public override void Update(float dt)
{
// check if we're moving outside the initial position or final positions
if (this.Position.X < initialPosition.X || this.Position.Y < initialPosition.Y)
{
movingTowardFinal = true;
}
else if (this.Position.X > finalPosition.X || this.Position.Y > finalPosition.Y)
{
movingTowardFinal = false;
}
velocity = maxVelocity;
// calculate the distance
if (GameConstants.DistanceBetweenTwoPoints(this.Position, initialPosition) < nearTargetPositionDistance)
{
distanceToTargetPosition = GameConstants.DistanceBetweenTwoPoints(this.Position, initialPosition);
}
else if (GameConstants.DistanceBetweenTwoPoints(this.Position, finalPosition) < nearTargetPositionDistance)
{
distanceToTargetPosition = GameConstants.DistanceBetweenTwoPoints(this.Position, finalPosition);
}
else
{
distanceToTargetPosition = 0;
}
if (distanceToTargetPosition > 0)
{
velocity *= (float)Math.Sqrt(distanceToTargetPosition / nearTargetPositionDistance);
}
if (!movingTowardFinal)
{
velocity = -velocity;
}
physicsLine.body.LinearVelocity = velocity;
}
public override void Update(float dt)
{
// first, get the centre point of the circle
Vector2 centrePoint = (finalPosition + initialPosition) * 0.5f;
float dx = centrePoint.X - this.Position.X;
float dy = centrePoint.Y - this.Position.Y;
// get the normal to the current point on the circle
Vector2 normal;
if (clockwise)
{
normal = new Vector2(dy, -dx);
}
else
{
normal = new Vector2(-dy, dx);
}
// normalize then multiply by the maxVelocity
float normalLength = (float)Math.Sqrt(normal.X * normal.X + normal.Y * normal.Y);
normal /= normalLength;
normal *= maxSpeed;
float radius = GameConstants.DistanceBetweenTwoPoints(initialPosition, centrePoint);
Vector2 toCentrePoint = new Vector2(centrePoint.X - this.Position.X, centrePoint.Y - this.Position.Y);
if (GameConstants.DistanceBetweenTwoPoints(this.Position, centrePoint) > radius)
{
physicsLine.body.LinearVelocity = (normal + toCentrePoint) * 0.5f;
}
else
{
physicsLine.body.LinearVelocity = normal;
}
}