When working with geospatial applications, a common operation is to convert coordinates between screen pixel coordinates and geographical coordinates. This can be useful in various cases, such as displaying the geographical coordinate for the mouse cursor position, working with custom tools for user interaction, editing feature geometries from code, and more.
Custom objects are a flexible plugin mechanism in Carmenta Engine for integrating customized operations in a regular map configuration. More functionality is added in new Carmenta Engine versions to make this integration more seamless compared to the built-in objects. In this guide, we will focus on the custom dataset use case, for retrieving a customized DataSetInfo, and dynamically instantiating the dataset based on a file on disk.
In Carmenta Engine we define data flows by linking operators together. An operator reads features from its input, processes or manipulates those features and pass the result to the next operator. In the typical case, operators are added and configured in a configuration file and calls are managed by the map view without direct user interaction with the operators.
But in some cases a more custom approach is necessary and the application need to access the processed features directly in code. For example, the application may want to display information produced by the operators or an external component (or service) may want to use the result as input. In this article, we will explain how to approach such use-case.