Pathfinding and movement range #5

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opened 2026-08-06 21:51:49 +00:00 by icub3d · 0 comments

icub3d commented

2026-08-06 21:51:49 +00:00

Owner

Movement: where can this unit go, what path does it take, and show it.

Scope

A* over the grid, respecting walkable tiles and step height. Occupied tiles block.
Flood-fill of the reachable set for a given movement allowance.
Render the reachable set with MOVEMENT_RANGE (teal) and the previewed path with
SELECTION_CONFIRMED (lavender), both from theme::semantic.

Acceptance criteria

Tie-breaking is deterministic and explicitly ordered — never dependent on
HashMap iteration (CLAUDE.md § Determinism). A test asserts the same start and
goal always yield the identical path, not merely an equal-cost one.
Unit tests cover: no path exists, path around an obstacle, path blocked by a unit,
allowance exactly reaching versus one short.
Pathfinding is pure logic with no rendering dependency, testable headlessly.
The range overlay is paired with a non-colour cue for accessibility.

Notes

Elevation cost and any climb rules are M2. This issue only needs paths to be correct
on the flat and to respect blocked tiles.

Movement: where can this unit go, what path does it take, and show it. ## Scope - A* over the grid, respecting walkable tiles and step height. Occupied tiles block. - Flood-fill of the reachable set for a given movement allowance. - Render the reachable set with `MOVEMENT_RANGE` (teal) and the previewed path with `SELECTION_CONFIRMED` (lavender), both from `theme::semantic`. ## Acceptance criteria - [ ] Tie-breaking is deterministic and explicitly ordered — never dependent on `HashMap` iteration (`CLAUDE.md` § Determinism). A test asserts the same start and goal always yield the identical path, not merely an equal-cost one. - [ ] Unit tests cover: no path exists, path around an obstacle, path blocked by a unit, allowance exactly reaching versus one short. - [ ] Pathfinding is pure logic with no rendering dependency, testable headlessly. - [ ] The range overlay is paired with a non-colour cue for accessibility. ## Notes Elevation *cost* and any climb rules are M2. This issue only needs paths to be correct on the flat and to respect blocked tiles.

icub3d added the

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2026-08-06 21:52:03 +00:00

icub3d added this to the M1 — Playable Vertical Slice milestone

2026-08-06 22:21:45 +00:00