Ant Colony Pheromone Simulation

class Ant {

  float dx = random(-1, 1);

  float dy = random(-1, 1);

  float x;

  float y;

  int intX;

  int intY;

  int lastX;

  int lastY;

  int homeX;

  int homeY;

​

  boolean hasFood = false;

​

  float homePher = 100;

  float foodPher = 100;

  private float USE_RATE = .995;

  private float WANDER_CHANCE = .92;

​

  int bored = 0;

​

  Map homeMap;

  Map foodMap;

​

  Ant(int _x, int _y, Map _homePher, Map _foodMap) {

    intX = homeX = _x;

    intY = homeY = _y;

    x = float(_x);

    y = float(_y);

    homeMap = _homePher;

    foodMap = _foodMap;

  }

​

  void step() {

    // Wander chance .1 

    if (random(1) > WANDER_CHANCE) dx += random(-1, 1);

    if (random(1) > WANDER_CHANCE) dy += random(-1, 1);

    if (random(1) > .99) bored += floor(random(15));

    if (bored>0) {

      // Ignore pheromones

      bored--;

    } else {

      // Sniff trails

      if (hasFood) {

        // Look for home 

        int[] direction = homeMap.getStrongest(intX, intY);

        dx += direction[0] * random(1.5);

        dy += direction[1] * random(1.5);

      }

      else

      {

        // Look for food 

        int[] direction = foodMap.getStrongest(intX, intY);

        dx += direction[0] * random(1.5);

        dy += direction[1] * random(1.5);

      }

    }

    // Bounding limits, bounce off of edge

    if (x<2) dx = 1;

    if (x>width-2) dx = -1;

    if (y<2) dy = 1;

    if (y>height-2) dy = -1;

    // Speed limit

    dx = Math.min(dx, 1);

    dx = Math.max(dx, -1);

    dy = Math.min(dy, 1);

    dy = Math.max(dy, -1);

    // Move

    x += dx;

    y += dy;

    intX = floor(x);

    intY = floor(y);

​

    // Only if ant has moved enough (to another pixel)

    if (lastX!=intX || lastY!=intY) {

      // Leave trails

      if (hasFood) {

        // Leave food pheromone trail

        foodPher = foodPher * USE_RATE;

        foodMap.setValue(intX, intY, foodPher);

      }

      else

      {

        // Leave home pheromone trail

        homePher = homePher * USE_RATE;

        homeMap.setValue(intX, intY, homePher);

      }

    }

​

    lastX = intX;

    lastY = intY;

  }

}

​

​