Feature Suggestion: Use RenderingDevice compute shader API to do large FFTs on GPU for performance

[tessarakkt]

Implementing the (I)FFT in a compute shader could significantly help to speed up the process time for larger FFTs.

As part of my ocean system addon, I have a Stockham IFFT implemented in a compute shader that is able to perform IFFT on multiple 2D 256x256 textures each frame at 100+FPS (if the vertex count of the water surface doesn't put too much load on the GPU). I could help in integrating that existing code into your project if you were interested.

This is all done with GDScript and GLSL shaders, so no C++, C#, or custom engine builds are needed.

These are the files which contain relevant code:

• addons/tessarakkt.oceanfft/components/Ocean3D.gd
  • See section titled by comment "Compile & Initialize FFT Shaders" in _ready() for initialization code
  • See section titled by comment "Execute Horizontal FFT Shader Cascades" in _process() for execution code
• addons/tessarakkt.oceanfft/shaders/OceanFFTHorizontal.glsl
• addons/tessarakkt.oceanfft/shaders/OceanFFTVertical.glsl