I'm not a big STL expert,
but one of the STL principia is:
"compare with end() ONLY using == or !="
mario
Robert Osfield wrote:
> Hi Michael,
>
> The file came through just fine this time, thanks.
>
> I'm reviewing the change and won't merge just yet as it took me a
> little while to figure out what the code was trying to do and the
> problem it was addressing. Code this is difficult for me to get my
> head around will be difficult for other too so may lead to mistakes in
> adjusting the code in the future so I'd like to refactor the code make
> it more readable even if its a bit more long winded.
>
> The original code is:
>
> Particle_vector::const_iterator i;
> Particle_vector::const_iterator i0 = _particles.begin();
> Particle_vector::const_iterator end = _particles.end();
>
> i0->beginRender();
>
> float scale = sqrtf(static_cast<float>(_detail));
> for (i=i0; i<end; i+=_detail) {
> ...
> }
>
> To me it looks like the original code should work as it, and the i
> iterator should never be accessed when it goes beyond the end of the
> vector it is iterating over as the iterator is incremented by _detail
> at the end of the for loop scope then the i<end is tested and should
> fail, for instance if i points to entry 10 and there are only end
> point to entry 9 it should return false.
>
> To me you bug fix clamps the increment so the last iteration of the
> loop take you to where i==end, which fails correctly.
>
> Is this a correct analysis? If so it suggest that the STL
> implementation of std::vector::iterator fails when i>end returning
> true for i<end expression in this case.
>
> Robert.
>
>
>
> Robert.
>
>
> On Feb 18, 2008 8:46 PM, Michael Ebner <[EMAIL PROTECTED]> wrote:
>> Hi Robert,
>>
>> buggy thunderbird :-(
>> attached a .zip, should finally work now.
>>
>>
>> regards,
>> Michael.
>>
>>
>>
>> Robert Osfield wrote:
>>> Hi Michael,
>>>
>>> It still came through inlined I'm afraid. Some mail tools are buggy.
>>> Could you send as a zipped file.
>>>
>>> On Feb 18, 2008 2:42 PM, Michael Ebner <[EMAIL PROTECTED]> wrote:
>>>> Hi Robert,
>>>>
>>>> thanks, disabled auto-inlining attachments, it should work now.
>>>>
>>>> regards,
>>>> Michael.
>>>>
>>>>
>>>>
>>>> Robert Osfield wrote:
>>>>> HI Michael,
>>>>>
>>>>> You you send the file zipped up as the file has come through inline
>>>>> (some emailer inline by default for text files). More details can be
>>>>> found at:
>>>>>
>>>>>
>>>>> http://www.openscenegraph.org/projects/osg/wiki/MailingLists/SubmissionsProtocol
>>>>>
>>>>> Robert.
>>>>>
>>>>> On Feb 18, 2008 11:22 AM, Michael Ebner <[EMAIL PROTECTED]> wrote:
>>>>>> Hello,
>>>>>>
>>>>>> the osgParticle LOD functionality is still marked experimental. I tested
>>>>>> it on Win2K and found an error where a std::vector iterator goes beyond
>>>>>> the end of the vector, which is not handled on Win32 STL implementation.
>>>>>> Therfore when using particle LOD the application crashed.
>>>>>>
>>>>>> Attached is a fix that avoids the iterator problem described above.
>>>>>> Could someone check (and notify me please) if this patch is ok and if
>>>>>> this is the only reason why particle LOD is marked experimental?
>>>>>>
>>>>>> thanks,
>>>>>> Michael.
>>>>>>
>>>>>>
>>
>> _______________________________________________
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>>
>>
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--
Ing. Mario Valle
Visualization Group | http://www.cscs.ch/~mvalle
Swiss National Supercomputing Centre (CSCS) | Tel: +41 (91) 610.82.60
v. Cantonale Galleria 2, 6928 Manno, Switzerland | Fax: +41 (91) 610.82.82
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