Generating imagery basemaps in the browser

Imagery Basemaps

From Implementation To Implementation

Python

Golang

• CLI
• Microservice wrapper

WASI

• Failure when trying to get both go-tilepacks and go-pmtiles to work with WASI
  • The problem is the underlying SQLite libraries
  • ncruces (based on WAZero) worked to compile, but the main issue is filesystem access for writing sqlite from WASI
  • WASI can in theory write to the filesystem, but this needs to be code output --> filesystem
  • The problem is the compiled SQLite code here is trying to access the .sqlite file directly from WASI, which doesn’t seem to work
  • Couldn’t work this out
• Tried many approaches for building go-pmtiles as WASI too, ending in failure: https://github.com/spwoodcock/go-pmtiles/tree/build/wasi
  • TinyGO
  • Standard Go compiler
  • Using many different C compilers including Zig
• Concluded we probably need to use SQLite WASM builds for pulling actual file interaction in JS?

JavaScript

• Back to basics
• Using WASM SQLite - facilitated this - to write MBTiles
• Need custom code to write MBTiles --> PMTiles… as the WASI build failed