computeRequiredInitialRootTileKeys

[blueRaining]

hello,
i like harpgl very much,and i want to read the source code about it,how can i understand the function of computeRequiredInitialRootTileKeys,when i set the offset is always zeor,it always Operates normally. If I can get the source-related documents, it will be my honor. i like harp very much

[nzjony]

@blueRaining , sorry for the delay.

Yes, this function may be confusing, sorry about that.

Basically, the function just estimates what initial root tile keys are in the viewport, it takes a very approximate approach, so it overestimates, but it is not expensive, so we didn't have a more complicated solution.

It is basically used to show the multiple worlds in a flat planar projection when you zoom out. I.e. for a globe projection, returning the tile key with 0 offset is enough. The offset just means which world used, see screenshot.

Regarding documentation, we don't have anything for this concept unfortunately.

Does that answer your questions, or do you need any more help?