"Minimal proj.db"?

[kylebarron]

In #184 I'm making an example with NAIP data. I didn't want to embed all of geotiff-geokeys-to-proj4, so I started just defining the specific UTM zones that I needed, and then I realized a lot of the CRS definitions are quite rote:

import proj4 from "proj4";

// Hard-code UTM definitions so we don't need all of geotiff-geokeys-to-proj4 in
// this example app.
// These defintions are from:
// https://epsg.io/26910.js
const utmDef = (zone: number) =>
  `+proj=utm +zone=${zone} +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs +type=crs`;

for (let zone = 10; zone <= 20; zone++) {
  proj4.defs(`EPSG:269${zone}`, utmDef(zone));
}

That bundle size is very tiny, especially since we can duplicate

I imagine there are many CRS definitions that have a pretty simple mapping from EPSG code to proj4 string.

We probably want this to be non-required?

Maybe we have a few different import declarations?

import "@developmentseed/deck.gl-geotiff/proj-minimal"

or, we don't call the methods in global scope ourselves, but we do like

import {defineUTM} from "@developmentseed/deck.gl-geotiff/proj-minimal";

and then the user calls defineUTM in their App?