How to size custom marker icons for Android Google Maps v2?

Question

I want to design custom icons for an Android app using Google Maps v2. I know there are a bunch of design resources which describe how one would create icons for various devices and densities. Here are some information sources:

• Android cheatsheet for graphic designers
• Android Asset Studio
• Android Developers Iconography

The Android SDK contains a sample project called maps. Though it does not contain marker icons in the resource folder.

Sample project in: $ANDROID_HOME/extras/google/google_play_services/samples/maps/

But how would you create marker icons for Google Maps similar to those seen on the following screenshot:

Is there any style guide telling about icon sizes for densities such as ldpi, mdpi, hdpi, xhdpi, xxhdpi or tvdpi?

Solution

All assets must follow the usual scaling: 0.75x (ldpi), 1x, 1.5x, 2x, 3x (xxhdpi). They also suggest you should not care too much about strange densities like tvdpi or xxxhdpi and create only for 3 major buckets: mdpi, hdpi and xhdpi.

Assuming all bugs are fixed and clickable area for Marker is the same as drawable's area, I suggest creating icons big enough, so they are easily pressed, e.g.: 48dp. Such an image would have only center (16x16dp or so) filled with opaque pixels.

If you want to have the same effect as in Google Maps app with info window appearing from the center of such image, add another Marker with 0x0px icon and force showing info window on that invisible Marker.