Re: [Geotools-gt2-users] How to optimize the rendering?

[<chr...@nv...>]

Zitat von Zheng Xudong <do...@gm...>:

> I tried the PreGeneralized following the two link, but I encounter two odd
> problems:
>
> 1. I found the pregeneralized shapefile is still the same size with the
> original, no matter which distance I set. Why? Does it means the
> pregeneralization method is not suitable for my shapefile?

Install the gdal utilities from www.gdal.org. Use

ogrinfo -al -geom=SUMMARY xxx.shp

to get detailed info.

>
> 2. When I tried to load the pregereralized shapefile following the code in
> http://docs.geotools.org/**latest/userguide/library/data/**
> pregeneralized.html<http://docs.geotools.org/latest/userguide/library/data/pregeneralized.html>,
> like:
>
>
> Repository repo = new RepositoryDSFinder();
> GeneralizationInfosProvider provider = new GeneralizationInfosProviderImpl();
> GeneralizationInfos infos = null;
> try {
>   infos = provider.getGeneralizationInfos("map_info.xml");
> } catch (IOException e) {
>   e.printStackTrace();
> }
> DataStore ds = new PreGeneralizedDataStore(infos,repo)
> FeatureSource<SimpleFeatureType, SimpleFeature> fs =   
> ds.getFeatureSource("XXX")
>
> and the map_info.xml is like:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <GeneralizationInfos version="1.0">
>   <GeneralizationInfo dataSourceName="file:XXX.shp" featureName="XXX"
> baseFeatureName="XXX" geomPropertyName="the_geom">

This should be something lime
<GeneralizationInfo dataSourceName="file:XXX.shp" featureName="YYY"
  baseFeatureName="XXX" geomPropertyName="the_geom">

YYY is the name you have to use when drawing.

>     <Generalization dataSourceName="file:map/5.0/XXX.shp" distance="5"
> featureName="XXX" geomPropertyName="the_geom"/>
>     <Generalization dataSourceName="file:map/10.0/XXX.shp"
> distance="10" featureName="XXX" geomPropertyName="the_geom"/>
>     <Generalization dataSourceName="file:map/20.0/XXX.shp"
> distance="20" featureName="XXX" geomPropertyName="the_geom"/>
>   </GeneralizationInfo>
> </GeneralizationInfos>
>
> the "XXX" is the filename of my shapefile.
>
> But when I invoke *fs.getSchema()*, it prompt "No such type : XXX". I
> suspect whether the featureName is set wrong, but I don't know how could I
> get the featureName or baseFeatureName in my shapefile.

Again, orginfo is your friend.

>
>
> On Mon, Feb 27, 2012 at 11:42 PM, <chr...@nv...> wrote:
>
>> You can use
>> http://docs.geotools.org/**latest/userguide/library/data/**
>> pregeneralized.html<http://docs.geotools.org/latest/userguide/library/data/pregeneralized.html>
>>
>> A tutorial using shape files is here
>> http://docs.geoserver.org/1.7.**5/user/tutorials/feature-**
>> pregeneralized/feature-**pregeneralized_tutorial.html<http://docs.geoserver.org/1.7.5/user/tutorials/feature-pregeneralized/feature-pregeneralized_tutorial.html>
>>
>> I would recommend using a spatial database like postgis, using shape files
>> has the disadvantage of duplicating all non geometry attributes for each
>> level.
>>
>> Christian
>>
>>
>> Zitat von Zheng Xudong <do...@gm...>:
>>
>>
>>  Hi all,
>>>
>>>    I use GeoTools 8.0M4 to load a shapefile contains about 10,000+
>>>  geometries (each is a multiline). The code is just like the demo in
>>> quickstart. But I found the rendering is a little slow, especially when I
>>> zoom in/out or drag the map, and even sometimes the rendering couldn't
>>> completed (leave some blank area).  What can I do to optimize the
>>> performance of rendering, or the demo is already the best solution? The
>>> CPU
>>> of my PC is Core Duo E6550, the memory is 2G, and the graphics card is ATI
>>> Radeon HD 2400.
>>>
>>>    Thanks and best regards!
>>>
>>> --
>>> Zheng Xudong
>>> State Key Laboratory of Software Development Environment
>>> School of Computer Science and Engineer, BeiHang University
>>>
>>>
>>
>>
>> ------------------------------**------------------------------**----
>> This message was sent using IMP, the Internet Messaging Program.
>>
>>
>> --
> Zheng Xudong
> State Key Laboratory of Software Development Environment
> School of Computer Science and Engineer, BeiHang University
>



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