Module: SFML::Audio

Defined in:
lib/sfml/audio/internal.rb

Class Method Summary collapse

Class Method Details

._build_effect_processor(callable) ⇒ Object

Build an FFI::Function that adapts CSFML’s effect-processor signature (raw float buffers, in/out frame counts) to a Ruby callable taking ‘(samples, channels)` and returning samples.

Returns the FFI::Function — callers must keep a strong Ruby reference to it for as long as it’s installed (otherwise GC collects the closure and the audio thread crashes).



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# 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