How to scale overlay icons with zoom on Android OSM

We’re currently developing a Open Source mobile security app for Android (AIMSICD) and have recently migrated from Google Maps to OSM. However, none of us are experts in the use of mapping in AOS. In the current implementation we have modified some point of interest icons via PNG files, but when you change zoom level on the map, these icons remain the same size. This is very unfortunate as any closely located icons will eventually end up on top of each other.

In addition, since the way-points or points of interest are fixed colored “dots” we could also consider using some direct drawing of colored circles on the map, instead of using PNG files. Since we’re mapping mobile antennas there will be ~100 of these dots in a radius of about 5 km.

What are the advantages or drawbacks of each of these?

How can we best resolve this issue?

Looking forward to any helpful and practical answers.

Without even looking at your app and code I suspect that you are trying to do the wrong thing. Changing the icon size is typically not something users would expect and on top of that won’t really work for small icons in any case. What you should be looking at is clustering, that is clustering multiple markers in to one when the density becomes too large.

You don’t mention which map library you are using, but for example mapsforge supports marker clustering and likely most other libraries too given that it is the standard way of handling such situations.