final07_AMBIENT.fsh

//
#version 130

uniform sampler2D sampler0;
uniform int worldTime;

vec4 TexCoord0 = gl_TexCoord[0];

#ifdef AMBIENT

vec4
getAmbient ()
{
    vec4 tint = vec4 (1.0, 1.0, 1.0, 1.0);
    float time;
    if (worldTime >= 22000.0)
    {                           // sunrise!
        time = min (max ((23000.0 - worldTime) / 1000.0, -1.0), 1.0);
        if (time > 0)
        {                       // Sky starts to colorize
            tint[0] = 0.95 + (0.15 * (1.0 - time)); // .95 to 1.1
            tint[1] = 0.95 - (0.05 * (1.0 - time)); // .95 to .9
            tint[2] = 1.1 - (0.1 * (1.0 - time));   // 1.1 to 1.0
        }
        else
        {                       // Sun rises
            tint[0] = 1.1 - (0.05 * (abs (time)));  // 1.1 to 1.05
            tint[1] = 0.9 + (0.0 * (abs (time)));   // .9 to .9
            tint[2] = 1.0 + (0.05 * (abs (time)));  // 1.0 to 1.05
        }
    }
    else if (worldTime >= 12000)
    {                           // night time !
        time = min (max ((13000.0 - worldTime) / 1000.0, -1.0), 1.0);
        if (time > 0)
        {                       // Sunset
            tint[0] = 1.1 + (0.15 * (1.0 - time));  // 1.1 to 1.25
            tint[1] = 1.0 - (0.05 * (1.0 - time));  // 1.0 to 0.95
            tint[2] = 0.9 - (0.15 * (1.0 - time));  // .9 to .75
        }
        else
        {                       // Night begins
            tint[0] = 1.25 - (0.3 * (abs (time)));  // 1.25 to .95
            tint[1] = 0.95 - (0.0 * (abs (time)));  // .95 to .95
            tint[2] = 0.75 + (0.35 * (abs (time))); // .65 to 1.1
        }
    }
    else if (worldTime >= 0)
    {                           // Day time, from dusk til dawn!
        time = min (max ((6000.0 - worldTime) / 6000.0, -1.0), 1.0);
        if (time > 0)
        {                       // Morning
            tint[0] = 1.05 - (0.05 * (1.0 - time)); // 1.05 to 1
            tint[1] = 0.9 + (0.1 * (1.0 - time));   // .9 to 1
            tint[2] = 1.05 - (0.05 * (1.0 - time)); // 1.05 to 1
        }
        else
        {                       // Afternoon
            tint[0] = 1 + (0.1 * (abs (time))); // 1 to 1.1
            tint[1] = 1 - (0.0 * (abs (time))); // 1 to 1
            tint[2] = 1 - (0.1 * (abs (time))); // 1 to .9
        }
    }
    return tint;
}
#endif

void
main ()
{
    vec4 baseColor = texture2D (sampler0, TexCoord0.st);

#ifdef AMBIENT
    baseColor *= getAmbient ();
#endif

    gl_FragColor = baseColor;
}