/// <summary>
/// Start a new command of a speicifc type with a global and/or local buffer on the EV3 brick
/// </summary>
/// <param name="commandType">The type of the command to start</param>
/// <param name="globalSize">The size of the global buffer in bytes (maximum of 1024 bytes)</param>
/// <param name="localSize">The size of the local buffer in bytes (maximum of 64 bytes)</param>
public void Initialize(CommandType commandType, ushort globalSize, int localSize)
{
if(globalSize > 1024)
throw new ArgumentException("Global buffer must be less than 1024 bytes", "globalSize");
if(localSize > 64)
throw new ArgumentException("Local buffer must be less than 64 bytes", "localSize");
_stream = new MemoryStream();
_writer = new BinaryWriter(_stream);
Response = ResponseManager.CreateResponse();
CommandType = commandType;
// 2 bytes (this gets filled in later when the user calls ToBytes())
_writer.Write((ushort)0xffff);
// 2 bytes
_writer.Write(Response.Sequence);
// 1 byte
_writer.Write((byte)commandType);
if(commandType == CommandType.DirectReply || commandType == CommandType.DirectNoReply)
{
// 2 bytes (llllllgg gggggggg)
_writer.Write((byte)globalSize); // lower bits of globalSize
_writer.Write((byte)((localSize << 2) | (globalSize >> 8) & 0x03)); // upper bits of globalSize + localSize
}
}
internal static Response CreateResponse()
{
ushort sequence = GetSequenceNumber();
Response r = new Response(sequence);
Responses[sequence] = r;
return r;
}
internal static async Task WaitForResponseAsync(Response r)
{
await Task.Run(() =>
{
if(r.Event.WaitOne(1000))
Responses.Remove(r.Sequence);
else
r.ReplyType = ReplyType.DirectReplyError;
});
}