Colony

/**

 * @file PositionMonitor.cpp

 *

 * @author Jason Knichel

 *

 * @date 2/4/08

 */

#include <assert.h>

#include <map>

#include <PositionMonitor.h>

#include <stdio.h>

#include <stdlib.h>

#include <vision.h>

using namespace std;

#define MAX_POSITIONS 20

#define SAME_ROBOT_DISTANCE_THRESHOLD 150

#define ROBOT_DELETE_BUFFER 10

#define CAM_UPDATE_PERIOD 100000

/**

 * @brief Constructor for the PositionMonitor class

 */

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);

}

/**

 * @brief Destructor for the PositionMonitor class

 */

PositionMonitor::~PositionMonitor() {

}

/**

 * @brief This function updates the positions of things in the image

 *

 * @return Void

 */

void PositionMonitor::run() {

  while (1) {

    if (updatePositions() == -1) {

      fprintf(stderr, "updatePositions failed.\n");

    }

    usleep(CAM_UPDATE_PERIOD);

  }

}

/**

 * @brief This function asks the vision code for the position of things it identifies

 */

int PositionMonitor::updatePositions() {

  VisionPosition* positions = NULL;

  int numPositions = vision_get_robot_positions(&positions);

  //debug output code

  /*  

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

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

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

  }

  printf("\n");

  */

  if (numPositions == -1) {

    fprintf(stderr, "%s: vision_get_robot_positions failed.\n", __FUNCTION__);

    return -1;

  } else {

    map<int, VisionPosition> newPositionMap;

    pthread_mutex_lock(&position_map_lock);

    //go through each of the positions the vision system identified

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

      VisionPosition newPos = positions[i];

      map<int, VisionPosition>::iterator iter;

      //go through all the positions we currently have in the position map

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

        VisionPosition oldPos = iter->second;

        //figure out if the new point is probably the same robot as one of the old positions

        if (isProbablySameRobot(newPos, oldPos)) {

          //if the new positions is the same robot as an old one, insert this new position into the new map

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

          //erase this robot from the map that is used to smooth over several frames in case of problems identifying robots

          deleteBufferMap.erase(iter->first);

          //insert this robot back into the map in order to refresh its delete buffer

          deleteBufferMap.insert(make_pair(iter->first, ROBOT_DELETE_BUFFER));

          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)\n", 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));

        deleteBufferMap.insert(make_pair(newIdToAssign, ROBOT_DELETE_BUFFER));

        newIdToAssign--;

      }

    }

    map<int, VisionPosition>::iterator iter2;

    for (iter2 = positionMap.begin(); iter2 != positionMap.end(); iter2++) {

      int currId = iter2->first;

      map<int, VisionPosition>::iterator checkContains = newPositionMap.find(currId);

      if (checkContains == newPositionMap.end()) {

        int bufferValue = deleteBufferMap[iter2->first];

        bufferValue--;

        if (bufferValue > 0) {

          newPositionMap.insert(make_pair(currId, iter2->second));

          deleteBufferMap.erase(currId);

          deleteBufferMap.insert(make_pair(currId, bufferValue));

        } else {

          deleteBufferMap.erase(currId);

        }

      }

    }

    positionMap = newPositionMap;

    //  printf("\npositionMap size is %d and deleteBufferMap size is %d\n", positionMap.size(), deleteBufferMap.size());

    /*

    //TODO: remove this debug information

    map<int, VisionPosition>::iterator iter;

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

    printf("%d has position (%d, %d) with delete buffer %d\n", iter->first, iter->second.x, iter->second.y, deleteBufferMap[iter->first]);

    }

    */

    pthread_mutex_unlock(&position_map_lock);

    assert(positions != NULL);

    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);

  int oldDeleteBuffer = deleteBufferMap[old_id];

  deleteBufferMap.insert(make_pair(real_id, oldDeleteBuffer));

  deleteBufferMap.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);

}