code

var gunLoaded = true;
var enemiesMovingLeft = false;
var gameStarted = false;
var enemiesRemaining = 4;
var startTime;
var elapsedTime;
var musicPlaying = getChecked("checkbox_music");
var toBeCollected = 3;
var gameOver = false;
var virusHealth = 4;
var wbcHealth = 4;

setScreen("screen_title");

if (musicPlaying === true) {
  playSound("sound://category_background/stride.mp3", true);
} else {
  stopSound("sound://category_background/stride.mp3");
}

onEvent("button_play", "click", function( ) {
  playSound("sound://category_alerts/retro_game_health_pickup_6.mp3", false);
  setScreen("screen_shooter");
});

timedLoop(5000, function() {
  setText("label_didYouKnow", "Remember to check your facts are from verified sources!");
});
timedLoop(10000, function() {
  setText("label_didYouKnow", "All facts in this app are from verified source, mainly from WHO...");
});

onEvent("screen_shooter", "keydown", function(event) {
  var drX = getXPosition("image_dr");
  var drY = getYPosition("image_dr");

  var distance = 12;

  if (event.key == "Up")
  {
    drY = drY - distance;
  }

  if (event.key == "Down")
  {
    drY = drY + distance;
  }

  if(event.key == "Enter")
  {
    fire();
  }

  setPosition("image_dr", drX, drY);
  verticalWrapAround("image_dr");
});

function verticalWrapAround(object)
{
  var objectX = getXPosition(object);
  var objectY = getYPosition(object);

  var objectHeight = getProperty(object, "height");

  if (objectY < 0 - (objectHeight / 2))
  {
    objectY = 450 - (objectHeight / 2);
  }

  else if (objectY > 450 - (objectHeight) / 2)
  {
    objectY = 0 - (objectHeight /2);
  }

  setPosition(object, objectX, objectY);
}

function fire()
{
  if(gunLoaded) //gunLoaded == true
  {
    gunLoaded = false;
    var drX = getXPosition("image_dr");
    var drY = getYPosition("image_dr");
    var drHeight = getProperty("image_dr", "height");
    var drWidth = getProperty("image_dr", "width");
    var goopHeight = getProperty("image_goop", "height");

    var goopX = drX + drWidth - 30;
    var goopY = drY + (drHeight / 2) - (goopHeight / 2) + 25;

    setPosition("image_goop", goopX, goopY);

  }
}
onEvent("button_start", "click", function(event) {
  if(!gameStarted)
  {
    gameStarted = true;
    setPosition("button_start", 100, 500);
    startTime = getTime();
    setPosition("image_goop", 400, 100);

 timedLoop(50, function() {
      updateTime();
      moveGoop();

      moveEnemy("image_enemy_one");
      moveEnemy("image_enemy_two");
      moveEnemy("image_enemy_three");
      moveEnemy("image_enemy_four");

      collisionDetection("image_enemy_one");
      collisionDetection("image_enemy_two");
      collisionDetection("image_enemy_three");
      collisionDetection("image_enemy_four");

      if(enemiesRemaining === 3)
        setText("label_info", "Wash your hands with water and soap for at least 20 seconds frequently");

      if(enemiesRemaining === 2)
        setText("label_info", "Avoid touching your face!");

      if(enemiesRemaining === 1)
        setText("label_info", "Disinfect frequently used items often, like your phone!");

      if(enemiesRemaining === 0)
      {
        setText("label_info", "Good Job! Now remember to stay at home to limit the spread of the virus, and help your doctors who are working very long hours during this pandemic...");
        showElement("button_next");

      }
    });

  }
});

onEvent("button_next", "click", function( ) {
  playSound("sound://category_alerts/retro_game_health_pickup_6.mp3", false);
  setScreen("screen_sidescroller");
});


function updateTime()
{
  var currentTime = getTime();
  elapsedTime = currentTime - startTime;
  elapsedTime = (elapsedTime / 1000).toFixed(1);
  setNumber("label_time", elapsedTime);
}

function moveGoop()
{
  var goopX = getXPosition("image_goop");
  var goopY = getYPosition("image_goop");
  var goopSpeed = goopX / 5;

  goopX = goopX + goopSpeed;

  setPosition("image_goop", goopX, goopY);

  if(goopX > 500)
  gunLoaded = true;

}

function moveEnemy(name)
{
  var enemyX = getXPosition(name);
  var enemyY = getYPosition(name);

  var minX = 156;
  var maxX = 280;
  var distanceFromMax = maxX - enemyX;

  var verticalSpeed = (distanceFromMax /10) + 20;
  var horizontalSpeed = Math.min((elapsedTime / 2), 15);

  enemyY = enemyY + verticalSpeed

  if(enemyX > maxX)
    enemiesMovingLeft = true;

  if (enemyX < minX)
    enemiesMovingLeft = false;

  if(enemiesMovingLeft) // enemiesMovingLeft == true
    enemyX = enemyX - horizontalSpeed;

  else
    enemyX = enemyX + horizontalSpeed;

  setPosition(name, enemyX, enemyY);

  verticalWrapAround(name);
}

function collisionDetection(object)
{
  var goop_X = getXPosition("image_goop");
  var goop_Y = getYPosition("image_goop");
  var objectX = getXPosition(object);
  var objectY = getYPosition(object);

  var goop_width = getProperty("image_goop", "width");
  var goop_height = getProperty("image_goop", "height");
  var objectWidth = getProperty(object, "width");
  var objectHeight = getProperty(object, "height");

  if(goop_X + goop_width >= objectX && goop_X <= objectX + objectWidth)
  {
    if(goop_Y + goop_height >= objectY && goop_Y <= objectY + objectHeight)
    {
      if(!getProperty(object, "hidden"))
      {
        hideElement(object);
        enemiesRemaining--; //enemiesRemaining = enemiesRemaining - 1

        if(enemiesRemaining <= 0)
        {
          stopTimedLoop();
          hideElement("image_goop");
        }
      }
    }
  }
}

// the following code is for screen_sidescroller

onEvent("screen_sidescroller", "keydown", function(event) {
  var dr_two_X = getXPosition("image_dr_two");
  var dr_two_Y = getYPosition("image_dr_two");

  var distance = 15;

  if(event.key == "Up")
  {
    dr_two_Y = dr_two_Y - distance;
  }

  if(event.key == "Down")
  {
    dr_two_Y = dr_two_Y + distance;
  }

  if(event.key == "Left")
  {
    dr_two_X = dr_two_X - distance;
  }

   if(event.key == "Right")
  {
    dr_two_X = dr_two_X + distance;
  }

  setPosition("image_dr_two", dr_two_X, dr_two_Y);
  wrapAround_two("image_dr_two");
});

function wrapAround_two(object)
{
  var objectX = getXPosition(object);
  var objectY = getYPosition(object);

  var objectWidth = getProperty(object, "width");
  var objectHeight = getProperty(object, "height");

  if(objectX < 0 - (objectWidth / 2))
  {
    objectX = 320 - (objectWidth / 2);
  }

  else if(objectX > 320 - (objectWidth / 2))
  {
    objectX = 0 - (objectWidth / 2);
  }

  else if(objectY < 0 - (objectHeight / 2))
  {
    objectY = 450 - (objectHeight / 2);
  }

  else if(objectY > 450 - (objectHeight / 2))
  {
    objectY = 0 - (objectHeight / 2);
  }

  setPosition(object, objectX, objectY);
}

function moveObject(object, xStep, yStep)
{
  var newX = getXPosition(object) + xStep;
  var newY = getYPosition(object) + yStep;
  setPosition(object, newX, newY);
  wrapAround_two(object);
}


onEvent("button_start_two", "click", function(event) {
  timedLoop(50, function() {
    hideElement("button_start_two");
    hideElement("image_info");

    moveObject("image_germ_one", 1, 1);
    moveObject("image_germ_two", 2, 1);
    moveObject("image_germ_three", 1, 2);
    moveObject("image_germ_four", 2, 2);

    moveObject("image_vaccine", 2, 2);
    moveObject("image_disinfectant", 2, 2);
    moveObject("image_sanitizer", 2, 2);

    collisionDetection_two("image_germ_one", true);
    collisionDetection_two("image_germ_two", true);
    collisionDetection_two("image_germ_three", true);
    collisionDetection_two("image_germ_four", true);

    collisionDetection_two("image_disinfectant", false);
    collisionDetection_two("image_sanitizer", false);
    collisionDetection_two("image_vaccine", false);
  });

});

function collisionDetection_two(object, isEnemy)
{
  var drX = getXPosition("image_dr_two");
  var drY = getYPosition("image_dr_two");
  var objectX = getXPosition(object);
  var objectY = getYPosition(object);

  var drWidth = getProperty("image_dr_two", "width");
  var drHeight = getProperty("image_dr_two", "height");
  var objectWidth = getProperty(object, "width");
  var objectHeight = getProperty(object, "height");

  if(drX + drWidth >= objectX && drX <= objectX + objectWidth)
  {
    if(drY + drHeight >= objectY && drY <= objectY + objectHeight)
    {
      if(isEnemy && !gameOver) //isEnemy === true, gameOver !== true
      {
        gameOver = true;
        setScreen("screen_lose");
    }

    else if(!isEnemy && !gameOver && !getProperty(object, "hidden"))
    {
      hideElement(object);
      toBeCollected--; //toBeCollected = toBeCollected -1

      if(toBeCollected <= 0 & !gameOver)
      {
        gameOver = true;
        showElement("button_sc2_next");
        showElement("image_sc2_next");
      }
    }
  }
}

onEvent("button_sc2_next", "click", function( ) {
  setScreen("screen_turn_based");
});

if(toBeCollected === 2)
{
 showElement("label_facts");
 setText("label_facts", "Follow local and international news! It's the best way to keep informed");
}

if(toBeCollected === 1)
  setText("label_facts","When telling people about coronavirus, be calm, avoid exaggeration and make sure your information is correct");
}

//these next lines of code are for screen_turn_based

onEvent("button_start_three", "click", function( ) {
  hideElement("button_start_three");
  setText("label_questions", "Can regularly rinsing your nose with saline help prevent infection with the new coronavirus?");
  showElement("button_yes");
  showElement("button_no");
});

onEvent("button_yes", "click", function( ) {
  wbcHealth == (wbcHealth - 1);
});

onEvent("button_no", "click", function( ) {
  virusHealth = (virusHealth - 1);
});

if(wbcHealth === 3){
  showElement("wbc_3_health");
  hideElement("image_wbc_health_full");
}