• SqlGeometry vs SqlGeography

All internals are based on SqlGeometry data type. This type provides useful methods such as STNumInteriorRings() and allows ring extraction via STInteriorRingN(). This allows to workaround a known bug in BingMaps where polygon with interior holes are not clean rendered.

SqlGeography is supported, but is converted to SqlGeometry after data query to allow safe handling. This has a potential performance impact that should be measured.

  • Simplification (Reduction)

Geometries are reduced to map resolution (degrees/ pixels) given by BoundingRectangle.Height / ViewportSize.Height.

Simplification introduces a problem : at low zoom levels, some artifacts appears : small polygons are simplified to points, or linestrings. This issue is handled with STDimension() : a simplified geometry must remain the same dimension than the original geometry. Polygon can be simplified as LineString but not as Point

Last edited Jan 11, 2013 at 9:51 AM by aixchile, version 2


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