Color.HSBtoRGB missing in WinRT - colors

Question

I'm builing a fractal application and need to generate a smooth color scheme, and I found a nice algorithm at Smooth spectrum for Mandelbrot Set rendering.
But that required me to call Color.HSBtoRGB and that method is not available in WinRT / Windows Store apps.
Is there some other built-in method to do this conversion?
Other tips on how to convert HSB to RGB?

Answer 1

I ended up using the HSB to RGB conversion algorithm found at http://www.adafruit.com/blog/2012/03/14/constant-brightness-hsb-to-rgb-algorithm/, I adopted the inital (long) version. Perhaps this can be further optimized but for my purpose this was perfect!
As the hsb2rgb method is in C and I needed C#, I'm sharing my version here:
private byte[] hsb2rgb(int index, byte sat, byte bright)
{
int r_temp, g_temp, b_temp;
byte index_mod;
byte inverse_sat = (byte)(sat ^ 255);
index = index % 768;
index_mod = (byte)(index % 256);
if (index < 256)
{
r_temp = index_mod ^ 255;
g_temp = index_mod;
b_temp = 0;
}
else if (index < 512)
{
r_temp = 0;
g_temp = index_mod ^ 255;
b_temp = index_mod;
}
else if ( index < 768)
{
r_temp = index_mod;
g_temp = 0;
b_temp = index_mod ^ 255;
}
else
{
r_temp = 0;
g_temp = 0;
b_temp = 0;
}
r_temp = ((r_temp * sat) / 255) + inverse_sat;
g_temp = ((g_temp * sat) / 255) + inverse_sat;
b_temp = ((b_temp * sat) / 255) + inverse_sat;
r_temp = (r_temp * bright) / 255;
g_temp = (g_temp * bright) / 255;
b_temp = (b_temp * bright) / 255;
byte[] color = new byte[3];
color[0] = (byte)r_temp;
color[1] = (byte)g_temp;
color[2] = (byte)b_temp;
return color;
}
To call it based on the code linked in the original post I needed to make some minor modifications:
private byte[] SmoothColors1(int maxIterationCount, ref Complex z, int iteration)
{
double smoothcolor = iteration + 1 - Math.Log(Math.Log(z.Magnitude)) / Math.Log(2);
byte[] color = hsb2rgb((int)(10 * smoothcolor), (byte)(255 * 0.6f), (byte)(255 * 1.0f));
if (iteration >= maxIterationCount)
{
// Make sure the core is black
color[0] = 0;
color[1] = 0;
color[2] = 0;
}
return color;
}