// colorf.java  compile    javac -cp . colorf.java

public class colorf extends Object
{
  // colorf   color wheel based on parameter  0 <= x <=1
  //          colorf(X, RGB[]) returns R,G,B in 0.0 to 1.0
  //          1/1/97 JSS initial version
  //          converted to java
  public void colorf(double X, double rgb[]) // rgb new double[3]
  {
    double A, AA, AAA; // temporaries
    double R, G, B;    // red, green, blue intensities

    A = 2.0*X-1.0;    // -1.0 < A < 1.0 
    if(A<-1.0) A = -1.0;
    if(A>1.0)  A = 1.0;
    R = 1.0 - Math.abs(A);
    AA = A - 2.0/3.0;
    if(AA < -1.0) AA = 2.0+AA;
    G = 1.0 - Math.abs(AA);
    AA = A + 2.0/3.0;
    if(AA > 1.0) AA = 2.0-AA;
    B = 1.0 - Math.abs(AA);

    // boost low end and normalize (this brightens colors) 
    R = R+0.2;
    G = G+0.2;
    B = B+0.2;
    AAA = Math.max(R, G);
    AAA = Math.max(AAA, B);
    rgb[0] = R/AAA;
    rgb[1] = G/AAA;
    rgb[2] = B/AAA;
  } // end colorf 
} // end colorf.java