How to bind a SubViewport's output texture with a Rd uniform?

Help Shaders
1

Godot Version

godot 4.4 dev6

Question

I’m trying to struct a shader to reprosses SubViewport’s(or Camera2D’s) output texture, witch has to use the data from the previous frame which the shader outputs. In this case, I must bind the subViewport’s texture with a uniform so that I can offer it to a compute shader written by glsl. However I cannot find a function transporting godot texture to Rd texture(without Low-performance get_image). I would appreciate it if you can raise some suggestions. Thanks so much!