On 26/05/2020 13:26, Christoph Hormann wrote:
As Joseph has hinted when it comes to accurate rendering for precise mapper feedback without unintentional incentives at the lower zoom levels there are other options based on pre-rasterizing the data which would still allow using the benefits of client side styling. I have demonstrated that in the past.
Rasterization is a data generalization technique too. Yes, in some cases it leaves no artifacts at all but that's not true in a general case and almost never true on mobile platforms. It is a viable solution but to make it work well the style should not use borders or bake in antialiasing (i.e. leave that to the client code).
I am concerned about something else - even with polygon generalization in place, the performance is not great. Zooming/panning is rather slow on my not so weak PC - the map would be unusable on a mobile device or at best it would be draining the battery quickly.
I've been looking into the code and I couldn't find anything related to polygon generalization. Where is it done? If it happens automatically in the Mapbox GL renderer that's too late - all the cost of preparing tiles, transmitting them, processing them in the client has already been incurred. Displaying data via WebGL is probably the cheapest part of the processing chain.
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