As long as there aren't too many shells, it's ok to use a linear search,
isn't it?
Did you confirm that OGR is actually reading and forming the
geometries? I still find it hard to believe that it can read the geoms
in only 4 s!
It's interesting about the envelope computation. In JTS these are
computed lazily, but in the ShapefileReader they're used right away to
test for candidate shells for holes.
On 4/21/2012 10:42 AM, Michaël Michaud wrote:
> Hi,
>
> Oh yes, the short circuit will not improve performance much in our case
> because most often, the equalsExact will also be performed.
> (I don't think equalsExact should be removed as it could break
> algorithms relying on it)
>
> Maybe the good structure would have been to map shells to hole lists
> with a IdentityHashMap ?
>
> I did some profiling to try to understand the difference between our
> reader and OGR's
> and found that most of the time in PolygonHandler was spent in Envelope
> computation
>
> I think envelope are required to display data efficiently,
> but I could not find where exactly they were computed
> (tried to deactivate envelope computation everywhere in FeatureDataset
> without performance gain).
>
> I also found that we missed a test for the single-ring case (where ccw
> computation
> can be avoided), but there is not much difference at the end.
>
> Michaël
>> Oh - except that in the cases where the geometries are *not* identical,
>> then a slower equals test is performed. So still better to just test
>> reference equality, I think.
>>
>> On 4/21/2012 8:05 AM, Martin Davis wrote:
>>> That does seem like a good idea. I'll look at adding that.
>>>
>>> On 4/21/2012 12:48 AM, Michaël Michaud wrote:
>>>> Implementing #3 I was wondering why not implementing the following
>>>> short circuit in Geometry equals method
>>>> public boolean equals(Object o) {
>>>> if (this == o) return true;
>>>> etc.
>>>> }
>>>> Can you see any drawback ?
>>>> Seems that this way, many algorithms could automatically benefit your
>>>> #3 trick.
>>>>
>>>>
>>> ------------------------------------------------------------------------------
>>> For Developers, A Lot Can Happen In A Second.
>>> Boundary is the first to Know...and Tell You.
>>> Monitor Your Applications in Ultra-Fine Resolution. Try it FREE!
>>> http://p.sf.net/sfu/Boundary-d2dvs2
>>> _______________________________________________
>>> Jump-pilot-devel mailing list
>>> [email protected]
>>> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
>>>
>>>
>>> -----
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2012.0.1913 / Virus Database: 2411/4950 - Release Date: 04/21/12
>>>
>>>
>>>
>> ------------------------------------------------------------------------------
>> For Developers, A Lot Can Happen In A Second.
>> Boundary is the first to Know...and Tell You.
>> Monitor Your Applications in Ultra-Fine Resolution. Try it FREE!
>> http://p.sf.net/sfu/Boundary-d2dvs2
>> _______________________________________________
>> Jump-pilot-devel mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
>>
>>
>
> ------------------------------------------------------------------------------
> For Developers, A Lot Can Happen In A Second.
> Boundary is the first to Know...and Tell You.
> Monitor Your Applications in Ultra-Fine Resolution. Try it FREE!
> http://p.sf.net/sfu/Boundary-d2dvs2
> _______________________________________________
> Jump-pilot-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.1913 / Virus Database: 2411/4950 - Release Date: 04/21/12
>
>
>
------------------------------------------------------------------------------
For Developers, A Lot Can Happen In A Second.
Boundary is the first to Know...and Tell You.
Monitor Your Applications in Ultra-Fine Resolution. Try it FREE!
http://p.sf.net/sfu/Boundary-d2dvs2
_______________________________________________
Jump-pilot-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
