FMod - Foreground highlight

Yesterday, I made little headway in implementing a "front" highlight mode for the Tile Properties view. I realized today that the best approach - in terms of ease of implementation now and of maintainability later - is to have a per-tile overlay system in addition to the existing per-property system.

Every foreground tile now has a per-tile overlay computed for it when called for. Currently the only kind of markup that can go on those images is the foreground highlight. That highlight is a translucent silhouette that only covers the area covered by the foreground tile itself.

The highlight in action