vrpn_VPJoystick.C

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#include "vrpn_Serial.h"
#include "vrpn_Shared.h"                // for timeval, vrpn_gettimeofday
#include "vrpn_VPJoystick.h"
 
class VRPN_API vrpn_Connection;
 
#define STATE_SYNCHING  (0)
#define STATE_READING   (1)
#define STATE_RECEIVED  (2)
 
#define SYNC_BYTE          (0xff)
 
#define VP_BUTTON_1  4096
#define VP_BUTTON_2  256
#define VP_BUTTON_3  1
#define VP_BUTTON_4  512
#define VP_BUTTON_5  2048
#define VP_BUTTON_6  2
#define VP_BUTTON_7  1024
#define VP_BUTTON_8  4
 
#define VP_HAT_UP    VP_BUTTON_5
#define VP_HAT_DOWN  VP_BUTTON_7
#define VP_HAT_LEFT  VP_BUTTON_8
#define VP_HAT_RIGHT VP_BUTTON_6
 
#define VP_TRIGGER         VP_BUTTON_4
#define VP_BUTTON_TOP      VP_BUTTON_3
#define VP_BUTTON_MIDDLE   VP_BUTTON_2
#define VP_BUTTON_BOTTOM   VP_BUTTON_1
 
 
#define VP_HAT_ALL    ( VP_HAT_UP | VP_HAT_DOWN | VP_HAT_LEFT | VP_HAT_RIGHT )
#define VP_BUTTON_ALL ( VP_TRIGGER | VP_BUTTON_TOP | VP_BUTTON_MIDDLE | VP_BUTTON_BOTTOM )
 
#include <stdio.h>                      // for fprintf, stderr
 
vrpn_VPJoystick::vrpn_VPJoystick(char* name, vrpn_Connection *c,
                       const char *port, long baud)
  :  vrpn_Button_Filter(name, c),
     serial_fd(0), state( STATE_SYNCHING )
{
  int i;
    
  // Open the serial port
  if ( (serial_fd=vrpn_open_commport(port, baud)) == -1) {
    fprintf(stderr,"vrpn_VPJoystick: Cannot Open serial port\n");
  }
  
  // find out what time it is - needed?
  vrpn_gettimeofday(&timestamp, 0);
    vrpn_Button::timestamp = timestamp;
 
    num_buttons = vrpn_VPJOY_NUM_BUTTONS;
 
    button_masks[0] = VP_BUTTON_1;
    button_masks[1] = VP_BUTTON_2;
    button_masks[2] = VP_BUTTON_3;
    button_masks[3] = VP_BUTTON_4;
    button_masks[4] = VP_BUTTON_5;
    button_masks[5] = VP_BUTTON_6;
    button_masks[6] = VP_BUTTON_7;
    button_masks[7] = VP_BUTTON_8;
    
    for( i=0; i< num_buttons; i++ ) {
        buttons[i] = lastbuttons[i] = VRPN_BUTTON_OFF;            
    }
}
 
 
vrpn_VPJoystick::~vrpn_VPJoystick()
{
  vrpn_close_commport(serial_fd);
}
 
void vrpn_VPJoystick::mainloop() 
{
    server_mainloop();
 
        // XXX Why not have a timeout of zero?  This would cause faster
        // update rates for other devices in the same server.
    struct timeval timeout = { 0,200000 };
 
        if (serial_fd == -1) {
          fprintf(stderr,"vrpn_VPJOystick::mainloop(): Bad serial port descriptor\n");
          return;
        }
 
    if( state == STATE_SYNCHING ) {
 
        // Read bytes from the incoming stream until
        // the synch byte is received
                          
        message_buffer[0] = 0;
        if( vrpn_read_available_characters( serial_fd, message_buffer, 1, &timeout ) ) {
            if( message_buffer[0] == SYNC_BYTE ) {
                state = STATE_READING;                              
                bytes_read = 1;
            }                         
        }
 
    }
        
        // The state may just have been set to this, so don't do this in a switch
        // or if-then-else statement because we may take another whole loop iteration
        // before checking it again.
        if( state == STATE_READING ) {
              
        // Read the remaining bytes of the packet
        //
                  
        bytes_read += vrpn_read_available_characters( serial_fd, message_buffer + bytes_read, vrpn_VPJOY_MESSAGE_LENGTH - bytes_read, &timeout );
        if( bytes_read == vrpn_VPJOY_MESSAGE_LENGTH ) {
            state = STATE_RECEIVED;                     
        }
 
    }
        
        // The state may just have been set to this, so don't do this in a switch
        // or if-then-else statement because we may take another whole loop iteration
        // before checking it again.
        if( state == STATE_RECEIVED ) {
 
        // decode a received packet
                          
        int i;
        int flag = ((int) message_buffer[1])*256 + message_buffer[2];
            flag = (~flag) & ( VP_BUTTON_ALL | VP_HAT_ALL );
 
        for( i = 0 ; i < num_buttons; i++ ) {
            buttons[ i ] =  static_cast<unsigned char>( ( ( flag & button_masks[i] ) == button_masks[i] ) ? VRPN_BUTTON_ON : VRPN_BUTTON_OFF );
        }
        
        vrpn_Button::report_changes();
        state = STATE_SYNCHING;           
    }
}