     // night
     if (sun_z < nighttime) {
         color = nightblue_color;
-        // color = vec3(phi_diff, 0,0 );
-
     // night to sunrise OR sunset to night
     } else if (sun_z > nighttime && sun_z < sun_start) {
         float size = sun_start - nighttime;

    if (phi_diff > 0.5) {
        phi_diff = 1.0 - phi_diff;
    }

    phi_diff *= 2.0;

    float sun_start;

    if (sun_x > 0) {
        sun_start = sunrise_start;
    } else {

        float percent= diff/size;
        color = (nightblue_color + (sunset_color - nightblue_color) * percent);
        color = mix(color, nightblue_color, phi_diff);
    // sunrise to high_noon OR high_noon to sunset
    } else if (sun_z > sun_start && sun_z < high_noon_start) {
        float size = high_noon_start - sun_start;
