Polyline Encoder/Decoder

C++ implementation of Google Encoded Polyline Algorithm Format

Installation

No installation required. Just compile polylineencoder.h(.cpp) in your project and use PolylineEncoder class.

Prerequisites

No special requirements except C++11 compliant compiler. The class is tested with gcc 4.8.4 and MSVC 12.0 (Visual Studio 2013). For more details see the CI badges (Travis CI & AppVeyor CI).

Usage Example:

PolylineEncoder encoder;

// Poles and equator.
encoder.addPoint(-90.0, -180.0);
encoder.addPoint(.0, .0);
encoder.addPoint(90.0, 180.0);

auto res = encoder.encode(); // "~bidP~fsia@_cidP_gsia@_cidP_gsia@"
encoder.clear(); // Clear the list of points.

// Decode a string using static function.
auto polyline = PolylineEncoder::decode("~bidP~fsia@_cidP_gsia@_cidP_gsia@");

// Iterate over all points and print coordinates of each.
for (const auto &point : polyline) {
    printf("(%f, %f)\n", std::get<0>(point), std::get<1>(point));
}

Test

There are unit tests provided for PolylineEncoder class. You can find them in the test/ directory. To run them you have to build and run the test application. For doing that you must invoke the following commands from the terminal, assuming that compiler and environment are already configured:

Linux (gcc)

cd test
g++ -std=c++11 main.cpp -o test
./test

Windows

cd test
cl /W4 /EHsc main.cpp /link /out:test.exe
test

See Also

• Encoded Polyline Algorithm