npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@kartotherian/tilelive-vector

v4.0.3-alpha.0

Published

Vector tile => raster tile backend for tilelive

Downloads

31

Readme

tilelive-vector

Implements the tilelive API for rendering mapnik vector tiles to raster images.

Build Status Coverage Status

new Vector(options, callback)

  • xml: a Mapnik XML string that will be used to render vector tiles.
  • source: Optional, a uri string suitable for use with tilelive.load(). This is fallback source that will be used if no source is found as part of the Mapnik XML parameters.
  • base: Optional, basepath for Mapnik map. Defaults to __dirname.
  • format: Optional, target output format. Defaults to png8:m=h.
  • scale: Optional, Mapnik scale factor. Defaults to 1.

Code concepts

  • Backend z/x/y: a request for a raster tile at, say, 3/3/3 does not always mean 3/3/3 is requested from the backend source. The z/x/y requested from the backend source is referred in code by bz/bx/by and generally represent the same or lower zoom level. This allows for features like overzooming, maskLevel tiles, and scale factor adjustment.
  • Overzooming: if a tile beyond the maxzoom of the backend is requested, Vector will attempt to render the tile using the parent of the request at maxzoom.
  • maskLevel tiles: to avoid requiring many duplicate or empty vector tiles to be generated at high zoom levels, the backend source can specify a maskLevel. If a vector tile is not initially found at some z > maskLevel, Vector will issue an additional request to the backend using the parent tile of of the request at maskLevel. This allows a lower zoom level to "backfill" high zoom levels.
  • Scale factor adjustment: the scale argument decrements the backend zoom level such that the requested tile is the visual equivalent (when viewed on the proper dpi device) of its parent counterpart. For example, scale: 2 decrements bz by 1, scale: 4 decrements by 2, and so on.

Backend headers

The Backend and Vector sources set the x-vector-backend-object header to indicate the type of backend source tile loaded. Possible values:

value | description --- | --- empty | backend returned no tile fillzoom | tile from the fillzoom of the backend (backfilled from a lower zoom) overzoom | tile from the maxzoom of the backend (overzoomed) default | normal tile

Bonus constructors

There are two additional constructors provided for slightly different workflows for loading vector sources.

Vector.tm2z(uri, callback)

Load a vector source from a uri (filepath or HTTP url) to a tm2-generated tm2z style package.

Vector.xray(options, callback)

Load a vector source with autogenerated data inspection ("xray") styles. xml is not required -- only the uri to a vector source backend is necessary.