/// <summary>
/// 朝向目标
/// </summary>
/// <param name="body"></param>
/// <param name="targetPoint"></param>
/// <param name="angularVelocityProc">角速度系数(0.1 - 1)</param>
/// <returns></returns>
public static float FowardToTarget(this Body body, Vector2 targetPoint, float angularVelocityProc, float deadArea = 0.95f)
{
if (Vector2.DistanceSquared(body.GetPosition(), targetPoint) < double.Epsilon)
{
return(0);
}
Vector2 tmp = targetPoint - body.GetPosition();
bool isClockwise = MathUtils.Cross(tmp, body.GetForward()) > 0;
float cos = CrazyUtils.IncludedAngleCos(tmp, body.GetForward());
body.ApplyAngularImpulse(-body.AngularVelocity * body.Inertia, true);
if (cos > deadArea)
{
return(cos);
}
if (isClockwise)
{
body.ApplyAngularImpulse(-angularVelocityProc * body.Inertia, true);
}
else
{
body.ApplyAngularImpulse(angularVelocityProc * body.Inertia, true);
}
return(cos);
}
/// <summary>
/// 圆形检测
/// </summary>
/// <param name="body"></param>
/// <param name="bodies"></param>
/// <param name="radius"></param>
/// <returns></returns>
public static List <Body> CircleDetection(this Body body, IEnumerable <Body> bodies, double radius)
{
List <tempBody> CollisionalBodies = new List <tempBody>();
foreach (var b in bodies)
{
var distance = Vector2.DistanceSquared(body.GetPosition(), b.GetPosition());
if (distance < radius * radius)
{
CollisionalBodies.Add(new tempBody(b, (float)Math.Sqrt(distance)));
}
}
return((from o in CollisionalBodies.OrderBy(o => o.Distance) select o.Body).ToList());
}
/// <summary>
/// 距离检测
/// </summary>
/// <param name="body"></param>
/// <param name="point"></param>
/// <param name="distance"></param>
/// <returns></returns>
public static bool DistanceDetection(this Body body, Vector2 point, double distance)
{
return(Vector2.DistanceSquared(body.GetPosition(), point) <= distance * distance);
}
