plhlsrgb: Convert HLS color to RGB 

DESCRIPTION:

    Convert HLS color coordinates to RGB 

SYNOPSIS:

plhlsrgb(h, l, s, p_r, p_g, p_b)

ARGUMENTS:

    h (PLFLT, input) :      Hue, in degrees on the colour cone (0.0-360.0) 

    l (PLFLT, input) :      Lightness, expressed as a fraction of the axis
    of the colour cone (0.0-1.0) 

    s (PLFLT, input) :      Saturation, expressed as a fraction of the
    radius of the colour cone (0.0-1.0) 

    p_r (PLFLT *, output) :    Pointer to red intensity (0.0-1.0) of the
    colour 

    p_g (PLFLT *, output) :    Pointer to green intensity (0.0-1.0) of the
    colour 

    p_b (PLFLT *, output) :    Pointer to blue intensity (0.0-1.0) of the
    colour