Monthly Archives: July 2012

Bye bye Plain Map

Hello again Marble fans! As August approaches, the process of replacing the Atlas map is progressing and producing pretty good results. Last time I posted, I managed to open SHP  and make them work with filtering. Right now, Marble has … Continue reading

Posted in Uncategorized | 4 Comments

Yuppy, SHP format is rendered properly!

The last week was pretty full of Marble for me, and my main two targets were to implement the last (and best 🙂 ) version of Douglas-Peucker filtering and to solve the Antarctica bug. Douglas-Peucker works as expected, so the … Continue reading

Posted in Uncategorized | 8 Comments

Performance analysis – III – Douglas-Peucker

The next measurement done was after implementing the Douglas-Peucker algorithm for filtering the line string. The principle behind this algorithm is pretty simple: after choosing an epsilon value, the smaller the epsilon the higher the precision and the lower the … Continue reading

Posted in Uncategorized | 2 Comments

Performance analysis – II

The times obtained for the entire 600000 nodes line string are decent, but luckily they can be improved. The ultimate purpose of this optimization is to apply the Douglas-Peucker filtering algorithm on the line, according to the zoom level. This … Continue reading

Posted in Uncategorized | Leave a comment

Performance analysis

As a preparatory step for changing the Atlas map, Marble’s vector graphics painter, the GeoPainter, needs to be tested and optimized as much as possible, by loading big KML files, using different filtering methods and comparing the results. Keeping in … Continue reading

Posted in Uncategorized | 1 Comment

Projections

Map projections are methods of representing the surface of a sphere / a three-dimensional object (i.e. the Earth) on a plane. Marble has a total number of three different kinds of projections: 1. Spherical Projection 2.Equirectangular Projection 3. Mercator Projection … Continue reading

Posted in Uncategorized | Leave a comment

Exemplification of Marble GeoData: GeoDataLineString and GeoPainter

In order to display features such as place marks, images, polygons, textual descriptions and so on, Marble implemented a set of classes, the GeoData ones, with a structure similar to Google’s KML Format. If you look inside Marble Namespace Reference, most … Continue reading

Posted in Uncategorized | Leave a comment