Zig WebGPU Compute Shader Example

This codebase uses WebGPU to run a really simple shader in zig. I use nix as the build tool to fetch wgpu-native and compile the rust code. It should be pretty easy to do without nix.

The compute shader is taken from here.

The flake.nix uses zig2nix for building and running the code. I set it to use Vulkan but it is pretty easy to use any other backend.

Running

To run the code, simply run:

nix run github:ethanthoma/zig-webgpu-compute-shader

Or clone the repo locally and run nix run.

Input and Output

The input to the compute shader is an array of 32 bit floats. The array is 64 elements long. The value of the elements start at 1 and count to 64. The code below is how it is initalized:

var input_data: [64]f32 = undefined;
for (input_data, 0..) |_, i| {
    input_data[i] = @floatFromInt(i + 1);
}

The output from the shader is each element multipled by 2 and then added to it by 1. The output is below:

[0] = 3e0, [1] = 5e0, [2] = 7e0, [3] = 9e0, [4] = 1.1e1, [5] = 1.3e1,
[6] = 1.5e1, [7] = 1.7e1, [8] = 1.9e1, [9] = 2.1e1, [10] = 2.3e1, [11] = 2.5e1,
[12] = 2.7e1, [13] = 2.9e1, [14] = 3.1e1, [15] = 3.3e1, [16] = 3.5e1, 
[17] = 3.7e1, [18] = 3.9e1, [19] = 4.1e1, [20] = 4.3e1, [21] = 4.5e1,
[22] = 4.7e1, [23] = 4.9e1, [24] = 5.1e1, [25] = 5.3e1, [26] = 5.5e1,
[27] = 5.7e1, [28] = 5.9e1, [29] = 6.1e1, [30] = 6.3e1, [31] = 6.5e1,
[32] = 6.7e1, [33] = 6.9e1, [34] = 7.1e1, [35] = 7.3e1, [36] = 7.5e1,
[37] = 7.7e1, [38] = 7.9e1, [39] = 8.1e1, [40] = 8.3e1, [41] = 8.5e1,
[42] = 8.7e1, [43] = 8.9e1, [44] = 9.1e1, [45] = 9.3e1, [46] = 9.5e1,
[47] = 9.7e1, [48] = 9.9e1, [49] = 1.01e2, [50] = 1.03e2, [51] = 1.05e2,
[52] = 1.07e2, [53] = 1.09e2, [54] = 1.11e2, [55] = 1.13e2, [56] = 1.15e2,
[57] = 1.17e2, [58] = 1.19e2, [59] = 1.21e2, [60] = 1.23e2, [61] = 1.25e2,
[62] = 1.27e2, [63] = 1.29e2,