rendering slowly while zoom in Constantly

Topics: SharpMap v0.9 / v1.x, Web Controls, WinForms Controls
Jul 14, 2014 at 6:58 AM
Edited Jul 14, 2014 at 7:01 AM
Hi, everyone:

I made a test on "SharpMap.Demo.Wms" sample to show map, I created layer by myself ,

at the beginning (normal zoom levels), it render fast , but when I zoom in map Constantly,

until the current envelope has only 1 or 2 geometries, I keep zooming in (I did not set the

MinimumZoom ), in my opinion, it should be rendering fast because of less geometries,

however, its so slowly and takes 20-30 seconds to render, even show white background, the

same happens in Winform samples which use Mapbox .

Do you know anything about the reasons?

Thanks in advance!
Jul 14, 2014 at 7:34 AM
What datasource are you using for the data? Is the data spatially indexed in the data source?
Jul 14, 2014 at 10:15 AM
Edited Jul 14, 2014 at 10:16 AM

I use “GeometryFeatureProvider” as the Provider, and added "QuadTree" to it by myself, I use wgs84 Coordinate

System, It's no problem to show thousands of geometries, but while zoom to a small bounding box , I keep zooming

in ( the map's Zoom value will become a very small number such as 0. 08) , and it will be very slowly, seems to that

the process is blocked, then I pan to other position of the map ,it's not display (white background ).