/// <summary>
/// Estimates the future position of target.
/// </summary>
/// <param name="player">The player on which the future position estimate is to be performed.</param>
/// <param name="target">The target position of the player.</param>
/// <param name="max">The maximum estimated time.</param>
/// <returns>The future position of the player.</returns>
public static Vector2 FuturePosition(IPointMass player, IPointMass target, float max)
{
Contract.Requires<ArgumentException>(player != null);
Contract.Requires<ArgumentException>(target != null);
Contract.Requires<ArgumentException>(max >= 0);
var estimatedTime = max;
var invSpeed = 1/player.Velocity.Length();
if (!float.IsNaN(invSpeed))
{
int p, f;
var offset = target.Position - player.Position;
var parallelness = Vector2.Dot(Vector2.Normalize(player.Velocity), Vector2.Normalize(target.Velocity));
if (float.IsNaN(parallelness)) p = 1;
else p = parallelness < -0.707f ? 2 : (parallelness > 0.707f ? 0 : 1);
var forwardness = Vector2.Dot(Vector2.Normalize(player.Velocity), Vector2.Normalize(offset));
if (float.IsNaN(forwardness)) f = 3;
else f = forwardness < -0.707f ? 6 : (forwardness > 0.707f ? 0 : 3);
estimatedTime = Math.Min(offset.Length()*invSpeed*TimeFactorTable[p + f], max);
}
return target.Position + target.Velocity*estimatedTime;
}
/// <summary>
/// Move toward a specified position.
/// </summary>
/// <param name="player">The player that should seek the specified position.</param>
/// <param name="target">The target position.</param>
/// <param name="desiredSpeed">The desired speed at which the player should move towards the target.</param>
/// <returns>The force vector that should be applied to the player.</returns>
public static Vector2 Seek(IPointMass player, Vector2 target, float desiredSpeed)
{
Contract.Requires<ArgumentException>(player != null);
Contract.Requires<ArgumentException>(desiredSpeed >= 0);
return Vector2.Normalize(target - player.Position)*desiredSpeed - player.Velocity;
}
public Spring(IPointMass end1, IPointMass end2, float stiffness, float damping) : base()
{
End1 = end1;
End2 = end2;
Stiffness = stiffness;
Damping = damping;
TargetLength = Vector3.Distance(end1.Position, end2.Position) * 0.95f;
}
/// <summary>
/// </summary>
/// <param name="player"></param>
/// <param name="target"></param>
/// <param name="otherPlayers"></param>
/// <param name="passingLaneWidth"></param>
/// <returns></returns>
public static bool IsPlayerOpenForPass(
IPointMass player,
IPointMass target,
IEnumerable<IPointMass> otherPlayers,
float passingLaneWidth)
{
var angle = Math.PI/2 -
Math.Atan2(target.Position.Y - player.Position.Y, target.Position.X - player.Position.X);
var v = passingLaneWidth/2*new Vector2((float) Math.Cos(angle), (float) Math.Sin(angle));
return
otherPlayers.All(
p => !PointInTriangle(p.Position, player.Position, v + target.Position, target.Position - v));
}
private static void DrawPointMass(IPointMass pointMass, Pen pen, Brush brush, Graphics g)
{
var triangle = new[] { new PointF(1, 0), new PointF(-0.7f, 0.7f), new PointF(-0.7f, -0.7f) };
using (var m = new Matrix())
{
m.Translate(pointMass.Position.X, pointMass.Position.Y);
m.Rotate((float)(Math.Atan2(pointMass.Velocity.Y, pointMass.Velocity.X) * 180 / Math.PI));
m.Scale(pointMass.Radius*0.9f, pointMass.Radius*0.9f);
m.TransformPoints(triangle);
}
g.FillPolygon(brush, triangle);
g.DrawCircle(pen, pointMass.Position, pointMass.Radius);
}
/// <summary>
/// Move to and stop at a specified position.
/// </summary>
/// <param name="player">The player that should arrive at the specified position.</param>
/// <param name="target">The target position.</param>
/// <param name="maxSpeed">The maximum speed at which the player should move towards the target position.</param>
/// <param name="slowingRadius">The radius in which the player should begin to slow down.</param>
/// <returns>The force vector that should be applied to the player.</returns>
public static Vector2 Arrive(IPointMass player, Vector2 target, float maxSpeed, float slowingRadius)
{
Contract.Requires<ArgumentException>(player != null);
Contract.Requires<ArgumentException>(maxSpeed >= 0);
Contract.Requires<ArgumentException>(slowingRadius >= 0);
var targetOffset = target - player.Position;
var distance = targetOffset.Length();
var rampedSpeed = maxSpeed*(distance/slowingRadius);
var clippedSpeed = Math.Min(rampedSpeed, player.MaxSpeed);
var direction = targetOffset/distance;
var desiredVelocity = clippedSpeed*direction;
return desiredVelocity - player.Velocity;
}
/// <summary>
/// </summary>
/// <param name="player"></param>
/// <param name="target"></param>
/// <param name="ball"></param>
/// <returns></returns>
// TODO: Finish this
public static Kick PassToPlayer(IPointMass player, IPointMass target, IPointMass ball)
{
var desiredDirection = target.Position - player.Position;
if (ball.Velocity.LengthSquared() < 0.1)
{
return new Kick(player, desiredDirection * 100000);
}
else
{
var projection = ball.Velocity.Projection(desiredDirection);
var rejection = ball.Velocity.Rejection(desiredDirection);
var difference = ball.Velocity - desiredDirection;
var force = desiredDirection - projection - rejection;
//var angle = Math.Atan2(difference.Y, difference.X);
//var force = ball.Velocity - rejection * 2;
//if (Math.Abs(angle) > Math.PI / 2)
// force -= projection * 2;
return new Kick(player, force * 100000);
}
}
private static void DrawDebugInfo(IPointMass pointMass, Brush brush, Font font, Graphics g)
{
}
private static IPointMass ClosestPlayerToPoint(IEnumerable<IPointMass> players, IPointMass target, float max, Vector2 goalMiddle)
{
return players.OrderBy(p => (p.Position - SteeringStrategies.FuturePosition(p, target, max)).LengthSquared() + DistanceBetween(p.Position, goalMiddle)).First();
}
/// <summary>
/// Creates a new instance of the <see cref="Kick" /> class with the specified player and force.
/// </summary>
/// <param name="player">The player to kick the ball.</param>
/// <param name="force">The desired force on the ball to be exerted by the player.</param>
public Kick(IPointMass player, Vector2 force)
{
Contract.Requires<ArgumentNullException>(player != null);
Player = player;
Force = force;
}
/// <summary>
/// </summary>
/// <param name="players"></param>
/// <param name="target"></param>
/// <param name="max"></param>
/// <returns></returns>
public static IPointMass ClosestPlayerToPoint(IEnumerable<IPointMass> players, IPointMass target, float max)
=> players.OrderBy(p => (p.Position - SteeringStrategies.FuturePosition(p, target, max)).LengthSquared()).First();
private bool IsKickValid(IPointMass player, ISimulation simulation) =>
Players.Any(p => p == player) &&
(player.Position - simulation.Ball.Position).Length() < player.Radius + simulation.Ball.Radius;
/// <summary>
/// </summary>
/// <param name="player"></param>
/// <returns></returns>
public static float GetSlowingRadius(IPointMass player)
{
Contract.Requires<ArgumentException>(player != null);
return player.MaxSpeed*player.MaxSpeed/(2*player.MaxForce/player.Mass);
}
/// <summary>
/// Move toward a target's future position. This method assumes the player will move at their maximum speed. It also
/// ignores friction on the target.
/// </summary>
/// <param name="player">The player that should pursue the specified location.</param>
/// <param name="target">The target position that the player should pursue.</param>
/// <param name="maxEstimatedTime">The maximum estimated time.</param>
/// <returns>The force vector that shoud be applied to the player.</returns>
public static Vector2 Pursue(IPointMass player, IPointMass target, float maxEstimatedTime)
=> Seek(player, FuturePosition(player, target, maxEstimatedTime), player.MaxSpeed);