Robots suiveurs 3 - Code Communication Intermédiaire (maître)

#include <webots/Robot.hpp>
#include <webots/Emitter.hpp>
#include <webots/Receiver.hpp>
#include <webots/Motor.hpp>
#include <webots/Keyboard.hpp>
#include <stdio.h>
#include <string.h>

#define COMMUNICATION_CHANNEL 1
#define MAX_SPEED 6.28

// All the webots classes are defined in the "webots" namespace
using namespace webots;

int main(int argc, char **argv) {

  // create the Robot instance.
  Robot *robot = new Robot();
  
  //get a handler to the peripherials
  Motor *left_motor = robot->getMotor("left wheel motor");
  Motor *right_motor = robot->getMotor("right wheel motor");
  Emitter *emitter = robot->getEmitter("emitter");
  
  //Motor initialisation
  left_motor->setVelocity(0);
  right_motor->setVelocity(0);
  left_motor->setPosition(INFINITY);
  right_motor->setPosition(INFINITY);
  
  // get the time step of the current world.
  int timeStep = (int)robot->getBasicTimeStep();
  
  //if wrong channel
  const int channel = emitter->getChannel();
    if (channel != COMMUNICATION_CHANNEL) 
    {
      emitter->setChannel(COMMUNICATION_CHANNEL);
    }
    
   emitter->setRange(0.4); //Defines the emitters range
  
  //get a handler to the keybord and enables it
  Keyboard keyboard = Keyboard();
  keyboard.enable(50);

  // Main loop:
  while (robot->step(timeStep) != -1) 
  {
  
     /* send null-terminated message */
      const char *message = "Hello!";
      emitter->send(message, strlen(message) + 1);


      //Keybord control
      int key = keyboard.getKey();
 
      if (key == -1) {
           left_motor->setVelocity(0);
           right_motor->setVelocity(0);
       }
    
      while (key > 0) {
        switch (key) { 
          case 'Z':
             left_motor->setVelocity(MAX_SPEED);
             right_motor->setVelocity(MAX_SPEED); 
            break;
          case 'S':
             left_motor->setVelocity(-MAX_SPEED);
             right_motor->setVelocity(-MAX_SPEED);
            break;
          case 'Q':
            left_motor->setVelocity(-0.49*MAX_SPEED);
             right_motor->setVelocity(0.49*MAX_SPEED);
            break;
          case 'D':
            left_motor->setVelocity(0.49*MAX_SPEED);
             right_motor->setVelocity(-0.49*MAX_SPEED);
            break;
          case 'A':
               left_motor->setVelocity(0.5*MAX_SPEED);
               right_motor->setVelocity(0.75*MAX_SPEED);
            break;
            case 'E':
               left_motor->setVelocity(0.75*MAX_SPEED);
               right_motor->setVelocity(0.5*MAX_SPEED);
            break;
          default:
             left_motor->setVelocity(0);
             right_motor->setVelocity(0);
            break;
        }
       
        key = keyboard.getKey();
  
       }
  
  }

  // Enter here exit cleanup code.

  delete robot;
  return 0;
}