cell2.x, cell2.y) = type;
+}
+
+MultilevelAStarEx::TerrainType MultilevelAStarEx::get_terrain(const Vector2i &cell) const
+{
+	DEV_ASSERT(_init);
+	DEV_ASSERT(_region.has_point(cell));
+
+	Vector2i cell2 = cell - _trans;
+	return TERRAIN(cell2.x, cell2.y);
+}
+
+void MultilevelAStarEx::set_unit(const Vector2i &cell, bool blocked)
+{
+	DEV_ASSERT(_init);
+	DEV_ASSERT(_region.has_point(cell));
+
+	Vector2i cell2 = cell - _trans;
+	UNITS(cell2.x, cell2.y) = blocked;
+}
+
+bool MultilevelAStarEx::get_unit(const Vector2i &cell) const
+{
+	DEV_ASSERT(_init);
+	DEV_ASSERT(_region.has_point(cell));
+
+	Vector2i cell2 = cell - _trans;
+	return UNITS(cell2.x, cell2.y);
+}
+
+bool MultilevelAStarEx::can_move(const Node* current, int x, int y) const
+{
+	if (UNITS(x, y)) return false;
+
+	TerrainType tc = TERRAIN(current->x, current->y);
+	TerrainType td = TERRAIN(x, y);
+
+	if (td == BLOCKED)
+	{
+		return false;
+	}
+	else if (td == tc)
+	{
+		return true;
+	}
+	else if (td < 0 && tc > 0) // td is stairs
+	{
+		if (-td == tc || -td == tc - 1) return true;
+	}
+	else if (td > 0 && tc < 0) // tc is stairs
+	{
+		if (-tc == td || -tc == td - 1) return true;
+	}
+	else if (td < 0 && tc < 0) // both are stairs
+	{
+		return abs(td - tc) < 2;
+	}
+
+	return false;
+}
+
+TypedArray<Vector2i> MultilevelAStarEx::generate_path(const Node* current) const
+{
+	TypedArray<Vector2i> arr;
+
+	while (current->parent != nullptr)
+	{
+		arr.insert(0, Vector2i(current->x, current->y) + _trans);
+		current = current->parent;
+	}
+
+	return arr;
+}
+
+Variant MultilevelAStarEx::find_path(const Vector2i &from, const Vector2i &to, const bool return_closest)
+{
+	DEV_ASSERT(_init);
+
+	DEV_ASSERT(_region.has_point(from));
+	DEV_ASSERT(_region.has_point(to));
+
+	Vector2i from2 = from - _trans;
+	Vector2i to2 = to - _trans;
+
+	Variant result;
+
+	std::vector<Node*> open;
+	std::vector<Node*> closed;
+
+	open.reserve(_width * _height);
+	closed.reserve(_width * _height);
+
+	Node* closest = &NODES(from2.x, from2.y);
+	closest->init(nullptr, 0, to2);
+	open.push_back(closest);
+
+	auto process = [this, &open, &closed, &to2, &closest](Node* current, int x, int y, int distance) {
+		Node* node = &NODES(x, y);
+		if (node->state == Node::UNUSED)
+		{
+			node->init(current, current->distanceFromStart + distance, to2);
+			open.push_back(node);
+		}
+		else if (node->state == Node::OPEN)
+		{
+			if (current->distanceFromStart < node->parent->distanceFromStart)
+			{
+				node->parent = current;
+				node->distanceFromStart = current->distanceFromStart + distance;
+			}
+		}
+
+		// find the closest cell
+		if (node->distanceToEndForClosest < closest->distanceToEndForClosest)
+		{
+			closest = node;
+		}
+		else if (node->distanceToEndForClosest == closest->distanceToEndForClosest)
+		{
+			if (node->distanceFromStart < closest->distanceFromStart)
+			{
+				closest = node;
+			}
+		}
+	};
+
+	while (open.size() > 0)
+	{
+		// find closest to destination
+		Node* current = open[0];
+		for (Node* n : open)
+		{
+			if (n->total_cost() < current->total_cost())
+			{
+				current = n;
+			}
+		}
+
+		if (current->distanceToEnd == 0)
+		{
+			// found the path
+			result = Variant(generate_path(current));
+			goto cleanup;
+		}
+
+		// close it
+		current->state = Node::CLOSED;
+		open.erase(std::remove(open.begin(), open.end(), current), open.end());
+		closed.push_back(current);
+
+		// expand it
+		if (current->x - 1 >= 0) // left
+		{
+			if (can_move(current, current->x - 1, current->y))
+			{
+				process(current, current->x - 1, current->y, 10);
+			}
+		}
+		if (current->x + 1 < _width) // right
+		{
+			if (can_move(current, current->x + 1, current->y))
+			{
+				process(current, current->x + 1, current->y, 10);
+			}
+		}
+		if (current->y - 1 >= 0) // up
+		{
+			if (can_move(current, current->x, current->y - 1))
+			{
+				process(current, current->x, current->y - 1, 10);
+			}
+		}
+		if (current->y + 1 < _height) // down
+		{
+			if (can_move(current, current->x, current->y + 1))
+			{
+				process(current, current->x, current->y + 1, 10);
+			}
+		}
+		if ((current->x - 1 >= 0) && (current->y - 1 >= 0)) // top left
+		{
+			if (can_move(current, current->x - 1, current->y - 1))
+			{
+				process(current, current->x - 1, current->y - 1, 14);
+			}
+		}
+		if ((current->x + 1 < _width) && (current->y - 1 >= 0)) // top right
+		{
+			if (can_move(current, current->x + 1, current->y - 1))
+			{
+				process(current, current->x + 1, current->y - 1, 14);
+			}
+		}
+		if ((current->x - 1 >= 0) && (current->y + 1 < _height)) // bottom left
+		{
+			if (can_move(current, current->x - 1, current->y + 1))
+			{
+				process(current, current->x - 1, current->y + 1, 14);
+			}
+		}
+		if ((current->x + 1 < _width) && (current->y + 1 < _height)) // bottom right
+		{
+			if (can_move(current, current->x + 1, current->y + 1))
+			{
+				process(current, current->x + 1, current->y + 1, 14);
+			}
+		}
+	}
+
+	// this is skipped if a path was found
+	if (return_closest)
+	{
+		// return path to closest
+		result = Variant(generate_path(closest));
+	}
+
+cleanup:
+	// release the nodes
+	for (Node* node : open)
+	{
+		node->state = Node::UNUSED;
+	}
+	for (Node* node : closed)
+	{
+		node->state = Node::UNUSED;
+	}
+
+	return result;
+}

src/MultilevelAStarEx.h

@@ -0,0 +1,85 @@
+#ifndef MultilevelAStarEx_H
+#define MultilevelAStarEx_H
+
+#include <gdextension_interface.h>
+#include <godot_cpp/classes/ref.hpp>
+#include <godot_cpp/variant/array.hpp>
+#include <godot_cpp/variant/vector2i.hpp>
+
+#include <vector>
+
+namespace godot {
+
+class Node {
+	friend class MultilevelAStarEx;
+
+public:
+	enum NodeState
+	{
+		UNUSED, OPEN, CLOSED
+	};
+
+private:
+	NodeState state;
+	int x, y;
+
+	Node* parent;
+	int distanceFromStart;
+	int distanceToEnd;
+
+	int distanceToEndForClosest;
+
+	Node(int x, int y);
+	void init(Node* parent, int distanceFromStart, const Vector2i &end);
+	int total_cost() const;
+
+public:
+	Node();
+};
+
+class MultilevelAStarEx : public RefCounted
+{
+	GDCLASS(MultilevelAStarEx, RefCounted)
+
+public:
+	enum TerrainType
+	{
+		STAIRS = -1,
+		BLOCKED = 0,
+		GROUND = 1,
+	};
+
+private:
+	bool _init;
+	std::vector<TerrainType> _terrain;
+	std::vector<bool> _units;
+	std::vector<Node> _nodes;
+
+	Rect2i _region;
+	Vector2i _trans;
+	int _width, _height;
+
+	bool can_move(const Node* current, int x, int y) const;
+	TypedArray<Vector2i> generate_path(const Node* current) const;
+
+protected:
+	static void _bind_methods();
+
+public:
+	MultilevelAStarEx();
+	~MultilevelAStarEx();
+
+	void init(const Rect2i &region);
+	Rect2i get_region() const;
+	void set_terrain(const Vector2i &cell, TerrainType type);
+	TerrainType get_terrain(const Vector2i &cell) const;
+	void set_unit(const Vector2i &cell, bool blocked);
+	bool get_unit(const Vector2i &cell) const;
+	Variant find_path(const Vector2i &from, const Vector2i &to, const bool return_closest);
+};
+
+}
+
+VARIANT_ENUM_CAST(MultilevelAStarEx::TerrainType);
+
+#endif

src/main.cpp

@@ -0,0 +1,36 @@
+#include "MultilevelAStarEx.h"
+
+#include <gdextension_interface.h>
+#include <godot_cpp/core/defs.hpp>
+#include <godot_cpp/godot.hpp>
+
+using namespace godot;
+
+void initialize_module(ModuleInitializationLevel p_level)
+{
+	if (p_level != MODULE_INITIALIZATION_LEVEL_SCENE) {
+		return;
+	}
+
+	ClassDB::register_class<MultilevelAStarEx>();
+}
+
+void uninitialize_module(ModuleInitializationLevel p_level)
+{
+	if (p_level != MODULE_INITIALIZATION_LEVEL_SCENE) {
+		return;
+	}
+}
+
+extern "C" {
+GDExtensionBool GDE_EXPORT my_astar_ext_init(GDExtensionInterfaceGetProcAddress p_get_proc_address, const GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization)
+{
+	godot::GDExtensionBinding::InitObject init_obj(p_get_proc_address, p_library, r_initialization);
+
+	init_obj.register_initializer(initialize_module);
+	init_obj.register_terminator(uninitialize_module);
+	init_obj.set_minimum_library_initialization_level(MODULE_INITIALIZATION_LEVEL_SCENE);
+
+	return init_obj.init();
+}
+}

term.cmd

@@ -0,0 +1,2 @@
+@set PATH=%PATH%;D:\Programs\scons
+@cmd