Scaling of the map by given factor

[rinigus]

This is not a bug, but probably a missing feature.

I am developing Pure Maps (Sailfish, other mobile and desktop Linux'es using Qt/QML) and I am considering to add support for official Qt Location bindings. However, I am missing a feature which would allow me to scale the map style by some factor. Not sure what's the current official proposed way to tackle the following case:

• on mobile, select map, calculate route and start navigation
• during navigation, position the device further away (car's windscreen)

To be able to navigate comfortably, map labels have to be increased. So far, while using unofficial QML bindings to Mapbox GL in Qt, I use a parameter that allows me to draw mapboxgl map on framebuffer which is larger than a map (https://github.com/rinigus/mapbox-gl-qml/blob/master/src/qsgmapboxglnode.cpp#L74 ; pixelRatio >= 1). Works decently well and allows users to set the zoom (usually 2x) while driving.

Note that while Map constructor allows to specify pixelRatio, I am looking for dynamic setting that can be adjusted on a fly.

When looking into QtLocation API, I cannot find any similar way or some other way to zoom the map. I suspect that we are expected to provide different styles for exploring the map and navigation, probably with different zoom factors. Taking into account that users are different, it may be not best for all.

Hence the question: is there a way to zoom the map via official Qt API or QtLocation API? I presume the same issue is for other mobile platforms as well.

Please close the issue if you think it doesn't belong here.

[brunoabinader]

Hence the question: is there a way to zoom the map via official Qt API or QtLocation API? I presume the same issue is for other mobile platforms as well.

Are you talking about this? https://github.com/mapbox/mapbox-gl-native/blob/master/platform/qt/include/qmapboxgl.hpp#L212

If this is about dynamic pixel ratio changes, we don't provide support for it at the moment. If you need to update your pixel ratio, then the current solution is to re-create the map object.

[rinigus]

Its about dynamic pixel ratio. What would be an alternative to allow users to scale map fonts and objects sizes when they put their phone on a car's windscreen, for example? Do you know how its resolved for Android apps? The only way I found that would lead to comfortable scale change was adjustment of FBO size, as in the code linked in my original message.

[1ec5]

A dynamic pixel ratio option would also fix the macOS map SDK’s behavior in multiple display scenarios: #7819 (comment).

[stale]

This issue has been automatically detected as stale because it has not had recent activity and will be archived. Thank you for your contributions.

[stale]

This issue has been automatically detected as stale because it has not had recent activity and will be archived. Thank you for your contributions.