TerraLib → Geometry → Serialization

Well-Known Binary (WKB)

TerraLib has support for encoding/decoding geometries to/from a binary data in the well-known binary format (WKB). The following classes provides this hability:

WKBWriter: a class that serializes a geometry to the WKB format.
WKBReader: a class that deserializes a geometry from a valid WKB.
WKBSize: a class that computes the number of bytes necessary to encode a geometry in WKB.

The code snippet shows how to convert from a Point to a Wkb and then getting back to Point:

te::gm::Point pt(1.5, 1.8);
 
// compute the buffer size needed to encode the point geometry
std::size_t wkbSize = te::gm::WKBSize::size(pt);
 
// allocate a buffer to encode the geometry to a wkb
char* wkb = new char[wkbSize];
 
// encode the point geometry to a wkb in little-endian
te::gm::WKBWriter::write(&pt, wkb, te::common::NDR);
 
// create/decode a geometry from the wkb
te::gm::Geometry* g = te::gm::WKBReader::read(wkb);
 
// check if the reader has done its job
bool result = g->equals(&pt, true);
 
std::cout << result;
 
delete g;
 
delete [] wkb;