vtk.proto

syntax = 'proto3';

package vtk;

/**
 * Protobuf definition file for Velocitek VTK file format.
 *
 * VTK files contain 0 or more Records where each record is written as:
 *   - 2 bytes that encode the length of the protobuf encoded Record (unsigned, little endian)
 *   - n bytes for the Protobuf serialized Record
 *
 * See: https://developers.google.com/protocol-buffers/docs/techniques#streaming
 */

message Record 
{
    oneof record 
    {
        // We reserve low id numbers for frequent messages...
        Trackpoint trackpoint = 1;
        TimerEvent timer_event = 2;

        // Messages with ids 16 and higher will take a bit more space to encode.
        ButtonEvent button_event = 16;
        HardwareDescription hardware_description = 17;
        MagneticDeclination magnetic_declination = 18;
    };
}

message Trackpoint
{
    uint32 seconds = 1;
    uint32 centiseconds = 2;

    // Latitude/Longitude are multiplied by 1E7 to 
    // facilitate storage as integers.
    sint32 latitudeE7 = 3;
    sint32 longitudeE7 = 4;

    // Speed over ground in deciknots (kts * 10-1)
    uint32 sog_knotsE1 = 5;

    // COG in degrees
    uint32 cog = 6;

    // Components of the quaternion, relative to local magnetic north,
    // multiplied by 1E3.
    sint32 q1E3 = 7;
    sint32 q2E3 = 8;
    sint32 q3E3 = 9;
    sint32 q4E3 = 10;
}


message TimerEvent
{
    enum TimerEventType 
    {
        // The first value must be 0 in protobuf and will be the default if that
        // field is missing. TIMER_NONE can be used to just update the
        // seconds without a specific event.
        TIMER_NONE = 0;
        TIMER_STARTED = 1;
        TIMER_STOPPED = 2;
        TIMER_EXPIRED = 3;
        TIMER_TICK = 4;
    }
    TimerEventType type = 1;
    int32 seconds = 2;
}

message ButtonEvent
{
    enum ButtonEventType 
    {
        BUTTON_NONE = 0;
        BUTTON_RC = 1;
        BUTTON_PIN = 2;
        BUTTON_LINE_CLEARED = 3;
        BUTTON_MAX = 4;
    }
    ButtonEventType type = 1;
}

message HardwareDescription
{
    int32 model_id = 1;
    int32 hardware_id = 2;
    int32 firmware_id = 3;
    int32 serial_number = 4;
}

message MagneticDeclination
{
    // Magnetic Declination measured in degrees. 
    // This must be added to the measured magnetic heading to get the true
    // heading.
    sint32 declination = 1;
}