private void MovementPrediction(ref PredictionOutput result, PredictionInput input)
{
var target = input.Unit;
var cosTheta = Vector2.Dot(target.Direction2D(), input.ToUnitDirection2D());
var targetRelativePosition = target.Position2D() - input.RangeCheckFrom.ToVector2();
var targetRelativeVelocity = -Math.Sign(cosTheta) * target.Velocity2D();
var a = Vector2.Dot(targetRelativeVelocity, targetRelativeVelocity) - (float)Math.Pow(input.Speed, 2);
var b = Vector2.Dot(targetRelativeVelocity, targetRelativePosition) * 2f;
var c = Vector2.Dot(targetRelativePosition, targetRelativePosition);
var discriminant = b * b - 4.0f * a * c;
var impactTime = 2f * c / (float)(Math.Sqrt(discriminant) - b);
if (float.IsNaN(impactTime))
{
result.Hitchance = HitChance.OutOfRange;
var speed = input.Speed - Math.Sign(cosTheta) * target.MoveSpeed;
impactTime = (float)Math.Sqrt(c) / speed;
}
result.UnitPosition = target.Position3D() + target.Velocity3D() * impactTime;
result.CastPosition = target.Position3D() + target.Velocity3D() * impactTime;
}
