Optimized performance for complex shaders and refactored some of the code - fixes #1

src/Camera.gd

@@ -1,17 +1,16 @@
 extends Camera2D
 
 var drag = false
-var _freeze = false
 
 @onready var user_interface_container = get_parent().get_node("UI_Layer/UserInterfaceContainer")
 @onready var image_viewport = get_parent().get_node("ImageViewport")
 
 func _input(event):
-	if event.is_action_pressed("zoom_out") && !_freeze:
+	if event.is_action_pressed("zoom_out") && !Globals.camera_freeze:
 		zoom_out()
-	elif event.is_action_pressed("zoom_in") && !_freeze:
+	elif event.is_action_pressed("zoom_in") && !Globals.camera_freeze:
 		zoom_in()
-	if event.is_action_pressed("drag") && !_freeze:
+	if event.is_action_pressed("drag") && !Globals.camera_freeze:
 		drag = true
 	elif event.is_action_released("drag"):
 		drag = false
@@ -20,7 +19,7 @@ func _input(event):
 
 func fit_image():
 	var ui_container_size = user_interface_container.size
-	var image_size = image_viewport.image_original.get_size()
+	var image_size = image_viewport.image_original_tex.get_size()
 	var viewport_size = get_viewport_rect().size
 	var zoomf = (viewport_size.x - ui_container_size.x) / image_size.x / 1.1
 	if zoomf * image_size.y > viewport_size.y:
@@ -38,11 +37,5 @@ func zoom_out():
 	zoom *= 1/1.2
 	global_position += old_mouse_pos - get_global_mouse_position()
 
-func freeze():
-	_freeze = true
-
-func unfreeze():
-	_freeze = false
-
 func _on_fit_image_button_pressed():
 	fit_image()

src/Editor.gd

@@ -2,10 +2,6 @@ extends Control
 
 @onready var preset_options = $PresetOptions
 @onready var code_editor = $CodeEdit
-
-@onready var camera_freeze = get_parent().get_parent().get_parent().find_child("Camera").freeze
-@onready var camera_unfreeze = get_parent().get_parent().get_parent().find_child("Camera").unfreeze
-
 var selected_preset_name = ShaderPresets.default_preset
 
 #
@@ -99,24 +95,30 @@ func _on_code_edit_code_completion_requested():
 
 #
 
+func _camera_freeze():
+	Globals.camera_freeze = true
+
+func _camera_unfreeze():
+	Globals.camera_freeze = false
+
 func _ready():
 	code_editor.code_completion_enabled = true
 	code_editor.syntax_highlighter = ShaderSyntaxHighlighter.new()
 	for c in get_children():
-		c.connect("mouse_entered", camera_freeze)
-		c.connect("mouse_exited", camera_unfreeze)
+		c.connect("mouse_entered", _camera_freeze)
+		c.connect("mouse_exited", _camera_unfreeze)
 	update()
 
 func _on_code_edit_text_changed():
 	var shader = Shader.new()
 	shader.code = code_editor.text
-	GlitchShader.shader = shader
-	GlitchShader.apply()
+	Globals.shader = shader
+	Globals.target_viewport.update()
 
 func _on_preset_options_item_selected(index):
 	selected_preset_name = preset_options.get_item_text(index)
-	GlitchShader.shader = ShaderPresets.presets[selected_preset_name]
-	GlitchShader.apply()
+	Globals.shader = ShaderPresets.presets[selected_preset_name]
+	Globals.target_viewport.update()
 	update()
 
 func update():
@@ -131,4 +133,4 @@ func update():
 		preset_options.add_item(p)
 	preset_options.select(current_p_idx)
 	# weirdness ends here
-	code_editor.text = GlitchShader.shader.code
+	code_editor.text = Globals.shader.code

src/GlitchShader.gd

@@ -1,10 +0,0 @@
-extends Node
-
-var target_sprite: Sprite2D
-
-@onready var shader: Shader = ShaderPresets.presets[ShaderPresets.default_preset]
-
-func apply():
-	var mat = ShaderMaterial.new()
-	mat.shader = shader
-	target_sprite.material = mat

src/Globals.gd

@@ -0,0 +1,5 @@
+extends Node
+
+var camera_freeze = false
+@onready var shader: Shader = ShaderPresets.presets[ShaderPresets.default_preset]
+var target_viewport: SubViewport

src/ImageViewport.gd

@@ -2,10 +2,26 @@ extends SubViewport
 
 @onready var image_sprite = $ImageSprite
 
-var image_original: ImageTexture
+var image_original_tex: ImageTexture
+var image_result: Image
 
 func set_original_image(image: Image):
-	image_original = ImageTexture.create_from_image(image)
-	image_sprite.texture = image_original
-	image_sprite.offset = image_original.get_size() / 2
-	size = image_original.get_size()
+	image_original_tex = ImageTexture.create_from_image(image)
+	image_sprite.texture = image_original_tex
+	image_sprite.offset = image_original_tex.get_size() / 2
+	size = image_original_tex.get_size()
+
+func update():
+	if image_original_tex != null:
+		image_sprite.texture = image_original_tex
+		var mat = ShaderMaterial.new()
+		mat.shader = Globals.shader
+		image_sprite.material = mat
+		# Get viewport texture
+		await RenderingServer.frame_post_draw # for good measure
+		image_result = get_texture().get_image()
+		image_sprite.material = null
+		image_sprite.texture = ImageTexture.create_from_image(image_result)
+
+func get_result():
+	return image_result

src/Main.gd

@@ -2,14 +2,12 @@ extends Node2D
 
 @onready var camera = $Camera
 @onready var image_viewport = $ImageViewport
-@onready var image_sprite = $ImageViewport/ImageSprite
 @onready var ui_container = $UI_Layer/UserInterfaceContainer
 @onready var ui_control_fileopen = $UI_Layer/UserInterfaceContainer/OpenFileDialog
 @onready var ui_control_filesave = $UI_Layer/UserInterfaceContainer/SaveFileDialog
 
 func _ready():
-	GlitchShader.target_sprite = image_sprite
-	GlitchShader.shader = ShaderPresets.presets[ShaderPresets.default_preset]
+	Globals.target_viewport = image_viewport
 
 func _on_open_image_button_pressed():
 	if OS.get_name() == "Android":
@@ -22,7 +20,7 @@ func _on_open_file_dialog_file_selected(path):
 	var err = img.load(path)
 	if err == OK:
 		image_viewport.set_original_image(img)
-		GlitchShader.apply()
+		image_viewport.update()
 		camera.fit_image()
 	else:
 		print("An error occured!")
@@ -31,9 +29,6 @@ func _on_save_image_button_pressed():
 	ui_control_filesave.show()
 
 func _on_save_file_dialog_file_selected(path):
-	# Get viewport texture
-	await RenderingServer.frame_post_draw # for good measure
-	var img = image_viewport.get_texture().get_image()
-	var err = img.save_png(path)
+	var err = image_viewport.get_result().save_png(path)
 	if err != OK:
 		print("An error occured!")