In the previous chapters, we learned how to create custom controls, and manage the view effectively, but we still don't know how rendering works in OpenLayers 3. In this chapter, we will discuss this subject in greater depth. In order to create a well-optimized, responsive application, we must know how rendering works and how we can make rendering-related considerations for different use cases.
In this chapter, we will cover the following topics:
In the previous chapter, we finalized our sample WebGIS application. That's it; we won't extend it anymore in this chapter or in future chapters. As we later need to create some controls for different operations, we go back to our layer tree model from Chapter 3, Working with Layers. We will use the ch03_layerorder example as our starting point and customize it later according to our needs.
We will not use any third-party library in this chapter; however, we need a large dataset so that we can try out the capabilities of the WebGL renderer. This dataset can be located in the res folder. It's name is switzerland_points_osm.geojson, and it contains 221,291 point features from the OpenStreetMap database.