How to ResourceSave an import plugin created Image object?

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1

Godot Version

v4.5.1.stable.arch_linux

Question

Hi community, I am trying to make a custom image importer, that remaps one image’s colours to the positions of where said colour is on another image. So far, I (think I) managed to make the biggest part of logic, but I fail in saving the resource.

# ...
func _get_save_extension() -> String:
	return "..." # What do I need to put here?


func _get_resource_type() -> String:
	return "..." # What do I need to put here?

# ...

func _import(source_file: String, save_path: String, options: Dictionary, platform_variants: Array[String], gen_files: Array[String]) -> Error:
#region Prepare UV-Map
	var uv_map := Image.load_from_file(options.uv_map)
	if uv_map == null:
		return ERR_CANT_ACQUIRE_RESOURCE

	var uv_size := uv_map.get_size()
	var color_positions: Dictionary[Color, Color]

	for y in uv_size.y:
		for x in uv_size.x:
			color_positions[uv_map.get_pixel(x, y)] = Color(x, y, 0, 1)
#endregion

#region Generate new Image
	var image := Image.load_from_file(source_file)
	var size: Vector2i = image.get_size()
	var new_image := Image.create(image.get_width(), image.get_height(), image.has_mipmaps(), image.get_format())
	new_image.copy_from(image)

	for y in size.y:
		for x in size.x:
			var color := image.get_pixel(x, y)
			new_image.set_pixel(x, y, color_positions[color])
#endregion

	# How do I save the image?
	return ResourceSaver.save(new_image, "%s.%s" % [save_path, _get_save_extension()])

My main questions are:

  • What format does it need?
    • I see that other imported PNGs get saved as ctex in .godot/imported/
    • They seem to be CompressedTexture2Ds
    • So the question is, what do I need to return in the methods _get_save_extension() and _get_resource_type()?
  • How do I save my custom Image with the ResourceSaver?
2

You won’t be able to save it as a CompressedTexture2D because this resource creation is internal to Godot and not exposed to scripting. You’ll need to use a ImageTexture instead. For the _get_save_extension() you can use return "res" and for the _get_resource_type() the type of the Resource which is return "Texture2D" in this case.

You may be able to use the PortableCompressedTexture2D resource instead but I’ve not tested it.

1 Like
3

You can also return "tres” for the extension if you want it to be saved in a human-readable format.

4

Thanks, before receiving your answer but after posting, I found this GitHub issue about a very similar issue:

I did use the PortableCompressedTexture2D, as simply using the CompressedTexture2D did indeed not work out.