public static int ComputeQuadLevel(Envelope env)
{
double dx = env.Width;
double dy = env.Height;
double dMax = dx > dy ? dx : dy;
int level = DoubleBits.Exponent(dMax) + 1;
return(level);
}
/// <summary>
/// Computes the exponent for the largest power of two
/// less than the absolute value of the argument.
/// In other words, finds the value n such that
/// 2ˆn <= abs(num) < 2ˆ(n+1)
/// </summary>
/// <param name="num"></param>
/// <returns>The exponent.</returns>
public static int Exponent(double num)
{
num = Math.Abs(num);
double log = Math.Log(num);
double log2 = log / LOG_2;
int exp = (int)Math.Floor(log2);
int exp2 = DoubleBits.Exponent(num);
if (exp != exp2)
{
//System.out.println(DoubleBits.toBinaryString(num));
//System.out.println(num + " pow2 mismatch: " + exp + " DoubleBits: " + exp2);
double pow2exp = DoubleBits.PowerOf2(exp);
double pow2exp2 = DoubleBits.PowerOf2(exp2);
//System.out.println(pow2exp + " pow2exp2 = " + pow2exp2);
}
return(exp);
}
