Hi Mohammed > How came this time gap?
A possible reason could be the following: In QGIS, most point renderers do some caching of the point symbols as QImage. So in case you invoke a QPainter->drawCircle/drawRectangle etc. command for every point, it helps a lot do do the rasterisation only once. Regards, Marco Am Dienstag, 27. September 2011, 16.18:25 schrieb Mohammed Rashad: > Hi All, > I am developing tiled vector rendering in OSSIM. I like the Qgis vector > rendering system > > point.shp contains 9,99,999 points which are generated by grass for using > v.random and ~27MB in size > roads.shp contains 2,28,068 linestrings and is ~50MB in size > > these point.shp and roads.shp data gets rendered in ~10 sec > > When I read vector using ogr and parse feature and draw point/linestring my > application taking about 40 sec to render point.shp > and > > I am using Qt4 with QPainter not QGraphicsView > > How came this time gap? > > i see Rtree and pal libs in src/core source code > Does they have any role in rendering? > > Does QGIS Rendering uses threading? > > How to get a minimal of QGIS code to hack it and build a new vector > rendering because I need it to make it tiled rendering vectors? > > How to improve performance in rendering without qgis? > --- > Regards, > Mohammed Rashad K M > M.S. (By Research) student > Lab for Spatial Informatics > Department of CSE > International Institute of Information Technology > Hyderabad, India _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
