Here are some tips that you might find useful as you develop icons or other drawable assets:
Try to name files so that related assets will group together inside a directory when they are sorted alphabetically. In particular, it helps to use a common prefix for each icon type. For example:
Sub-folder that holds all 48×48 *.png icons for display in Mixxx library widget
Sub-folder that holds all 48×48 *.png icons for display displayed in Mixxx preferences dialog
Sub-folder that holds various templates for image files
The naming convention in the icon containers is: icon_<sizeinpoints>x<sizeinpoints>[@<scale>].png where <sizeinpoints> is the size of the icon in points, and <scale> is @2x for the high-resolution version. (Don’t add a scale for standard resolution.) Additionally, the filename must use the icon_ prefix.
holds all the unused files lurking for some reasons in mixxx/res/images/ until