public override FP ComputeSubmergedArea(ref TSVector2 normal, FP offset, ref Transform xf, out TSVector2 sc)
{
sc = TSVector2.zero;
TSVector2 p = MathUtils.Mul(ref xf, Position);
FP l = -(TSVector2.Dot(normal, p) - offset);
if (l < -Radius + Settings.Epsilon)
{
//Completely dry
return(0);
}
if (l > Radius)
{
//Completely wet
sc = p;
return(Settings.Pi * _2radius);
}
//Magic
FP l2 = l * l;
FP area = _2radius * (FP)((TSMath.Asin((l / Radius)) + TSMath.PiOver2) + l * TSMath.Sqrt(_2radius - l2));
// TODO - PORT
//FP com = -2.0f / 3.0f * (FP)Math.Pow(_2radius - l2, 1.5f) / area;
//FP com = new FP(-2) / new FP(3) * (FP)Math.Pow((_2radius - l2).AsFloat(), 1.5f) / area;
FP com = new FP(-2) / new FP(3) * TSMath.Pow(_2radius - l2, (FP)1.5) / area;
sc.x = p.x + normal.x * com;
sc.y = p.y + normal.y * com;
return(area);
}
private FP GetPercent(FP distance, FP radius)
{
//(1-(distance/radius))^power-1
// TODO - PORT
// FP percent = (FP)Math.Pow(1 - ((distance - radius) / radius), Power) - 1;
//FP percent = (FP)Math.Pow((1 - ((distance - radius) / radius)).AsFloat(), Power.AsFloat()) - 1;
FP percent = TSMath.Pow(FP.One - ((distance - radius) / radius), Power) - FP.One;
if (FP.IsNaN(percent))
{
return(FP.Zero);
}
return(TSMath.Clamp(percent, FP.Zero, FP.One));
}
public FP Distance(FP x, FP y)
{
FP distanceSquared = 0;
FP greatestMin = TSMath.Max(X1, x);
FP leastMax = TSMath.Min(X2, x);
if (greatestMin > leastMax)
{
distanceSquared += TSMath.Pow(greatestMin - leastMax, 2);
}
greatestMin = TSMath.Max(Y1, y);
leastMax = TSMath.Min(Y2, y);
if (greatestMin > leastMax)
{
distanceSquared += TSMath.Pow(greatestMin - leastMax, 2);
}
return((FP)TSMath.Sqrt(distanceSquared));
}