fuel system issues

im creating a fuel system and it is bugging me to death, im not realy the most math skilled and well i think it showed XD

i threw this script togethor fast so it may not be the most streight forward eather each 1/4 of a tank will give a llSetText [||||] and when i am at a empty tank it dose [||||] insted of [----]

id be greatfull for the help

==================================
=========Homewood's fuel system==========
=========Mrc Homewood 9/13/08==========
==========give credit where do===========
==================================

float odo;
integer max = 500;
vector old_pos;
integer out;
default
{
    state_entry()
    {
        llSetTimerEvent(1);
        old_pos = llGetRegionCorner() + llGetPos();
    }
    timer()
    {
        odo += llVecDist(llGetRegionCorner() + llGetPos(),old_pos);
        old_pos = llGetRegionCorner() + llGetPos();
        if(odo >= max)
        {
            llSetText("[----]\n\n\n\n\n\n",<1,0,0>,1);
            llMessageLinked(LINK_SET,0,"out of gas",NULL_KEY);
            out = TRUE;
            llSetStatus(STATUS_PHYSICS,FALSE);
            llSetTimerEvent(0);
            state fuelout;
        }
        else if(odo >= ((max/4)*3)-10 && odo <= ((max/4)*3)+10)
        {
            llSetText("[---|]\n\n\n\n\n\n",<1,1,1>,1);
        }
        else if(odo >= (max/2)-10 && odo <= (max/2)+10)
        {
            llSetText("[--||]\n\n\n\n\n\n",<1,1,1>,1);
        }
        else if(odo >= (max/4)-10 && odo <= (max/4)+10)
        {
            llSetText("[-|||]\n\n\n\n\n\n",<1,1,1>,1);
        }
        else if(odo >= (max/4)+10 && odo <= (max))
        {
            llSetText("[||||]\n\n\n\n\n\n",<1,1,1>,1);
            llMessageLinked(LINK_SET,0,"full tank",NULL_KEY);
            odo = 0;
        }
    }
}
state fuelout
{
    state_entry()
    {
        llListen(-1287,"","","");
        llSetStatus(STATUS_PHYSICS,FALSE);
    }
    changed(integer b)
    {
        if(b & CHANGED_LINK)
        {
            if(out)
            {
                llWhisper(0,"You Are Out of Fuel");
            }
        }
    }
    listen(integer chan, string name, key id, string msg)
    {
        if(msg == "gas up")
        {
            out = FALSE;
            state default;
        }
    }
}

anyone?

Probably it's because (style aside) the reason for the issue isn't obvious from a quick code read... try putting a debug line in the timer event just before if(odo >= max), e.g...
llOwnerSay("odo=" + (string)odo); and see if the numbers make sense

hth
/esc

You need to add spaces around the operators as in;

" ((max/4)*3)-10 && odo <= ((max/4)*3)+10)"

that is a negative 10, NOT subtract 10.

"(max/4)*3) - 10 && odo <= ((max/4)*3) + 10)"

Also take out the definition of old_pos that is redeclared in the timer.

Oh yeah -- good one Jesse


I think that line must stay as it's necessary to keep the odo cumulative.

/me hates algebra related math

[EDIT]
nope, now it just stays [----] (out of fuel)

Could the vehicle be moving too fast for your code? It looks like you're trying to make it change within fairly narrow windows (3/4 of max +/- 10m, and so on), so is it possible that within a second, you're moving from one side of that window to another?

Concrete example: Let's say at a given second, you have odo = 239. This is in the 1/2 - 3/4 tank range (125 - 250). Let's say your script worked correctly so far, and the text shows -|||.

One second later, your vehicle is at odo = 261. This requires it to move 22 m/s... not sure if that's possible in SL or not But if it did, walk through your script, and (I think) you'd see that it wouldn't trigger any of the display changes. You're looking for 250 +/- 10, and the vehicle moved from 250 - 11 to 250 + 11, and your code won't catch that.

So... see if it works better when you're driving slowly That might give you some clues as to what's happening.

Or you could simplify the script for now, at the cost of potentially adding to lag by calling llSetText more often that you need to. But you could change the logic to say:

if (odo >= max)
--- display empty tank

else if (odo >= 3/4 max)
--- display 1/4 tank

else if (odo >= 1/2 max)
--- display 1/2 tank

... and so on.

It only goes to an "else if" if the previous "if" check failed, so by the 2nd check, you already know that odo is not >= max, by the 3rd check you already know odo isn't >= 3/4 max, and so on.

Hope that helps. Disclaimer: haven't tried this in-world, so I could be pretty far off.