Module path 

The movement path arrow, as every grid skin draws it (game ADR-0018): a 3-px line through tile centres, under the glyphs, from the edge of the unit’s tile, ending in a single arrowhead over the destination tile. Worked out from the skin’s tile size: on the glyph skin’s 16 px tiles the line is pixels 7..=9.

Constants

LINE_W

The path line’s thickness, in pixels.

Functions

path_overlays

The overlays drawing path (the unit’s tile first) in color: the line Under the glyphs, then the arrowhead Over them; nothing for a path of one tile. Clipped to the tiles of grid. On a zoomed grid the line and the arrowhead are the art-sized tile’s, every pixel a square of the zoom’s.