I'm using Mapbox API to generate bitmap tiles. First of all I have generated whole world tile with zoom 1 (seems it doesn't matter 0 or 1) and resolution 1280x1280. This tile perfectly positioned from -180 to 180 lon.
Next I would want to generate 4 tiles for next zoom 2. If I correct first tile would be at -90.0,90.0 position (around North America).
But I noticed that size of resulted tile is not as I wanted. It is bigger.
So how to found appropriate zoom level or something else to get tiles for my grid like this, and then for factor 4, 8 etc.