I'm building a game with graphic assets in hdpi resolutions (hence I put the files in drawable-hdpi directory). I don't want to have a corresponding mdpi resolution of the images, and I will code everything in 240-dpi based pixel coordinates.
Is it possible to still allow mdpi and ldpi devices to run the app, by automatically scaling the graphics from the hdpi version?
If you put the graphic assets in drawable (with no qualifier) they will be used by all 1.6+ phones and scaled as appropriate for the screen resolution of the phone. You only need to use hdpi if you want to provide different assets for different screen densities.