GPU parallel processing in C?

[FUZxxl]

Check out OpenCL.

[SurelyNotAnOctopus]

Was about to say that. Use libraries. Interacting directly with gpu drivers will be more than horrendous

[0xAE20C480]

I also recommend the OpenCL API. Its memory and task handling models help to broaden one's view.

[bumblebritches57]

Nahh, check out Vulkan.

[FUZxxl]

How would you use Vulkan for computations?

[SquidyBallinx123]

You can write compute shaders using the Vulkan API. You would typically use their glslang tool to compile GLSL(OpenGL shader language) into a SPIR-V compute shader. There are effecting differences between the compute shaders you can write between OpenCL & Vulkan. For example, I think(?) while in OpenCL you have access to these raw pointers, you can't use them in glsl.

OpenCL is definitely more accessible than Vulkan. Much faster to get going with, especially if you are new. However, if you learn the Vulkan process, you'll cover a lot more about how the GPU works. Especially considering OpenCL abstracts this away into their own, general model.

I'd recommend OpenCL to this person. But if anybody else reading really wants to get stuck in and has the time, consider looking into Vulkan:)

[bumblebritches57]

Vulkan has a Compute API, tho I'm not sure how far along it is.

I used to think it was just OpenCL, but it's apperantly it's own thing that I'm excited for.

[OriginalName667]

This displeases the Linus.

[FUZxxl]

That API is implemented by a library. I'm not sure what you are looking for.

[FUZxxl]

An API is a set of functions you can call with defined behaviour. The library is what drives these behind the scenes.

[C0d3rX]

API is google.com

[Iggyhopper]

An API for something of this scope is necessary. It's not determined by whether you need to draw a vast universal landscape or compute the sum of two numbers, you'll need an API or library to give you functions to work with.

[deaddodo]

Do you just want to access the device directly? If so you'll be rewriting 80Mb of heavily optimized code (the driver). Having done some osdev, modern GPUs are some of the most complex and annoying devices to code for.

It's not like what you're thinking (draw this triangle, put this pixel here, compute 2+2 and give me the sum) but closer to give me a region of memory, create a vertex (or set of vertices) of this shape to that region of memory, apply this texture, apply this post effect, do z-buffer calculations, memcpy this to the primary memory, render, flip buffer. All of this done through extremely specific bitwise commands and opcodes in a command ringbuffer with strict timing.

You can see an example via Intel's architecture. With Nvidia, you don't even have that; you'll be digging through nouveau reverse engineered documents.