Creating a New Projection

This section explains how to extend the Views Maps projection library with your own projections. The example used in this section is a simplified version of the Mercator projection.

The example is subdivided into three steps, each step showing a different aspect of the library.

• Step 1 explains the minimum requirement to subtype a projection. It focusses on how to implement the forward and inverse functions of a projection.

• Step 2 explains how to add parameters to a projection and how to write the Input/Output functions to support these additional parameters. It also shows how to create specific error codes.

• Step 3 explains how to add the accessor support for the specific parameters of a projection.

The sample source files are located in the directory:

<installdir>/samples/maps/userman/src

for the source files, named proj_step1.cpp, proj_step2.cpp and proj_step3.cpp and

<installdir>/samples/maps/userman/include

for the corresponding include files.