How to Get Value of a GradientTexture2d

I am trying to make a procedurally generated island. I think I am almost finished with actual terrain generation part using OpenSimplex noise, only thing left is making it into a island surrounded by water. For that I am using a radial gradient Texture something that looks a bit like the picture below:

Only issue is I don't know how to get the Gradiant value. Preferably I am looking for a function that can return value from 0-1 based on the white and black areas of the map. I checked docs countless times and searched online, only thing I could find is get_offset() function but I am not sure how it works or if its what I am looking for. Thanks in advance.

If you want to read the pixels of a Texture from GDScript, you need to:

• Get a reference to the Texture. GradientTexture2d is a Texture.
• Get an Image of the Texture by calling the get_data method.
• Call the lock method on the Image, so you can access the pixels. Remember to call unlock later.
• Call either the get_pixel method or the get_pixelv method on it, which gives you a Color.
• Call the unlock method on the image.

On the other hand, if you want to work with the Gradient from GDScript, you need to:

• Call the interpolate method on the Gradient which gives you a Color. You can get the Gradient of a GradientTexture2D by reading the gradient property.

Either way, you would have a Color. Now, you probably want to read one of the channels of the Color. For that you can access the r, g, b and a properties of the Color. If your image is gray scale, the r, g, b properties of the Colors you get from it should be equal, so either of them will do.

Addendum: On Godot 4.x we no longer need to use lock/unlock.