go-mapnik

Go bindings for mapnik 2.2 and Mapnik 3.0 (http://www.mapnik.org or http://github.com/mapnik/mapnik)

These bindings rely on http://github.com/springmeyer/mapnik-c-api.

Installation

Linux / MacOS

1. Install Mapnik build environmnent,

   • e.g. Ubuntu: apt-get install libmapnik-dev

2. Download the sources, either by

   • git clone the repository to $GOPATH/src/fawick/go-mapnik

   OR

   • go get -d github.com/fawick/go-mapnik/mapnik

3. cd mapnik and run the configuration script ./configure.bash. That script will setup the correct paths for including Mapnik headers and linking against the Mapnik shared library, as well as download the Mapnik C API source and go install the bindings.

Windows

On Windows, go-mapnik is restricted to GOARCH=386 and Mapnik 2.2 for the moment, as the precompiled 2.2 SDK is build with MSVC 32-bit and the C api must be build with a compatible compiler as a DLL before the Go bindings can be linked against it.

You also need to have the MSVC 10 compiler installed on your system.

So, make sure go version reports windows/386 as your toolchain. If you happen to have the windows/amd64 toolchain, either download Go binaries for windows/386 or put a MinGW 32-bit compiler in your path and rebuild the Go binaries on your own.

1. Install Mapnik 2.2 Windows 32bit SDK from http://mapnik.org/pages/downloads.html

2. Download the sources, either by

   • git clone the repository to $GOPATH/src/fawick/go-mapnik

   OR

   • go get -d github.com/fawick/go-mapnik/mapnik

3. Run configure.cmd in the folder mapnik to compile a C DLL that can be used by Go/CGO/GCC later (sources will be downloaded automatically). Also, the script will go install the bindings.

4. Run go run demo.go and open view_tileserver.html in a browser. (Make sure your %PATH% environment variable contains the paths of both mapnik.dll and the newly created mapnik_c_api.dll.)

Usage

See demo.go for some usage examples.

Related Work

There is another Go package that offers access to mapnik at https://github.com/omniscale/go-mapnik by Oliver Tonnhofer of Omniscale. According to them, it is inspired by/based on this package. Instead of fetching the latest mapnik-c-api they vendor their own c-code so, their package supports some more features of libmapnik directly, such as version information access and logging. It has support for Mapnik 3.0 built within.