We would like to be relatively target-agnostic. OpenGL could be one of targets, but not only one. We also would like to work on regular and/or GPU-equipped cluster machines, etc.

On the suggestion in your second part: why use Halide then? Should it be responsibility of Halide to work out the best loop nesting and best use of threads?

Again, Halide was put aside and we used CUDA for final version, exactly because of inability of Halide to do good work in our case.

> Should it be responsibility of Halide to work out the best loop nesting and best use of threads?

I don't know about "should", but it seems to me that it would still be valuable, even if working out the threading and organization.of the data into an array.

> Again, Halide was put aside and we used CUDA for final version, exactly because of inability of Halide to do good work in our case

I didn't say anything about that. I'm not sure why you are restating it.

I suppose Halide was mainly involved for this part:

> transform a series of angle-amplitude pairs (radioastronomy) to the image