// ReadSysExBytes reads 4*max sysex bytes from the input stream.
func (s *Stream) ReadSysExBytes(max int) ([]byte, error) {
if max > maxEventBufferSize {
return nil, errMaxBuffer
}
if max < minEventBufferSize {
return nil, errMinBuffer
}
buffer := make([]C.PmEvent, max)
numEvents := C.Pm_Read(unsafe.Pointer(s.pmStream), &buffer[0], C.int32_t(max))
msg := make([]byte, 4*numEvents)
for i := 0; i < int(numEvents); i++ {
msg[4*i+0] = byte(buffer[i].message & 0xFF)
msg[4*i+1] = byte((buffer[i].message >> 8) & 0xFF)
msg[4*i+2] = byte((buffer[i].message >> 16) & 0xFF)
msg[4*i+3] = byte((buffer[i].message >> 24) & 0xFF)
}
return msg, nil
}
func (s SystemPort) readEvent() (event Event, err error) {
if s.IsInputPort {
err = errors.New("Can only write, not read from input SystemPort.")
return Event{}, err
}
var buffer C.PmEvent
// Only read one event at a time.
eventsRead := int(C.Pm_Read(s.stream, &buffer, C.int32_t(1)))
if eventsRead > 0 {
status := int(buffer.message) & 0xFF
event.Channel = int(status & 0x0F)
event.Command = int(status & 0xF0)
event.Data1 = int((buffer.message >> 8) & 0xFF)
event.Data2 = int((buffer.message >> 16) & 0xFF)
return event, nil
}
return Event{}, nil // Nothing to read.
}
// Reads from the input stream, the max number events to be read are
// determined by max.
func (s *Stream) Read(max int) (events []Event, err error) {
if max > maxEventBufferSize {
return nil, errMaxBuffer
}
if max < minEventBufferSize {
return nil, errMinBuffer
}
buffer := make([]C.PmEvent, max)
numEvents := C.Pm_Read(unsafe.Pointer(s.pmStream), &buffer[0], C.int32_t(max))
events = make([]Event, numEvents)
for i := 0; i < int(numEvents); i++ {
events[i] = Event{
Timestamp: Timestamp(buffer[i].timestamp),
Status: int64(buffer[i].message) & 0xFF,
Data1: (int64(buffer[i].message) >> 8) & 0xFF,
Data2: (int64(buffer[i].message) >> 16) & 0xFF,
}
}
return
}