vrpn_Button.C

#ifndef _WIN32_WCE
#include <time.h>
#endif
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#ifndef _WIN32_WCE
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#endif
#include <string.h> // for memcpy

#ifdef linux
#include <linux/lp.h>
#include <sys/ioctl.h>
#endif

// Include vrpn_Shared.h _first_ to avoid conflicts with sys/time.h 
// and unistd.h
#include "vrpn_Shared.h"

#ifdef _WIN32

#ifndef __CYGWIN__
#ifndef _WIN32_WCE
#include <conio.h>  // for _inp()
#endif
#endif

#ifndef VRPN_USE_WINSOCK_SOCKETS
#include <netinet/in.h>
#endif

#else
#include <netinet/in.h>
#endif // _WIN32

#if (defined(sgi)&&(!defined(VRPN_CLIENT_ONLY)))
//need these for the gl based setdblight calls
#include <gl/gl.h>
#include <gl/device.h>
#endif


#include "vrpn_Button.h"

#define BUTTON_READY 	  (1)
#define BUTTON_FAIL	  (-1)

// Bits in the status register
#ifndef VRPN_CLIENT_ONLY
static const unsigned char PORT_ERROR = (1 << 3);
static const unsigned char PORT_SLCT = (1 << 4);
static const unsigned char PORT_PE = (1 << 5);
static const unsigned char PORT_ACK = (1 << 6);
static const unsigned char PORT_BUSY = (1 << 7);
static const unsigned char 
	BIT_MASK = PORT_ERROR | PORT_SLCT | PORT_PE | PORT_ACK | PORT_BUSY;
#endif

// message constants for the PinchGolve code.
const unsigned char PG_START_BYTE_DATA(0x80);
const unsigned char PG_START_BYTE_DATA_TIME(0x81);
const unsigned char PG_START_BYTE_TEXT(0x82);
const unsigned char PG_END_BYTE(0x8F);

static int VRPN_CALLBACK client_msg_handler(void *userdata, vrpn_HANDLERPARAM p);

#define PACK_ADMIN_MESSAGE(i,event) { \
  char	msgbuf[1000]; \
  vrpn_int32	len = encode_to(msgbuf,i, event); \
  if (d_connection->pack_message(len, timestamp, \
			       admin_message_id, d_sender_id, msgbuf, vrpn_CONNECTION_RELIABLE)) {\
      		fprintf(stderr,"vrpn_Button: can't write message: tossing\n");\
      	}\
        }
#define PACK_ALERT_MESSAGE(i,event) { \
  char	msgbuf[1000]; \
  vrpn_int32	len = encode_to(msgbuf,i, event); \
  if (d_connection->pack_message(len, timestamp, \
			       alert_message_id, d_sender_id, msgbuf, vrpn_CONNECTION_RELIABLE)) {\
      		fprintf(stderr,"vrpn_Button: can't write message: tossing\n");\
      	}\
        }

#define PACK_MESSAGE(i,event) { \
  char	msgbuf[1000]; \
  vrpn_int32	len = encode_to(msgbuf,i, event); \
  if (d_connection->pack_message(len, timestamp, \
			       change_message_id, d_sender_id, msgbuf, vrpn_CONNECTION_RELIABLE)) {\
      		fprintf(stderr,"vrpn_Button: can't write message: tossing\n");\
      	}\
        }

vrpn_Button::vrpn_Button(const char *name, vrpn_Connection *c)
	: vrpn_BaseClass(name, c),
	num_buttons(0)
{
    vrpn_BaseClass::init();

   // Set the time to 0 just to have something there.
   timestamp.tv_usec = timestamp.tv_sec = 0;
   for (vrpn_int32 i=0; i< vrpn_BUTTON_MAX_BUTTONS; i++) {
	buttons[i] = lastbuttons[i]=0;
   }
}

int vrpn_Button::register_types(void)
{
      //used to handle button strikes
      change_message_id = d_connection->register_message_type("vrpn_Button Change");
      
      //to handle button state changes -- see Buton_Filter should register a handler
      //for this ID -- ideally the message will be ignored otherwise
      admin_message_id = d_connection->register_message_type("vrpn_Button Admin");

      return 0;
}

// virtual
vrpn_Button::~vrpn_Button (void) {

  // do nothing

}


vrpn_Button_Filter::vrpn_Button_Filter(const char *name, vrpn_Connection *c)
	:vrpn_Button(name, c)
{
      if ( (d_sender_id == -1) || (admin_message_id == -1) ) {
        fprintf(stderr,"vrpn_Button: Can't register IDs\n");
         d_connection = NULL;
      }
      register_autodeleted_handler(admin_message_id, client_msg_handler, this);

      //setup message id type for alert messages to alert a device about changes
      alert_message_id = d_connection->register_message_type("vrpn_Button Alert");
      send_alerts=0;	//used to turn on/off alerts -- send and admin message from
			//remote to turn it on -- or server side call set_alerts();

      //set button default buttonstates
      for (vrpn_int32 i=0; i< vrpn_BUTTON_MAX_BUTTONS; i++) {
           buttonstate[i] = vrpn_BUTTON_MOMENTARY;
      }
      return;
}
void vrpn_Button_Filter::set_alerts(vrpn_int32 i){
	if(i==0 || i==1) send_alerts=i;
	else fprintf(stderr,"Invalid send_alert state\n");
	return;
}

void vrpn_Button_Filter::set_momentary(vrpn_int32 which_button) {
  if (which_button >= num_buttons) {
      char msg[200];
       sprintf(msg, "vrpn_Button::set_momentary() buttons id %d is greater than the number of buttons(%d)\n", which_button, num_buttons);
       send_text_message(msg, timestamp, vrpn_TEXT_ERROR);
    return;
  }
  buttonstate[which_button] = vrpn_BUTTON_MOMENTARY;
  if(send_alerts)PACK_ALERT_MESSAGE(which_button,vrpn_BUTTON_TOGGLE_OFF);
}

void vrpn_Button::set_momentary(vrpn_int32 which_button) {
  if (which_button >= num_buttons) {
      char msg[200];
       sprintf(msg, "vrpn_Button::set_momentary() buttons id %d is greater than the number of buttons(%d)\n", which_button, num_buttons);
       send_text_message(msg, timestamp, vrpn_TEXT_ERROR);
    return;
  }
  PACK_ADMIN_MESSAGE(which_button,vrpn_BUTTON_MOMENTARY);
}

void vrpn_Button_Filter::set_toggle(vrpn_int32 which_button, vrpn_int32 current_state) {
  if (which_button >= num_buttons) {
    char msg[200];
    sprintf(msg, "vrpn_Button::set_toggle() buttons id %d is greater then the number of buttons(%d)\n", which_button, num_buttons);
    send_text_message(msg, timestamp, vrpn_TEXT_ERROR);
    return;
  }
  if (current_state==vrpn_BUTTON_TOGGLE_ON){
     buttonstate[which_button] = vrpn_BUTTON_TOGGLE_ON;
     if(send_alerts)PACK_ALERT_MESSAGE(which_button,vrpn_BUTTON_TOGGLE_ON);
  }
  else{ 
    buttonstate[which_button] = vrpn_BUTTON_TOGGLE_OFF;
    if(send_alerts)PACK_ALERT_MESSAGE(which_button,vrpn_BUTTON_TOGGLE_OFF);
  }
    
}
void vrpn_Button::set_toggle(vrpn_int32 which_button, vrpn_int32 current_state) {
  if (which_button >= num_buttons) {
    char msg[200];
    sprintf(msg, "vrpn_Button::set_toggle() buttons id %d is greater then the number of buttons(%d)\n", which_button, num_buttons);
    send_text_message(msg, timestamp, vrpn_TEXT_ERROR);
    return;
  }
  if (current_state==vrpn_BUTTON_TOGGLE_ON) {
    PACK_ADMIN_MESSAGE(which_button,vrpn_BUTTON_TOGGLE_ON);
  }
  else{
    PACK_ADMIN_MESSAGE(which_button,vrpn_BUTTON_TOGGLE_OFF);
  }
}

void vrpn_Button_Filter::set_all_momentary(void) {
  for (vrpn_int32 i=0; i< num_buttons; i++){
    if (buttonstate[i] != vrpn_BUTTON_MOMENTARY) {
      buttonstate[i] = vrpn_BUTTON_MOMENTARY;  
      if(send_alerts) PACK_ALERT_MESSAGE(i,vrpn_BUTTON_TOGGLE_OFF);
    }
  }
}


void vrpn_Button::set_all_momentary(void) {
    PACK_ADMIN_MESSAGE(vrpn_ALL_ID,vrpn_BUTTON_MOMENTARY);
}

void vrpn_Button::set_all_toggle(vrpn_int32 default_state) {
        PACK_ADMIN_MESSAGE(vrpn_ALL_ID,default_state);
}

void vrpn_Button_Filter::set_all_toggle(vrpn_int32 default_state) {
  for (vrpn_int32 i=0; i< num_buttons; i++){
    if (buttonstate[i] == vrpn_BUTTON_MOMENTARY){
        buttonstate[i] = default_state;
	if(send_alerts){PACK_ALERT_MESSAGE(i,default_state); }
    }
  }
}

void	vrpn_Button::print(void)
{
   vrpn_int32	i;
   printf("CurrButtons: ");
   for (i = num_buttons-1; i >= 0; i--) {
   	printf("%c",buttons[i]?'1':'0');
   }
   printf("\n");

   printf("LastButtons: ");
   for (i = num_buttons-1; i >= 0; i--) {
   	printf("%c",lastbuttons[i]?'1':'0');
   }
   printf("\n");
}

/** Encode a message describing the new state of a button.
    Assumes that there is enough room in the buffer to hold
    the bytes from the message. Returns the number of bytes
    sent.
*/

vrpn_int32 vrpn_Button::encode_to(char *buf,
		vrpn_int32 button, vrpn_int32 state)
{
	char	*bufptr = buf;
	int 	buflen = 1000;

	// Message includes: vrpn_int32 buttonNum, vrpn_int32 state
	vrpn_buffer( &bufptr, &buflen, button );
	vrpn_buffer( &bufptr, &buflen, state );

	return 1000 - buflen;
}


static int VRPN_CALLBACK client_msg_handler(void *userdata, vrpn_HANDLERPARAM p) {
  vrpn_Button_Filter * instance = (vrpn_Button_Filter *) userdata;
  const char *bufptr = p.buffer;
  vrpn_int32 event;
  vrpn_int32 buttonid;

  vrpn_unbuffer(&bufptr, &buttonid);
  vrpn_unbuffer(&bufptr, &event);

  if (event== vrpn_BUTTON_MOMENTARY) {
    if (buttonid == vrpn_ALL_ID)
      instance->set_all_momentary();
    else instance->set_momentary(buttonid);
  }else if (event== vrpn_BUTTON_TOGGLE_OFF || event==vrpn_BUTTON_TOGGLE_ON ){
    if (buttonid == vrpn_ALL_ID)
      instance->set_all_toggle(event);
    else instance->set_toggle(buttonid,event);
  } 
  return 0;
}


void vrpn_Button_Filter::report_changes (void){
   vrpn_int32 i;

//   vrpn_Button::report_changes();
   if (d_connection) {
      for (i = 0; i < num_buttons; i++) {
	switch (buttonstate[i]) {
        case vrpn_BUTTON_MOMENTARY:
              if (buttons[i] != lastbuttons[i])
              PACK_MESSAGE(i, buttons[i]);
          break;
        case vrpn_BUTTON_TOGGLE_ON:
          if (buttons[i] && !lastbuttons[i]) {
            buttonstate[i] = vrpn_BUTTON_TOGGLE_OFF;
            if(send_alerts) PACK_ALERT_MESSAGE(i,vrpn_BUTTON_TOGGLE_OFF);
            PACK_MESSAGE(i, 0);
          }
          break;
        case vrpn_BUTTON_TOGGLE_OFF:
          if (buttons[i] && !lastbuttons[i]) {
            buttonstate[i] = vrpn_BUTTON_TOGGLE_ON;
            if(send_alerts)PACK_ALERT_MESSAGE(i,vrpn_BUTTON_TOGGLE_ON);
            PACK_MESSAGE(i, 1);
          }
          break;
        default:
 		fprintf(stderr,"vrpn_Button::report_changes(): Button %d in \
			invalid state (%d)\n",i,buttonstate[i]);
        }
        lastbuttons[i] = buttons[i];
      }

   } else {
        fprintf(stderr,"vrpn_Button: No valid connection\n");
   }
}

void	vrpn_Button::report_changes(void)
{
  vrpn_int32	i;

   if (d_connection) {
      for (i = 0; i < num_buttons; i++) {
	if (buttons[i] != lastbuttons[i])
	      PACK_MESSAGE(i, buttons[i]);
	lastbuttons[i] = buttons[i];
      }

   } else {
   	fprintf(stderr,"vrpn_Button: No valid connection\n");
   }
}


#ifndef VRPN_CLIENT_ONLY

vrpn_Button_Server::vrpn_Button_Server(const char *name, vrpn_Connection *c,
				       int numbuttons) : vrpn_Button_Filter(name, c)
{
    if (numbuttons > vrpn_BUTTON_MAX_BUTTONS) {
	num_buttons = vrpn_BUTTON_MAX_BUTTONS;
    } else {
	num_buttons = numbuttons;
    }
}

int vrpn_Button_Server::number_of_buttons(void)
{
    return num_buttons;
}

void	vrpn_Button_Server::mainloop(void)
{
    server_mainloop();
    report_changes();
}

int vrpn_Button_Server::set_button(int button, int new_value)
{
    if ( (button < 0) || (button >= num_buttons) ) {
	return -1;
    }

    buttons[button] = (unsigned char)(new_value != 0);

    return 0;
}

static	unsigned long	duration(struct timeval t1, struct timeval t2)
{
	return (t1.tv_usec - t2.tv_usec) +
	       1000000L * (t1.tv_sec - t2.tv_sec);
}

vrpn_Button_Example_Server::vrpn_Button_Example_Server(const char *name,
						       vrpn_Connection *c,
						       int numbuttons,
						       vrpn_float64 rate)
	: vrpn_Button_Filter(name, c)
{
	if (numbuttons > vrpn_BUTTON_MAX_BUTTONS) {
		num_buttons = vrpn_BUTTON_MAX_BUTTONS;
	} else {
		num_buttons = numbuttons;
	}

	_update_rate = rate;

	// IN A REAL SERVER, open the device that will service the buttons here
}

void vrpn_Button_Example_Server::mainloop()
{
	struct timeval current_time;
	int	i;

	// Call the generic server mainloop, since we are a server
	server_mainloop();

	// See if its time to generate a new report (every 1 second).
	// IN A REAL SERVER, this check would not be done; although the
	// time of the report would be updated to the current time so
	// that the correct timestamp would be issued on the report.
	vrpn_gettimeofday(&current_time, NULL);
	if ( duration(current_time,timestamp) >= 1000000.0/_update_rate) {

	  // Update the time
	  timestamp.tv_sec = current_time.tv_sec;
	  timestamp.tv_usec = current_time.tv_usec;

	  // Update the values for the buttons, to say that each one has
	  // switched its state.
	  // THIS CODE WILL BE REPLACED by the user code that
	  // actually reads from the button devices and fills in buttons[]
	  // appropriately.
	  for (i = 0; i < num_buttons; i++) {
		  buttons[i] = !lastbuttons[i];
	  }

	  // Send reports. Stays the same in a real server.
	  report_changes();
	}
}


// changed to take raw port hex address
vrpn_Button_Parallel::vrpn_Button_Parallel(const char *name,
					   vrpn_Connection *c,
					   int portno, unsigned porthex)
	: vrpn_Button_Filter(name, c)
{      
#ifdef linux
    const char *portname;
    switch (portno) {
	case 1: portname = "/dev/lp0";
		break;
	case 2: portname = "/dev/lp1";
		break;
	case 3: portname = "/dev/lp2";
		break;
	default:
	    fprintf(stderr, "vrpn_Button_Parallel: "
			    "Bad port number (%x) for Linux lp#\n",portno);
	    status = BUTTON_FAIL;
	    portname = "UNKNOWN";
	    break;
    }

      // Open the port
    if ( (port = open(portname, O_RDWR)) < 0) {
	perror("vrpn_Button_Parallel::vrpn_Button_Parallel(): "
	       "Can't open port");
	fprintf(stderr, "vrpn_Button_Parallel::vrpn_Button_Parallel(): "
		        "Can't open port %s\n",portname);
	status = BUTTON_FAIL;
	return;
    }
#elif _WIN32
      // if on NT we need a device driver to do direct reads
      // from the parallel port
    if (!openGiveIO()) {
       fprintf(stderr, "vrpn_Button: need giveio driver for port access!\n");
       fprintf(stderr, "vrpn_Button: can't use vrpn_Button()\n");
       status = BUTTON_FAIL;
       return;
    }
	if (porthex != 0)    // using direct hex port address
			port = porthex;
	else {               // using old style port 1, 2, or 3
	    switch (portno) {
			// we use this mapping, although LPT? can actually
			// have different addresses.
		case 1: port = 0x378; break;  // usually LPT1
		case 2: port = 0x3bc; break;  // usually LPT2
		case 3: port = 0x278; break;  // usually LPT3
		default:
			fprintf(stderr,"vrpn_Button_Parallel: Bad port number (%d)\n",portno);
			status = BUTTON_FAIL;
			break;
		}
    }
	fprintf(stderr,"vrpn_Button_Parallel: Using port %x\n",port);
#else  // _WIN32      
    fprintf(stderr, "vrpn_Button_Parallel: not supported on this platform\n?");
    status = BUTTON_FAIL;
    portno = portno;  // unused argument
    return;
#endif

#if defined(linux) || defined(_WIN32)
      // Set the INIT line on the device to provide power to the python
      //  update: don't need this for builtin LPT1 on DELLs, but do need it
      //    for warp9 PCI parallel port. Added next lines.  BCE Nov07.00
      // Setting Bit 1 high also for a specific HiBall system
      //  requirement (IR blocking device on same port)
      //  - BCE 08 July 03

#ifdef _outp
        static const unsigned short DATA_REGISTER_OFFSET = 0;
        _outp((unsigned short)(port + DATA_REGISTER_OFFSET), 3);
#else
	fprintf(stderr,"vrpn_Button_Parallel: Not setting bit 0 on Linux, may not work with all ports\n");
#endif

     // Zero the button states
    num_buttons = 5;	//XXX This is specific to the python
    for (vrpn_int32 i = 0; i < num_buttons; i++) {
	buttons[i] = lastbuttons[i] = 0;
    }

    status = BUTTON_READY;
    vrpn_gettimeofday(&timestamp, NULL);
#endif
}

vrpn_Button_Python::vrpn_Button_Python (const char * name, vrpn_Connection * c, int p) :
    vrpn_Button_Parallel (name, c, p) {

}


vrpn_Button_Python::vrpn_Button_Python (const char * name, vrpn_Connection * c, int p, unsigned ph) :
    vrpn_Button_Parallel (name, c, p, ph) {
}

void vrpn_Button_Python::mainloop()
{
  // Call the generic server mainloop, since we are a server
  server_mainloop();

  switch (status) {
      case BUTTON_READY:
	read();
	report_changes();
      	break;
      case BUTTON_FAIL:
      	{	static int first = 1;
         	if (first) {
         		first = 0;
	      		fprintf(stderr, "vrpn_Button_Python failure!\n");
			send_text_message("Failure", timestamp, vrpn_TEXT_ERROR);
         	}
        }
      	break;
   }
}


// Fill in the buttons[] array with the current value of each of the
// buttons.  Debounce the buttons (make sure that they have had the
// same value for the past several times to debounce noise).
void vrpn_Button_Python::read(void)
{
    int i;
    const int debounce_count = 30;
    int   status_register[debounce_count];
    
    // Make sure we're ready to read
    if (status != BUTTON_READY) {
	    return;
    }

    // Read from the status register, read 3 times to debounce noise.
#ifdef	linux
    for (i = 0; i < debounce_count; i++) 
      if (ioctl(port, LPGETSTATUS, &status_register[i]) == -1) {
	    perror("vrpn_Button_Python::read(): ioctl() failed");
	    return;
      }

#elif _WIN32
  #ifndef __CYGWIN__
	static const unsigned short STATUS_REGISTER_OFFSET = 1;
    for (i = 0; i < debounce_count; i++) {
      #ifdef _inp
	status_register[i] = _inp((unsigned short)(port + STATUS_REGISTER_OFFSET));
      #else
        status_register[i] = 0;
      #endif
    }
  #else
    for (i = 0; i < debounce_count; i++) {
      status_register[i] = 0;
    }
  #endif
#else
    for (i = 0; i < debounce_count; i++) {
      status_register[i] = 0;
    }
#endif
    for (i = 0; i < debounce_count; i++) {
      status_register[i] = status_register[i] & BIT_MASK;
    }
    
    // Make sure they are all the same; if not, return and assume that
    // we are still debouncing.
    for (i = 1; i < debounce_count; i++) {
      if (status_register[0] != status_register[i]) {
	return;
      }
    }

    // Assign values to the bits based on the control signals
    buttons[0] = ((status_register[0] & PORT_SLCT) == 0);
    buttons[1] = ((status_register[0] & PORT_BUSY) != 0);
    buttons[2] = ((status_register[0] & PORT_PE) == 0);
    buttons[3] = ((status_register[0] & PORT_ERROR) == 0);
    buttons[4] = ((status_register[0] & PORT_ACK) == 0);

    vrpn_gettimeofday(&timestamp, NULL);
}


vrpn_Button_Serial::vrpn_Button_Serial(const char* name, vrpn_Connection *c, 
                    const char *port, long baud) :
vrpn_Button_Filter(name, c)
{
   // port name and baud rate
   if (port == NULL) {
	   fprintf(stderr,"vrpn_Button_Serial: NULL port name\n");
	   status = BUTTON_FAIL;
	   return;
   } else {
	   strncpy(portname, port, sizeof(portname));
	   portname[sizeof(portname)-1] = '\0';
   }
   baudrate = baud;

   // Open the serial port
   if ( (serial_fd=vrpn_open_commport(portname, baudrate)) == -1) {
	   fprintf(stderr,"vrpn_Button_Serial: Cannot Open serial port\n");
	   status = BUTTON_FAIL;
   }

   // Reset the tracker and find out what time it is
   status = BUTTON_READY;
   vrpn_gettimeofday(&timestamp, NULL);
}

vrpn_Button_Serial::~vrpn_Button_Serial() {
   vrpn_close_commport(serial_fd);
}

// init pinch glove to send hand data only
vrpn_Button_PinchGlove::vrpn_Button_PinchGlove(const char* name, vrpn_Connection *c, 
               const char *port, long baud) : vrpn_Button_Serial(name, c, port, baud)
{ 
   num_buttons = 10;   // 0-4: right, 5-9: left starting from thumb
   status = BUTTON_READY;

   // check if the number of buttons is not more than max allowed.
   if (num_buttons > vrpn_BUTTON_MAX_BUTTONS) {
	   fprintf(stderr,"vrpn_Button_PinchGlove: Too many buttons. The limit is ");
      fprintf(stderr,"%i but this device has %i.\n",vrpn_BUTTON_MAX_BUTTONS,num_buttons);
	   status = BUTTON_FAIL;
   }

   // set glove to report with no timestamp
   report_no_timestamp();
 
   // initialize the buttons
   for (vrpn_int32 i=0; i<num_buttons; i++)
      buttons[i] = lastbuttons[i] = VRPN_BUTTON_OFF;

   // Reset the tracker and find out what time it is
   vrpn_gettimeofday(&timestamp, NULL);
}

void vrpn_Button_PinchGlove::mainloop()
{
   // Call the generic server mainloop, since we are a server
   server_mainloop();

   switch (status) {
      case BUTTON_READY:
	      read();
	      report_changes();
      	break;
      case BUTTON_FAIL: 
         {  static int first = 1;
            if (first) {
         	   first = 0;
	      	   fprintf(stderr, "vrpn_Button_PinchGlove failure!\n");
            }
         }
      	break;
   }
   return;

}

// Pinch glove should only report hand data(see contructor). If the message has
// time stamp data change the the message type by sending command to just send
// hand data. Any other kind of message is ignored and the buffer is read until
// end of message byte(PG_END_BYTE) is reached.
void vrpn_Button_PinchGlove::read()
{
   // check if button is ready
   if (status != BUTTON_READY)   return;

   // check if there is something to read
   if (vrpn_read_available_characters(serial_fd,buffer,1) != 1)   return;

   // This while loop is to keep reading messages until its empty.
   while (buffer[0] != PG_END_BYTE ) {
      // switch according to its message start byte
      if (buffer[0] == PG_START_BYTE_DATA) {
         // reset button state
         for (vrpn_int32 i=0; i<num_buttons; i++)   buttons[i] = VRPN_BUTTON_OFF;

         // read next message
         bufcount = vrpn_read_available_characters(serial_fd,buffer,2);

         // read until end of message
         while (buffer[0] != PG_END_BYTE) {
         
            // if only one byte read, read the left hand byte
            while (bufcount != 2)
               bufcount += vrpn_read_available_characters(serial_fd,buffer+1,1);

            unsigned char mask = 0x10;
            // set button states 
            for (int j=0; j<5; j++, mask=(unsigned char)(mask>>1)) {
               if (mask & buffer[1])  {  // right hand
                  buttons[j] = VRPN_BUTTON_ON;
               }
               if (mask & buffer[0])  {  // left hand
                  buttons[j+5] = VRPN_BUTTON_ON;
               }

            }

            // read next bytes
            bufcount = vrpn_read_available_characters(serial_fd,buffer,2);
         } // while (buffer[0] != PG_END_BYTE)
         // if there is another message read it
         if (bufcount != 1)   buffer[0] = buffer[1];
      } // if (buffer[0] == PG_START_BYTE_DATA) {
      else if (buffer[0] == PG_START_BYTE_DATA_TIME) {
         send_text_message("vrpn_Button_PinchGlove message start byte: time stamped byte!", timestamp, vrpn_TEXT_ERROR);
         report_no_timestamp();
      }
      else {    // ignore any other type of messages: empty butter till PG_END_BYTE
         // clear messages
         while(buffer[0] != PG_END_BYTE)
            vrpn_read_available_characters(serial_fd,buffer,1);
	    send_text_message("vrpn_Button_PinchGlove wrong message start byte", timestamp, vrpn_TEXT_ERROR);
      } // else
   } // while (buffer[0] != PG_END_BYTE )
   
   vrpn_gettimeofday(&timestamp, NULL);
   return;
}

// set the glove to report data without timestamp
void vrpn_Button_PinchGlove::report_no_timestamp()
{
  struct timeval timeout = {0, 30000}; // time_out for response from glove: 30 msec
  struct timeval timeout_to_pass;

  // read until correct reply is recieved
  do {
       vrpn_flush_input_buffer(serial_fd);
       vrpn_write_characters(serial_fd, (unsigned char *)"T0", 2);
       vrpn_drain_output_buffer(serial_fd);
       timeout_to_pass.tv_sec = timeout.tv_sec;
       timeout_to_pass.tv_usec = timeout.tv_usec;
       bufcount = vrpn_read_available_characters(serial_fd,buffer,3,&timeout_to_pass) ;
  } while ( (bufcount!=3) || (buffer[1]!='0') || (buffer[2]!=PG_END_BYTE) );
  
  return;
}

#endif  // VRPN_CLIENT_ONLY


vrpn_Button_Remote::vrpn_Button_Remote(const char *name, vrpn_Connection *cn):
	vrpn_Button(name, cn)
{
	vrpn_int32	i;

	// Register a handler for the change callback from this device,
	// if we got a connection.
	if (d_connection != NULL) {
	  if (register_autodeleted_handler(change_message_id, handle_change_message,
	    this, d_sender_id)) {
		fprintf(stderr,"vrpn_Button_Remote: can't register handler\n");
		d_connection = NULL;
	  }
	} else {
		fprintf(stderr,"vrpn_Button_Remote: Can't get connection!\n");
	}

	// XXX These should be read from a description message that comes
	// from the button device (as a response to a query?).  For now,
	// we assume an SGI button box.
	num_buttons = 32;
	for (i = 0; i < num_buttons; i++) {
		buttons[i] = lastbuttons[i] = 0;
	}
	vrpn_gettimeofday(&timestamp, NULL);
}

// virtual
vrpn_Button_Remote::~vrpn_Button_Remote (void)
{
}

void vrpn_Button_Remote::mainloop()
{
	if (d_connection) {
		d_connection->mainloop(); 
	}
	client_mainloop();
}

int vrpn_Button_Remote::handle_change_message(void *userdata,
	vrpn_HANDLERPARAM p)
{
	vrpn_Button_Remote *me = (vrpn_Button_Remote *)userdata;
	const char *bufptr = p.buffer;
	vrpn_BUTTONCB	bp;

	// Fill in the parameters to the button from the message
	if (p.payload_len != 2*sizeof(vrpn_int32)) {
		fprintf(stderr,"vrpn_Button: change message payload error\n");
		fprintf(stderr,"             (got %d, expected %lud)\n",
			p.payload_len, static_cast<unsigned long>(2*sizeof(vrpn_int32)));
		return -1;
	}
	bp.msg_time = p.msg_time;
	vrpn_unbuffer(&bufptr, &bp.button);
	vrpn_unbuffer(&bufptr, &bp.state);

	// Go down the list of callbacks that have been registered.
	// Fill in the parameter and call each.
	me->d_callback_list.call_handlers(bp);

	return 0;
}

  // We use _inp (inport) to read the parallel port status register
  // since we haven't found a way to do it through the Win32 API.
  // On NT we need a special device driver (giveio) to be installed
  // so that we can get permission to execute _inp.  On Win95 we
  // don't need to do anything.
  //
  // The giveio driver is from the May 1996 issue of Dr. Dobb's,
  // an article by Dale Roberts called "Direct Port I/O and Windows NT"
  //
  // This function returns 1 if either running Win95 or running NT and
  // the giveio device was opened.  0 if device not opened.
#ifndef VRPN_CLIENT_ONLY
#ifdef _WIN32
int vrpn_Button_Parallel::openGiveIO(void)
{
    OSVERSIONINFO osvi;

    memset(&osvi, 0, sizeof(OSVERSIONINFO));
    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
    GetVersionEx(&osvi);

      // if Win95: no initialization required
    if (osvi.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS) {	
	return 1;
    }

      // else if NT: use giveio driver
    if (osvi.dwPlatformId == VER_PLATFORM_WIN32_NT) {
	HANDLE h = CreateFile("\\\\.\\giveio", GENERIC_READ, 0, NULL,
				OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
	if (h == INVALID_HANDLE_VALUE) {
	      // maybe driver not installed?
	    return 0;
	}
	CloseHandle(h);
	  // giveio opened successfully
	return 1;
    }

	// else GetVersionEx gave unexpected result
    fprintf(stderr, "vrpn_Button_Parallel::openGiveIO: unknown windows version\n");
    return 0;
}
#endif // _WIN32
#endif // VRPN_CLIENT_ONLY