Font or Polygon

Put an icon in a font file
Use a bitmap
Use a polygon

Compare memory usage in the simulator's "View Memory" screen

peterdedecker said:

I  d bet the polygon uses least then the font then the  bitmap

It seems like it would depend on how many points were needed and what quality was acceptable.

I made tests and system fonts uses less memory than polygon, went down form 17.2 to 16.8

For the Garmin Weather widget on the fenix watches, it looks like the weather icons are bitmaps from the screenshots I take. I would think that creating the icons using polygons or other shapes would save on memory, correct? 

Well, fonts are nothing but a bitmap that is reused like a sprite so, why would it take less memory than a bitmap?

Colors.. Custom fonts are simple.

That's one advantage of custom fonts for things like this.  It's easy to change the color, as it's just like any font. I have a custom font for the icons I use in watch faces, and the user can set their color to be anything, and no reason to have a bitmap for each color.

I can do the same with bitmaps. I just use black and white bitmaps and then I select the pallette when I render them. At least this is possible on layout.xml, I guess it will be the same for dynamic ones.

This has the advantage that I don't need to compile the font using an external program that is not available for macOS.