Enhance!

[1ec5]

For raster and video sources, fetch tiles from one zoom level higher when the map’s logical zoom level is halfway or greater. So z14.49 loads z14 tiles like before, but z14.5 loads z15 tiles. This behavior avoids blurriness in styles such as Satellite, given that the zoom level is rarely integral, especially after the user manually pinches to zoom. Leaflet apparently does the same thing.

Fixes #963.

/cc @incanus @peterqliu

[peterqliu]

👏

[1ec5]

z	Before	After
14.4
14.6

[incanus]

Oh man this looks soooooo good. I have just been testing with latest gl-styles@mb-pages Satellite style, which doesn't have any vectors. It'd be good to test with that, too, to see the interplay.

[1ec5]

Yep, I'm working with mapbox/mapbox-gl-styles#161 locally.

[incanus]

Raster styles look great too (color is off in this screenshot, but looks great on device).

[mb12]

@1ec5 this could also have been fixed by just modifying the style.json file for raster and video source. In your style.json just add "tileSize": 256 for the raster source. This would have the equivalent effect because in Source::getZoom we also compute an offset like this.

mapbox-gl-native/src/mbgl/map/source.cpp

Line 307 in 58b9355

double Source::getZoom(const TransformState& state) const {

[1ec5]

@mb12, the Satellite style in question did already have "tileSize": 256, but the issue here was that we needed to be more tolerant of downloading and displaying higher-resolution imagery than the truncated zoom level would call for. This comment illustrates the problem well: mapbox/mapbox-gl-js#1030 (comment).

[mb12]

Thanks a lot for the clarification @1ec5. .