struct DrawIndirectArgs {
  vertexCount : atomic<u32>;
}

[[group(0), binding(5)]] var<storage, read_write> drawOut : DrawIndirectArgs;

var<private> cubeVerts : u32 = 0u;

[[stage(compute), workgroup_size(1)]]
fn computeMain([[builtin(global_invocation_id)]] global_id : vec3<u32>) {
  let firstVertex : u32 = atomicAdd(&(drawOut.vertexCount), cubeVerts);
}