module SFML::Audio

# File lib/sfml/audio/internal.rb, line 14
def _build_effect_processor(callable)
  FFI::Function.new(
    :void,
    [:pointer, :pointer, :pointer, :pointer, :uint32, :pointer],
  ) do |in_ptr, in_cnt_ptr, out_ptr, out_cnt_ptr, channels, _user|
    in_count  = in_cnt_ptr.read_uint32
    out_count = out_cnt_ptr.read_uint32

    written = 0
    if in_count > 0
      input = in_ptr.read_array_of_float(in_count * channels)
      output =
        begin
          callable.call(input, channels) || []
        rescue => e
          warn "ruby-sfml effect_processor raised: #{e.class}: #{e.message}"
          []
        end

      written = [output.length / channels, out_count].min
      out_ptr.write_array_of_float(output.first(written * channels)) if written.positive?
    end

    out_cnt_ptr.write_uint32(written)
  end
end