/**
 * Strength in numbers
 *
 * <p>Elie Zananiri<br>
 * CART 253, Winter 2008</p>
 */

// ----------------------------------------------------------------------
// GLOBAL CONSTANTS
// ----------------------------------------------------------------------
int MAX_SOLDIERS = 200;

// ----------------------------------------------------------------------
// GLOBAL VARIABLES
// ----------------------------------------------------------------------
int numSoldiers = 0;
Soldier army[] = new Soldier[MAX_SOLDIERS];

PFont font;

// ----------------------------------------------------------------------
// BUILT-IN FUNCTIONS
// ----------------------------------------------------------------------
void setup() {
  size(400, 400);
  smooth();
  noStroke();
  
  // set up the font
  font = loadFont("Georgia.vlw");
  textFont(font, 12);
  textAlign(CENTER, CENTER);
}

void draw() {
  background(0);
  step();

  // draw all the soldiers
  for (int i=0; i < numSoldiers; i++) {
    army[i].draw(); 
  }
}

void mousePressed() {
  addSoldier(mouseX, mouseY); 
}

void mouseDragged() {
  addSoldier(mouseX, mouseY); 
}

void keyPressed() {
  if (key == ' ') {
    // clear all
    numSoldiers = 0;
  } 
}

// ----------------------------------------------------------------------
// USER FUNCTIONS
// ----------------------------------------------------------------------
/* adds a new soldier to the display */
void addSoldier(int newX, int newY) {
  if (numSoldiers < MAX_SOLDIERS) {
    army[numSoldiers] = new Soldier(newX, newY);

    numSoldiers++;
  }
}

/* moves all the soldiers and if any collide, make them fight */
void step() {
  // move all the soldiers
  for (int i=0; i < numSoldiers; i++) {
    army[i].move();
  }

  // see if any two soldiers collide
  for (int i=0; i < numSoldiers-1; i++) {
    Soldier currSoldier = army[i];
    // if the current soldier is alive...
    if (currSoldier.isAlive) {
      // ...go through all the current soldier's right neighbours
      for (int j=i+1; j < numSoldiers; j++) {
        Soldier otherSoldier = army[j];
        // if the neighbour is alive...
        if (otherSoldier.isAlive) {
          // ...and they collide...
          if (currSoldier.collidesWith(otherSoldier)) {
            // ...call a fight
            fight(currSoldier, otherSoldier);
          }
        }
      }
    } 
  }
  
  // array to hold all soldiers that will live to the next frame
  Soldier survivors[] = new Soldier[MAX_SOLDIERS];
  int numSurvivors = 0;
  
  // keep only the live soldiers for the next round
  for (int i=0; i < numSoldiers; i++) {
    if (army[i].isAlive) {
      survivors[numSurvivors] = army[i];
      numSurvivors++;
    }
  }

  army = survivors;
  numSoldiers = numSurvivors;
}

/* makes two soldiers fight, with the loser dying and the winner gaining his strength */
void fight(Soldier soldier1, Soldier soldier2) {
  Soldier winner;
  Soldier loser;

  // randomly generate the outcome of the fight
  if (random(1) < 0.5) {
    winner = soldier1;
    loser = soldier2;
  } else { 
    winner = soldier2;
    loser = soldier1;
  }

  // make the winner gain the loser's strength
  winner.strength += loser.strength;
  // kill the loser
  loser.isAlive = false;
}