protected override void InitializeWorld()
{
World.SetWorldCoordinate(new Vector2(0, 0), kWorldWidth);
mPatrols = new List <PatrolObject>();
mPatrols.Add(new PatrolObject());
mHero = new HeroObject();
}
private const float kDistToBeginChase = 10f; // this is the distance to trigger partol chasing of hero
private void DetectHero(HeroObject hero)
{
Vector2 toHero = hero.Center - Center;
if (toHero.Length() < kDistToBeginChase)
{
mStateTimer = kStateTimer * 2; // 5 times as much time for chasing
Speed *= 3f; // twice the current speed!
mCurrentState = PatrolState.ChaseHero;
mTargetPosition = hero.Center;
Color = Color.Red;
}
}
private bool UpdateChaseHeroState(HeroObject hero, float distToHero)
{
bool caught = false;
caught = Collided(hero);
mTargetPosition = hero.Center;
if (caught || (mStateTimer < 0))
{
if (caught)
{
hero.Caught();
}
Color = new Color(XNACS1Base.RandomFloat(0f, 0.4f),
XNACS1Base.RandomFloat(0f, 0.4f),
XNACS1Base.RandomFloat(0f, 0.4f));
// now tansit out of current state ...
Vector2 midPt = 0.5f * (XNACS1Base.World.WorldMax - XNACS1Base.World.WorldMin);
if (CenterX > midPt.X)
{
if (CenterY > midPt.Y)
{
mCurrentState = PatrolState.TopRightRegion;
mTargetPosition = RandomTopRightPosition();
}
else
{
mCurrentState = PatrolState.BottomRightRegion;
mTargetPosition = RandomBottomRightPosition();
}
}
else
{
if (CenterY > midPt.Y)
{
mCurrentState = PatrolState.TopLeftRegion;
mTargetPosition = RandomTopLeftPosition();
}
else
{
mCurrentState = PatrolState.BottomLeftRegion;
mTargetPosition = RandomBottomLeftPosition();
}
}
mStateTimer = kStateTimer;
ComputePositionAndVelocity();
}
return(caught);
}
private void UpdateTopLeftState(HeroObject hero, float distToTarget)
{
DetectHero(hero); // check if we should transit to ChaseHero
if ((mStateTimer < 0) || (distToTarget < 5f))
{
mStateTimer = (int)(kStateTimer * XNACS1Base.RandomFloat(0.8f, 1.2f)); // 20% randomness
if (XNACS1Base.RandomFloat() > 0.5f)
{
mCurrentState = PatrolState.BottomLeftRegion;
mTargetPosition = RandomBottomLeftPosition();
}
else
{
mCurrentState = PatrolState.TopRightRegion;
mTargetPosition = RandomTopRightPosition();
}
ComputePositionAndVelocity();
}
}
public bool Update(HeroObject hero)
{
bool caught = false;
// perform operation common to all states ...
mStateTimer--;
Vector2 toTarget = mTargetPosition - Center;
float distToTarget = toTarget.Length();
toTarget /= distToTarget; // this is the same as normalization
ComputeNewDirection(toTarget);
// operations specific to each states// operations specific to each states
switch (mCurrentState)
{
case PatrolState.BottomLeftRegion:
UpdateBottomLeftState(hero, distToTarget);
break;
case PatrolState.BottomRightRegion:
UpdateBottomRightState(hero, distToTarget);
break;
case PatrolState.TopRightRegion:
UpdateTopRightState(hero, distToTarget);
break;
case PatrolState.TopLeftRegion:
UpdateTopLeftState(hero, distToTarget);
break;
case PatrolState.ChaseHero:
caught = UpdateChaseHeroState(hero, distToTarget);
break;
}
return(caught);
}