Barend Gehrels wrote:
Phil Endecott wrote: My particular interest is in efficient containers for points (and perhaps lines) with iterators over 2D ranges; have you done anything like that?
There are three kinds of iterators can be used in our library: - you can use the standard std::for_each to iterate over the points of for example a linestring or a multi_point, or a part of a them (using begin() end() or so) because it's all std:: container implementation here - besides that the library supports a for_each_point which iterates over all points of a linestring, polygon, and all multi geometries - furthermore the library supports a for_each_segment which iterates over all segments of the relevant geometries I don't know if this answers your question?
Say I have N points, randomly distributed. I want to iterate over the M points within some region (e.g. a rectangle), where M is much smaller than N. I need to be able to do this in much better than O(N) time, e.g. O(log N + M) time. Or I have N lines and I want to find the M of them that cross a rectangular region (harder!). I get the impression that you don't have this sort of thing.
- A feature of GTL is that it can accommodate arbitrary point types by means of suitable adapters.
I don't know the GTL details. However, in our case the geometries doesn't contain any data but x and y. If a user wants more, he can derive from our point type to include for example SRID or color or anything. Or he can implement his own point type. So I think it approaches your "arbitrary structs".
Well not if I have lat and long in my legacy code instead of x and y, for example. I'm not certain how useful this is, but the GTL proponents were very enthusiastic about it. Regards, Phil.