Iván Sánchez Ortega
Iván has been a web developer and FLOSS advocate since the early 2000s; then he bought a GPS receiver and got involved in OpenStreetMap and OSGeo. He’s worked with nautical charts, indoor positioning, USB microcontrollers, LibreOffice, multispectral rasters, all of it with unhealthy amounts of Javascript.
Sessions
WebGL has enabled fast rendering of maps on the web (including MapLibreGL and OpenLayers renderers), but from the software development point of view, is a notoriously cumbersome technology to work with.
This session introduces Gleo, a JavaScript+WebGL map display library aiming to cover similar use cases than Leaflet, OpenLayers, MapZen and MapLibreGL.
A few architectural features of Gleo will be outlined, including:
- "One GL shader per type of cartographic symbol" rendering & framebuffer compositing approach
- Object-oriented design: symbols as instances; allocation/deallocation of GPU resources for each symbol
- ES6 javascript features: classes, modules, private fields; symbol as DOM EventTarget; deprecation of mouse/touch events in favour of pointer events
- Sliding window algorithm in a wrapped WebGL texture for tile caching
- On-the-fly reprojection enabled by updating just one WebGL data structure
- On-the-fly CRS offsetting to prevent floating-point precision artifacts
- Coordinate wrapping and display tessellation to avoid antimeridian artifacts