Draw Direct To Screen With CUDA/OPENCL

Question

Is it possible yet to draw CUDA/OPENCL results directly to the screen with any existing API (opengl, directx, something else)? Skipping the typical drawing a textured quad method.

Even with registering resources and using modern CUDA interop methods, we still have to march through entire rendering pipelines just to render an array of colors. For applications like mine where every ms counts, this is a problem.

Answer 1

There's no way to draw directly on the screen with OpenCL or CUDA.

It is a solvable problem, but as far as I know, NVIDIA has not provided the needed APIs because they would be very complicated both to implement and to use, and the performance benefits would be limited at best.

The two main issues are:

1) the differing layouts of the buffers used for rendering (i.e. you'd have to use surface load/store functionality - a mapping into CUDA's address space is not suitable for graphics because the pitch-linear layout has poor performance in that context) and

2) the platform-specific details of incorporating your CUDA/OpenCL output into the presentation model (be it the desktop or a page-flipped full-screen experience, like a Direct3D game, or incorporating your app's output into the desktop). Bear in mind that most desktops these days are themselves page-flipped, so scribbling on the front buffer is frowned upon in any case.