// Parse the serialized data into a Element struct
// When the end of ride is encountered a EndOfRide error is returned
// Documentation from
// http://freerct.github.io/RCTTechDepot-Archive/trackQualifier.html
func unmarshalElement(rawElement []byte) (te Element, e error) {
if len(rawElement) != 2 {
return Element{}, errors.New("invalid length for element input")
}
// XXX hack for brakes
if rawElement[0] == 0xd8 {
rawElement[0] = ELEM_BRAKES
}
te.Segment = TS_MAP[SegmentType(rawElement[0])]
if te.Segment.Type == ELEM_END_OF_RIDE {
return Element{}, EndOfRide
}
q := int(rawElement[1])
te.ChainLift = bits.On(q, 7)
te.InvertedTrack = bits.On(q, 6)
te.Station = bits.On(q, 3)
if te.Station {
fmt.Println("found station piece")
fmt.Println(te.Segment)
}
te.StationNumber = q & 3
te.BoostMagnitude = float32(q&15) * 7.6
te.Rotation = (q&15)*45 - 180
return
}
// XXX, this doesn't correctly handle s-bends, which only move sideways by 1
// piece, I think.
func SidewaysDelta(sidewaysDeltaByte int) int {
if sidewaysDeltaByte == 0 {
return 0
}
if bits.On(sidewaysDeltaByte, 7) {
return 1 + (256-sidewaysDeltaByte)>>5
}
return -(1 + sidewaysDeltaByte>>5)
}
func testMarshalControlFlags(t *testing.T) {
t.Parallel()
cFlags := ControlFlags{
Load: 3,
UseMaximumTime: true,
}
n := marshalControlFlags(cFlags)
if !bits.On(n, 7) {
t.Errorf("Maximum time bit should have been set, but wasn't, n is %d", n)
}
}
// Get list of entrances/exits for a ride from raw data
// Copied mostly from "Scenery Items" here:
// http://freerct.github.io/RCTTechDepot-Archive/TD6.html
func unmarshalEgress(buf []byte) []*Egress {
var egrs []*Egress
for i := 0; true; i += 6 {
if buf[i] == 0xff {
break
}
features := int(buf[i+1])
egr := &Egress{
Exit: bits.On(features, 7),
// Direction set in lower two bits
Direction: features & 3,
XOffset: int16(binary.LittleEndian.Uint16(buf[i+2 : i+4])),
YOffset: int16(binary.LittleEndian.Uint16(buf[i+4 : i+6])),
}
egrs = append(egrs, egr)
}
return egrs
}
func hasBit(n int, pos uint) bool {
return bits.On(n, pos)
}
func hasLoop(n int) bool {
return bits.On(n, BIT_VERTICAL_LOOP)
}
// Take a compressed byte stream representing a ride and turn it into a Ride
// struct. Returns an error if the byte array is too short.
func Unmarshal(buf []byte, r *Ride) error {
if len(buf) < IDX_TRACK_DATA {
return errors.New("buffer too short to be a ride")
}
r.RideType = RideType(buf[IDX_RIDE_TYPE])
featuresBit0 := int(buf[IDX_FEATURES_0])
r.SteepLiftChain = bits.On(featuresBit0, BIT_STEEP_LIFT_CHAIN)
r.CurvedLiftChain = bits.On(featuresBit0, BIT_CURVED_LIFT_CHAIN)
r.Banking = bits.On(featuresBit0, BIT_BANKING)
r.HasLoop = bits.On(featuresBit0, BIT_VERTICAL_LOOP)
featuresBit1 := int(buf[IDX_FEATURES_1])
r.SteepSlope = bits.On(featuresBit1, BIT_STEEP_SLOPE)
r.FlatToSteep = bits.On(featuresBit1, BIT_FLAT_TO_STEEP)
r.SlopedCurves = bits.On(featuresBit1, BIT_SLOPED_CURVES)
r.SteepTwist = bits.On(featuresBit1, BIT_STEEP_TWIST)
r.SBends = bits.On(featuresBit1, BIT_S_BENDS)
r.SmallRadiusCurves = bits.On(featuresBit1, BIT_SMALL_RADIUS_CURVES)
r.SmallRadiusBanked = bits.On(featuresBit1, BIT_SMALL_RADIUS_BANKED)
r.OperatingMode = OperatingMode(buf[IDX_OPERATING_MODE])
r.ControlFlags = unmarshalControlFlags(int(buf[IDX_CONTROL_FLAG]))
r.NumTrains = uint8(buf[IDX_NUM_TRAINS])
r.CarsPerTrain = uint8(buf[IDX_CARS_PER_TRAIN])
r.MinWaitTime = uint8(buf[IDX_MIN_WAIT_TIME])
r.MaxWaitTime = uint8(buf[IDX_MAX_WAIT_TIME])
r.NumInversions = uint8(buf[IDX_NUM_INVERSIONS])
r.MaxSpeed = uint8(buf[IDX_MAX_SPEED])
r.AverageSpeed = uint8(buf[IDX_AVERAGE_SPEED])
d := new(tracks.Data)
tracks.Unmarshal(buf[IDX_TRACK_DATA:], d)
r.TrackData = *d
r.VehicleType = VehicleType(string(buf[IDX_VEHICLE_TYPE_STRING : IDX_VEHICLE_TYPE_STRING+LENGTH_VEHICLE_TYPE]))
r.XSpaceRequired = int(buf[IDX_X_SPACE])
r.YSpaceRequired = int(buf[IDX_Y_SPACE])
r.DatData = buf[0x70:0x80]
// XXX, not sure if this fn should know about this, or the track data
entranceExitIdx := IDX_TRACK_DATA + 2*len(r.TrackData.Elements) + 1
r.Egresses = unmarshalEgress(buf[entranceExitIdx:])
r.Excitement = int16(buf[IDX_EXCITEMENT])
r.Intensity = int16(buf[IDX_INTENSITY])
r.Nausea = int16(buf[IDX_NAUSEA])
// Ignore scenery data for now.
// sceneryIdx := entranceExitIdx + 6*len(r.Egresses) + 1
return nil
}