udpDevice/udpDevice.cpp

//-
// ==========================================================================
// Copyright 2020 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
// ==========================================================================
//+

// Description:
// A simple client device node that uses UDP to transfer data.
// Sample only runs on Linux.
//
// Run Maya and execute the MEL code below.  In a shell,
// run the Python code and enter 3 numbers to update the
// cube's translate. 
//

/*

// MEL:
loadPlugin udpDevice;
string $node = `createNode udpDevice`;
string $cube[] = `polyCube`;
connectAttr ( $node + ".outputTranslate" ) ( $cube[0] + ".translate" );
setAttr ( $node + ".live" ) 1;

# Python: run from a Linux command line as a Python script
import socket
clientSocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
while True:
    data = raw_input("Type 3 numbers for translate(. to exit): ")
    if data != '.':
        clientSocket.sendto(data, ("localhost",7555))
    else:
        break
clientSocket.close()

*/

#ifdef __linux__
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#endif

#include <maya/MFnPlugin.h>
#include <maya/MTypeId.h>

#include "api_macros.h"
#include <maya/MIOStream.h>

#include <maya/MString.h>
#include <maya/MStringArray.h>
#include <maya/MPlug.h>
#include <maya/MDataBlock.h>
#include <maya/MFnNumericAttribute.h>
#include <maya/MPxClientDeviceNode.h>

class udpDeviceNode : public MPxClientDeviceNode
{

public:
                udpDeviceNode();
            ~udpDeviceNode() override;
    
    void        postConstructor() override;
    MStatus     compute( const MPlug& plug, MDataBlock& data ) override;
    void        threadHandler( const char* serverName, const char* deviceName ) override;
    void        threadShutdownHandler() override;

    static void*        creator();
    static MStatus      initialize();

public:

    static MObject      outputTranslate;
    static MObject      outputTranslateX;
    static MObject      outputTranslateY;
    static MObject      outputTranslateZ;

    static MTypeId      id;

private:
};

MTypeId udpDeviceNode::id( 0x00081052 );
MObject udpDeviceNode::outputTranslate;
MObject udpDeviceNode::outputTranslateX;
MObject udpDeviceNode::outputTranslateY;
MObject udpDeviceNode::outputTranslateZ;

udpDeviceNode::udpDeviceNode() 
{}

udpDeviceNode::~udpDeviceNode()
{
    destroyMemoryPools();
}

void udpDeviceNode::postConstructor()
{
    MObjectArray attrArray;
    attrArray.append( udpDeviceNode::outputTranslate );
    setRefreshOutputAttributes( attrArray );

    // we'll be reading one character line of size 1024
    createMemoryPools( 1, 1024, sizeof(char));
}

void udpDeviceNode::threadHandler( const char* serverName, const char* deviceName )
{
    setDone( false );
    if ( serverName != NULL && deviceName != NULL )
        printf("udpThreadHandler: %s %s\n",serverName,deviceName);

#ifdef __linux__
    int sock;
    int bytesRead;
    socklen_t addressLength;
    struct sockaddr_in serverAddress , clientAddress;
    

    serverAddress.sin_family = AF_INET;
    serverAddress.sin_port = htons(7555);
    serverAddress.sin_addr.s_addr = INADDR_ANY;
    bzero(&(serverAddress.sin_zero),8);

    addressLength = sizeof(struct sockaddr);

    if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) 
    {
        return;
    }

    if (bind(sock,(struct sockaddr *)&serverAddress,
        sizeof(struct sockaddr)) == -1)
    {
        return;
    }

    MStatus status;
    MCharBuffer buffer;
    char receiveBuffer[1025];

    while ( !isDone() )
    {
        if ( ! isLive() )
            continue;
        
        // select() modifies its parameters so reset everytime
        fd_set read_set;
        FD_ZERO( &read_set );
        FD_SET( sock, &read_set );
        struct timeval tv;
        tv.tv_sec = 0;
        tv.tv_usec = 500000; // 1/2 second
        if ( select( sock+1, &read_set, NULL, NULL, &tv ) == -1 )
            break;
        if ( ! FD_ISSET( sock, &read_set ) )
            continue;

        receiveBuffer[0] = 0;
        bytesRead = recvfrom(sock,receiveBuffer,1024,0,
            (struct sockaddr *)&clientAddress, &addressLength);
            
        const char *receivedFromServer = inet_ntoa(clientAddress.sin_addr);
        unsigned short receivedFromPort = ntohs(clientAddress.sin_port);
        
        if ( NULL == receivedFromServer )
            continue;
        
        printf("(%s , %d) connection : %s \n",receivedFromServer,receivedFromPort, receiveBuffer);

        // Simple test to make sure we are getting data from the right server
        // printf("%s %s\n",serverName, receivedFromServer);
        if ( 0 != strcmp( serverName, receivedFromServer ) )
            continue;

        // Get the storage once we have data from the server
        status = acquireDataStorage(buffer);
        if ( ! status )
            continue;

        beginThreadLoop();
        {
            receiveBuffer[bytesRead] = '\0';
            double* doubleData = reinterpret_cast<double*>(buffer.ptr());
            doubleData[0] = 0.0 ; doubleData[1] = 0.0; doubleData[2] = 0.0;
            MStringArray sa;
            MString s( receiveBuffer );
            if ( s.split( ' ', sa ) )
            {
                if ( sa.length() == 3 )
                {
                    int i = 0;
                    for ( i = 0; i < 3; i++ )
                    {
                        doubleData[i] = ( sa[i].isDouble() ? sa[i].asDouble() : 0.0 );
                    }
                }   
            }
            pushThreadData( buffer );
        }
        endThreadLoop();

    }
    
    // Close the socket
    close( sock );
    
#endif // __linux__

    setDone( true );
}

void udpDeviceNode::threadShutdownHandler()
{
    setDone( true );
}

void* udpDeviceNode::creator()
{
    return new udpDeviceNode;
}

MStatus udpDeviceNode::initialize()
{
    MStatus status;
    MFnNumericAttribute numAttr;

    outputTranslateX = numAttr.create("outputTranslateX", "otx", MFnNumericData::kDouble, 0.0, &status);
    MCHECKERROR(status, "create outputTranslateX");
    outputTranslateY = numAttr.create("outputTranslateY", "oty", MFnNumericData::kDouble, 0.0, &status);
    MCHECKERROR(status, "create outputTranslateY");
    outputTranslateZ = numAttr.create("outputTranslateZ", "otz", MFnNumericData::kDouble, 0.0, &status);
    MCHECKERROR(status, "create outputTranslateZ");
    outputTranslate = numAttr.create("outputTranslate", "ot", outputTranslateX, outputTranslateY, 
                                     outputTranslateZ, &status);
    MCHECKERROR(status, "create outputTranslate");
    
    ADD_ATTRIBUTE(outputTranslate);

    ATTRIBUTE_AFFECTS( live, outputTranslate);
    ATTRIBUTE_AFFECTS( frameRate, outputTranslate);
    ATTRIBUTE_AFFECTS( serverName, outputTranslate);
    ATTRIBUTE_AFFECTS( deviceName, outputTranslate);

    return MS::kSuccess;
}

MStatus udpDeviceNode::compute( const MPlug& plug, MDataBlock& block )
{
    MStatus status;
    if( plug == outputTranslate || plug == outputTranslateX ||
        plug == outputTranslateY || plug == outputTranslateZ )
    {
        MCharBuffer buffer;
        if ( popThreadData(buffer) )
        {
            double* doubleData = reinterpret_cast<double*>(buffer.ptr());

            MDataHandle outputTranslateHandle = block.outputValue( outputTranslate, &status );
            MCHECKERROR(status, "Error in block.outputValue for outputTranslate");

            double3& outputTranslate = outputTranslateHandle.asDouble3();
            outputTranslate[0] = doubleData[0];
            outputTranslate[1] = doubleData[1];
            outputTranslate[2] = doubleData[2];

            block.setClean( plug );

            releaseDataStorage(buffer);
            return ( MS::kSuccess );
        }
        else
        {
            return MS::kFailure;
        }
    }

    return ( MS::kUnknownParameter );
}

MStatus initializePlugin( MObject obj )
{
    MStatus status;
    MFnPlugin plugin(obj, PLUGIN_COMPANY, "3.0", "Any");

    status = plugin.registerNode( "udpDevice", 
                                  udpDeviceNode::id,
                                  udpDeviceNode::creator,
                                  udpDeviceNode::initialize,
                                  MPxNode::kClientDeviceNode );
    if( !status ) {
        status.perror("failed to registerNode udpDeviceNode");
    }

    return status;
}

MStatus uninitializePlugin( MObject obj )
{
    MStatus status;
    MFnPlugin plugin(obj);

    status = plugin.deregisterNode( udpDeviceNode::id );
    if( !status ) {
        status.perror("failed to deregisterNode udpDeviceNode");
    }

    return status;
}