Implement the ability to load custom shaders and image and layer effects

Finally expose the feature of importing custom shaders as image effects, and implement custom shader loading for layer effects as well. To load a shader, drag and drop a .gdshader file into Pixelorama and it will get copied into `user://shaders`. Then, in the Effects menu, a new "Loaded" submenu will appear, and the new shaders will also be available in the layer effects dialog. Since they are stored on a persistent location, the shaders will also be available on the next times Pixelorama will launch as well.

src/Autoload/Global.gd

@@ -71,7 +71,7 @@ enum EffectsMenu {
 	GAUSSIAN_BLUR,
 	GRADIENT,
 	GRADIENT_MAP,
-	SHADER
+	LOADED_EFFECTS
 }
 ## Enumeration of items present in the Select Menu.
 enum SelectMenu { SELECT_ALL, CLEAR_SELECTION, INVERT, TILE_MODE, MODIFY }

src/Autoload/OpenSave.gd

@@ -3,6 +3,9 @@ extends Node
 
 signal project_saved
 signal reference_image_imported
+signal shader_copied(file_path: String)
+
+const SHADERS_DIRECTORY := "user://shaders"
 
 var preview_dialog_tscn := preload("res://src/UI/Dialogs/ImportPreviewDialog.tscn")
 var preview_dialogs := []  ## Array of preview dialogs
@@ -39,12 +42,13 @@ func handle_loading_file(file: String) -> void:
 	elif file_ext in ["pck", "zip"]:  # Godot resource pack file
 		Global.control.get_node("Extensions").install_extension(file)
 
-	elif file_ext == "shader" or file_ext == "gdshader":  # Godot shader file
+	elif file_ext == "gdshader":  # Godot shader file
 		var shader := load(file)
 		if not shader is Shader:
 			return
-		var file_name: String = file.get_file().get_basename()
-		Global.control.find_child("ShaderEffect").change_shader(shader, file_name)
+		var new_path := SHADERS_DIRECTORY.path_join(file.get_file())
+		DirAccess.copy_absolute(file, new_path)
+		shader_copied.emit(new_path)
 	elif file_ext == "mp3":  # Audio file
 		open_audio_file(file)
 

src/Classes/ImageEffect.gd

@@ -144,8 +144,10 @@ func set_nodes() -> void:
 	selection_checkbox = $VBoxContainer/OptionsContainer/SelectionCheckBox
 	affect_option_button = $VBoxContainer/OptionsContainer/AffectOptionButton
 	animate_panel = $"%AnimatePanel"
-	animate_panel.image_effect_node = self
-	live_checkbox.button_pressed = live_preview
+	if is_instance_valid(animate_panel):
+		animate_panel.image_effect_node = self
+	if is_instance_valid(live_checkbox):
+		live_checkbox.button_pressed = live_preview
 
 
 func display_animate_dialog() -> void:

src/Classes/Layers/BaseLayer.gd

@@ -232,7 +232,7 @@ func display_effects(cel: BaseCel, image_override: Image = null) -> Image:
 		return image
 	var image_size := image.get_size()
 	for effect in effects:
-		if not effect.enabled:
+		if not effect.enabled or not is_instance_valid(effect.shader):
 			continue
 		var shader_image_effect := ShaderImageEffect.new()
 		shader_image_effect.generate_image(image, effect.shader, effect.params, image_size)

src/UI/Dialogs/ImageEffects/ShaderEffect.gd

@@ -3,8 +3,7 @@ extends ImageEffect
 var shader: Shader
 var params := {}
 
-@onready var shader_loaded_label: Label = $VBoxContainer/ShaderLoadedLabel
-@onready var shader_params: BoxContainer = $VBoxContainer/ShaderParams
+@onready var shader_params := $VBoxContainer/ShaderParams as VBoxContainer
 
 
 func _about_to_popup() -> void:
@@ -17,36 +16,22 @@ func _about_to_popup() -> void:
 	super._about_to_popup()
 
 
+func set_nodes() -> void:
+	aspect_ratio_container = $VBoxContainer/AspectRatioContainer
+	preview = $VBoxContainer/AspectRatioContainer/Preview
+
+
 func commit_action(cel: Image, project := Global.current_project) -> void:
-	if !shader:
+	if not is_instance_valid(shader):
 		return
-
 	var gen := ShaderImageEffect.new()
 	gen.generate_image(cel, shader, params, project.size)
 
 
-func _on_ChooseShader_pressed() -> void:
-	if OS.get_name() == "Web":
-		Html5FileExchange.load_shader()
-	else:
-		$FileDialog.popup_centered(Vector2(300, 340))
-
-
-func _on_FileDialog_file_selected(path: String) -> void:
-	var shader_tmp = load(path)
-	if !shader_tmp is Shader:
-		return
-	change_shader(shader_tmp, path.get_file().get_basename())
-
-
-func set_nodes() -> void:
-	preview = $VBoxContainer/AspectRatioContainer/Preview
-
-
 func change_shader(shader_tmp: Shader, shader_name: String) -> void:
 	shader = shader_tmp
 	preview.material.shader = shader_tmp
-	shader_loaded_label.text = tr("Shader loaded:") + " " + shader_name
+	title = shader_name
 	params.clear()
 	for child in shader_params.get_children():
 		child.queue_free()

src/UI/Dialogs/ImageEffects/ShaderEffect.tscn

@@ -1,11 +1,13 @@
-[gd_scene load_steps=4 format=3 uid="uid://bkr47ocij684y"]
+[gd_scene load_steps=4 format=3 uid="uid://b1ola6loro5m7"]
 
 [ext_resource type="Script" path="res://src/UI/Dialogs/ImageEffects/ShaderEffect.gd" id="1"]
 [ext_resource type="PackedScene" uid="uid://3pmb60gpst7b" path="res://src/UI/Nodes/TransparentChecker.tscn" id="2"]
 
 [sub_resource type="ShaderMaterial" id="1"]
 
 [node name="ShaderEffect" type="ConfirmationDialog"]
+position = Vector2i(0, 36)
+size = Vector2i(612, 350)
 script = ExtResource("1")
 
 [node name="VBoxContainer" type="VBoxContainer" parent="."]
@@ -15,17 +17,14 @@ anchor_bottom = 1.0
 offset_left = 8.0
 offset_top = 8.0
 offset_right = -8.0
-offset_bottom = -36.0
-
-[node name="Label" type="Label" parent="VBoxContainer"]
-layout_mode = 2
-text = "This is an experimental feature and may not be included in the stable version"
+offset_bottom = -49.0
 
 [node name="AspectRatioContainer" type="AspectRatioContainer" parent="VBoxContainer"]
 layout_mode = 2
 size_flags_vertical = 3
 
 [node name="Preview" type="TextureRect" parent="VBoxContainer/AspectRatioContainer"]
+texture_filter = 1
 material = SubResource("1")
 custom_minimum_size = Vector2(200, 200)
 layout_mode = 2
@@ -39,22 +38,5 @@ anchors_preset = 0
 anchor_right = 1.0
 anchor_bottom = 1.0
 
-[node name="ChooseShader" type="Button" parent="VBoxContainer"]
-layout_mode = 2
-mouse_default_cursor_shape = 2
-text = "Choose Shader"
-
-[node name="ShaderLoadedLabel" type="Label" parent="VBoxContainer"]
-layout_mode = 2
-text = "No shader loaded!"
-
 [node name="ShaderParams" type="VBoxContainer" parent="VBoxContainer"]
 layout_mode = 2
-
-[node name="FileDialog" type="FileDialog" parent="." groups=["FileDialogs"]]
-access = 2
-filters = PackedStringArray("*gdshader; Godot Shader File")
-show_hidden_files = true
-
-[connection signal="pressed" from="VBoxContainer/ChooseShader" to="." method="_on_ChooseShader_pressed"]
-[connection signal="file_selected" from="FileDialog" to="." method="_on_FileDialog_file_selected"]

src/UI/Timeline/LayerEffects/LayerEffectsSettings.gd

@@ -37,6 +37,11 @@ var effects: Array[LayerEffect] = [
 func _ready() -> void:
 	for effect in effects:
 		effect_list.get_popup().add_item(effect.name)
+	if not DirAccess.dir_exists_absolute(OpenSave.SHADERS_DIRECTORY):
+		DirAccess.make_dir_recursive_absolute(OpenSave.SHADERS_DIRECTORY)
+	for file_name in DirAccess.get_files_at(OpenSave.SHADERS_DIRECTORY):
+		_load_shader_file(OpenSave.SHADERS_DIRECTORY.path_join(file_name))
+	OpenSave.shader_copied.connect(_load_shader_file)
 	effect_list.get_popup().id_pressed.connect(_on_effect_list_id_pressed)
 
 
@@ -49,7 +54,8 @@ func _on_about_to_popup() -> void:
 	var layer := Global.current_project.layers[Global.current_project.current_layer]
 	enabled_button.button_pressed = layer.effects_enabled
 	for effect in layer.effects:
-		_create_effect_ui(layer, effect)
+		if is_instance_valid(effect.shader):
+			_create_effect_ui(layer, effect)
 
 
 func _on_visibility_changed() -> void:
@@ -59,6 +65,14 @@ func _on_visibility_changed() -> void:
 			child.queue_free()
 
 
+func _load_shader_file(file_path: String) -> void:
+	var file := load(file_path)
+	if file is Shader:
+		var effect_name := file_path.get_file().get_basename()
+		effects.append(LayerEffect.new(effect_name, file))
+		effect_list.get_popup().add_item(effect_name)
+
+
 func _on_effect_list_id_pressed(index: int) -> void:
 	var layer := Global.current_project.layers[Global.current_project.current_layer]
 	var effect := effects[index].duplicate()

src/UI/TopMenuContainer/TopMenuContainer.gd

@@ -14,6 +14,7 @@ const HEART_ICON := preload("res://assets/graphics/misc/heart.svg")
 var recent_projects := []
 var selected_layout := 0
 var zen_mode := false
+var loaded_effects_submenu: PopupMenu
 
 # Dialogs
 var new_image_dialog := Dialog.new("res://src/UI/Dialogs/CreateNewImage.tscn")
@@ -40,7 +41,7 @@ var gradient_map_dialog := Dialog.new("res://src/UI/Dialogs/ImageEffects/Gradien
 var palettize_dialog := Dialog.new("res://src/UI/Dialogs/ImageEffects/PalettizeDialog.tscn")
 var pixelize_dialog := Dialog.new("res://src/UI/Dialogs/ImageEffects/PixelizeDialog.tscn")
 var posterize_dialog := Dialog.new("res://src/UI/Dialogs/ImageEffects/Posterize.tscn")
-var shader_effect_dialog := Dialog.new("res://src/UI/Dialogs/ImageEffects/ShaderEffect.tscn")
+var loaded_effect_dialogs: Array[Dialog] = []
 var manage_layouts_dialog := Dialog.new("res://src/UI/Dialogs/ManageLayouts.tscn")
 var window_opacity_dialog := Dialog.new("res://src/UI/Dialogs/WindowOpacityDialog.tscn")
 var about_dialog := Dialog.new("res://src/UI/Dialogs/AboutDialog.tscn")
@@ -79,21 +80,24 @@ class Dialog:
 
 	func popup(dialog_size := Vector2i.ZERO) -> void:
 		if not is_instance_valid(node):
-			var scene := load(scene_path)
-			if not scene is PackedScene:
-				return
-			node = scene.instantiate()
-			if not is_instance_valid(node):
-				return
-			Global.control.get_node("Dialogs").add_child(node)
+			instantiate_scene()
 		node.popup_centered(dialog_size)
 		var is_file_dialog := node is FileDialog
 		Global.dialog_open(true, is_file_dialog)
 
+	func instantiate_scene() -> void:
+		var scene := load(scene_path)
+		if not scene is PackedScene:
+			return
+		node = scene.instantiate()
+		if is_instance_valid(node):
+			Global.control.get_node("Dialogs").add_child(node)
+
 
 func _ready() -> void:
 	Global.project_switched.connect(_project_switched)
 	Global.cel_switched.connect(_update_current_frame_mark)
+	OpenSave.shader_copied.connect(_load_shader_file)
 	_setup_file_menu()
 	_setup_edit_menu()
 	_setup_view_menu()
@@ -457,15 +461,45 @@ func _setup_effects_menu() -> void:
 		"Gaussian Blur": "gaussian_blur",
 		"Gradient": "gradient",
 		"Gradient Map": "gradient_map",
-		# "Shader": ""
+		"Loaded": ""
 	}
 	var i := 0
 	for item in menu_items:
-		_set_menu_shortcut(menu_items[item], effects_menu, i, item)
+		if item == "Loaded":
+			_setup_loaded_effects_submenu()
+		else:
+			_set_menu_shortcut(menu_items[item], effects_menu, i, item)
 		i += 1
 	effects_menu.id_pressed.connect(effects_menu_id_pressed)
 
 
+func _setup_loaded_effects_submenu() -> void:
+	if not DirAccess.dir_exists_absolute(OpenSave.SHADERS_DIRECTORY):
+		DirAccess.make_dir_recursive_absolute(OpenSave.SHADERS_DIRECTORY)
+	var shader_files := DirAccess.get_files_at(OpenSave.SHADERS_DIRECTORY)
+	if shader_files.size() == 0:
+		return
+	for shader_file in shader_files:
+		_load_shader_file(OpenSave.SHADERS_DIRECTORY.path_join(shader_file))
+
+
+func _load_shader_file(file_path: String) -> void:
+	var file := load(file_path)
+	if file is not Shader:
+		return
+	var effect_name := file_path.get_file().get_basename()
+	if not is_instance_valid(loaded_effects_submenu):
+		loaded_effects_submenu = PopupMenu.new()
+		loaded_effects_submenu.set_name("loaded_effects_submenu")
+		loaded_effects_submenu.id_pressed.connect(_loaded_effects_submenu_id_pressed)
+		effects_menu.add_child(loaded_effects_submenu)
+		effects_menu.add_submenu_item("Loaded", loaded_effects_submenu.get_name())
+	loaded_effects_submenu.add_item(effect_name)
+	var effect_index := loaded_effects_submenu.item_count - 1
+	loaded_effects_submenu.set_item_metadata(effect_index, file)
+	loaded_effect_dialogs.append(Dialog.new("res://src/UI/Dialogs/ImageEffects/ShaderEffect.tscn"))
+
+
 func _setup_select_menu() -> void:
 	# Order as in Global.SelectMenu enum
 	var select_menu_items := {
@@ -770,6 +804,17 @@ func _snap_to_submenu_id_pressed(id: int) -> void:
 		snap_to_submenu.set_item_checked(id, Global.snap_to_perspective_guides)
 
 
+func _loaded_effects_submenu_id_pressed(id: int) -> void:
+	var dialog := loaded_effect_dialogs[id]
+	if is_instance_valid(dialog.node):
+		dialog.popup()
+	else:
+		dialog.instantiate_scene()
+		var shader := loaded_effects_submenu.get_item_metadata(id) as Shader
+		dialog.node.change_shader(shader, loaded_effects_submenu.get_item_text(id))
+		dialog.popup()
+
+
 func _panels_submenu_id_pressed(id: int) -> void:
 	if zen_mode:
 		return
@@ -950,8 +995,6 @@ func effects_menu_id_pressed(id: int) -> void:
 			pixelize_dialog.popup()
 		Global.EffectsMenu.POSTERIZE:
 			posterize_dialog.popup()
-		#Global.EffectsMenu.SHADER:
-		#shader_effect_dialog.popup()
 		_:
 			_handle_metadata(id, effects_menu)