How to pass a Texture2D to a CompositorEffect shader?

[dalzotto]

Godot Version

Windows 10, v4.3.stable.official [77dcf97d8]

Question

Does anyone know how the Compositor works?

I’m trying to read a Texture2D in a Compositor shader, a simple noise texture, but this data size error keeps happening.

E 0:00:01:0598   effect_compositor.gd:118 @ create_channel_texture(): Data for slice index 0 (mapped to layer 0) differs in size (supplied: 1398100) than what is required by the format (1048576).
  <C++ Error>    Condition "(uint32_t)p_data[i].size() != required_size" is true. Returning: RID()
  <C++ Source>   servers/rendering/rendering_device.cpp:722 @ texture_create()
  <Stack Trace>  effect_compositor.gd:118 @ create_channel_texture()
                 effect_compositor.gd:208 @ _render_callback()

Based in some tutorials on the matter, I am correctly converting the texture to the right format, but looks like it’s not working. My function for creating the RID textures:

...

var device: RenderingDevice

func create_channel_texture(texture: Texture2D) -> RID:
	if not device:
		return RID()

	var image: Image = texture.get_image()
	image.convert(Image.FORMAT_RF)

	var format: RDTextureFormat = RDTextureFormat.new()
	format.width = image.get_width()
	format.height = image.get_height()
	format.format = RenderingDevice.DATA_FORMAT_R32_SFLOAT
	format.usage_bits = RenderingDevice.TEXTURE_USAGE_SAMPLING_BIT

	return device.texture_create(format, RDTextureView.new(), [image.get_data()])

...

I need help so bad, documentation simply do not exist on this.

[dalzotto]

For any person looking for it

There is a very comprehensive blog post I founded on Textures and Compute Shaders in Godot 4 made by @leopeltola on it, this helped.

But for my error, I use Image.clear_mipmaps(), I don’t needed.

Make sure that the minimaps parameters in the Image and RDTextureFormat are the same too!