private Color randNonSecretColor()
{
Color randColor;
bool badRand = true;
while (badRand)
{
byte randR = (byte)rand.Next(0, 255);
byte randG = (byte)rand.Next(0, 255);
byte randB = (byte)rand.Next(0, 255);
bool tooClose = false;
for (int i = 0; i < secretColors.Count; i++)
{
Color secret = secretColors[i];
CIELab secretLab = XYZtoLab(RGBtoXYZ(secret.R, secret.G, secret.B));
CIELab randLab = XYZtoLab(RGBtoXYZ(randR, randG, randB));
double delta = delta1994(randLab.L, randLab.A, randLab.B, secretLab.L, secretLab.A, secretLab.B);
if (delta <= 25)
{
tooClose = true;
break;
}
}
if (!tooClose)
{
badRand = false;
randColor = Color.FromArgb(255, randR, randG, randB);
}
}
return(randColor);
}
/// <summary>
/// Converts CIEXYZ to CIELab.
/// </summary>
public CIELab XYZtoLab(CIEXYZ xyz)
{
CIELab lab = CIELab.Empty;
lab.L = 116.0 * Fxyz(xyz.Y / CIEXYZ.D65.Y) - 16;
lab.A = 500.0 * (Fxyz(xyz.X / CIEXYZ.D65.X) - Fxyz(xyz.Y / CIEXYZ.D65.Y));
lab.B = 200.0 * (Fxyz(xyz.Y / CIEXYZ.D65.Y) - Fxyz(xyz.Z / CIEXYZ.D65.Z));
return(lab);
}