Coarse and Local Pathfinding (PATH.C)

src/PATH.C contains six functions: unit_goal, path_coarse, path_select, path_search, path_probe, and wrap_x. Its code combines coarse connectivity, a cached local cost search, and directional fallback scoring.

path_coarse traverses 20×13 land or sea connectivity cells using a circular queue. It selects an intermediate target near a 4×4 cell center. path_select tries nearby connected cells when the initial coarse cell is unavailable.

path_search clears a 256-byte local cost grid and propagates costs outward from the target using the shared queue. It restricts coordinates to a window within eight tiles of the target, relaxes cheaper arrivals, and limits processing with tail6 < 225. The next direction is selected from neighboring cells using stored costs, with stack and distance tie breakers. Queue indices wrap through unsigned-byte conversion. This is not an unbounded optimal-path guarantee.

unit_goal tries local and coarse searches before scoring adjacent directions. The fallback includes distance, movement cost and a penalty for changing direction. path_probe reuses the local search with temporary probe state. wrap_x adds or subtracts 80 once, preserving the original behavior rather than providing arbitrary modulo normalization.

The source declarations list shared entry points. Shared scratch storage remains external to this translation unit.