message: sample_pixel_impl() also generates rays
diff: @@ -356,16 +356,16 @@ template <
  typename K,
  typename R,
  typename Generator,
  - pixel_format CF,
  + typename RenderTargetRef,
  typename Camera
  >
  VSNRAY_FUNC
  inline void sample_pixel_impl(
  K kernel,
  - pixel_sampler::jittered_type /* */,
  - R const& r,
  + pixel_sampler::jittered_type ps,
  + R const& /* */,
  Generator& gen,
  - render_target_ref<CF> rt_ref,
  + RenderTargetRef rt_ref,
  int x,
  int y,
  int width,
  @@ -375,9 +375,31 @@ inline void sample_pixel_impl(
  {
  VSNRAY_UNUSED(cam);
  + using RR = decltype(invoke_kernel(kernel, R{}, gen, x, y));
  + using S = typename RR::scalar_type;
  +
  + auto r = make_primary_ray(
  + R{},
  + ps,
  + gen,
  + x,
  + y,
  + width,
  + height,
  + cam
  + );
  +
  auto result = invoke_kernel(kernel, r, gen, x, y);
  +
  + // Arbitrarily assign the depth of _one_ pixel that recorded a hit
  + if (RenderTargetRef::depth_format != PF_UNSPECIFIED)
  + {
  + result.depth = select(result.hit, depth_transform(r, result.depth, cam), S(1.0));
  + }
  +
  +
  pixel_access::store(
  - pixel_format_constant<CF>{},
  + pixel_format_constant<RenderTargetRef::color_format>{},
  pixel_format_constant<PF_RGBA32F>{},
  x,
  y,
  