/// <summary>
/// See <see cref="IForce.ApplyToObject(TPhysicalObject)"/>.
/// </summary>
public void ApplyToObject(IBody <TShapeFigure> physicalObject)
{
ArgumentChecks.AssertNotNull(physicalObject, nameof(physicalObject));
// TODO: make this class "more generic", so it could be used for particles as well. Add a strategy to determine the "point to apply the force to".
var pointClosestToBlastCenter = this._supportFunctions.GetFigureOutlinePointClosestToPosition(
physicalObject.Shape.Current,
this._position);
// Is the object within reach of the blast?
var offset = pointClosestToBlastCenter.GetOffsetFrom(this._position);
if (offset.Magnitude() > this._currentBlastRadius)
{
return;
}
var forceVector = offset.Norm().Multiply(this._currentForce);
physicalObject.ApplyForceAtPointInSpace(forceVector, pointClosestToBlastCenter);
}
/// <summary>
/// See <see cref="IForce{TPhysicalObject}.ApplyToObject(TPhysicalObject)"/>.
/// </summary>
public void ApplyToObject(IBody <TShapeFigure> physicalObject)
{
ArgumentChecks.AssertNotNull(physicalObject, nameof(physicalObject));
var velocity = physicalObject.CurrentState.Velocity;
if (velocity.SquaredMagnitude() == 0)
{
return;
}
var forceDirection = velocity.Invert();
var supportPointLeft = this._supportFunctions.GetSupportPoint(physicalObject.Shape.Current, forceDirection.Get90DegreesLeft());
var supportPointRight = this._supportFunctions.GetSupportPoint(physicalObject.Shape.Current, forceDirection.Get90DegreesRight());
var intersectionWithPerpendicular = this._lineCalculationHelper.GetIntersectionWithPerpendicularThroughPoint(
new Line(physicalObject.CurrentState.Position, physicalObject.CurrentState.Position.AddVector(forceDirection)),
supportPointLeft);
var pointOppositeLeftSupportPoint = this._lineCalculationHelper.GetIntersectionWithPerpendicularThroughPoint(
new Line(supportPointLeft, intersectionWithPerpendicular),
supportPointRight);
var offset = pointOppositeLeftSupportPoint.GetOffsetFrom(supportPointLeft);
// Determine the exposed "area".
var exposedArea = offset.SquaredMagnitude();
// Determine force.
var forceMagnitude = exposedArea * this._density * velocity.SquaredMagnitude() / 2;
var forceVector = forceDirection.Norm().Multiply(forceMagnitude);
// Determine the point to apply force to.
var pointToApplyForceTo = supportPointLeft.AddVector(offset.Divide(2));
// Apply force.
physicalObject.ApplyForceAtPointInSpace(forceVector, pointToApplyForceTo);
}