[Qgis-developer] QGIS Engine development

[Marco Hugentobler]

>Are there any plans for development of Qt-independent GIS core (with AGG
>rendering engine, maybe)?

I don't know if AGG would be faster than the Qt raster paint engine and 
how much. It would be very interesting to have the comparison AGG <-> Qt 
raster engine (and maybe libcairo as well).

With AGG / cairo, the approach would be to create a new Qt paint engine 
based on these libs (rather than changing the code in qgis core to be Qt 
free). If someone knows of an AGG paint engine implementation or likes 
to create one, that would be very interesting.

Regards,
Marco

On 20.11.2012 22:57, Tim Sutton wrote:
> Hi
>
> On Tue, Nov 20, 2012 at 11:26 PM, Marco Hugentobler
> <marco.hugentobler at sourcepole.ch> wrote:
>>> Not currently. By the way as far as I know the Arthur paint system in
>>> Qt4 is based on AGG.
>>
>> Afaik it is not based on AGG. The QImage rasterizer is based on the freetype
>> scan-converter.
>> There is an article about it
>> (http://blog.qt.digia.com/blog/2009/12/18/qt-graphics-and-performance-the-raster-engine/).
>> The authors of Qt seem to have considered building it on top of AGG first,
>> then decided that it is not a good idea (template based approach of AGG, too
>> many conversions).
> Ah interesting, thanks for the correction Marco!
>
> Regards
>
> Tim
>
>> Regards,
>> Marco
>>
>>
>> On 20.11.2012 22:04, Tim Sutton wrote:
>>> Hi
>>>
>>> On Tue, Nov 20, 2012 at 4:30 PM, Олег Михалёв <mihis.sakh at gmail.com>
>>> wrote:
>>>> Hi all,
>>>>
>>>> I have one global question about QGIS.
>>>> What is the situation with the development of Quantum GIS Engine?
>>>> I mean non-gui classes built on the top of Qt framework, which are
>>>> responsible for spatial data management and rendering.
>>>
>>> Ok so in our terminlogy that would be libqgis_core
>>>
>>>
>>>> Is there any active work on the significant improving of rendering
>>>> performance (http://hub.qgis.org/wiki/quantum-gis/Rendering_Performance)
>>>> or
>>>> redesign of QGIS Engine object model
>>> The next main task is for Martin to merge his threading branch which
>>> we hope will improve rendering performance somewhat. I also have some
>>> ideas about using a compositing so that we can boost performance at
>>> the possible expense of greater memory usage while rendering.
>>>
>>>> (http://hub.qgis.org/wiki/quantum-gis/Redesign_of_QGIS_data_model)?
>>>> Are there any plans for development of Qt-independent GIS core (with AGG
>>>> rendering engine, maybe)?
>>> Not currently. By the way as far as I know the Arthur paint system in
>>> Qt4 is based on AGG.
>>>
>>>> Looking through developer mailing lists of last years (2010-2012), I
>>>> haven't
>>>> found active discussion about the development of QGIS engine.
>>>> Is there another information about this topic?
>>>
>>> Not formally that I can think of. Rendering performance in my opinion
>>> should be the major focus of the 2.x release series - we have rich
>>> functionality now but we need to deliver that quickly to the display
>>> device or the user gets frustrated.
>>>
>>> Regards
>>>
>>> Tim
>>>
>>>> Oleg.
>>>>
>>>> _______________________________________________
>>>> Qgis-developer mailing list
>>>> Qgis-developer at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/qgis-developer
>>>>
>>>
>>> --
>>> Tim Sutton - QGIS Project Steering Committee Member (Release  Manager)
>>> ==============================================
>>> Please do not email me off-list with technical
>>> support questions. Using the lists will gain
>>> more exposure for your issues and the knowledge
>>> surrounding your issue will be shared with all.
>>>
>>> Visit http://linfiniti.com to find out about:
>>>    * QGIS programming and support services
>>>    * Mapserver and PostGIS based hosting plans
>>>    * FOSS Consulting Services
>>> Skype: timlinux
>>> Irc: timlinux on #qgis at freenode.net
>>> ==============================================
>>> _______________________________________________
>>> Qgis-developer mailing list
>>> Qgis-developer at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/qgis-developer
>>
>>
>> --
>> Dr. Marco Hugentobler
>> Sourcepole -  Linux & Open Source Solutions
>> Weberstrasse 5, CH-8004 Zürich, Switzerland
>> marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
>> Technical Advisor QGIS Project Steering Committee
>>
>>
>> _______________________________________________
>> Qgis-developer mailing list
>> Qgis-developer at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/qgis-developer
>
>
> --
> Tim Sutton - QGIS Project Steering Committee Member (Release  Manager)
> ==============================================
> Please do not email me off-list with technical
> support questions. Using the lists will gain
> more exposure for your issues and the knowledge
> surrounding your issue will be shared with all.
>
> Visit http://linfiniti.com to find out about:
>   * QGIS programming and support services
>   * Mapserver and PostGIS based hosting plans
>   * FOSS Consulting Services
> Skype: timlinux
> Irc: timlinux on #qgis at freenode.net
> ==============================================


-- 
Dr. Marco Hugentobler
Sourcepole -  Linux & Open Source Solutions
Weberstrasse 5, CH-8004 Zürich, Switzerland
marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
Technical Advisor QGIS Project Steering Committee