Indexing - What is it!?

[NarGalloth]

Hi.

I want to know what is this thing called "indexing".
I am a GUI user, and I often search in the spells section of THW, looking for cool spells, to download them and learn new things from them.
A short time ago I introduced myself to hashtables and IDs, doing exactly this.
However, I've recently seen a lot of spells that use this "indexing" thing. I can't understand what is it, or how can I use it.
Could someone give me a quick explanation so I can figure out what's it?

Thanks in advance.

Regards

 

[Spartipilo]

The Unit Indexer is a system that assigns a value to every unit based on it's custom value. That value is between 0 and 8190 (the max array size) so you can access any unit by the custom value of the picked unit, instead of using hashtables, which is slower and more resource consuming.

 

[Dr Super Good]

Indexing in WarCraft III is a form of memory allocation algorithm that allocates working set in a non-fragmented way. Within the working set the allocation can become fragmented but any modifications to the working set will be non-fragmented. It is used in WarCraft III arrays as they are dynamic arrays that support increasing only in powers of 2 with a maximum size of 2^13. This keeps memory allocation for such arrays as low as possible since new indexes will be next to already allocated indices and used only if all previously used indices have been allocated.

 

[mckill2009]

ehem, I'll just make it simple in addition to the above posts, indexing is like this:

• Set unitU[1] = UNIT_A
• Set unitU[2] = UNIT_B

here, uses the same variable (unitU) but assigns different index (1 and 2), so the unitU variable has different pointers and this makes the spell MUI...

 

[defskull]

• Set unitU[1] = UNIT_A
• Set unitU[2] = UNIT_B

In addition to this, it allows stacking data too;

• Set unitU[1] = UNIT_A
• Set unitU[2] = UNIT_B
• Set unitU[3] = UNIT_A

Meaning that if you want your spell to have stacking effect, indexing is the way.

 

[WaterKnight]

Basically said, it grants different objects different labels to be able assign data to these objects via their labels as a form of memory separation.

 

[Dr Super Good]

It should be noted that arrays start from index 0. Failing to use index 0 by an off by 1 error wastes an array index.

The size field in GUI arrays is only how many indices are initialized on map load. The actual array size is defined during runtime based on what indicies become set. The algorthim used is a dynamic array which lacks the capability to reduce in size.

 

[NarGalloth]

I see. Thanks for the information, guys!
Now I'm going to check those spells and see if I can understand them a bit better.

Regards