[Liblas-devel] Re: Reading N Points

[Gary Huber]

Michael, Andrew, Howard,

On this list the following suggestion was made:

It would be Good Thing to have a ReadPoints function, which would have
the ability to return N points at once.  For some workflows, this would
be arguably more efficient and cleaner than calling ReadPoint N times
manually.


A couple months ago I implemented a similar ability from within the 
Index interface. You might have a look at it and see if something 
similar would work for you. The index is created once and can be called 
upon to deliver points back in a variety of useful ways. The index can 
be filtered with wide open bounds so that in effect it is not a filter 
at all, just an efficient way to retrieve a set of points with 
cell-based spatial organization.

Look at file lasindex.hpp line 467 for the iterator functionality. You 
control the flow of points returned in both quantity and continuity, 
allowing you to retrieve any number of points in a pass with any amount 
of gap between sets of points. The iterator is random access but is much 
more efficient for forward iterations than reverse or random.

Let me know if you have questions about the workings of the index 
iterator and I'll be glad to help you.

-Gary Huber