This tutorial shows how to import the required OpenLayers modules into a Vue project, configure a map, add a Polygon draw interaction, handle the drawend event to compute and format the polygon's area using OpenLayers' getArea function, and provides a complete working example with code.
This article explains the concepts of polygons, including simple, convex, and concave types, describes vertex visibility, ear clipping, and various algorithms for polygon triangulation and convex decomposition, discussing their complexities and practical considerations.
This article explains how China's map is represented by three closed polygons, describes the text file format containing longitude‑latitude point groups, and provides a complete PySimpleGUI Python script to read the data and render the map as red polygons.
This tutorial explains how to obtain geographic coordinates, store them as MySQL POLYGON types following OGC standards, insert campus area data, and query with spatial functions and SPATIAL indexes to determine whether a user is within a defined check‑in region.
