Method: PSD::Compose#multiply

Defined in:
lib/psd/renderer/compose.rb

#multiply(fg, bg, opacity) ⇒ Object 



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# File 'lib/psd/renderer/compose.rb', line 43

def multiply(fg, bg, opacity)
  return apply_opacity(fg, opacity) if fully_transparent?(bg)
  return bg if fully_transparent?(fg)

  mix_alpha, dst_alpha = calculate_alphas(fg, bg, opacity)
  new_r = blend_channel(r(bg), r(fg) * r(bg) >> 8, mix_alpha)
  new_g = blend_channel(g(bg), g(fg) * g(bg) >> 8, mix_alpha)
  new_b = blend_channel(b(bg), b(fg) * b(bg) >> 8, mix_alpha)

  rgba(new_r, new_g, new_b, dst_alpha)
end