Colony

/**

 * @file PositionMonitor.cpp

 *

 * @author Jason Knichel

 *

 * @date 2/4/08

 */

//TODO: make this file asynchronous

#include <PositionMonitor.h>

#include <stdlib.h>

#include <vision.h>

#include <stdio.h>

#include <map>

using namespace std;

PositionMonitor::PositionMonitor() {

  //TODO: don't hardcode this file name

  //TODO: check for error returned from init

  vision_init("/var/www/colonet.jpg");

  newIdToAssign = -1;

  pthread_mutex_init(&position_map_lock, NULL);

}

PositionMonitor::~PositionMonitor() {

}

void PositionMonitor::run() {

  while (1) {

    updatePositions();

    usleep(500000);

  }

}

int PositionMonitor::updatePositions() {

  VisionPosition * positions = NULL;

  //TODO: check for error returned

  int numPositions = vision_get_robot_positions(&positions);

  printf("numPositions is %d\n", numPositions);

  for (int i = 0; i < numPositions; i++) {

    printf("{%d,%d} ", positions[i].x, positions[i].y);

  }

  printf("\n");

  map<int, VisionPosition> newPositionMap;

  pthread_mutex_lock(&position_map_lock);

  //TODO: also remove robots that might have disappeared

  int i;

  for (i = 0; i < numPositions; i++) {

    VisionPosition newPos = positions[i];

    map<int, VisionPosition>::iterator iter;

    for (iter = positionMap.begin(); iter != positionMap.end(); iter++) {

      VisionPosition oldPos = iter->second;

      if (isProbablySameRobot(newPos, oldPos)) {

        //TODO: is this the right use of an iterator?

        newPositionMap.insert(make_pair(iter->first, newPos));

        break;

      }

    }

    if (iter == positionMap.end()) {

      //a position was found that probably isn't a known 

      //  robot so add it in case a new robot entered the field

      printf("Inserting new robot: %d (%d,%d)", newIdToAssign, newPos.x, newPos.y);

      //a position was found that probably isn't a known robot so add it in case a new robot entered the field

      newPositionMap.insert(make_pair(newIdToAssign, newPos));

      newIdToAssign--;

    }

  }

  positionMap = newPositionMap;

  //TODO: remove this debug information

  map<int, VisionPosition>::iterator iter;

  for (iter = positionMap.begin(); iter != positionMap.end(); iter++) {

    printf("%d has position (%d, %d)\n", iter->first, iter->second.x, iter->second.y);

  }

  pthread_mutex_unlock(&position_map_lock);

  if (positions) {

    free(positions);

  }

  return 0;

}

int PositionMonitor::assignRealId(int old_id, int real_id) {

  printf("assigning real_id %d to old_id %d\n", real_id, old_id);

  pthread_mutex_lock(&position_map_lock);

  map<int,VisionPosition>::iterator iter = positionMap.find(old_id);

  if (iter == positionMap.end()) {

    fprintf(stderr, "assignRealId: old_id not found\n");

    pthread_mutex_unlock(&position_map_lock);

    return -1;

  }

  positionMap.insert(make_pair(real_id, iter->second));

  positionMap.erase(old_id);

  pthread_mutex_unlock(&position_map_lock);

  return 0;

}

map<int, VisionPosition> PositionMonitor::getAllRobotPositions() {

  // TODO return a copy instead of the actual map for synch purposes

  return positionMap;

}

int PositionMonitor::getNumVisibleRobots() {

  return positionMap.size();

}

VisionPosition PositionMonitor::getFirstPosition(void) {

  return positionMap.begin()->second;

}

int PositionMonitor::getRobotPosition(int robot_id, int* xbuf, int* ybuf) {

  //TODO: figure out what a map returns if the element doesn't exist

  pthread_mutex_lock(&position_map_lock);

  if (positionMap.find(robot_id) == positionMap.end()){

    pthread_mutex_unlock(&position_map_lock);    

    return -1;

  } else {

    VisionPosition pos = positionMap[robot_id];

    pthread_mutex_unlock(&position_map_lock);

    *xbuf = pos.x;

    *ybuf = pos.y;

    return 0;

  }

}

bool PositionMonitor::isProbablySameRobot(VisionPosition p1, VisionPosition p2) {

  int xDiff = p1.x - p2.x;

  int yDiff = p1.y - p2.y;

  return (xDiff*xDiff + yDiff*yDiff < SAME_ROBOT_DISTANCE_THRESHOLD*SAME_ROBOT_DISTANCE_THRESHOLD);

}