private Point2D GetShotTargetPosition(
ChickenUnitState unitState,
ChickenViewData enemyUnit)
{
if (!_features.IsAnySet(Features.PredictiveShot))
{
return(enemyUnit.Position);
}
Point2D?predictiveShotTargetPosition = null;
var enemyUnitBeakTip = GameHelper.GetBeakTipPosition(enemyUnit.Position, enemyUnit.BeakAngle);
var enemyUnitVector = enemyUnitBeakTip - enemyUnit.Position;
var enemyToMeVector = unitState.Position - enemyUnit.Position;
var cosAlpha = enemyUnitVector.GetAngleCosine(enemyToMeVector);
var distanceToEnemySqr = enemyToMeVector.GetLengthSquared();
var distanceToEnemy = distanceToEnemySqr.Sqrt();
if (!(cosAlpha.Abs() - 1f).IsZero())
{
var equation = new QuadraticEquation(
GameConstants.ShotToChickenRectilinearSpeedRatio.Sqr() - 1f,
2f * distanceToEnemy * cosAlpha,
-distanceToEnemySqr);
float d1, d2;
if (equation.GetRoots(out d1, out d2) > 0)
{
var d = new[] { d1, d2 }
.Where(item => item > 0f)
.OrderBy(item => item)
.FirstOrDefault();
if (d.IsPositive())
{
predictiveShotTargetPosition = GameHelper.GetNewPosition(
enemyUnit.Position,
enemyUnit.BeakAngle,
d);
}
}
}
var result = predictiveShotTargetPosition
?? GameHelper.GetNewPosition(
enemyUnit.Position,
enemyUnit.BeakAngle,
GameConstants.ChickenUnit.DefaultRectilinearSpeed);
return(result);
}
//---------------------------------------------------------------------------------------------
//Координаты x, соответствующие координате y
public double[] GetCoordinatesX(double y)
{
double a = 1;
double b = -2 * this.centre.X;
double c =
(y - this.centre.Y) * (y - this.centre.Y) +
this.centre.X * this.centre.X -
radius * radius;
QuadraticEquation quadraticEquation = new QuadraticEquation(a, b, c);
Complex[] complexRoots = quadraticEquation.GetRoots();
double[] realRoots = NumbersManager.GetRealParts(complexRoots);
return(realRoots);
}
//-----------------------------------------------------------------------------------------------
//Точки пересечения прямой и окружности
public static Point2D[] IntersectionPointsOfLineAndCircle(
LineDescriptor lineDescriptor,
CircleDescriptor circleDescriptor
)
{
double a = lineDescriptor.CoefficientOfX;
double b = lineDescriptor.CoefficientOfY;
double c = lineDescriptor.AbsoluteTerm;
double xc = circleDescriptor.Centre.X;
double yc = circleDescriptor.Centre.Y;
double r = circleDescriptor.Radius;
double x1, x2, y1, y2;
if (b != 0)
{
double koefficientA = 1 + ((a * a) / (b * b));
double koefficientB = 2 * (c * a / (b * b) + yc * a / b - xc);
double koefficientC =
xc * xc + yc * yc + (c * c) / (b * b) + 2 * yc * c / b - r * r;
QuadraticEquation quadraticEquation =
new QuadraticEquation(koefficientA, koefficientB, koefficientC);
Complex[] complexRoots = quadraticEquation.GetRoots();
double[] realRoots = NumbersManager.GetRealParts(complexRoots);
x1 = realRoots[0];
y1 = (-c - a * x1) / b;
x2 = realRoots[1];
y2 = (-c - a * x2) / b;
}
else
{
double x = -c / a;
x1 = x2 = x;
double[] coordinatesY = circleDescriptor.GetCoordinatesY(x);
y1 = coordinatesY[0];
y2 = coordinatesY[1];
}
Point2D intersectionPoint1 = new Point2D(x1, y1);
Point2D intersectionPoint2 = new Point2D(x2, y2);
Point2D[] intersectionPoints = new Point2D[] { intersectionPoint1, intersectionPoint2 };
return(intersectionPoints);
}
