#define RTHRESH_BLACK 50
#define LTHRESH_BLACK 50
#define RTHRESH_GREY 40
#define LTHRESH_GREY 40

int LSENSOR=1;
int RSENSOR=2;
int retval=0;
int nothing;

void untilfunction(int obst)
{
 switch (obst)
 {
  /* The first selection */
  /* turn left opun black line */
  case 1:
   if (LSENSOR<=LTHRESH_BLACK || RSENSOR<=RTHRESH_BLACK)
   { retval=1; }
   else
   { retval=0; }
   break;

  /* pre-gate selection */
  /* returns true wgeb both sensors hit grey */
  case 2:
   //printf ("if %d<=%d",LSENSOR,LTHRESH_GREY);
   if (LSENSOR<=LTHRESH_GREY && RSENSOR<=RTHRESH_GREY)
   { retval=1; }
   else
   { retval=0; }
   break;
  

 }
}


void initsensors()
{
/*
 SetSensor(SENSOR_1,SENSOR_LIGHT);
 SetSensor(SENSOR_2,SENSOR_TOUCH);
 SetSensor(SENSOR_3,SENSOR_LIGHT);
 SetSensorMode(SENSOR_1, SENSOR_MODE_PERCENT);
 SelectDisplay(DISPLAY_SENSOR_1);
 */
}

void turnleft()
{
 /*
 OnFwd(LMOTOR);
 OnRev(RMOTOR);
 Wait(200);
 Off(OUT_A+OUT_C);
 */
}

void leftpath() {
 //printf("PATH: %s SENSOR: %d\n", "LEFT  ", LSENSOR );
}
void rightpath() {
 //printf("PATH: %s SENSOR: %d\n", "RIGHT ", LSENSOR);
}

void followline(int untilobst)
{
 while (1)
 {
 untilfunction(untilobst);
 if (retval==1) { return; }

   if (LSENSOR<=LTHRESH_BLACK)
   {
    rightpath();
   }
   else if (RSENSOR<=RTHRESH_BLACK)
   {
    //printf("%s", "HELLO");
    leftpath();
   }
   else { //printf("CURRENT PATH: %s SENSOR: %d\x0a", "PREVIOUS ",LSENSOR);
      }
   if (LSENSOR==49) { RSENSOR=51; } 
   LSENSOR-=1;
   RSENSOR-=1;

 }
 //printf("grey sensors hit\x0a");

}

task main()
{
 LSENSOR=60;
 RSENSOR=60;
 followline(2);
}