/// <summary>
/// Activate the explosion at the specified position.
/// </summary>
/// <param name="pos">The position (center) of the explosion.</param>
/// <param name="radius">The radius of the explosion.</param>
/// <param name="force">The force applied</param>
/// <param name="maxForce">A maximum amount of force. When force gets over this value, it will be equal to maxForce</param>
/// <returns>A list of bodies and the amount of force that was applied to them.</returns>
// FP - public Dictionary<Body, Vector2> Activate(Vector2 pos, FP radius, FP force, FP maxForce = FP.MaxValue)
public Dictionary <Body, FPVector2> Activate(FPVector2 pos, FP radius, FP force, FP maxForce)
{
HashSet <Body> affectedBodies = new HashSet <Body>();
AABB aabb;
aabb.LowerBound = pos - new FPVector2(radius);
aabb.UpperBound = pos + new FPVector2(radius);
// Query the world for bodies within the radius.
World.QueryAABB(fixture =>
{
if (FPVector2.Distance(fixture.Body.Position, pos) <= radius)
{
if (!affectedBodies.Contains(fixture.Body))
{
affectedBodies.Add(fixture.Body);
}
}
return(true);
}, ref aabb);
return(ApplyImpulse(pos, radius, force, maxForce, affectedBodies));
}
public static FP DistanceBetweenPointAndLineSegment(ref FPVector2 point, ref FPVector2 start, ref FPVector2 end)
{
if (start == end)
{
return(FPVector2.Distance(point, start));
}
FPVector2 v = FPVector2.Subtract(end, start);
FPVector2 w = FPVector2.Subtract(point, start);
FP c1 = FPVector2.Dot(w, v);
if (c1 <= 0)
{
return(FPVector2.Distance(point, start));
}
FP c2 = FPVector2.Dot(v, v);
if (c2 <= c1)
{
return(FPVector2.Distance(point, end));
}
FP b = c1 / c2;
FPVector2 pointOnLine = FPVector2.Add(start, FPVector2.Multiply(v, b));
return(FPVector2.Distance(point, pointOnLine));
}
public List <FPVector> SubdivideEvenly(int divisions)
{
List <FPVector> verts = new List <FPVector>();
FP length = GetLength();
FP deltaLength = length / divisions + 0.001f;
FP t = 0.000f;
// we always start at the first control point
FPVector2 start = ControlPoints[0];
FPVector2 end = GetPosition(t);
// increment t until we are at half the distance
while (deltaLength * 0.5f >= FPVector2.Distance(start, end))
{
end = GetPosition(t);
t += 0.0001f;
if (t >= 1f)
{
break;
}
}
start = end;
// for each box
for (int i = 1; i < divisions; i++)
{
FPVector2 normal = GetPositionNormal(t);
FP angle = FP.Atan2(normal.y, normal.x);
verts.Add(new FPVector(end.x, end.y, angle));
// until we reach the correct distance down the curve
while (deltaLength >= FPVector2.Distance(start, end))
{
end = GetPosition(t);
t += 0.00001f;
if (t >= 1f)
{
break;
}
}
if (t >= 1f)
{
break;
}
start = end;
}
return(verts);
}
public FP?IntersectsWithRay(FPVector2 origin, FPVector2 direction)
{
FP largestDistance = FPMath.Max(A.Position.x - origin.x, B.Position.x - origin.x) * 2f;
LineSegment raySegment = new LineSegment(new Vertex(origin, 0), new Vertex(origin + (direction * largestDistance), 0));
FPVector2?intersection = FindIntersection(this, raySegment);
FP? value = null;
if (intersection != null)
{
value = FPVector2.Distance(origin, intersection.Value);
}
return(value);
}
public FP GetLength()
{
List <FPVector2> verts = GetVertices(ControlPoints.Count * 25);
FP length = 0;
for (int i = 1; i < verts.Count; i++)
{
length += FPVector2.Distance(verts[i - 1], verts[i]);
}
if (Closed)
{
length += FPVector2.Distance(verts[ControlPoints.Count - 1], verts[0]);
}
return(length);
}
private Dictionary <Body, FPVector2> ApplyImpulse(FPVector2 pos, FP radius, FP force, FP maxForce, HashSet <Body> overlappingBodies)
{
Dictionary <Body, FPVector2> forces = new Dictionary <Body, FPVector2>(overlappingBodies.Count);
foreach (Body overlappingBody in overlappingBodies)
{
if (IsActiveOn(overlappingBody))
{
FP distance = FPVector2.Distance(pos, overlappingBody.Position);
FP forcePercent = GetPercent(distance, radius);
FPVector2 forceVector = pos - overlappingBody.Position;
forceVector *= 1f / FP.Sqrt(forceVector.x * forceVector.x + forceVector.y * forceVector.y);
forceVector *= FPMath.Min(force * forcePercent, maxForce);
forceVector *= -1;
overlappingBody.ApplyLinearImpulse(forceVector);
forces.Add(overlappingBody, forceVector);
}
}
return(forces);
}
