Class: Portmidi::Output

Inherits:
Object
  • Object
show all
Defined in:
lib/portmidi/output.rb

Instance Method Summary collapse

Constructor Details

#initialize(device_id = 0, buffer_size = 0, latency = 0) ⇒ Output

open a device with the given ID



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# File 'lib/portmidi/output.rb', line 7

def initialize(device_id = 0, buffer_size = 0, latency = 0)
  out_stream_ptr = FFI::MemoryPointer.new(:pointer)
  if (errnum = PM_Map.Pm_OpenOutput(out_stream_ptr, device_id, nil, buffer_size, nil, nil, latency)) == 0
    @out_stream = out_stream_ptr.read_pointer
  else
    raise Portmidi::DeviceError, errnum, "Could not open Device #{device_id} as output device"
  end
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/portmidi/output.rb', line 16

def close
  PM_Map.Pm_Close(@out_stream)
end

#write(messages) ⇒ Object 



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# File 'lib/portmidi/output.rb', line 28

def write(messages)
  buffer = FFI::MemoryPointer.new(PM_Map::Event, messages.length)
  messages.length.times do |i|
    event = PM_Map::Event.new(buffer[i])
    event[:timestamp] = messages[i][:timestamp]
    event[:message] = packEvent(messages[i][:message])
  end
  PM_Map.Pm_Write(@out_stream, buffer, messages.length)
end

#write_short(status, data1, data2) ⇒ Object

write a single three byte message



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# File 'lib/portmidi/output.rb', line 24

def write_short(status, data1, data2)
  PM_Map.Pm_WriteShort(@out_stream, 0, PM_Map.encode_message(status, data1, data2))
end

#write_sysex(sysex) ⇒ Object

sends the sysex, the message should be an array of byte values



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# File 'lib/portmidi/output.rb', line 43

def write_sysex(sysex)
  raise "Invalid Sysex Format" if (sysex.first != 0xF0 || sysex.last != 0xF7)
  msg = FFI::Buffer.alloc_in(:uchar, sysex.length)
  sysex.each_with_index do |sysx, i|
    msg.put_uchar(i, sysx & 0xFF)
  end
  PM_Map.Pm_WriteSysEx(@out_stream, 0, msg)
end