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Subject: Re: [boost] [gsoc] Interest check for 3d geometry proposal
From: Kornel Kisielewicz (kornel.kisielewicz_at_[hidden])
Date: 2009-03-27 08:44:50

On Fri, Mar 27, 2009 at 12:23 PM, Phil Endecott
<spam_from_boost_dev_at_[hidden]> wrote:
> Kornel Kisielewicz <kornel.kisielewicz_at_[hidden]> wrote:
>> One example is object hierarchy via oct or kd trees.
> Would you like to implement these spatial containers?  I think this would be
> a very useful contribution.  Ideally your implementation would be generic,
> i.e. usable with fixed-size point types or the variable-size uBLAS types; at
> the end of the project we would then be able to evaluate the benefit of
> removing the size field.  2D & 3D please.

This is exactly my intention.

> - Although I doubt that wasting a word on a size field has much effect on
> speed, I would want to avoid it when dealing with large collections of
> points because of the memory overhead.

I'm not too much worried about the memory, as I am about data
alignment. Also, in the case of 4d vectors, you'd have 5 values, which
doesn't scale well ( 4*32 bits = 128bits which is nice -- an addition
would ruin this niceness ).

> - I have using uBLAS for some simple 2D matrix transformation and found it a
> little bit more difficult than I expected; a special-purpose API, even if
> implemented as a thin wrapper around uBLAS or something else, would have the
> benefit of simplifying things for the end user.

Fully agreed.

Kornel Kisielewicz

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