the gears to ascension comments on Raemon’s Shortform

[the gears to ascension]

a ui on your user page where you get to pick a four letter shortening of your name and a color. the shortening is displayed as

t g
t a

in a tiny color-of-your-choice box. when picking your name, each time you pick a hue and saturation in the color picker (use a standard one, don’t build a color picker), it does a query (debounced—I hope you have a standard way to debounce in react elements) for other people on the site who have that initialism, and shows you their colors in a list, along with an indicator min(color_distance(you.color, them.color) for them in other_users).

the color distance indicator could be something like the one from here, which would need transliterating into javascript:

This formula has results that are very close to L^*u^*v^* (with the modified lightness curve) and, more importantly, it is a more stable algorithm: it does not have a range of colours where it suddenly gives far from optimal results. The weights of the formula could be optimized further, but again, the selection of the closest colour is subjective. My goal was to find a reasonable compromise.

typedef struct {
   unsigned char r, g, b;
} RGB;

double ColourDistance(RGB e1, RGB e2)
{
  long rmean = ( (long)e1.r + (long)e2.r ) / 2;
  long r = (long)e1.r - (long)e2.r;
  long g = (long)e1.g - (long)e2.g;
  long b = (long)e1.b - (long)e2.b;
  return sqrt((((512+rmean)*r*r)>>8) + 4*g*g + (((767-rmean)*b*b)>>8));
}