struct Simulation {
  i : u32;
};

struct Particle {
  position : array<vec3<f32>, 8>;
  lifetime : f32;
  color    : vec4<f32>;
  velocity : vec3<f32>;
};

struct Particles {
  p : array<Particle>;
};

[[group(1), binding(3)]] var<storage, read> particles : Particles;
[[group(1), binding(4)]] var<uniform> sim : Simulation;

[[stage(compute), workgroup_size(1)]]
fn main() {
  var particle = particles.p[0];
  particle.position[sim.i] = particle.position[sim.i];
}