README.md

Modern Tile Layer

The modern tile layer is a rework of the original tile layer which:

• should be significantly more flexible (-> provide better integration support for plugins)
• resolve some hard-to-debug bugs
• improve performance in the default case

It does this by:

• splitting the logic of the current TileLayer & TileProvider into 3-5 parts:

  • BaseTileLayer: responsible for tile management (initial workings provided by @mootw)

  • a tile loader: responsible for getting the data for individual tiles given the coordinates from the manager
    In the default implementation, this is further split:

    • a source generator: responsible for telling the source fetcher what to fetch for the tile
    • a source fetcher: responsible for actually fetching the tile data
      In the default implementation, this is further split:
      • a bytes fetcher: responsible for actually fetching the tile data

  • a tile renderer: responsible for painting tiled data

• using a canvas implementation for the default raster tile layer

Significant questions remaining:

• Is the default tile loader setup (with two stages) too much frameworking/overly-complicated?
• Simulating retina mode affects all parts of the system - but only (conceptually/for reasoning) applies to raster tiles (although technically it's no different to a top layer option). How should this be represented?
• What should the top-level options be (TileLayerOptions)? See also retina mode simulation.
• Who's responsibility is enforcing the max-zoom level? Is max-zoom = native max-zoom or MapOptions.maxZoom?

This new functionality has no deadline or estimated completion date - although it's something we've been wanting to do for a while, and we have some work in the background which may be integrating with this.

Contribution greatly appriciated!