Refactor Material Creator Plugin Demo to use custom resource-based data (#1219)

plugins/addons/material_creator/README.md

@@ -1,20 +1,25 @@
 # Material Creator Plugin Demo
 
-This plugin demo contains a custom material creator
-interface using a custom dock in the editor.
+This plugin demo contains a custom material creation dock
+inside the Godot editor.
 
 Custom docks are made of Control nodes, they run in the
 editor, and any behavior must be done through `tool` scripts.
 For more information, see this documentation article:
 https://docs.godotengine.org/en/latest/tutorials/plugins/editor/making_plugins.html#a-custom-dock
 
-This plugin allows you to specify color, metallic, and
-roughness values, and then use it as a material.
+## Features
+- Adjust albedo color, metallic and rouphness values interactively.
+- Apply the generated material to selected 3D nodes in the editor.
+- Save and load materials in two ways:
+	- `.silly_mat`: Custom Godot Resource type, handled by custom saver/loader
+	included in the plygin.
+	- `.mtxt`: Plain-text format. Useful for external editing or as an
+	interchange format.
+	- `.tres`: Standard Godot resource format (works without the custom
+	loader).
 
-You can apply this material directly to Spatial
-nodes by selecting them and then clicking "Apply".
-This shows how a plugin can interact closely with the
-editor, manipulating nodes the user selects.
-
-Alternatively, you can also save the material to
-a file, and then load it back into the plugin later.
+## Implementation notes
+- `.silly_mat` format is registered through `SillyMatFormatSaver` and
+`SillyMatFormatLoader` in the plugin.
+- Custm docks are built from `Control` nodes and run as `@tool` scripts.

plugins/addons/material_creator/material_creator.gd

@@ -2,7 +2,7 @@
 extends Panel
 # In this file, the word "silly" is used to make it obvious that the name is arbitrary.
 
-var silly_material_resource = preload("res://addons/material_creator/material_resource.gd")
+var silly_material_resource := preload("res://addons/material_creator/material_resource.gd")
 var editor_interface: EditorInterface
 
 
@@ -11,8 +11,26 @@ func _ready() -> void:
 	$VBoxContainer/ApplyButton.pressed.connect(apply_pressed)
 	$VBoxContainer/SaveButton.pressed.connect(save_pressed)
 	$VBoxContainer/LoadButton.pressed.connect(load_pressed)
-	$SaveMaterialDialog.file_selected.connect(save_file_selected)
+
+	$SaveMaterialDialog.file_mode = FileDialog.FILE_MODE_SAVE_FILE
+	$SaveMaterialDialog.access = FileDialog.ACCESS_RESOURCES
+	$SaveMaterialDialog.current_dir = "res://materials"
+	$SaveMaterialDialog.current_file = "new_material.silly_mat"
+	$SaveMaterialDialog.filters = PackedStringArray([
+		"*.silly_mat ; Silly Material (resource)",
+		"*.tres ; Godot Resource (resource)",
+		"*.mtxt ; Silly Material (source)"
+	])
+	$SaveMaterialDialog.confirmed.connect(_on_save_confirmed)
+
+	$LoadMaterialDialog.access = FileDialog.ACCESS_RESOURCES
+	$LoadMaterialDialog.filters = PackedStringArray([
+		"*.silly_mat ; Silly Material (resource)",
+		"*.tres ; Godot Resource (resource)",
+		"*.mtxt ; Silly Material (source)"
+	])
 	$LoadMaterialDialog.file_selected.connect(load_file_selected)
+
 	RenderingServer.canvas_item_set_clip(get_canvas_item(), true)
 
 
@@ -24,12 +42,55 @@ func load_pressed() -> void:
 	$LoadMaterialDialog.popup_centered_ratio()
 
 
+func _on_save_confirmed() -> void:
+	var path = $SaveMaterialDialog.get_current_path()
+	if path.is_empty():
+		push_error("Material Creator: No path chosen for saving.")
+		return
+
+	# If user typed no extension, default to .silly_mat (resource path).
+	if not path.get_file().contains("."):
+		path += ".silly_mat"
+
+	var ext = path.get_extension().to_lower()
+
+	# Ensure directory exists under res:// when saving inside project.
+	var dir = path.get_base_dir()
+	if path.begins_with("res://") and not DirAccess.dir_exists_absolute(dir):
+		var mk := DirAccess.make_dir_recursive_absolute(dir)
+		if mk != OK:
+			push_error("Material Creator: Can't create folder: %s (%s)" % [dir, error_string(mk)])
+			return
+
+	var res: Resource = _silly_resource_from_values()
+
+	match ext:
+		"mtxt":
+			# Write SOURCE file (no ResourceSaver, works anywhere).
+			var ok := _write_source_silly(path, res)
+			if not ok:
+				push_error("Material Creator: Failed to write source .mtxt at %s" % path)
+			else:
+				print("Material Creator: Wrote source to ", path)
+		"silly_mat", "tres":
+			# Save RESOURCE (requires your custom saver for .silly_mat).
+			res.resource_path = path
+			var err := ResourceSaver.save(res, path)
+			if err != OK:
+				push_error("Material Creator: Failed to save resource: %s (%s)" % [path, error_string(err)])
+			else:
+				print("Material Creator: Saved resource to ", path)
+		_:
+			push_error("Material Creator: Unsupported extension: ." + ext)
+
+
 func apply_pressed() -> void:
 	# Using the passed in editor interface, get the selected nodes in the editor.
 	var editor_selection: EditorSelection = editor_interface.get_selection()
 	var selected_nodes := editor_selection.get_selected_nodes()
 	if selected_nodes.is_empty():
 		push_error("Material Creator: Can't apply the material, because there are no nodes selected!")
+		return
 
 	var new_material: StandardMaterial3D = _silly_resource_from_values().make_material()
 	# Go through the selected nodes and see if they have the "set_surface_override_material"
@@ -40,57 +101,65 @@ func apply_pressed() -> void:
 			node.set_surface_override_material(0, new_material)
 
 
-func save_file_selected(path: String) -> bool:
-	var silly_resource: Variant = _silly_resource_from_values()
-	# Make a file, store the silly material as a JSON string.
-	var file := FileAccess.open(path, FileAccess.WRITE)
-	file.store_string(silly_resource.make_json())
-
-	return true
-
-
 func load_file_selected(path: String) -> bool:
-	var SpatialMaterial_Silly: StandardMaterial3D = null
+	var ext := path.get_extension().to_lower()
 
-	# Make a new silly resource (which in this case actually is a node)
-	# and initialize it.
-	var silly_resource: Variant = silly_material_resource.new()
-	#silly_resource.init()
-
-	# If the file exists, then open it.
-	if FileAccess.file_exists(path):
-		var file := FileAccess.open(path, FileAccess.READ)
-
-		# Get the JSON string and convert it into a silly material.
-		var json_dict_as_string := file.get_line()
-		if json_dict_as_string != null:
-			silly_resource.from_json(json_dict_as_string)
-		else:
+	if ext == "mtxt":
+		# Load SOURCE by manual parse (works inside/outside res://)
+		var loaded := _read_source_silly(path)
+		if loaded == null:
+			push_error("Material Creator: Failed to parse source at %s" % path)
+			return false
+		$VBoxContainer/AlbedoColorPicker.color = loaded.albedo_color
+		$VBoxContainer/MetallicSlider.value = loaded.metallic_strength
+		$VBoxContainer/RoughnessSlider.value = loaded.roughness_strength
+		return true
+	else:
+		# Load RESOURCE via ResourceLoader (silly_mat via your loader, tres via built-in)
+		var silly_resource: Resource = ResourceLoader.load(path)
+		if silly_resource == null:
+			push_error("Material Creator: Failed to load resource at %s" % path)
 			return false
-
 		$VBoxContainer/AlbedoColorPicker.color = silly_resource.albedo_color
 		$VBoxContainer/MetallicSlider.value = silly_resource.metallic_strength
 		$VBoxContainer/RoughnessSlider.value = silly_resource.roughness_strength
-
-		# Return `true` to indicate success.
 		return true
 
-	# If the file does not exist, then return `false` to indicate failure.
-	return false
 
-
-func _silly_resource_from_values() -> Variant:
-	# Get the values from the sliders and color picker.
+func _silly_resource_from_values() -> Resource:
 	var color: Color = $VBoxContainer/AlbedoColorPicker.color
 	var metallic: float = $VBoxContainer/MetallicSlider.value
 	var roughness: float = $VBoxContainer/RoughnessSlider.value
-	# Make a new silly resource (which in this case actually is a node) and initialize it.
-	var silly_resource: Variant = silly_material_resource.new()
-	#silly_resource.init()
+	var silly_res: Resource = silly_material_resource.new()
+	silly_res.albedo_color = color
+	silly_res.metallic_strength = metallic
+	silly_res.roughness_strength = roughness
+	return silly_res
 
-	# Assign the values.
-	silly_resource.albedo_color = color
-	silly_resource.metallic_strength = metallic
-	silly_resource.roughness_strength = roughness
+# ---------------------------------------------------------------
+# Source (.mtxt) helpers.
+# ---------------------------------------------------------------
 
-	return silly_resource
+func _write_source_silly(path: String, res: Resource) -> bool:
+	var mat_file := FileAccess.open(path, FileAccess.WRITE)
+	if mat_file == null:
+		return false
+	mat_file.store_line("SILLY_MAT v1")
+	mat_file.store_line(res.albedo_color.to_html(true)) # RGBA hex
+	mat_file.store_line(str(res.metallic_strength))
+	mat_file.store_line(str(res.roughness_strength))
+	return true
+
+
+func _read_source_silly(path: String) -> Resource:
+	var mat_file := FileAccess.open(path, FileAccess.READ)
+	if mat_file == null:
+		return null
+	var header := mat_file.get_line()
+	if not header.begins_with("SILLY_MAT"):
+		return null
+	var mat_res := silly_material_resource.new()
+	mat_res.albedo_color = Color(mat_file.get_line()) # from hex string
+	mat_res.metallic_strength = float(mat_file.get_line())
+	mat_res.roughness_strength = float(mat_file.get_line())
+	return mat_res

plugins/addons/material_creator/material_format_loader.gd

@@ -0,0 +1,40 @@
+@tool
+extends ResourceFormatLoader
+class_name SillyMatFormatLoader
+## Custom loader for the .silly_mat file format.
+## Allows Godot to recognize and load SillyMaterialResource files.
+## Register this loader in the EditorPlugin to enable saving/loading resources.
+
+
+## Returns the list of file extensions this loader supports.
+func _get_recognized_extensions() -> PackedStringArray:
+	# Returns only ".silly_mat"
+	return PackedStringArray(["silly_mat"])
+
+
+## Returns what resource type this loader handles.
+func _handles_type(typename: StringName) -> bool:
+	return typename == "SillyMaterialResource"
+
+
+## Returns the resource type name based on file extension.
+func _get_resource_type(path: String) -> String:
+	return "SillyMaterialResource" if path.get_extension() == "silly_mat" else ""
+
+
+## Main load function. Reads .silly_mat and constructs a SillyMaterialResource.
+func _load(path: String, original_path: String, use_sub_threads, cache_mode):
+	var mat_file = FileAccess.open(path, FileAccess.READ)
+	if mat_file == null:
+		return ERR_CANT_OPEN
+
+	# Check header line to validate file format version.
+	if mat_file.get_line() != "SILLY_MAT v1":
+		return ERR_PARSE_ERROR
+
+	# Create and Fill SillyMaterialResource
+	var mat_res: SillyMaterialResource = SillyMaterialResource.new()
+	mat_res.albedo_color = Color(mat_file.get_line())
+	mat_res.metallic_strength = float(mat_file.get_line())
+	mat_res.roughness_strength = float(mat_file.get_line())
+	return mat_res

plugins/addons/material_creator/material_format_saver.gd

@@ -0,0 +1,35 @@
+@tool
+extends ResourceFormatSaver
+class_name SillyMatFormatSaver
+## Custom saver for the .silly_mat file format.
+## Works together with SillyMatFormatLoader to make SillyMaterialResource.
+
+
+## This saver only supports SilluMaterialResource.
+func _recognize(resource: Resource) -> bool:
+	return resource is SillyMaterialResource
+
+
+## Return list of file extensions this saver will write.
+func _get_recognized_extensions(resource: Resource) -> PackedStringArray:
+	return PackedStringArray(["silly_mat"])
+
+
+## Main save function.
+## Serializes a SillyMaterialResource into .silly_mat format.
+##
+## It will write simple text-based format, one property per line.
+func _save(resource: Resource, path: String, flags: int) -> int:
+	var mat_res: SillyMaterialResource = resource as SillyMaterialResource
+	if mat_res == null:
+		return ERR_INVALID_DATA
+
+	var mat_file := FileAccess.open(path, FileAccess.WRITE)
+	if mat_file == null:
+		return ERR_CANT_OPEN
+
+	mat_file.store_line("SILLY_MAT v1")
+	mat_file.store_line(mat_res.albedo_color.to_html(true)) # Stored in HTML hex.
+	mat_file.store_line(str(mat_res.metallic_strength))
+	mat_file.store_line(str(mat_res.roughness_strength))
+	return OK

plugins/addons/material_creator/material_plugin.gd

@@ -12,9 +12,16 @@
 extends EditorPlugin
 
 var io_material_dialog: Panel
+var _loader: SillyMatFormatLoader
+var _saver: SillyMatFormatSaver
 
 
 func _enter_tree() -> void:
+	_loader = SillyMatFormatLoader.new()
+	_saver = SillyMatFormatSaver.new()
+	ResourceLoader.add_resource_format_loader(_loader)
+	ResourceSaver.add_resource_format_saver(_saver)
+
 	io_material_dialog = preload("res://addons/material_creator/material_dock.tscn").instantiate()
 	io_material_dialog.editor_interface = get_editor_interface()
 	add_control_to_dock(DOCK_SLOT_LEFT_UL, io_material_dialog)
@@ -22,3 +29,10 @@ func _enter_tree() -> void:
 
 func _exit_tree() -> void:
 	remove_control_from_docks(io_material_dialog)
+
+	if _loader:
+		ResourceLoader.remove_resource_format_loader(_loader)
+		_loader = null
+	if _saver:
+		ResourceSaver.remove_resource_format_saver(_saver)
+		_saver = null

plugins/addons/material_creator/material_resource.gd

@@ -1,15 +1,14 @@
 @tool
-extends Node
-# NOTE: In theory, this would extend from Resource, but until saving and loading resources
-# works in Godot, we'll stick with extending from Node and using JSON files to save/load data.
-#
-# See `material_import.gd` for more information.
+extends Resource
+class_name SillyMaterialResource
 
-var albedo_color := Color.BLACK
-var metallic_strength := 0.0
-var roughness_strength := 0.0
+# Use export to make properties visible and serializable in the inspector and for resource saving/loading.
+@export var albedo_color: Color = Color.BLACK
+@export var metallic_strength: float = 0.0
+@export var roughness_strength: float = 0.0
 
 
+# Create a StandardMaterial3D from the resource's properties.
 # Convert our data into an dictionary so we can convert it
 # into the JSON format.
 func make_json() -> String:
@@ -41,10 +40,8 @@ func from_json(json_dict_as_string: String) -> void:
 
 # Make a StandardMaterial3D using our variables.
 func make_material() -> StandardMaterial3D:
-	var material := StandardMaterial3D.new()
-
-	material.albedo_color = albedo_color
-	material.metallic = metallic_strength
-	material.roughness = roughness_strength
-
-	return material
+	var mat = StandardMaterial3D.new()
+	mat.albedo_color = albedo_color
+	mat.metallic = metallic_strength
+	mat.roughness = roughness_strength
+	return mat