func marshalControlFlags(c ControlFlags) (n int) {
n = bits.SetCond(n, 7, c.UseMaximumTime)
n = bits.SetCond(n, 6, c.UseMinimumTime)
n = bits.SetCond(n, 5, c.SyncWithAdjacentStation)
n = bits.SetCond(n, 4, c.LeaveIfAnotherTrainArrives)
n = bits.SetCond(n, 3, c.WaitForLoad)
n |= int(c.Load)
return n
}
// Turn track elements back into bytes (opposite of above function)
//
// Taken from http://freerct.github.io/RCTTechDepot-Archive/trackQualifier.html
func marshalElement(e Element) ([]byte, error) {
buf := make([]byte, 2)
buf[0] = byte(e.Segment.Type)
featureBit := 0
featureBit = bits.SetCond(featureBit, 7, e.ChainLift)
featureBit = bits.SetCond(featureBit, 6, e.InvertedTrack)
featureBit = bits.SetCond(featureBit, 3, e.Station)
if e.Segment.Type == ELEM_END_STATION || e.Segment.Type == ELEM_BEGIN_STATION || e.Segment.Type == ELEM_MIDDLE_STATION {
// Set the station bit
featureBit |= e.StationNumber
}
// XXX booster?
if e.Segment.Type == ELEM_BRAKES || e.Segment.Type == ELEM_BLOCK_BRAKES {
bm := e.BoostMagnitude / 7.6
featureBit |= int(bm)
} else {
// 2nd bit seems to be set in most cases.
featureBit |= 1 << 2
}
// XXX, rotation for multi dimensional coasters
buf[1] = byte(featureBit)
return buf, nil
}
func marshalEgress(egr Egress) ([]byte, error) {
buf := make([]byte, 6)
ftrBit := egr.Direction
ftrBit = bits.SetCond(ftrBit, 7, egr.Exit)
buf[1] = byte(ftrBit)
b := new(bytes.Buffer)
err := binary.Write(b, binary.LittleEndian, egr.XOffset)
if err != nil {
return []byte{}, err
}
copy(buf[2:4], b.Bytes())
b.Reset()
err = binary.Write(b, binary.LittleEndian, egr.YOffset)
if err != nil {
return []byte{}, err
}
copy(buf[4:6], b.Bytes())
return buf, nil
}