[kde-edu]: Marble 0.5: The Road ahead

Torsten Rahn torsten.rahn at credativ.de
Mon Aug 20 10:52:33 CEST 2007


Now that we (finally!) got Marble 0.4 out of the door, I'd like to offer my 
thoughts on what features should be part of the Marble 0.5 release:

In my opinion Marble 0.5 should emphasize the work of the Google Summer of 
Code students. All features need to get finished for the public (So the 
features need to look finished and well integrated into the user interface, 
work as expected and should be easy to use).

So to get into details:

* GPS/GPX support: Not too much left as far as I can tell.

- Make "File View" only appear if a document has been opened and further fix 
the UI. 
- Do further tests for GPX file format compliance

Andrew: Anything I forgot?

* KML Support:

From what I have seen the following essential features on Murad's kml-tasks 
list haven't been implemented yet (correct me if I'm wrong):

1. Show list view on the left that indicates opened kml/gpx files. List view 
should only appear if there are more than one opened file:

This is partially done already:
- The "File View" has already been integrated by Andrew for GPX. We need to 
add KML support to it now as well.

2. Initial support of KML style objects (icon style, label style)

The latter is rather unfortunate but I think we can live without it for the 
0.5 release.

There are two more show stoppers for 0.5 which are not on the kml-tasks list:

3. Translation of KML files which is pretty much needed for KDE 4. The idea to 
solve this problem was to use Wikipedia's data as an online download and get 
their individual language data of the cities for translation. So a user who 
is from spain would have a database of cities downloaded in the background 
which is compiled from the city data from http://es.wikipedia.org/ and 
http://en.wikipedia.org/. That means: http://en.wikipedia.org/ has the 
largest amount of cities among all languages (about 160.000) The data base 
compiled for spanish would contain those city names from en.wikipedia.org 
with the ones that also exist in http://es.wikipedia.org/ replacing the 
entries from http://en.wikipedia.org/ to make sure that they get properly 
translated. This is just the rough idea.
I'll take care of compiling the data needed (with input from Tim Alder from 

4. Country support: For initial very basic country support it would be nice if 
we'd just add countries as "invisible" placemarks (i.e. placemarks with no 
symbols). Problems:
- Where do we take the country data from (needs to have a Debian compliant 
license)? This isn't too hard to solve though.
- The label for the country names needs to be specially aligned and layouted 
to make it look like a country name. So in opposite to real placemarks there 
will be only a single place tested (instead of 4), the label will have a 
larger font, will be center justified and will probably be displayed 
We need to adjust PlaceMarkPainter to either process the countries as a 
different "layer" that gets rendered before the city data (seperate 
KMLDocument). Or we need to change it to display city data and country data 
from a single KMLDocument (I'd rather prefer the further).

Later on (for 0.6) this feature will get extended to make countries to 
get "area support" (so the application is aware of each area/shape covered by 
each single country.
Murad: is there anything I forgot?

* Flat Map:

There are three visible bugs in the implementation right now. I'm pretty sure 
all of them can be fixed within the next week. Except for that further 
cleaning up and performance optimizations are needed.

Furthermore there are two features that would be nice to have for the 0.5 

1. Mercator projection (like Google Maps does)

2. Make texturemapper only update newly shown regions and reuse the parts on 
the screen that got rendered already before. This didn't work for spherical 
projection for obvious reasons so right now Marble still renders and updates 
the whole screen for each frame. However this trick would work nicely for the 
flat projection and would make moving around in Marble much smoother and 
faster than for the flat projection (in fact as fast as scrolling in khtml 
and kpdf).

The latter would be something that we can live without (however I'd really 
like to see it in 0.5).

Carlos: Is there anything I forgot?

Also we need to solve the remaining "Known issues" of the 0.4 release no 
latter than for 0.5 (Especially: fix the embarrassing Wikipedia browser).

None of the features we need for Marble 0.5 require further translation string 
changes as far as I can tell (and if there should be a few left then please 
add them before the string freeze on August 26).
We also need to make sure that work on all the features left still gets 
started before August 26, so we are still in accordance with the feature 
freeze. Except for the country feature I think all of the other essential 
features have been worked on to some degree. So that's the only issue left of 

Apart from beginning work on country support there is another feature high on 
the wish list: OpenStreetMap support: However I think we should declare this 
feature "optional" for Marble 0.5. It really should need only little work on 
Marble's source code to get this implemented (most work being to setup the 
server with the right settings for the tile render software). However 0.5 is 
meant to focus on the work of the students and I'd like to see 0.5 released 
within the next 4 weeks. 

So that's my thoughts on Marble 0.5. Are there any things I've been missing?

 Torsten Rahn

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