public void Step(GameFrame gameFrame, float deltaTime)
{
Contact contact;
float time;
int numIterations = 0; // to prevent infinite loops when squeezed
int maxIterations = 10;
ApplyTurbulence(gameFrame, deltaTime);
ClampVelocity(gameFrame);
while (FindFirstContact(gameFrame.Paddles, gameFrame.Puck, deltaTime, out contact, out time) &&
numIterations < maxIterations)
{
deltaTime -= time * 0.999f;
Integrate(gameFrame, time * 0.999f); //TODO: should ensure GapEpsilon seperation, this is arbitrary
ResolveContact(gameFrame.Puck, contact);
numIterations++;
}
// integrate the rest of the frame
Integrate(gameFrame, deltaTime);
ClampPaddlePosition(gameFrame.Paddles, 0);
ClampPaddlePosition(gameFrame.Paddles, 1);
PositionCorrection(gameFrame.Puck, gameFrame.Paddles);
// apply drag
gameFrame.Puck.velocity *= Constants.puckDrag;
}
void Integrate(GameFrame gameFrame, float deltaTime)
{
foreach (Body body in gameFrame.Bodies)
{
body.position += body.velocity * deltaTime;
}
}
void ClampVelocity(GameFrame gameFrame)
{
if (gameFrame.Puck.velocity.GetLength() > Constants.maxPuckSpeed)
{
gameFrame.Puck.velocity = Constants.maxPuckSpeed * gameFrame.Puck.velocity / gameFrame.Puck.velocity.GetLength();
}
}
void ApplyTurbulence(GameFrame gameFrame, float deltaTime)
{ //TODO: temp, make good
Random rand = new Random();
int i = rand.Next(0, 100);
float a = 3.14f * 2 * (float)i / 100.0f;
Vector2 turbulence = new Vector2(MathFunctions.Cos(a), MathFunctions.Sin(a)) * deltaTime * 2;
gameFrame.Puck.velocity += turbulence;
}
public void Update(GameFrame gameFrame, float deltaTime)
{
Body playerPaddle = gameFrame.Paddles[1];
Body opponentPaddle = gameFrame.Paddles[0];
Body puck = gameFrame.Puck;
thinkTimer += deltaTime;
if (thinkTimer > 0.4)
{
thinkTimer = 0.0f;
if (puck.position.Y < 0) // puck is on player side, move towards defensive position(close to goal).
{
state = AIState.Defense;
}
// else if (puck.velocity.Y < 0)
// aiState = AIState.Defense;
// else if ((puck.position - paddles[1].position).Y + Constants.puckRadius + Constants.paddleRadius > 0)
// aiState = AIState.Defense;
else
{
state = AIState.Attack;
}
}
Vector2 trajectory;
if (state == AIState.Defense)
{
target = new Vector2(0, 0.4f * Constants.tableHeight);
target.X += puck.position.X;
}
else
{
target = puck.position + new Vector2(0, Constants.puckRadius * 0.6f); // try to hit near the top but a little inside
}
trajectory = target - playerPaddle.position;
trajectory.Normalize();
playerPaddle.velocity = trajectory * speed;
// don't overshoot target
if (speed * deltaTime > (target - playerPaddle.position).GetLength() - Constants.puckRadius - Constants.paddleRadius && state == AIState.Defense)
{ //TODO: this is wrong, the impulse should not necessarily be small when we are really close...
playerPaddle.velocity = trajectory * ((target - playerPaddle.position).GetLength() - Constants.puckRadius - Constants.paddleRadius) / deltaTime;
}
}
public int CheckForScore(GameFrame gameFrame)
{
Body puck = gameFrame.Puck;
if (puck.position.Y - Constants.puckRadius > Constants.tableHeight * 0.5f) // let the puck get inside the goal before showing the score.
{
return(0);
}
else if (puck.position.Y + Constants.puckRadius < -Constants.tableHeight * 0.5f) // let the puck get inside the goal before showing the score.
{
return(1);
}
return(-1);
}
public PlayingState(StateManager stateManager,
ISoundEngine soundEngine,
Renderer renderer,
ResourceManager resourceManager) : base(stateManager)
{
physics = new Physics();
contacts = new List <Physics.Contact>();
physics.Collision += (sender, contact) =>
{
if (contact.collider == Collider.Paddle)
{
soundEngine.Play2D(ResourceManager.MediaPath + "puckHitPaddle.wav");
contacts.Add(contact);
}
if (contact.collider == Collider.Table)
{
soundEngine.Play2D(ResourceManager.MediaPath + "puckHitWall.wav");
contacts.Add(contact);
}
};
tableGraphicsObject = new Visual(
GeometryFactory.CreateBox(
new Box2(-Constants.tableWidth * 0.5f, Constants.tableHeight * 0.5f,
Constants.tableWidth * 0.5f, -Constants.tableHeight * 0.5f)),
new TextureEffect("table.png"));
puckGraphicsObject = new Visual(
GeometryFactory.CreateCircle(Constants.puckRadius, new Color4(1, 0, 0, 1)),
new VertexColorEffect());
paddleGraphicsObjects = new Visual[2];
paddleGraphicsObjects[0] = new Visual(
GeometryFactory.CreateCircle(Constants.paddleRadius, new Color4(1, 1, 1, 1)),
new VertexColorEffect());
paddleGraphicsObjects[1] = new Visual(
GeometryFactory.CreateCircle(Constants.paddleRadius, new Color4(1, 1, 1, 1)),
new VertexColorEffect());
gameFrame = new GameFrame();
ai = new AIPlayer();
}
