3 replies to this topic

[Lord_Vader]

Hello everybody,

Can someone write me a few words about what is a toroidal array data type and how it compares with a normal array. The way that I understand it is that it is almost like a circular double linked list with constant size.
If you provide me a link even better.

I did a search over the internet and some books about data structures but I didn't find any relevant and explanatory link.

Thanks

[Antheus]

For a 2D array with dimensions NxM:

torodial[i, j] = regular[i % N, j % M];

It doesn't have a use as such, but some algorithms may benefit from this property. For example:

A B
C D

// toroidal array now contains sequence:
ABABABABAB
and
ACACACACACACACACACAC....

It basically just says that rows and columns wrap around.

[Slavik81]

I don't think this would normally be a double-linked list if it's of constant size. You can achieve the same effect by using modulo (%) on the index accessors of a normal 2D array, bounding them within the width or height of the array.

[swiftcoder]

It doesn't have a use as such, but some algorithms may benefit from this property.

It is however very useful for representing game maps that wrap around at the edges - for instance, when implementing Conway's Game of Life.

Also worth mentioning that GPU texture lookups wrap by default, which provides a very simple case of toroidal access.