public static void MoveStars(StarscapeModel starList)
{
foreach (var star in starList.Stars)
{
star.ShuntPosition();
}
}
public static void ConsiderAddingStar(double gameTimeSeconds, StarscapeModel StarsList, Random RandomGenerator) // Quiz: This is very similar to ConsiderAddingAlien(). What could you do about that?
{
var elapsedTime = gameTimeSeconds - StarsList.LastTimeWeConsideredAddingAStar;
if (elapsedTime > StarscapeModel.TimeBetweenAddingStars)
{
if (StarsList.Stars.Count < StarscapeModel.MaxStarsOnScreenAtOnce)
{
var starY = RandomGenerator.Next(0, RetroScreen.HeightInPixels); // NB: Y axis runs the other way up from normal mathematics!
var speed = RandomGenerator.Next(1, 4);
var newStar = new StarModel(new Point(RetroScreen.WidthInPixels, starY), speed);
StarsList.Stars.Add(newStar);
}
StarsList.LastTimeWeConsideredAddingAStar = gameTimeSeconds; // Quiz: Why are we doing this here?
}
}
public static void RemoveOffScreenObjects(AlienListModel aliensList, ShipBulletListModel shipBulletList, AlienBulletListModel alienBulletList, StarscapeModel starList, ScoreModel scoring)
{
shipBulletList.ShipBullets.RemoveAll(b => b.CentrePoint.x > RetroScreen.WidthInPixels);
alienBulletList.AlienBullets.RemoveAll(b => b.CentrePoint.x < 0);
starList.Stars.RemoveAll(s => s.CentrePoint.x < 0);
int numberOfAliensRemoved = aliensList.Aliens.RemoveAll(a => a.CentrePoint.x < 0);
scoring.SetScore(Math.Max(0, scoring.Score - numberOfAliensRemoved));
}
