/// <summary>
/// Steps the color.
/// </summary>
/// <param name="clr">The color.</param>
/// <param name="alpha">The alpha.</param>
/// <returns>Color.</returns>
public static Color StepColor(Color clr, int alpha)
{
if (alpha == 100)
{
return(clr);
}
byte a = clr.A;
byte r = clr.R;
byte g = clr.G;
byte b = clr.B;
float bg = 0;
int _alpha = Math.Min(alpha, 200);
_alpha = Math.Max(alpha, 0);
double ialpha = ((double)(_alpha - 100.0)) / 100.0;
if (ialpha > 100)
{
// blend with white
bg = 255.0F;
ialpha = 1.0F - ialpha; // 0 = transparent fg; 1 = opaque fg
}
else
{
// blend with black
bg = 0.0F;
ialpha = 1.0F + ialpha; // 0 = transparent fg; 1 = opaque fg
}
r = (byte)(ZeroitLBColorManager.BlendColour(r, bg, ialpha));
g = (byte)(ZeroitLBColorManager.BlendColour(g, bg, ialpha));
b = (byte)(ZeroitLBColorManager.BlendColour(b, bg, ialpha));
return(Color.FromArgb(a, r, g, b));
}
