llDetectedLinkNumber

Anyone have a script that returns the LinkNumber of a prim within an object? I have messed with this all evening, and for the life of me, cannot make one that works.

default
{
    touch_start(integer a)
    {
        for(;a;a--)
            llSay(0."Link Touched: "+ (string)llDetectedLinkNumber(a - 1));
    }
}

or to be evil

default
{
    touch_start(integer a)
    {
        while(a)
            llSay(0."Link Touched: "+ (string)llDetectedLinkNumber(--a));
    }
}

Excellent, 2nd one works, thanks!

I am starting to feel very silly, but I don't understand why you have to decrement a before getting the link number?

The decrement has nothing to do with the links, but rather, how touch works. Strife's solution is there to compensate for events where more than one avatar is touching the object. Hence, the decrement and while loop are there to check for each touch occurance.

Thanks, Jeffery. What I'm not understanding it why you decrement a before calling llDetectedLinkNumber()

For example, if two avatars touch the object:

while(a) // true, a=2
llSay(0."Link Touched: "+ (string)llDetectedLinkNumber(--a)); // says the link no for touch #1
while(a) // true, a=1
llSay(0."Link Touched: "+ (string)llDetectedLinkNumber(--a)); // says the link no for touch #0, but there is no touch 0?
while(a) // false, a=0

So it will report twice, there are two touches, fair enough.


But it fails if I use:

while(a)
{
llSay(0."Link Touched: "+ (string)llDetectedLinkNumber(a));
a--;
}

I've only tested with one touch, and no matter which prim in the linked object I touch, llDetectedLinkNumber() returns 0.

So it works using the Strife's code, but it's giving me the heebie-jeebies that I don't understand why my example doesn't work.

Thanks again,
Fairge

It's because the 'a' returns the total number for a zero-indexed array; basically:


Total Number = 5

0 => Link 1
1 => Link 2
2 => Link 3
3 => Link 4
4 => Link 5

-Adam

there are a couple things going on.

default
{
    touch_start(integer a)
    {
        while(a)
            llSay(0."Link Touched: "+ (string)llDetectedLinkNumber(--a));
    }
}

nicely writen becomes...

default
{
    touch_start(integer num)
    {
        while(num != 0)
        {
            --num;
            llSay(0."Link Touched: "+ (string)llDetectedLinkNumber(num));
        }
    }
}

you see the first touch is numbered zero; the second, one; the third, two. This is the standard in computing. Now the paramater is (num) is how many there are total in the stack. The last entry is (num - 1). This script reads the stack backwords. In most cases in scripting it won't matter which way you read it (the sensor event sorts the entries by how close they are).

So first we test to make sure we haven't run out of entries. Then subtract one.
Then use that to get the last entry of the stack we haven't gotten before.

See i'm lazy, if i can avoid decaring variables at the expense of read backwords thats fine with me

Got it now, thanks for the clear explanations. I'd mixed it up, and thought that touch_start was giving me an index number, not a count. <grin>

And it is splendid how helpful you all are!

Cheers,
Fairge

default
{
touch_start(integer total_number)
{
llSay(0,(string)llDetectedLinkNumber(total_number - 1));
}
}


If you're going to have multiple people click it, this may not be a good way, but it does spit out the link number if you're just trying to get it to use in linked messages and stuff.

Strife's being clever. It's a bit more readable like this, and it's probably not any noticeably less efficient:

default
{
    touch_start(integer num_touching)
    {
        integer i;
        for(i=0; i<num_touching; i++)
            llSay(0."Link Touched: "+ (string)llDetectedLinkNumber(i));
    }
}