"Janek Kozicki"
Geoffrey Irving said: (by the date of Wed, 14 Jun 2006 14:19:39 -0700)
I suppose no one said it explicitly, but I'm pretty sure everyone who's been talking about vector<3> was actually talking about a general vector<d> template.
true.
I have been following the geometry debate with interest. It probably doesnt need to be stated that geometry on numeric types is a sophisticated field. Geometry on strongly typed quantities in C++ is I think a relatively unexplored field. I thought I should say where I am planning to go with PQS library, especially to Janek , as he has experimented with using the library in his own work. First a lot depends on the outcome of the review. If accepted into boost, I can put the library into Boosts CVS. If not I will have to look around and put it elsewhere, possibly on sourceforge. I'm basing that on the high level of interest in the subject of quantities brought up by the PQS review. Either way I am planning a major upheaval of the code (including possibly a change of the library name etc), which will break the current interface. Its also clear that I need to redo the documentation, which is a time consuming process. Regarding the geometry end, it seems to me that the geometry doesnt need to be tied to the particular pqs type. Using Boost.Typeof it should be possible to implement geometric entities that will work with the types in pqs or others if written in terms of Concepts. I can however see some issues with using Typeof (mainly related to gcc), which I will bring up in another thread. The whole area of geometry on quantities is extremely interesting ( In a similar way to the question, Why climb Mount Everest, to which the reply was given, "Because its there"), however I think it is also a relatively unknown field( though Leland Brown seems to have done a fair amount of work on the subject) and with that in mind and with my skill level I reckon that my best bet is to try to implement vectors, quaternions and matrices in the absolute simplest way possible within PQS (This is actually the same philosophy I have used in PQS till now).I dont see PQS as being able to cover the field with authority or high performance etc to start with, but I currently view the work more as an experiment to start to answer the question. What happens if we try to implement geometry on strongly typed quantities? From following comments re pqs it is obvious that there is a real potential benefit, namely helping with debugging, code review etc, however it is only in trying to implement such a library fully that the problems will reveal themselves. I dont know what the answer to the above question is yet of course and I think it is quite important to those interested in the subject to point that out! At the moment I am not making the assumption that using quantities for geometry is beneficial over using floats ( Although what Leland has said is very encouraging). I guess the only way to find out is to try to implement the functionality... Of course, whether a half finished experiment in strongly typed quantities is a suitable candidate for a Boost library, luckily I can leave that to my Review Manager to answer! regards Andy Little