var
    daytime = ""    // Used by mob/Stat() to disply the time of day

world
    New()
        ..()
#if DM_VERSION>=400
        // Only use the alpha blended icon if supported
        sd_SetDarkIcon('sd_dark_alpha7.dmi',4)
#endif
        // kick off the daylight cycles
        spawn() DemoDayCycle()

proc/DemoDayCycle()
    // a simple day/night cycle
    var
        time = 10 // how long it stays in this light state
        light = 0    // how much light there is outside
        d = 1        // amount of light increase
    while(1) // keep doing until the program ends
        sleep(time) // wait time ticks
        time = 10 // set time to the default
        light += d  // shift the light amount

        // if light level is outside the allowed range
        if((light < 0) || (light > 4))
            d = -d  // switch the direction of light changes
            light += d  // put light back where it was
            time = 100 // make this light period last longer

        // just sets the time of day for the stat display
        switch(d*light)
            if(-4,4)
                daytime = "Day"
            if(-3,-2,-1)
                daytime = "Dusk"
            if(0)
                daytime = "Night"
            if(1,2,3)
                daytime = "Dawn"

        sd_OutsideLight(light)