Add industrial metal soundtrack with seamless loop

- assets/audio/music/zombie_industrial_loop.ogg: 57.60 s Ogg Vorbis loop
  generated locally with YuE2-3B on the Tesla V100 (score written for this
  track; vocals removed with HTDemucs). The loop is spliced at the track's
  structural repeat with a 0.6 s crossfade: measured seam dip <= 1.6 dB.
- scripts/main.gd: "Music" AudioStreamPlayer at -11 dB, started at boot on
  desktop and on the start click on Web (browser autoplay policy). It forces
  stream.loop at runtime because the Web staging step re-imports the OGG with
  loop=false.
- tools/test_music.gd: soundtrack test (loop, length, volume, playback,
  still playing after player death).
- docs/MUSIC.md: source, loop construction, verification, licence.
- docs/WEB-DEPLOY.md: release ab6054111f5919a8 notes.

Initial commit of the project.

addons/goldsrc/goldsrc.gdextension

@@ -0,0 +1,22 @@
+[configuration]
+entry_symbol = "goldsrc_library_init"
+compatibility_minimum = "4.6"
+reloadable = true
+
+[libraries]
+
+macos.debug.arm64         = "res://addons/goldsrc/bin/libgoldsrc.macos.template_debug.arm64.dylib"
+macos.release.arm64       = "res://addons/goldsrc/bin/libgoldsrc.macos.template_release.arm64.dylib"
+macos.debug.x86_64        = "res://addons/goldsrc/bin/libgoldsrc.macos.template_debug.x86_64.dylib"
+macos.release.x86_64      = "res://addons/goldsrc/bin/libgoldsrc.macos.template_release.x86_64.dylib"
+
+windows.debug.x86_64      = "res://addons/goldsrc/bin/libgoldsrc.windows.template_debug.x86_64.dll"
+windows.release.x86_64    = "res://addons/goldsrc/bin/libgoldsrc.windows.template_release.x86_64.dll"
+
+linux.debug.x86_64        = "res://addons/goldsrc/bin/libgoldsrc.linux.template_debug.x86_64.so"
+linux.release.x86_64      = "res://addons/goldsrc/bin/libgoldsrc.linux.template_release.x86_64.so"
+linux.debug.arm64         = "res://addons/goldsrc/bin/libgoldsrc.linux.template_debug.arm64.so"
+linux.release.arm64       = "res://addons/goldsrc/bin/libgoldsrc.linux.template_release.arm64.so"
+
+android.debug.arm64       = "res://addons/goldsrc/bin/libgoldsrc.android.template_debug.arm64.so"
+android.release.arm64     = "res://addons/goldsrc/bin/libgoldsrc.android.template_release.arm64.so"

addons/goldsrc/goldsrc.gdextension.uid

@@ -0,0 +1 @@
+uid://dsy8u3hdjay5p

addons/goldsrc/importer/bsp_importer.gd

@@ -0,0 +1,221 @@
+@tool
+extends EditorImportPlugin
+
+
+func _get_importer_name() -> String:
+	return "goldsrc.bsp"
+
+
+func _get_visible_name() -> String:
+	return "GoldSrc BSP"
+
+
+func _get_recognized_extensions() -> PackedStringArray:
+	return PackedStringArray(["bsp"])
+
+
+func _get_save_extension() -> String:
+	return "scn"
+
+
+func _get_resource_type() -> String:
+	return "PackedScene"
+
+
+func _get_preset_count() -> int:
+	return 1
+
+
+func _get_preset_name(preset_index: int) -> String:
+	return "Default"
+
+
+func _get_priority() -> float:
+	return 1.0
+
+
+func _get_import_order() -> int:
+	return 1 # Must run after MDL/SPR importers (order 0) so their scenes are available.
+
+
+# Must run on main thread — ArrayMesh/ImageTexture serialization deadlocks
+# when ResourceSaver.save() is called from import worker threads.
+func _can_import_threaded() -> bool:
+	return false
+
+
+func _get_import_options(_path: String, _preset_index: int) -> Array[Dictionary]:
+	return [
+		{
+			"name": "wad_directory",
+			"default_value": "",
+			"property_hint": PROPERTY_HINT_DIR,
+			"hint_string": "",
+		},
+		{
+			"name": "scale_factor",
+			"default_value": 0.025,
+			"property_hint": PROPERTY_HINT_RANGE,
+			"hint_string": "0.001,1.0,0.001",
+		},
+		# Base res:// path for resolving entity model/sprite references.
+		# Set this to the folder that mirrors your GoldSrc game root inside the
+		# project (e.g. res://res), so "models/headcrab.mdl" resolves correctly.
+		# Leave empty when your project root already mirrors the game root.
+		{
+			"name": "model_directory",
+			"default_value": "",
+			"property_hint": PROPERTY_HINT_DIR,
+			"hint_string": "",
+		},
+	]
+
+
+func _get_option_visibility(_path: String, _option_name: StringName, _options: Dictionary) -> bool:
+	return true
+
+
+func _import(source_file: String, save_path: String, options: Dictionary,
+		_platform_variants: Array[String], _gen_files: Array[String]) -> Error:
+	var wad_directory: String = options.get("wad_directory", "")
+	var scale_factor: float = options.get("scale_factor", 0.025)
+	var model_directory: String = options.get("model_directory", "")
+
+	var bsp := GoldSrcBSP.new()
+	bsp.set_scale_factor(scale_factor)
+
+	bsp.load_bsp(source_file)
+
+	# Resolve WAD files. If an explicit directory is given, scan it; otherwise
+	# read the WADs the BSP itself declares in worldspawn's "wad" key and look
+	# them up next to the .bsp and at the project root — so a stock project
+	# textures correctly with no per-file import config.
+	if wad_directory != "":
+		var dir := DirAccess.open(wad_directory)
+		if dir:
+			dir.list_dir_begin()
+			var file_name := dir.get_next()
+			while file_name != "":
+				if not dir.current_is_dir() and file_name.get_extension().to_lower() == "wad":
+					var wad := GoldSrcWAD.new()
+					var wad_path := wad_directory.path_join(file_name)
+					wad.load_wad(wad_path)
+					bsp.add_wad(wad)
+				file_name = dir.get_next()
+			dir.list_dir_end()
+		else:
+			push_warning("BSP Importer: Could not open WAD directory '%s'" % wad_directory)
+	else:
+		_load_declared_wads(bsp, source_file)
+
+	bsp.build_mesh()
+
+	# Reparent children to a plain Node3D so the saved scene is GDExtension-independent
+	var root := Node3D.new()
+	var root_name := source_file.get_file().get_basename()
+	if root_name.is_empty():
+		root_name = "bsp_root"
+	root.name = root_name
+
+	var children := bsp.get_children()
+	for child in children:
+		bsp.remove_child(child)
+		root.add_child(child)
+
+	_instantiate_entity_models(root, model_directory)
+
+	# Bake the stripped BSP (PLANES/NODES/CLIPNODES/LEAFS/VISIBILITY/MODELS) so
+	# VisibilityManager (PVS) and hull collision can both initialise from the .scn
+	# without the original .bsp. Collision bodies carry only a "bsp_model" index
+	# and walk up the tree to find this. build_mesh() already parked it on the BSP
+	# node, so read it back rather than rebuilding the whole payload —
+	# PackedByteArray is copy-on-write, so this is a refcount.
+	var bsp_blob: PackedByteArray = bsp.get_meta("bsp_data", PackedByteArray())
+	if not bsp_blob.is_empty():
+		root.set_meta("bsp_data", bsp_blob)
+
+	_set_owner_recursive(root, root)
+
+	var scene := PackedScene.new()
+	var pack_err := scene.pack(root)
+	if pack_err != OK:
+		push_error("BSP Importer: Failed to pack scene: %s" % error_string(pack_err))
+		return pack_err
+
+	var save_err := ResourceSaver.save(scene, save_path + "." + _get_save_extension())
+	return save_err
+
+
+# Load the WADs a BSP declares in worldspawn's "wad" key (a ';'-separated list
+# of GoldSrc paths). Only the basename is used; each is searched for beside the
+# .bsp first, then at the project root. This mirrors the runtime WAD lookup so
+# the editor and the game texture maps identically without any import options.
+func _load_declared_wads(bsp: GoldSrcBSP, source_file: String) -> void:
+	var wad_string := ""
+	for ent in bsp.get_entities():
+		if ent.get("classname", "") == "worldspawn":
+			wad_string = ent.get("wad", "")
+			break
+
+	var search_dirs := [source_file.get_base_dir(), "res://"]
+	var seen := {}
+	for wad_path in wad_string.split(";", false):
+		var wad_name := wad_path.get_file().to_lower()
+		if wad_name.is_empty() or seen.has(wad_name):
+			continue
+		seen[wad_name] = true
+		for base in search_dirs:
+			var full_path: String = base.path_join(wad_name)
+			if FileAccess.file_exists(full_path):
+				var wad := GoldSrcWAD.new()
+				if wad.load_wad(full_path) == OK:
+					bsp.add_wad(wad)
+				break
+
+
+func _set_owner_recursive(node: Node, owner: Node) -> void:
+	for child in node.get_children():
+		child.owner = owner
+		# Don't recurse into instanced sub-scenes — their internal nodes belong
+		# to that scene, not to this one. Setting owner on the root is enough.
+		if child.scene_file_path == "":
+			_set_owner_recursive(child, owner)
+
+
+# Instantiate MDL/SPR scenes for each point entity that has a "model" key.
+# Resolves entity paths relative to model_dir (if set) or res:// (if empty),
+# mirroring the GoldSrc layout at that root.
+# Falls back to a placeholder box if the asset is not found.
+func _instantiate_entity_models(root: Node3D, model_dir: String) -> void:
+	var base := model_dir if model_dir != "" else "res://"
+	for child in root.get_children():
+		if not child.has_meta("entity"):
+			continue
+		var ent: Dictionary = child.get_meta("entity")
+		var model_path: String = ent.get("model", "")
+
+		# Brush entities reference internal BSP sub-models ("*N") — skip them.
+		if model_path.is_empty() or model_path.begins_with("*"):
+			continue
+
+		var res_path := base.path_join(model_path)
+		var instance: Node3D = null
+
+		if ResourceLoader.exists(res_path):
+			var scene := load(res_path) as PackedScene
+			if scene:
+				instance = scene.instantiate() as Node3D
+
+		if instance == null:
+			var mi := MeshInstance3D.new()
+			var box := BoxMesh.new()
+			box.size = Vector3(0.3, 0.3, 0.3)
+			mi.mesh = box
+			instance = mi
+			push_warning("BSP Importer: model not found, using placeholder for '%s'" % res_path)
+
+		var node_name := model_path.get_file().get_basename()
+		if node_name.is_empty():
+			node_name = "unnamed_entity_model"
+		instance.name = node_name
+		child.add_child(instance)

addons/goldsrc/importer/bsp_importer.gd.uid

@@ -0,0 +1 @@
+uid://bkjulqpbo8sjd

addons/goldsrc/importer/mdl_importer.gd

@@ -0,0 +1,112 @@
+@tool
+extends EditorImportPlugin
+
+
+func _get_importer_name() -> String:
+	return "goldsrc.mdl"
+
+
+func _get_visible_name() -> String:
+	return "GoldSrc MDL"
+
+
+func _get_recognized_extensions() -> PackedStringArray:
+	return PackedStringArray(["mdl"])
+
+
+func _get_save_extension() -> String:
+	return "scn"
+
+
+func _get_resource_type() -> String:
+	return "PackedScene"
+
+
+func _get_preset_count() -> int:
+	return 1
+
+
+func _get_preset_name(preset_index: int) -> String:
+	return "Default"
+
+
+## What shape of scene this importer builds. 1: meshes merged into one MeshInstance3D per
+## bodypart. 2: triangle corners welded back into shared vertices.
+##
+## Godot records it in each .import file but does not act on a bump — neither --import nor an
+## editor session reimports on its own (checked on 4.7). Changing the built scene means clearing
+## .godot/imported/*.mdl-* by hand; the number is here so it is visible which build a cache came
+## from.
+func _get_format_version() -> int:
+	return 2
+
+
+func _get_priority() -> float:
+	return 1.0
+
+
+func _get_import_order() -> int:
+	return 0
+
+
+func _can_import_threaded() -> bool:
+	return false
+
+
+func _get_import_options(_path: String, _preset_index: int) -> Array[Dictionary]:
+	return [
+		{
+			"name": "scale_factor",
+			"default_value": 0.025,
+			"property_hint": PROPERTY_HINT_RANGE,
+			"hint_string": "0.001,1.0,0.001",
+		},
+	]
+
+
+func _get_option_visibility(_path: String, _option_name: StringName, _options: Dictionary) -> bool:
+	return true
+
+
+func _import(source_file: String, save_path: String, options: Dictionary,
+		_platform_variants: Array[String], _gen_files: Array[String]) -> Error:
+	var scale_factor: float = options.get("scale_factor", 0.025)
+
+	var mdl := GoldSrcMDL.new()
+	mdl.set_scale_factor(scale_factor)
+
+	var err = mdl.load_mdl(source_file)
+	if err != OK:
+		push_error("MDL Importer: Failed to load '%s': %s" % [source_file, error_string(err)])
+		return err
+
+	mdl.build_model()
+
+	# Reparent children to a plain Node3D so the saved scene is GDExtension-independent
+	var root := Node3D.new()
+	var root_name := source_file.get_file().get_basename()
+	if root_name.is_empty():
+		root_name = "mdl_root"
+	root.name = root_name
+	# GoldSrc models face -Z after axis swizzle; rotate to match GoldSrc game orientation
+	root.rotation_degrees.y = 90.0
+
+	var children := mdl.get_children()
+	for child in children:
+		mdl.remove_child(child)
+		root.add_child(child)
+	_set_owner_recursive(root, root)
+
+	var scene := PackedScene.new()
+	var pack_err := scene.pack(root)
+	if pack_err != OK:
+		push_error("MDL Importer: Failed to pack scene: %s" % error_string(pack_err))
+		return pack_err
+
+	return ResourceSaver.save(scene, save_path + "." + _get_save_extension())
+
+
+func _set_owner_recursive(node: Node, owner: Node) -> void:
+	for child in node.get_children():
+		child.owner = owner
+		_set_owner_recursive(child, owner)

addons/goldsrc/importer/mdl_importer.gd.uid

@@ -0,0 +1 @@
+uid://bp0377di4pbve

addons/goldsrc/importer/spr_importer.gd

@@ -0,0 +1,103 @@
+@tool
+extends EditorImportPlugin
+
+
+func _get_importer_name() -> String:
+	return "goldsrc.spr"
+
+
+func _get_visible_name() -> String:
+	return "GoldSrc SPR"
+
+
+func _get_recognized_extensions() -> PackedStringArray:
+	return PackedStringArray(["spr"])
+
+
+func _get_save_extension() -> String:
+	return "scn"
+
+
+func _get_resource_type() -> String:
+	return "PackedScene"
+
+
+func _get_preset_count() -> int:
+	return 1
+
+
+func _get_preset_name(preset_index: int) -> String:
+	return "Default"
+
+
+func _get_priority() -> float:
+	return 1.0
+
+
+func _get_import_order() -> int:
+	return 0
+
+
+func _can_import_threaded() -> bool:
+	return false
+
+
+func _get_import_options(_path: String, _preset_index: int) -> Array[Dictionary]:
+	return [
+		{
+			"name": "animation_fps",
+			"default_value": 10.0,
+			"property_hint": PROPERTY_HINT_RANGE,
+			"hint_string": "1.0,60.0,0.5",
+		},
+		{
+			"name": "loop",
+			"default_value": true,
+		},
+	]
+
+
+func _get_option_visibility(_path: String, _option_name: StringName, _options: Dictionary) -> bool:
+	return true
+
+
+func _import(source_file: String, save_path: String, options: Dictionary,
+		_platform_variants: Array[String], _gen_files: Array[String]) -> Error:
+	var fps: float = options.get("animation_fps", 10.0)
+	var loop: bool = options.get("loop", true)
+
+	var spr := GoldSrcSPR.new()
+	var err = spr.load_spr(source_file)
+	if err != OK:
+		push_error("SPR Importer: Failed to load '%s': %s" % [source_file, error_string(err)])
+		return err
+
+	var frame_count = spr.get_frame_count()
+	if frame_count == 0:
+		push_error("SPR Importer: No frames in '%s'" % source_file)
+		return ERR_INVALID_DATA
+
+	var sprite = spr.build_scene()
+	if not sprite:
+		push_error("SPR Importer: build_scene() failed for '%s'" % source_file)
+		return ERR_CANT_CREATE
+
+	var sprite_name := source_file.get_file().get_basename()
+	if sprite_name.is_empty():
+		sprite_name = "sprite_root"
+	sprite.name = sprite_name
+
+	# Bake import options into the SpriteAnimationPlayer child
+	var sap = sprite.get_node_or_null(^"SpriteAnimationPlayer")
+	if sap:
+		sap.fps = fps
+		sap.loop_animation = loop
+
+	var scene := PackedScene.new()
+	var pack_err := scene.pack(sprite)
+	sprite.free()
+	if pack_err != OK:
+		push_error("SPR Importer: Failed to pack scene for '%s': %s" % [source_file, error_string(pack_err)])
+		return pack_err
+
+	return ResourceSaver.save(scene, save_path + "." + _get_save_extension())

addons/goldsrc/importer/spr_importer.gd.uid

@@ -0,0 +1 @@
+uid://n8cr2s2yyhqe

addons/goldsrc/importer/wad_importer.gd

@@ -0,0 +1,110 @@
+@tool
+extends EditorImportPlugin
+## Imports a GoldSrc WAD file.
+##
+## The WAD is saved as a minimal .tres marker so Godot tracks it as a known
+## asset. The BSP importer loads WAD files directly via the C++ GoldSrcWAD
+## class — it does not use extracted PNGs.
+##
+## PNG extraction is opt-in (extract_textures = false by default) for cases
+## where individual textures are needed outside of BSP rendering.
+
+
+func _get_importer_name() -> String:
+	return "goldsrc.wad"
+
+
+func _get_visible_name() -> String:
+	return "GoldSrc WAD"
+
+
+func _get_recognized_extensions() -> PackedStringArray:
+	return PackedStringArray(["wad"])
+
+
+func _get_save_extension() -> String:
+	return "tres"
+
+
+func _get_resource_type() -> String:
+	return "Resource"
+
+
+func _get_preset_count() -> int:
+	return 1
+
+
+func _get_preset_name(preset_index: int) -> String:
+	return "Default"
+
+
+func _get_priority() -> float:
+	return 1.0
+
+
+func _get_import_order() -> int:
+	return 0
+
+
+func _can_import_threaded() -> bool:
+	return false
+
+
+func _get_import_options(_path: String, _preset_index: int) -> Array[Dictionary]:
+	return [
+		{
+			"name": "extract_textures",
+			"default_value": false,
+		},
+		{
+			"name": "output_directory",
+			"default_value": "",
+			"property_hint": PROPERTY_HINT_DIR,
+			"hint_string": "Leave empty to extract next to the WAD file",
+		},
+	]
+
+
+func _get_option_visibility(_path: String, _option_name: StringName, _options: Dictionary) -> bool:
+	if _option_name == "output_directory":
+		return _options.get("extract_textures", true)
+	return true
+
+
+func _import(source_file: String, save_path: String, options: Dictionary,
+		_platform_variants: Array[String], _gen_files: Array[String]) -> Error:
+	var extract: bool = options.get("extract_textures", true)
+
+	var wad := GoldSrcWAD.new()
+	var err = wad.load_wad(source_file)
+	if err != OK:
+		push_error("WAD Importer: Failed to load '%s': %s" % [source_file, error_string(err)])
+		return err
+
+	if extract:
+		var output_dir: String = options.get("output_directory", "")
+		if output_dir.is_empty():
+			# Default: create a folder named after the WAD next to it
+			output_dir = source_file.get_base_dir().path_join(
+				source_file.get_file().get_basename())
+
+		DirAccess.make_dir_recursive_absolute(output_dir)
+
+		var names = wad.get_texture_names()
+		var count := 0
+		for tex_name in names:
+			var tex = wad.get_texture(tex_name)
+			if tex == null:
+				continue
+			var img = tex.get_image()
+			if img == null:
+				continue
+			var png_path := output_dir.path_join(tex_name.to_lower() + ".png")
+			img.save_png(png_path)
+			count += 1
+
+		print("WAD Importer: Extracted %d textures to %s" % [count, output_dir])
+
+	# Save a minimal marker resource so Godot considers the import complete
+	var res := Resource.new()
+	return ResourceSaver.save(res, save_path + "." + _get_save_extension())

addons/goldsrc/importer/wad_importer.gd.uid

@@ -0,0 +1 @@
+uid://dl2ri2g5ai8cf

addons/goldsrc/plugin.cfg

@@ -0,0 +1,7 @@
+[plugin]
+
+name="GoldSrc"
+description="Import GoldSrc engine assets (BSP maps, WAD textures, MDL models, SPR sprites)"
+author="goldsrc-godot"
+version="0.1.0"
+script="plugin.gd"

addons/goldsrc/plugin.gd

@@ -0,0 +1,29 @@
+@tool
+extends EditorPlugin
+
+var bsp_importer: EditorImportPlugin
+var mdl_importer: EditorImportPlugin
+var spr_importer: EditorImportPlugin
+var wad_importer: EditorImportPlugin
+
+
+func _enter_tree() -> void:
+	bsp_importer = preload("res://addons/goldsrc/importer/bsp_importer.gd").new()
+	mdl_importer = preload("res://addons/goldsrc/importer/mdl_importer.gd").new()
+	spr_importer = preload("res://addons/goldsrc/importer/spr_importer.gd").new()
+	wad_importer = preload("res://addons/goldsrc/importer/wad_importer.gd").new()
+	add_import_plugin(bsp_importer)
+	add_import_plugin(mdl_importer)
+	add_import_plugin(spr_importer)
+	add_import_plugin(wad_importer)
+
+
+func _exit_tree() -> void:
+	remove_import_plugin(bsp_importer)
+	remove_import_plugin(mdl_importer)
+	remove_import_plugin(spr_importer)
+	remove_import_plugin(wad_importer)
+	bsp_importer = null
+	mdl_importer = null
+	spr_importer = null
+	wad_importer = null

addons/goldsrc/plugin.gd.uid

@@ -0,0 +1 @@
+uid://eql0skovdole